Sharks of Onslow County

Category: Other Marine Species

Foraminifera: The Marsh’s Memory Keepers

What microscopic shells along Topsail and Surf City tell us about ancient seas, living marshes, and the future coastline

On a winter walk along the marsh edge in Topsail or Surf City, the landscape feels quiet. Cordgrass has faded to straw, tidal creeks run clear, and storm tides have pulled back layers of sediment that were hidden just months ago. Winter slows the marsh, but it also reveals it. Along exposed creek banks and tidal flats, the smallest residents of these ecosystems leave behind subtle traces — grains, spirals, and pin-sized shells that most people would mistake for sand.

These are the remains of foraminifera, key marsh indicators, and they carry a record far older than the marsh itself (Murray, 2006; Scott et al., 2001).

What Are Foraminifera?

Foraminifera, often called forams, are single-celled marine organisms — not animals, but protists — that live in oceans, estuaries, and salt marshes around the world (Murray, 2006). Despite their microscopic size, most foraminifera build protective shells, known as tests, made either from calcium carbonate or from tiny grains of sediment cemented together (Scott et al., 2001; Debenay & Guillou, 2002).

Different species occupy very specific zones within a marsh. Some live high in the intertidal, others closer to open water. Their distribution reflects precise environmental conditions such as salinity, tidal elevation, oxygen availability, and sediment type (Edwards et al., 2004; Culver & Horton, 2005). Because of this tight ecological coupling, foraminifera respond quickly when conditions change (Debenay & Guillou, 2002).

Peneropolis proteus is the one of three most dominant species of fossil foraminifera in the Onslow Bay area, occurring in about 15% of samples (Schnitker, 1971).

Why Winter Reveals the Record

In summer, marsh surfaces are busy and obscured. Dense vegetation, algae, burrowing organisms, and constant sediment mixing make it difficult to see what lies beneath. In winter, vegetation thins, biological activity slows, and storm tides rework creek edges and tidal flats. Fine sediments are redistributed, exposing layers that formed years, decades, or even centuries earlier (Scott et al., 2001; Gehrels, 1994).

Winter does not create this record — it simply makes it visible (Murray, 2006).

Size, Stability, and Ancient Seas

Some fossil foraminifera grew to the size of coins, while most living forms today are no larger than grains of sand (Murray, 2006). This contrast reflects the environments they evolved within. In ancient shallow seas, conditions were often warm, stable, and chemically consistent for long periods of time. Temperature, salinity, and carbonate availability changed slowly, allowing foraminifera to grow over many years, build thick and complex shells, and, in some cases, form partnerships with symbiotic algae — similar to the relationship between corals and the algae that live within their tissues — which provided an additional energy source through photosynthesis (Hallock, 1981; Murray, 2006). These systems favored persistence and size.

Over time, coastlines shifted and sea levels changed, giving rise to the highly dynamic estuaries and marshes we see today. In these modern environments, conditions can fluctuate over hours or seasons. Salinity rises and falls, oxygen levels vary, sediments are rearranged, and water chemistry responds quickly to storms and freshwater input (Debenay & Guillou, 2002; Culver & Horton, 2005). Under such variability, smaller foraminifera that grow rapidly and tolerate change are more likely to survive. Because foraminifera respond directly to these environmental conditions, even subtle shifts can reorganize their communities, altering shell size, composition, and diversity in ways that can persist in sediments long after the initial change has occurred (Edwards et al., 2004; Kemp et al., 2013).

Tiny Shells, Deep Time: How Marshes Remember

Foraminifera are among the most powerful tools scientists use to reconstruct ancient coastal ecosystems because the conditions they live in are permanently recorded in their shells. Individual species occupy narrow ecological ranges defined by salinity, tidal elevation, oxygen availability, temperature, and sediment type. Because of this specificity, the particular mix of foraminifera preserved in a layer of marsh sediment reflects the environmental conditions present when that layer formed.

When scientists extract sediment cores from marshes, they are not looking for isolated snapshots in time, but for transitions. As layers accumulate, changes in species composition, shifts between calcium-based shells and sediment-built shells, and variations in diversity reveal how marsh conditions evolved. These biological signals can indicate changes in flooding frequency, sediment stability, freshwater influence, and tidal reach — often aligning with known shifts in sea level or shoreline position.

What makes foraminifera especially valuable is that they record change continuously. Each generation reflects the conditions it experienced, leaving behind a layered biological archive that links past marshes to present ones — comparable to how sedimentary layers exposed in the Grand Canyon record changing environments over deep time.This continuity allows scientists to distinguish gradual environmental adjustment from more abrupt change and to assess whether modern conditions resemble states marshes have previously endured — or represent departures from historical patterns.

Quinqueloculina seminula (left) and Plancopsilina confusa (right) are the top three most dominant species of fossil foraminifera in the Onslow Bay area, each occurring in about 20% of samples (Schnitker, 1971).

What Lives in a Handful of Marsh Sand

If you scoop a small handful of sand or mud from a North Carolina marsh and let it dry, it looks ordinary—grains, bits of plant matter, flecks of shell. Where sediment cores reveal depth at the scale of decades and centuries, living marsh surfaces show that same pattern compressed into just a few centimeters. But research from the Outer Banks suggests that even this unremarkable material holds a surprisingly rich living community.

Foraminifera under biological microscope with sand.

In a detailed study of marsh sediments along the North Carolina coast, scientists examined not just which foraminifera were present, but which ones were alive at the time of sampling. What they found was not a thin layer of life resting at the surface, but a vertically structured community extending down into the sediment itself (Culver, 2005).

Some foraminifera lived right at the surface, where tides regularly wash over the marsh. Others occupied sediments a centimeter or more below, in darker, less oxygenated layers. In total, more than twenty species were documented living within marsh sediments, their distributions shaped by subtle differences in tidal flooding, salinity, and marsh elevation (Culver, 2005).

Not all species were equally widespread. A few, including Jadammina macrescens and Tiphotrocha comprimata, appeared across multiple sites and depths, suggesting a tolerance for changing marsh conditions. Many others were more selective, occurring only in certain zones or at particular depths. This means that even small changes in where you stand—closer to a tidal creek or higher on the marsh platform—can correspond to a different microscopic community beneath your feet (Culver, 2005).

Upper image: Jadammina macrescens under microscope.| Image credit: Parker, G. G., Phleger, et al. 1953. Cushman Found.Foram.Research Spec.Pub. (n.2): 15, pl.3,f.8.
Lower image: Tiphotrocha comprimata under microscope | Image credit: Hesemann, M., The Foraminifera.eu Database (2026). Accessed at http://www.foraminifera.eu.
https://doi.org/10.13140/RG.2.2.22727.11680/1.

As these organisms die, their shells remain. Layer by layer, those shells become part of the sediment, preserving a record of where tides reached, how often flooding occurred, and how stable the marsh surface was at that moment in time (Scott et al., 2001). What begins as a living community quietly becomes part of the marsh’s long-term record.

Although the Outer Banks are not identical to the marshes behind Topsail and Surf City, the pattern holds across North Carolina’s coast: foraminifera respond to local conditions at very small scales. Their presence, abundance, and depth within the sediment shift from place to place, reflecting the marsh’s relationship with water, salt, and time (Edwards et al., 2004; Culver & Horton, 2005).

Cibicidoides bradyi (horizontal scale bar = 200μm, vertical scale bar = 400μm) occur in less than 20 m at about 1% of samples in the Onslow County area (Schnitker, 1971).

For someone walking the marsh in winter, this means that the sand exposed along a creek bank carries more than the imprint of the last storm. It carries traces of countless tides before it—each one leaving behind shells small enough to escape notice, yet durable enough to remember.

What Changes in Foraminifera Mean for the Ecosystem

An example of how shifts in reef communities reflect shifts in foraminiferal communities below (Prazeres, Martínez-Colón & Hallock, 2020).

Foraminifera do not exist in isolation. They are part of the marsh food web, contributing to the transfer of energy and nutrients from microscopic primary producers to larger organisms (Murray, 2006). Many small invertebrates consume foraminifera directly, while others rely on the microbial communities and organic matter associated with their shells (Debenay & Guillou, 2002). In turn, these invertebrates support fish, crabs, and birds that depend on marsh productivity (Scott et al., 2001).

When foraminiferal communities shift, the effects can ripple outward. A decline in diversity or a move toward stress-tolerant species often reflects changes in sediment stability, oxygen availability, or salinity — conditions that also influence marsh plants, benthic invertebrates, and juvenile fish habitat (Culver & Horton, 2005; Edwards et al., 2004). In this way, changes in foraminifera can foreshadow broader ecological adjustments, even when the marsh surface still appears healthy (Debenay & Guillou, 2002).

Because foraminifera respond quickly to environmental change, they often register these shifts before larger organisms do. Their shells capture early signals of altered flooding patterns, reduced sediment input, or changing water chemistry (Gehrels, 1994; Kemp et al., 2013). What follows may be changes in plant community structure, altered nutrient cycling, or shifts in the species that use marshes as nursery grounds. Foraminifera do not cause these changes, but they reveal when the system’s internal balance begins to shift (Scott et al., 2001).

Reading Change in Living Marshes

Salt marshes are dynamic systems by nature. They grow, erode, migrate, and rebuild as sediment moves and sea level changes (Kemp et al., 2013). The challenge for scientists is distinguishing normal variability from directional change — shifts that push marshes beyond the conditions they have historically been able to tolerate. Foraminifera are especially useful in making that distinction because they respond quickly and directly to their surroundings (Debenay & Guillou, 2002).

When marsh conditions move outside typical ranges — whether through altered hydrology, changes in sediment supply, or shifts in salinity — foraminiferal communities reorganize. Species diversity may decline, stress-tolerant forms can become dominant, and assemblages tied to specific tidal elevations may disappear (Culver & Horton, 2005). These changes often occur before larger, more visible signs of stress appear, such as widespread plant die-off or shoreline erosion (Edwards et al., 2004). In this sense, foraminifera act as early responders, recording change while the marsh still appears intact at the surface (Scott et al., 2001).

Along the marshes behind Topsail and Surf City, this sensitivity gives foraminifera particular importance. They help establish local baselines for what healthy marsh conditions look like, provide context for interpreting present-day shifts, and preserve a record of the conditions that supported marsh stability in the past (Culver & Horton, 2005; Kemp et al., 2013). By linking modern observations to sedimentary records, foraminifera allow scientists to ask not only what is changing, but how quickly change is occurring and whether it remains within the range marshes have previously endured. Understanding marsh resilience in this way is not abstract or theoretical — it is grounded in the specific history and behavior of this coastline.

Salt marsh in Surf City, NC. | Photo credit: Mitchell (2026)

Closing

Standing at the marsh edge in winter, it is easy to miss the smallest details. Yet beneath the quiet surface, microscopic shells record centuries of change — how water moved, how shorelines shifted, and how marshes adapted (Murray, 2006). Foraminifera remind us that long before satellites or tide gauges, coastlines were already keeping their own records. All we have to do is learn how to read them.

References

Culver, S. J. (2005). Infaunal marsh foraminifera from the Outer Banks, North Carolina, U.S.A. The Journal of Foraminiferal Research, 35(2), 148-170. https://doi.org/10.2113/35.2.148

Debenay, J., & Guillou, J. (2002). Ecological transitions indicated by foraminiferal assemblages in paralic environments. Estuaries, 25(6), 1107-1120. https://doi.org/10.1007/bf02692208

Edwards, R., Wright, A., & Van de Plassche, O. (2004). Surface distributions of salt-marsh foraminifera from Connecticut, USA: Modern analogues for high-resolution sea level studies. Marine Micropaleontology, 51(1-2), 1-21. https://doi.org/10.1016/j.marmicro.2003.08.002

Gehrels, W. R., & Kemp, A. C. (2021). Salt marsh sediments as recorders of Holocene relative sea-level change. Salt Marshes, 225-256. https://doi.org/10.1017/9781316888933.011

Hallock, P. (1981). Algal symbiosis: A mathematical analysis. Marine Biology, 62(4), 249-255. https://doi.org/10.1007/bf00397691

Kemp, A. C., Horton, B. P., Vane, C. H., Berhhardt, C. E., Corbett, D. R., Engelhart, S. E., Anisfeld, S. C., Parnell, A. C., & Cahill, N. (2013). Sea-level change during the last 2500 years in New Jersey, USA. Quaternary Science Reviews, 81(2013), 90-104. https://www.whoi.edu/cms/files/Kemp2013QSR_170144.pdf

Murray, J. W. (2006). Ecology and applications of benthic foraminifera. Cambridge University Press.

Schnitker, D. (1971). Distribution of Foraminifera on the North Carolina Continental Shelf. Tulane Studies in Geology and Paleontology, 8(4), 169-215. https://journals.tulane.edu/tsgp/article/view/560

Scott, D. B., Medioli, F. S., & Schafer, C. T. (2001). Monitoring in coastal environments using foraminifera and Thecamoebian indicators. Cambridge University Press.

January 3, 2026
Threshold Species at the Year’s Turn

Winter birds and hidden skates in a changing coastal system

Late December along the coast does not announce itself loudly. The holidays have passed, the shoreline empties, and the light—almost imperceptibly—begins to return. The winter solstice marks the shortest day of the year, but its ecological counterpart is quieter. The water does not reset. It settles.

This is the moment when the coastal ecosystem stops negotiating with the season and begins to accept it. That acceptance is visible, if you know where to look—above the waterline in the form of a small diving duck, and below the surface in the stillness of a benthic predator that does not announce its presence at all.

In our region, ecologists recognize certain animals as threshold species: species whose presence, or subtle change in behavior, signals that the system has crossed a seasonal threshold in energy, behavior, and stability — moving from late year into what comes next.

Above the Water: When Winter Is No Longer a Question

Male (left) and female (right) Bufflehead ducks enjoying a winter swim | Photo credit: Judy Gallagher, iNaturalist

By late December, one species begins to appear with quiet regularity across protected sounds and estuaries: the Bufflehead (Bucephala albeola).

Buffleheads are not early winter arrivals. They do not surge in during the first cold fronts of autumn, nor do they linger indecisively during seasonal transition. Instead, their presence reflects commitment. By the time buffleheads settle into coastal waters, water temperatures have stabilized at winter lows, turbulence has eased in protected areas, and benthic prey communities—particularly small crustaceans and mollusks—have shifted into predictable winter distributions (Eadie et al., 2000; Goudie et al., 1994).

Ecologically, buffleheads are specialists. They forage by diving, relying on clear water and reliable prey patches. Their winter distribution is shaped not by calendar dates but by energy economics: cold water increases metabolic demands, and winter habitats must reliably repay that cost (Eadie & Kehoe, 2022). Where buffleheads remain, the system has crossed a threshold from fluctuation to stability.

In this way, they function less as migrants and more as indicators. Their presence signals that the coastal year has finished rearranging itself. Winter has arrived—not dramatically, but decisively.

Below the Water: When Stillness Makes Life Visible

Clearnose skate in winter waters | Photo credit: NOAA Fisheries

Below the surface, the signal is subtler.

Skates do not arrive in winter with the clarity of birds overhead. Species such as the Clearnose skate (Rostroraja eglanteria) are present along the southeastern U.S. coast throughout much of the year. What changes in late December is not their location, but their visibility.

As water temperatures drop, skates reduce activity, conserving energy through decreased movement and prolonged periods of resting on the seafloor (Di Santo & Bennett, 2011). This metabolic slowdown coincides with seasonal increases in water clarity driven by reduced biological productivity, lower sediment resuspension, and diminished boat traffic (Cloern et al., 2014). The result is a paradox: winter reveals what summer conceals.

In these conditions, skates become easier to observe—not because they have increased in number, but because the system itself has slowed enough to make persistence visible. Their flattened bodies blend seamlessly into sandy or muddy substrates, a strategy optimized for ambush predation and energy conservation rather than movement (Carrier et al., 2012).

If buffleheads announce that winter has settled, skates confirm it. They represent endurance over motion, patience over migration.

The Ecological Hinge Between Years

Neither of these species marks a beginning. Neither signals renewal or arrival in the way spring migrants do. Instead, they occupy the hinge between years—the moment when the ecosystem accepts the constraints of winter and reorganizes around them.

Late December is not biologically empty. It is a period of recalibration. Energy budgets tighten. Movements become deliberate. Survival depends less on abundance than on efficiency.

Above the water, buffleheads gather where the math works. Below it, skates persist by minimizing expenditure altogether. One is easily seen, the other almost never. Together, they reveal the same truth: the system has crossed a line.

After the Turn

January will bring its own changes. Cold will deepen, or ease. Migratory patterns will sharpen. New signals will emerge. But the moment just after the solstice—just after the holidays—is different. It is when the coast pauses, holds, and commits.

The year does not turn loudly here.
It settles, and then it holds.

References

Carrier, J. C., Musick, J. A., & Heithaus, M. R. (2012). Biology of sharks and their relatives (2nd ed.). CRC Press. https://doi.org/10.1201/b11867

Cloern, J. E., Foster, S. Q., & Kleckner, A. E. (2014). Phytoplankton primary production in the world’s estuarine–coastal ecosystems. Biogeosciences, 11(9), 2477–2501. https://doi.org/10.5194/bg-11-2477-2014

Di Santo, V., & Bennett, W. A. (2011). Is post-feeding thermotaxis advantageous in elasmobranch fishes? Journal of Fish Biology, 78(7), 1950–1965. https://doi.org/10.1111/j.1095-8649.2011.02976.x

Eadie, J. M., & Kehoe, F. P. (2022). Energetics and foraging ecology of diving ducks. In P. G. Rodewald (Ed.), The birds of North America. Cornell Lab of Ornithology.
https://doi.org/10.2173/bna

Eadie, J. M., Savard, J. P. L., & Mallory, M. L. (2000). Barrow’s Goldeneye (Bucephala islandica) and Bufflehead (Bucephala albeola). In A. Poole & F. Gill (Eds.), The birds of North America. Cornell Lab of Ornithology. https://doi.org/10.2173/bna.548

Goudie, R. I., Brault, S., Conant, B., Kondratyev, A. V., Petersen, M. R., & Vermeer, K. (1994). The status of sea ducks in the North Pacific Rim: Toward their conservation. Transactions of the North American Wildlife and Natural Resources Conference, 59, 27–49. https://pubs.usgs.gov/publication/70187692

December 27, 2025
5 Marine Myths Under the Mistletoe: Folklore and Real Creatures in North Carolina’s Waters
Winter Stories Along the Water’s Edge

Winter settles softly over Onslow County. The marshes turn the color of worn rope, the New River flows like cold steel between its banks, and the wind carries the sharp scent of salt and pine. December is the quiet season — the estuary’s heartbeat slows, nights stretch longer than tides, and the imagination grows louder than the surf.

This is also when stories rise like mist from the water. Coastal families have passed down tales of mysterious shapes in winter surf, glowing wakes following skiffs, and ghostly sounds echoing across moonlit water. These legends don’t appear in ship logs or lighthouse reports — they survive instead in memories, dockside conversations, and the long tradition of storytelling that has shaped coastal community identity for generations (Cecelski, 2001; Carmichael, 2018).

Yet behind every winter myth lies a real creature — moving, feeding, navigating the season’s challenges. The line between wonder and wildlife is thin along North Carolina’s coast. These are the marine myths under the mistletoe — stories rooted in an enchanted and scientifically alive winter sea.

Mermaids of the Winter Shoals

The shimmering ghosts of the inlet

The Legend

Stories collected from coastal residents sometimes describe pale forms just beyond the surf — long shapes rising from green water, a head here, an arm-like movement there, then gone. In fog or dusk, when horizon and water dissolve into the same dull light, figures appear closer to humans than animals.

The Science — Manatees and Mirage Tricks

Although uncommon, West Indian manatees (Trichechus manatus) occasionally visit North Carolina waters during warmer periods or anomalous Gulf Stream intrusions (Deutsche et al., 2003). Through Fata Morgana, a mirage formed when warm water meets cold air, large mammals in the water can look elongated or upright — a trick that has sparked mermaid sightings worldwide (Pinney, 2018).

Reduced daylight, fatigue at sea, and the human brain’s pattern-seeking instincts complete the illusion.

A legend, yes — but one that begins with a real, gentle giant in cold coastal waters.

A pair of manatees resemble mermaids swimming in the water

The Kraken of Cape Lookout

Monsters in the storm-worn deep

The Legend

When Atlantic gales hammered the coast, some fishermen believed immense tentacled beasts rose from deeper waters and brushed their vessels — massive, silent shapes that existed more in feeling than sight. Winter storms made the ocean seem alive with things too large to name.

The Science — Giant Squid and Deep-Sea Drifters

Off Cape Lookout, the continental shelf plunges sharply into canyon habitats that host large cephalopods. Giant squid (Architeuthis dux), while rarely seen alive, have been recorded washing ashore along the U.S. East Coast and retrieved from research and commercial nets in the broader Northwest Atlantic (Guerra et al., 2011; Roper et al., 2015; Roper & Boss, 1982).

Winter nor’easters can dislodge deep-sea life, delivering strange shapes to shoals or leaving long white arms tangled in wrack.

What was once interpreted as a monster was instead a rarely seen animal from the dark beneath winter waves.

A deceased giant squid (Architeuthis dux) on Golden Mile Beach in Britannia Bay, South Africa | Image credit: Adéle Grosse

The Ghost Lights of Bogue Banks

Blue sparks swirling under December stars

The Legend

Local night fishermen describe glowing water that erupts into blue light when a net drops or a school passes below — a phenomenon that feels supernatural under a new moon in the stillness.

The Science — Bioluminescent Dinoflagellates

The glow comes from dinoflagellates, such as Noctiluca scintillans, which emit bright light when disturbed. Warmer months, calmer seas and reduced sediment can make these flashes stand out like underwater meteors (Haddock, Moline & Case., 2010; Johnson & Allen, 2005).

A natural process — but dazzling enough to inspire talk of spirits beneath the tide.

U.S. Navy photo of bioluminescence | Image Credit: Specialist 3rd Class Devin M. Langer

The Siren of the Shoals

Voices carried by cold seas

The Legend

Some boaters recall hearing a sound — a long moan or rising wail — seeming unmistakably like a human voice drifting over calm winter water. One sound can feel like a warning. Another, like grief.

The Science — Migrating Whales and Phantom Songs

Every winter, North Atlantic right whales (Eubalaena glacialis) migrate through waters off North Carolina, including Onslow Bay (Keller et al., 2012). Their massive bodies, seen at dusk, can resemble the curves of a human torso rising unexpectedly from the deep.

But the haunting songs that travel tens of kilometers belong to humpback whales (Megaptera novaeangliae) farther offshore (Dunlop, Cato & Noad, 2008; Handel, Todd & Zoidis, 2012). Sound refracts through cold, dense winter water — bending, echoing, transforming — until a distant whale becomes a mysterious voice in the marsh.

A ghost in the story.
A whale in the science.
A song carried home by the sea.

A breaching humpback whale

The Marsh Giant

A slow breath in frozen reeds

The Legend

In winter stillness, some describe hearing something large moving in marsh grass — heavy, careful steps that push aside reeds, a dark back slipping between creek holes. Too cold for gators, they say — so what else could it be?

The Science — North Carolina’s Cold-Tolerant Alligators

The American alligator (Alligator mississippiensis) reaches its northernmost range in coastal North Carolina. Even in winter, they can surface and move during brief warm spells — and they maintain openings in ice by pushing upward with their snouts (Brisban, Standora & Vargo, 1982).

Slow movement in a hushed marsh can feel enormous.
The “giant” is real — scaled and silent in the cold.

Alligator in Onslow County, NC | Photo credit: G. Newman

Where Myth and Marsh Converge

Winter strips the coast to its bones. Sound travels farther. Shapes blur quicker. The familiar becomes unfamiliar beneath cold air and low light.

And so legends rise.

Behind them:
- a manatee distorted by mirage
- a giant squid arm pushed ashore by storms
- living lanterns beneath December water
- whale voices refracted through the sea
- an alligator surfacing to breathe through ice
Folklore and biology share the same tides — wonder and curiosity driving us to explain what the winter coast reveals only in glimpses.

Even in the quietest months, the estuary is alive with mystery that create marine myths under the mistletoe.

Learn more about winter estuary ecology here.

References

Brisbin, I. L., Standora, E. A., & Vargo, M. J. (1982). Body temperatures and behavior of American alligators during cold winter weather. American Midland Naturalist, 107(2), 209. https://doi.org/10.2307/2425371

Carmichael, S. (2018). Mysterious tales of coastal North Carolina. Arcadia Publishing.

Cecelski, D. S. (2001). The waterman’s song: Slavery and freedom in maritime North Carolina.

Deutsch, C. J., Reid, J. P., Bonde, R. K., Easton, D. E., Kochman, H. I., & O’Shea, T. J. (2003). Seasonal Movements, Migratory Behavior, and Site Fidelity of West Indian Manatees along the Atlantic Coast of the United States. Journal of Wildlife Management, 67(1), 1-77. https://www.jstor.org/stable/3830830

Dunlop, R. A., Cato, D. H., & Noad, M. J. (2008). Non‐song acoustic communication in migrating humpback whales (Megaptera novaeangliae). Marine Mammal Science, 24(3), 613-629. https://doi.org/10.1111/j.1748-7692.2008.00208.x

Guerra, Á., González, Á. F., Pascual, S., & Dawe, E. G. (2011). The giant squid Architeuthis: An emblematic invertebrate that can represent concern for the conservation of marine biodiversity. Biological Conservation, 144(7), 1989-1997. https://doi.org/10.1016/j.biocon.2011.04.021

Haddock, S. H., Moline, M. A., & Case, J. F. (2010). Bioluminescence in the Sea. Annual Review of Marine Science, 2(2010), 443-493. https://www.annualreviews.org/content/journals/10.1146/annurev-marine-120308-081028

Handel, S., Todd, S. K., & Zoidis, A. M. (2012). Hierarchical and rhythmic organization in the songs of humpback whales (Megaptera novaeangliae). Bioacoustics, 21(2), 141-156. https://www.tandfonline.com/doi/abs/10.1080/09524622.2012.668324

Johnson, W. S., & Allen, D. M. (2005). Zooplankton of the Atlantic and Gulf coasts: A guide to their identification and ecology. JHU Press.

Keller, C., Garrison, L., Baumstark, R., Ward-Geiger, L., & Hines, E. (2012). Application of a habitat model to define calving habitat of the North Atlantic right whale in the southeastern United States. Endangered Species Research, 18(1), 73-87. https://doi.org/10.3354/esr00413

Pinney, C. (2018). The waterless sea: A curious history of mirages. Reaktion Books.

Roper, C. F., & Boss, K. J. (1982, April). The Giant Squid. Scientific American, a division of Nature America, Inc, 246(4), 96-105. https://www.jstor.org/stable/24966572

Roper, C. F., Judkins, H., Voss, N. A., Shea, E., Dawe, E., Ingrao, D., Rothman, P. L., & Roper, I. H. (2015). A compilation of recent records of the giant Squid, Architeuthis dux (Steenstrup, 1857) (Cephalopoda) from the western North Atlantic Ocean, Newfoundland to the Gulf of Mexico. American Malacological Bulletin, 33(1), 78-88. https://doi.org/10.4003/006.033.0116
December 19, 2025
The 12 Days of Estuary Christmas | New River Estuary

In the season of chilly tides and twinkling pier lights, the New River estuary doesn’t quiet down — it parties in its own salty way. So grab your cocoa, bundle up, and join us for a winter countdown of festive fins, feathers, and the ecological magic beneath the misty surface.

(Sing along if you dare — apologies in advance.)

Day 12: Twelve Dolphins Dancing

Bottlenose dolphins along the mid-Atlantic coast shift into cooperative foraging teams in the cooler months — synchronized movements that feel almost choreographed (Torres & Read, 2009). Their leaping, circling, and flipper-flicking tactics help herd fish just like dancers driving the story across a winter stage.

Cue underwater Nutcracker ballet.

Day 11: Eleven Stripers Schooling

Atlantic striped bass move into estuarine channels when the water cools, fueling popular winter fisheries (Boyd, 2011).

Cold water? Hot bite.

Day 10: Ten Blue Crabs Burrowing

Blue crabs overwinter right here — burrowed into sediment, metabolism slowed, waiting for spring, or when water temperatures rise above 9℃ (Glandon, Kilborn & Miller, 2019).

The ultimate cozy blanket fort.

Day 9: Nine Oysters Filtering

Oysters continue filtering water through the winter, though more slowly — still improving water quality and boosting biodiversity (Grabowski & Peterson, 2007).

Nature’s tiny elves never clock out.

Day 8: Eight Croakers Drumming

Atlantic croaker remain common in NC coastal waters during cooler months, shifting to deeper estuarine areas (Miller et al., 2003).

Rumble, rumble — underwater holiday percussion.

Day 7: Seven Specks Still Striking

Speckled seatrout stay active in winter, especially in deeper holes and marsh channels where prey concentrates and water temperatures remain above 7℃ (Ellis, Buckle & Hightower, 2017).

Even cold-blooded fish love a good holiday snack.

Day 6: Six Sharks Snow-Birding

Juvenile coastal sharks like sandbars and sharpnose depart estuaries in late fall, migrating offshore and southward (Bangley et al., 2018).

“See you after the thaw!”

Day 5: FIVE… OYS-TER REEFS!

Oyster reefs provide the essential winter housing market — structured refuge for juvenile fish, crustaceans, and invertebrates (Coen et al., 2007).

Deck the reefs with beds and breakfasts..

Day 4: Four Buffleheads Diving

These small sea ducks, buffleheads, arrive from the Arctic and forage in our coastal waters all winter long (Gauthier, 2014).

Feathered travelers escaping the Arctic freeze.

Day 3: Three Terrapins Burrowed

Diamondback terrapins overwinter in marsh sediments, lowering heart rate and waiting out the cold (Harden, Midway & Willard, 2015).

A brumation vacation.

Day 2: Two Menhaden Shoals

Atlantic menhaden form huge winter schools offshore and near inlet mouths, fueling predator energy budgets (Orth, 2023).

The estuary’s holiday punch bowl.

Day 1: And a Red Drum in the Mar-sh-Tree

Red drum remain year-round, feeding in creeks and marsh edges even in winter low-temp slow-motion (Bacheler et al., 2009).

Our coastal Christmas (and state) mascot.

The Estuary Never Sleeps

Even as we wrap gifts and check lists twice, life beneath the cold surface hustles on — feeding, moving, filtering, and keeping the New River ecosystem healthy through the darkest season.

So here’s to the citizens of our winter waters —
May your tides be merry and bright!

References

Bacheler, N., Paramore, L., Buckel, J., & Hightower, J. (2009). Abiotic and biotic factors influence the habitat use of an estuarine fish. Marine Ecology Progress Series, 377, 263-277. https://doi.org/10.3354/meps07805

Bangley, C. W., Paramore, L., Dedman, S., & Rulifson, R. A. (2018). Delineation and mapping of coastal shark habitat within a shallow lagoonal Estuary. PLOS ONE, 13(4), e0195221. https://doi.org/10.1371/journal.pone.0195221

Boyd, J. B. (2011). Maturation, fecundity, and spawning frequency of the Albemarle/Roanoke striped bass stock (2011. 1510474) [Doctoral dissertation]. ProQuest Dissertations and Theses Global.

Coen, L., Brumbaugh, R., Bushek, D., Grizzle, R., Luckenbach, M., Posey, M., Powers, S., & Tolley, S. (2007). Ecosystem services related to oyster restoration. Marine Ecology Progress Series, 341, 303-307. https://doi.org/10.3354/meps341303

Ellis, T., Buckel, J., & Hightower, J. (2017). Winter severity influences spotted seatrout mortality in a southeast US estuarine system. Marine Ecology Progress Series, 564, 145-161. https://doi.org/10.3354/meps11985

Gauthier, G. (2014, July 14). Bufflehead – Bucephala albeola. Birds of the World – Cornell Lab of Ornithology. Retrieved November 29, 2025, from https://birdsoftheworld.org/bow/historic/bna/buffle/2.0/introduction

Glandon, H. L., Kilbourne, K. H., & Miller, T. J. (2019). Winter is (not) coming: Warming temperatures will affect the overwinter behavior and survival of blue crab. PLOS ONE, 14(7), e0219555. https://doi.org/10.1371/journal.pone.0219555

Grabowski, J. H., & Peterson, C. H. (2007). Restoring oyster reefs to recover ecosystem services. Theoretical Ecology Series, 281-298. https://doi.org/10.1016/s1875-306x(07)80017-7

Harden, L. A., Midway, S. R., & Williard, A. S. (2015). The blood biochemistry of overwintering diamondback terrapins (Malaclemys terrapin). Journal of Experimental Marine Biology and Ecology, 466, 34-41. https://doi.org/10.1016/j.jembe.2015.01.017

Mead, J. G., & Potter, C. W. (1995). Recognizing two populations off the bottlenose dolphin (Tursiops Truncatus) of the Atlantic coast of North America-Morphologic and Ecologic Considerations. https://repository.si.edu/server/api/core/bitstreams/9c563919-2b27-4ac4-bba1-92e7d090fd72/content

Orth, D. J. (2023). Fish, fishing and conservation. Blacksburg: Virginia Tech Department of Fish and Wildlife Conservation.Torres, L. G., & Read, A. J. (2009). Where to catch a fish? The influence of foraging tactics on the ecology of bottlenose dolphins (Tursiops truncatus) in Florida Bay, Florida. Marine Mammal Science, 25(4), 797-815. https://doi.org/10.1111/j.1748-7692.2009.00297.x

December 13, 2025
The Leftovers: What Happens to Summer’s Prey When the Big Fish Leave?

The Quiet Season Begins

When the red drum, flounder, and summer sharks follow the cooling tides offshore, Onslow County’s estuaries fall quiet. The flashy chases fade, and the splashes that once rippled through the creeks give way to stillness. But the story doesn’t end. Beneath November’s calm water, the estuary begins to rewrite itself.

The absence of its top hunters leaves behind both energy and opportunity — a banquet for the small and the overlooked. The currents no longer echo with the heavy pulse of pursuit. Instead, what remains is a more deliberate rhythm — a slow exchange between detritus, crabs, and the smaller fish that endure the cold months ahead.

Winter in the New River Estuary: The Vacancy in the Food Web

Every migration leaves an ecological vacancy. When red drum and southern flounder depart, they take with them both predatory pressure and nutrient export. The estuary briefly relaxes its guard. Prey fish, shrimp, and crabs experience a momentary release from predation from top predator populations that cause a cascade that momentarily alters predation pressure on lower-level prey (Clark et al., 2003).

In this lull, energy that once fueled apex biomass lingers in the system, stored in crustaceans and schooling fish that escaped the hunt (Baird et al., 1998). The estuary, ever adaptive, redistributes that energy downward. Blue crabs (Callinectes sapidus) and juvenile spot (Leiostomus xanthurus) surge in number, exploiting the leftovers of summer’s feast (Allen et al., 2024). The marsh becomes a recycling ground — energy looping through smaller players instead of flowing outward to the sea.

Late-fall estuarine food web diagram showing energy flow from detritus to shrimp, fish, and mesopredators.

The Winter Guardians

But not all predators have gone. When the warm-water hunters leave, colder visitors arrive. Along the inlets and nearshore waters of Onslow Bay, Atlantic spiny dogfish (Squalus acanthias) drift in with the falling temperatures. They are the quiet inheritors of the season — small sharks with silver eyes and slate-gray backs, moving in disciplined schools just offshore.

Atlantic spiny dogfish (Squalus acanthius) — the “winter guardians” — patrol coastal waters when larger predators have departed, sustaining the rhythm of predation. | Photo credit: Andy Murch

Where the big sharks of summer — sandbars, blacktips, and bulls — have vanished southward or deeper, the dogfish remain. Their bodies are built for cold water, thriving where others slow (Carlson et al., 2014). And while their size may not inspire awe, their purpose is no less vital: they fill the empty seats at the top of the table.

Dogfish are mesopredators, but in winter they act as temporary apex hunters, patrolling the inlet and inner shelf where menhaden, herring, and squid still linger (Carlson et al., 2014). Their presence keeps the ecosystem in motion. They thin out the schools that might otherwise explode in number, preventing imbalance and decay. Like patient custodians, they maintain the continuity of predation, ensuring that energy continues to flow up and down the food web even in the cold months (Prugh et al., 2009).

In their absence, the estuary might collapse inward — prey would overgraze, detritus would pile, and oxygen would vanish from the mud. But the dogfish, efficient and tireless, keep the waters breathing.

Crabs and Killifish Take the Stage

Blue crabs roam the winter marsh, feeding on detritus and benthic invertebrates. Their slow foraging helps recycle nutrients and sustain the estuary’s energy balance through the cold season.

Within the estuary itself, the smaller actors continue their work. By December, the New River’s mudflats and marsh creeks host a quieter cast — mummichogs (Fundulus heteroclitus), sheepshead minnows (Cyprinodon variegatus), and grass shrimp (Palaemonetes pugio). These resident species, often unnoticed, now carry the estuary’s metabolism on their backs.

They thrive on detritus and microbial mats, converting decay into new life (Kneib, 2015). Blue crabs roam like slow-moving janitors, shifting through sediment to feed on worms and organic matter (Kennedy & Cronin, 2007). Each movement releases trapped nutrients, fueling microbial blooms that will later nourish the first plankton of spring.

While the spiny dogfish patrol the edges of the continental shelf, these smaller species sustain the inner heart of the estuary. Their labor keeps the water alive long after the glamour of migration fades.

Nutrient Loops and Winter Stability

Without large predators, the estuary depends on microbial and detrital loops to keep its energy cycling. Up to 70% of carbon transfer between November and February occurs through benthic detritivory and microbial remineralization rather than direct predation (Friedrichs & Perry, 2001).

This invisible economy sustains the overwintering fish and crustaceans — the leftovers that, in time, will become the first meal of spring’s returning predators. It’s the estuary’s savings account: energy stored as biomass and sediment, ready to be withdrawn when the tides warm again.

When winter quiets the hunt, the estuary turns inward. Instead of predators driving the cycle, nutrients move through the mud itself — microbes and detritivores recycling what’s left behind. This unseen flow keeps the New River alive until spring’s return (adapted from Erler et al., 2020).

A Resilient Feast

By January, the estuary seems dormant to the casual eye, but beneath its glassy surface, life reorganizes with quiet precision. Crabs clean the table. Dogfish patrol the edge. Minnows and shrimp sift through the silt for remnants of summer.

The New River continues to breathe — slower, deeper, deliberate.
When the big fish return with the first warm tides, the table is set once more, and the energy once left behind has been transformed — recycled through countless small mouths and patient currents into the promise of another season’s chase.

References

Allen, D. M., Govoni, J. J., Able, K. W., Buckel, J. A., Hale, E. A., Hilton, E. J., Kellison, G. T., Targett, T. E., Taylor, J. C., & Walsh, H. J. (2024). Long-term dynamics of larval and early juvenile spot (Leiostomus xanthurus) off the U.S. East Coast: Relating ocean origins, estuarine Ingress, and changing environmental conditions. Fishery Bulletin, 122(4), 162-185. https://doi.org/10.7755/fb.122.4.3

Baird, D., Luczkovich, J., & Christian, R. (1998). Assessment of spatial and temporal variability in ecosystem attributes of the St marks national wildlife refuge, Apalachee Bay, Florida. Estuarine, Coastal and Shelf Science, 47(3), 329-349. https://doi.org/10.1006/ecss.1998.0360

Carlson, A. E., Hoffmayer, E. R., Tribuzio, C. A., & Sulikowski, J. A. (2014). The use of satellite tags to redefine movement patterns of spiny dogfish (Squalus acanthias) along the U.S. East Coast: Implications for fisheries management. PLoS ONE, 9(7), e103384. https://doi.org/10.1371/journal.pone.0103384

Clark, K. L., Ruiz, G. M., & Hines, A. H. (2003). Diel variation in predator abundance, predation risk and prey distribution in shallow-water estuarine habitats. Journal of Experimental Marine Biology and Ecology, 287(1), 37-55. https://doi.org/10.1016/s0022-0981(02)00439-2

Foster, S. Q., & Fulweiler, R. W. (2014). Spatial and historic variability of benthic nitrogen cycling in an anthropogenically impacted Estuary. Frontiers in Marine Science, 1. https://doi.org/10.3389/fmars.2014.00056

Friedrichs, C. T., & Perry, J. E. (2001). Tidal Salt Marsh Morphodynamics: A Synthesis. Journal of Coastal Research, (27), 7-37. https://www.jstor.org/stable/25736162

Kennedy, V. S., & Cronin, L. E. (2007). The blue crab: Callinectes Sapidus. Maryland Sea Grant College University of Maryland.

Kneib, R. T. (1986). The role of Fundulus heteroclitus in salt marsh trophic dynamics. American Zoologist, 26(1), 259-269. https://doi.org/10.1093/icb/26.1.259

Prugh, L. R., Stoner, C. J., Epps, C. W., Bean, W. T., Ripple, W. J., Laliberte, A. S., & Brashares, J. S. (2009). The rise of the Mesopredator. BioScience, 59(9), 779-791. https://doi.org/10.1525/bio.2009.59.9.9

November 29, 2025
Thanksgiving Tides: New River Inlet Fish Migration in Fall

A Different Kind of Thanksgiving Journey

Each November, when highways fill with travelers heading home for Thanksgiving, the waters of Onslow County’s New River Estuary host a quieter kind of migration. Beneath the surface, schools of silvery menhaden, golden spot, croaker, and even small sharks begin the New River Inlet fish migration, drawn by instincts older than any holiday tradition. The tides quicken. Water cools. Marsh grasses brown and whisper in the wind. And with every falling tide, the river seems to breathe outward, carrying its pilgrims toward the sea.

The Gate Between River and Sea

New River Inlet is not simply a passage between Sneads Ferry and North Topsail Beach—it is a living threshold.

The New River winds toward its inlet, where marsh channels, sandbars, and tidal creeks converge into a single hydrodynamic corridor — the living gateway between Onslow County’s estuary and the open Atlantic.

As autumn advances, the estuary’s chemistry shifts: cooler water holds more oxygen, salinity rises with lower rainfall, and winds begin steering surface currents southward. These changes open a corridor that hundreds of thousands of fish follow instinctively from the creeks to the ocean shelf.

For species like spot (Leiostomus xanthurus) and Atlantic croaker (Micropogonias undulatus), this downstream journey completes the first half of a circular life cycle. After spending spring and summer feeding in the calm nurseries of the estuary, they now join the coastal current to overwinter in deeper, warmer water—traveling the same path their parents once took (Odell et al., 2017).

This path is more than instinct. It follows the physical architecture of the river itself—the deep, tidally flushed channels that connect Stones Bay and the main river to the inlet’s thalweg. When autumn winds push water seaward, these channels become a hydrodynamic migration corridor, a natural conveyor that funnels fish from the upper river toward the mouth (Odell et al., 2017).

The inlet becomes a moving parade: ripples flashing silver, gulls diving, and every outgoing tide pulling another wave of life toward the horizon.

Menhaden: The Silver Procession

A vast school of Atlantic menhaden (Brevoortia tyrannus) moves as one body near the surface — a living current of silver that links the New River Estuary to the open Atlantic each fall.

Among the first to leave are Atlantic menhaden (Brevoortia tyrannus), the shimmering filter-feeders that fuel much of the coastal food web. Juveniles spend the warmer months feeding in the upper river, turning sunlight and plankton into pure energy. When the water dips below 18 °C, they form tight schools and funnel through the inlet, their bodies reflecting the low winter sun like coins scattered across the tide.

Studies of otolith chemistry show that these migrants come from multiple estuarine nurseries along the Atlantic seaboard, each contributing recruits to the coast-wide population (Anstead et al., 2016). Their exodus through the New River Inlet is not just a local event—it’s part of a continental rhythm that keeps the Atlantic alive.

Beyond the inlet, menhaden rarely swim straight into the deep. Instead, they travel through the nearshore transition zone, staying within roughly 10 kilometers of the coast, guided by southward longshore currents driven by seasonal winds (Lozano et al., 2013). Here they join massive coastal schools that drift toward Cape Fear and beyond, remaining within waters of 12–18 °C—their preferred thermal band. Each year, these moving rivers of fish carry the New River’s energy down the Atlantic coast like a living current of light.

Spot and Croaker: The Drummers of the Migration

Spot (Leiostomus xanthurus) and Atlantic croaker (Micropogonias undulatus) — schooling estuarine “drummers” whose late-fall migration carries the New River’s summer energy seaward through New River Inlet.

Close behind move the “drums”—spot (Leiostomus xanthurus) and Atlantic croaker (Micropogonias undulatus)—so named for the sound they make vibrating muscles against their swim bladders. By late autumn, they too feel the pull of the current. Their bodies, now heavy from a summer of estuarine abundance, drift downstream in schools that seem to hum with the low percussion of their name.

In coastal surveys, researchers have traced these migrations from estuarine creeks to the continental shelf, where the fish spend the winter in relative warmth before returning north in spring (Odell et al., 2017). In ecological terms, it’s an energy transfer: the nutrients once locked in the mud and detritus of the New River now exported to the open sea.

Once through the inlet, spot and croaker follow two primary routes—some hugging the coast within the surf zone, others settling on the inner continental shelf at 15–35 meters depth. They drift southward along the Carolina Coastal Current, a steady, wind-driven flow that connects Onslow Bay to warmer waters off South Carolina and Georgia. Beneath the surface, these fish form vast, undulating layers—millions of tiny drummers keeping rhythm with the season.

Juvenile Sharks: The Shadow Pilgrims

Juvenile coastal sharks glide over a sandy inlet floor — quiet travelers of the New River system, following ancient tidal cues that guide them from sheltered estuaries to the open Atlantic.

Following the smaller fish come the quiet shadows—juvenile coastal sharks moving through the inlet on their own pilgrimage. Tagging studies across North Carolina reveal that blacktip, sandbar, and bull sharks use shallow estuarine margins as summer nurseries before shifting offshore in late fall when the water cools (Bangley et al., 2018; Rulifson & Bangley, 2015).

In the turbid water at the inlet’s mouth, these young predators trace invisible highways along sandbars and channels, following the scent of prey schools that have already departed. Many continue to ride the same southward current as the drum and menhaden but at greater depth—sometimes reaching the outer continental shelf (30–80 meters) where the water remains above 18 °C. For a few short weeks, river and sea mingle in one shared migration—prey, predator, and current moving together through the same watery passage.

The Importance of the Journey

The departure is not random. Temperature, daylight, and shifting prey availability synchronize this movement. When shrimp and plankton thin in the creeks, the fish follow the energy gradient seaward. In doing so, they maintain the seasonal connectivity that defines an estuary’s health: nutrients exported from the marsh become the foundation of offshore food webs, feeding mackerel, tuna, and seabirds far beyond the New River’s mouth (Lozano et al., 2013).

Alongshore winds along the North Carolina coast generate offshore surface flow through Ekman transport. This movement is balanced by deeper onshore currents and localized upwelling, circulating nutrients and carrying estuarine water and organisms seaward. Adapted from Job Dronkers (2025), Coastal Wiki.

This corridor of movement also depends on the forces of wind and tide. During late fall, northwest winds push surface waters offshore through Ekman transport, enhancing the ebb flow that draws fish outward. Each tide functions as a breath of the estuary—an exhalation of life—carrying energy from the marshes to the sea (Odell et al., 2017).

This is the river’s gift to the ocean—the annual offering that ensures what leaves the estuary returns as new life months later.

A Thanksgiving of Currents

North Topsail Beach at sunset | Photo Credit: David Ogorman

If seen from above, the late-autumn water resembles a conveyor of light: streaks of silver menhaden, bronze drum, and dark shark fins blending into the green-blue inlet plume. Each species is a pilgrim, carried by tides instead of highways, guided by magnetic fields instead of maps. Their departure is as old as the coastline itself—a Thanksgiving procession written in currents and instincts rather than calendars. For those standing on the dunes at North Topsail Beach, the scene feels both ancient and immediate: the hush of wind, the roll of the tide, and somewhere beneath, the silent travelers heading home.

References

Anstead, K. A., Schaffler, J. J., & Jones, C. M. (2016). Coast-wide nursery contribution of new recruits to the population of Atlantic menhaden. Transactions of the American Fisheries Society, 145(3), 627–636. https://doi.org/10.1080/00028487.2016.1150345

Bangley, C. W., Paramore, L., Dedman, S., & Rulifson, R. A. (2018). Delineation and mapping of coastal shark habitat within a shallow lagoonal estuary. PLOS ONE, 13(4), e0195221. https://doi.org/10.1371/journal.pone.0195221

Lozano, C. J., Houde, E. D., & Severin, K. P. (2013). Factors contributing to variability in larval ingress of Atlantic menhaden (Brevoortia tyrannus) to Chesapeake Bay. Estuarine, Coastal and Shelf Science, 118, 1–10. https://doi.org/10.1016/j.ecss.2012.12.018

Odell, J., Adams, D. H., Boutin, B., Collier, W., Deary, A., Havel, L. N., Johnson, J. A. Jr., Midway, S. R., Murray, J., Smith, K., Wilke, K. M., & Yuen, M. W. (2017). Atlantic Sciaenid habitats: A review of utilization, threats, and recommendations for conservation, management, and research (Habitat Management Series No. 14). Atlantic States Marine Fisheries Commission. https://asmfc.org/wp-content/uploads/2024/12/HMS14_AtlanticSciaenidHabitats_Winter2017.pdf

Rulifson, R. A., & Bangley, C. W. (2015). Quantifying estuarine habitat use by multiple coastal shark species (NOAA Technical Report). NOAA Institutional Repository. https://repository.library.noaa.gov/view/noaa/46115

November 21, 2025
Gratitude for Marsh Predators: How Egrets, Herons, and Fish-Hunting Birds Shape the New River
A Thanksgiving for the Watchers at the Water’s Edge

By late November, the New River of Onslow County—the slow, tidal estuary rising in Jacksonville and emptying into the Atlantic at New River Inlet—transforms. The grasses brown, the water clarifies, and the familiar pulse of summer predators fades. Flounder slip offshore. Red drum feed less frequently. Sharks leave the inlet behind in search of warmer currents.

But along the marsh edges, another group of predators steps forward.

Great egrets, snowy egrets, tricolored herons, great blue herons, kingfishers, cormorants, pelicans, and the few ospreys that overwinter become the defining hunters of the cold season. Their presence is not merely ornamental—they keep the estuary functioning when the fish and sharks of summer retreat.

This is a season to be thankful for the feathered predators who bridge water and land, carrying the New River through winter.

Egrets: The Marsh’s Quiet Engineers

Snowy Egrets and Great Egrets share the New River’s marsh edges, but their size, bill color, and foraging styles shape the estuary differently. Together, these two “marsh engineers” help regulate small fish and crustaceans throughout the colder months. | Photo Mia McPherson

Great blue (Ardea alba) and snowy egrets (Egretta thula) line the mudbanks of the New River like pale sentinels during late fall. Their precision hunting—patient standing, slow stepping, sudden striking—remains one of the most effective predatory strategies in shallow water. But egrets do much more than remove prey from the system.

Their feet stir the marsh. With every step, they oxygenate the upper sediment and dislodge hidden invertebrates—worms, amphipods, and tiny crabs. This stirring, known as bioturbation, is essential when larger predators leave for the season. It keeps nutrients moving upward through the food web instead of becoming locked in low-oxygen mud pockets (Green & Elmberg, 2014).

Egrets also function as indicator species. Their presence in good numbers along the New River—especially snowy egrets—signals healthy populations of juvenile fish and crustaceans, as these birds are sensitive to reductions in prey availability and water-quality decline (Gawlik, 2002).

In winter, when the big fish leave, the egrets’ quiet engineering keeps the marsh breathing.

Herons: Sentinels of the Shallows

A Great Blue Heron wades through the quiet shallows in North Carolina, its slow, deliberate steps stirring life from the sediment. In winter, this patient hunter becomes one of the estuary’s most influential predators.

Herons are the deliberate hunters of the New River’s cooler months. Great blue herons (Ardea herodias) stalk deeper edge-waters near Wilson Bay and Stones Bay, while tricolored and green herons hunt the narrow creeks and flooded grass near Sneads Ferry.

Their predatory pressure plays a critical stabilizing role.

When red drum, flounder, and juvenile sharks reduce feeding or migrate offshore, herons become the primary top-down regulators in shallow zones. Without them, schooling fish such as killifish and silversides can become overly abundant and overgraze algae mats, uproot detrital layers, and reduce habitat for invertebrates (Caldwell & Gawlik, 2020).

Herons prevent this imbalance, maintaining the delicate structure of marsh edges through the winter lull.

They are also highly sensitive to habitat degradation. If marsh edges are destroyed or water quality declines, herons disappear quickly—making them early warning signals of ecosystem stress.

When the estuary grows quiet, herons hold the line.

Kingfishers: The River’s Aerial Regulators

The New River bends—particularly between Jacksonville and Camp Lejeune—echo with the rattling call of the belted kingfisher (Megaceryle alcyon). These birds hunt where no heron can reach: suspended midair, diving into deeper channels for small mullet, anchovies, and menhaden.

Their role is uniquely important in winter.

Kingfishers distribute prey movement across the river. Their dive-bombing predation prevents baitfish from clustering into dense, oxygen-demanding schools. This reduces the chance of hypoxic pockets and helps keep prey species spreading through multiple river habitats, supporting overall food-web stability (Green & Elmberg, 2014).

As indicator species, kingfishers require:
- Clear water,
- Steep undisturbed banks for burrow nests, and
- Intact riparian vegetation.
A decline in their numbers often indicates erosion, turbidity, or human disturbance along the New River corridor.

When water clears and fish slow down, kingfishers regulate the mid-channel flow.

Cormorants & Pelicans: Divers of the Deep Channels

Double-crested cormorants and brown pelicans share the New River’s deeper channels, one diving beneath the surface and the other striking from above—two winter hunters shaping the river’s mid-channel food web. | Photo credits: © Patty Teague and Walker Golder

Where the marsh deepens toward New River Inlet, winter belongs to the divers.

Double-crested cormorants (Phalacrocorax auritus) gather in rafts, plunging beneath the surface in coordinated group hunts. Brown pelicans (Pelecanus accidentalis), though more numerous in summer, often overwinter near the inlet, diving from above for surface schooling fish.

These two species maintain control over mid-water prey populations during a time when bluefish, larger trout, and sharks are absent.

Cormorants keep cold-tolerant fish like anchovies and menhaden from becoming hyperabundant—preventing prey schools from stripping plankton layers or concentrating into stressed, oxygen-poor pockets. Pelicans, meanwhile, remove weak or diseased fish from the surface, helping maintain water quality and reducing pathogen spread (Green & Elmberg, 2014).

In winter, when predation usually thins, the divers take up the mantle offshore.

Ospreys: Winter’s Remaining Apex Hunters

An osprey returns to its nest with a freshly caught fish—one of the last true apex hunters still patrolling the New River as winter approaches. | Photo Credit: Steve Gorin

Most ospreys (Pandion haliaetus) migrate south, but a handful stay near New River Inlet and the Onslow County coastline each winter. Those that remain become the estuary’s apex aerial predators, taking mullet, juvenile trout, and medium-sized fish that no other bird consistently targets.

Their presence means something.
Ospreys are recognized worldwide as indicators of estuarine health, reflecting the state of fish recruitment, water clarity, and shoreline integrity (Green & Elmberg, 2014).

If ospreys disappear, it often signals a breakdown already underway.

Even in winter, they serve as a reminder of the estuary’s resilience—and vulnerability.

When the Feathered Predators Are Lost

When fish-hunting birds decline, the system changes quickly:
- Prey fish populations spike and overgraze marsh surfaces.
- Detritus accumulates, creating low-oxygen mud layers.
- Nutrient cycling slows, as birds supply essential nitrogen and phosphorus.
- Marsh plants thin, increasing erosion along the New River’s edges.
- Winter loses its predators, leaving the estuary unregulated until spring.
Their disappearance is not cosmetic—it is structural.

These birds are the framework that holds the winter ecosystem together.

A Season to Give Thanks

As fall deepens into the quiet months, the New River’s story becomes one of subtle but powerful relationships. Egrets stir the mud and release life into motion. Herons regulate the shallows. Kingfishers keep the channels moving. Cormorants and pelicans manage the deeper waters. Ospreys, if they stay, rule the sky.

They do not roar or thrash or leap.
They shape the estuary one step, one strike, and one dive at a time.

This Thanksgiving, the gratitude belongs to them as well—the birds who carry the New River through winter and keep the connection between land and sea alive.

References

Able, K. W., & Fodrie, F. J. (2015). Fish habitat use in salt marshes: Linking ecology and conservation. Marine Ecology Progress Series, 527, 1–5. https://doi.org/10.3354/meps11344

Caldwell, A. W., & Gawlik, D. E. (2020). Wading birds as top predators in shallow estuarine food webs: Behavioral influence on fish distribution. Estuaries and Coasts, 43(6), 1273–1286. https://doi.org/10.1007/s12237-020-00734-1

Gawlik, D. E. (2002). The effects of prey availability on the foraging behavior of wading birds. Ecological Monographs, 72(3), 329–346. https://doi.org/10.1890/0012-9615

Green, A. J., & Elmberg, J. (2014). Ecosystem services provided by waterbirds. Biological Reviews, 89(1), 105–122. https://doi.org/10.1111/brv.12045

Vance-Chalcraft, H. D., Duffey, R., & Knott, D. (2021). Linking avian and aquatic predators stabilizes estuarine food webs. Ecology, 102(12), e03540. https://doi.org/10.1002/ecy.3540
November 21, 2025
The Estuary Feast: November Predators of the New River Estuary, NC
Each November, as the hardwoods fade to rust and the air over Onslow County turns crisp, the New River estuary begins its quiet transformation. Beneath the calm surface, baitfish, shrimp, and crabs gather in the creeks and channels like guests arriving early to dinner. Cooling waters, shifting salinity, and autumn tides all cue a feeding frenzy among the river’s top hunters – red drum (Sciaenops ocellatus), southern flounder (Paralichthys lethostigma), and spotted seatrout (Cynoscion nebulosus).

To the casual observer, it’s just another turn of the season. But for these predators, November is the defining moment of survival – the “estuary feast” that powers them through the winter ahead.

The Science Behind the Feast

As water temperatures drop, oxygen and prey shift. Shrimp slow, mullet school tightly, and predators move into perfect feeding conditions. In November, the estuary’s food web compresses – a short, fierce burst of activity before winter quiets the water.

Autumn brings an ecological reshuffling. As air temperatures drop, water density increases, pushing oxygen-rich layers deeper into the estuary. Cooler water slows the metabolism of small prey, but keeps predators in their metabolic sweet spot – a narrow temperature window where they can feed efficiently (Facendola & Scharf, 2012).

In the New River, this dynamic compresses the food web: prey such as mullet, menhaden, and shrimp concentrate in fewer, warmer microhabitats, and predators follow. Southern flounder and red drum migrate from the upper estuary toward the inlet, using the last strong tides of the season to feed before moving offshore to spawn (Midway et al., 2024).

At the same time, spotted seatrout remain nearshore longer than most species, prowling deep bends and channel edges for sluggish crustaceans and cold-stunned baitfish (Bortone, 2003; TinHan et al., 2018; Whaley et al., 2023). This makes November one of the few months when all three predators share overlapping hunting grounds – a temporary “banquet hall” of intersecting habits and appetites.

Predators at the Table

Red Drum

Known locally as “channel bass”, red drum rely heavily on macro-crustaceans and juvenile fishes during the late fall surge (Facendola & Scharf, 2012). In the New River estuary, they patrol marsh edges and oyster-reef margins where baitfish funnel out with the ebbing tide. These habitats not only provide prey but also structure – a three-dimensional refuge network that concentrates food in predictable corridors.

Red drum are particularly sensitive to dissolved oxygen and salinity changes; they exploit the higher oxygen zones along shell hash and sandy bottoms where shrimp and crabs are most active.

Southern Flounder

Flat, camouflage, and opportunistic, southern flounder are the ambush specialists of November. As they stage for ocean migration, they feed voraciously along the lower estuary and inlet shoals, striking from beneath the sand when shrimp or menhaden schools pass overhead.

Telemetry data show that most adult flounder exit the estuary between mid-October and mid-November (Midway et al., 2024), making this their final feeding push before winter. The energy stored in liver and muscle tissue during this period directly fuels their offshore spawning.

Spotted Seatrout

The spotted seatrout, or “speckled trout”, represents a different strategy: persistence.Unlike flounder or drum, they remain within the estuary for much of the winter. Their adaptive physiology lets them remain active in cooler water, hunting shrimp and small schooling fish even below 15℃, or 59℉ (Bortone, 2003; TinHan et al., 2018; Whaley et al., 2023).

This endurance gives them a late-season advantage – fewer competitors and concentrated prey. In Onslow County’s deeper channels, dock lights and tidal flows create perfect feeding grounds long after other predators have departed.

Prey and Energy Flow

From marsh to mouth: The energy of the estuary: Energy flows up the ladder – detritus -> shrimp -> baitfish -> predator. This seasonal burst fuels migrations and maintains balance in Onslow County’s estuary ecosystem. But when prey species are overfished, that balance falters.

Every feast depends on abundance. In the New River system, fall prey peaks come from several sources:
- Penaeid shrimp (brown, pink and white shrimp) and blue crabs provide high-calorie meals critical to red drum and flounder growth (Facendola & Scharf, 2012).
- Striped mullet (Mugil cephalus) migrate seaward in vast schools during November, offering short bursts of energy-rich prey (NCDMF, 2022).
- Juvenile fishes – menhaden, spot, croaker – linger in the brackish middle reaches, serving as transitional prey before exiting the estuary.
As predators consume these resources, energy moves up the trophic ladder. That transfer of biomass – from detritus to shrimp to fish to apex predator – defines the estuary’s productivity and resilience (Bortone, 2003; TinHan et al., 2018; Whaley et al., 2023).

Beyond the Feast: Ecological Balance

The estuary’s “Thanksgiving” is not just a seasonal event. It’s a reset of the entire system. By removing weaker or late-season prey, predators help balance populations and redistribute nutrients through excretion and predation scars. Their feeding activity also stirs sediments and oxygenates bottom layers, improving microbial decomposition that recycles organic matter for the next year’s growth.

But this rhythm is vulnerable. Habitat loss, water-quality decline, and overfishing can all truncate the feast. Striped mullet, a keystone prey species, remains overfished statewide (NCDMF, 2022), while southern flounder face chronic recruitment declines. (Recruitment is the process of small, young fish transitioning into their older, larger lifestage.) Each missing link reduces the estuary’s resilience – and the energy pulse that sustains these predators through winter.

Climate Notes: A Shifting Season

Recent NOAA data suggests that fall water temperatures in coastal North Carolina are trending 1°-2℃, or 1.8°-3.6℉, warmer than historical averages. Warmer autumns can delay predator migrations, alter prey timing, and extend disease risks for estuarine fish (Bortone, 2003; TinHan et al., 2018; Whaley et al., 2023; Llansó et al., 1998). For Onslow County, this means the “feast” could increasingly occur later, or not at all, in some years. Tracking these shifts can help monitor how climate variability reshapes local predator cycles.

Conclusion

In the quiet weeks before winter, the New River estuary hosts its grandest ritual: a final surge of life and energy. Flounder lie in wait beneath the sand; red drum sweep through oyster channels; speckled trout strike in the moonlit current. Together they embody the estuary’s cyclical resilience – a natural Thanksgiving built on balance, adaptation, and timing.

For those who walk the riverbanks or wade the flats in November, the story unfolding beneath the surface is as rich and meaningful as any holiday tradition: a reminder that even in cooling waters, the rhythm of life continues, fierce and beautiful.

References

Bortone, S. A. (2002). Biology of the spotted Seatrout. CRC Press.

Facendola, J. J., & Scharf, F. S. (2012). Seasonal and ontogenetic variation in the diet and daily ration of estuarine red drum as derived from field-based estimates of gastric evacuation and consumption. Marine and Coastal Fisheries, 4(1), 546-559. https://doi.org/10.1080/19425120.2012.699018

Llansó, R. J., Bell, S. S., Vose, F. E., & Llanso, R. J. (1998). Food habits of red drum and spotted Seatrout in a restored mangrove impoundment. Estuaries, 21(2), 294. https://doi.org/10.2307/1352476

Midway, S. R., Scharf, F. S., Dance, M. A., Brown-Peterson, N. J., Ballenger, J. C., Beeken, N. S., Borski, R. J., Darden, T. L., Erickson, K. A., Farmer, T. M., Fincannon, A., Godwin, J., Graham, P. M., Green, J. L., Hershey, H., Kiene, D., Lee, L. M., Loeffler, M. S., Markwith, A., & McGarigal, C. (2024). Southern Flounder: Major Milestones and Remaining Knowledge Gaps in Their Biology, Ecology, and Fishery Management. Reviews in Fisheries Science & Aquaculture, 32(3), 450-478. https://www.stevemidway.com/publication/midway2024rfsa/midway2024RFSA.pdf

North Carolina Division of Marine Fisheries (NCDMF). (2022, August). Fishery Management Plan Update Striped Mullet. NC Dept. of Environmental Quality (NCDEQ). https://www.deq.nc.gov/marine-fisheries/fisheries-management/annual-fmp-review/2023/2023-striped-mullet-fmp-review/open

TinHan, T. C., Mohan, J. A., Dumesnil, M., DeAngelis, B. M., & Wells, R. J. (2018). Linking habitat use and trophic ecology of spotted Seatrout (Cynoscion nebulosus) on a restored oyster reef in a subtropical Estuary. Estuaries and Coasts, 41(6), 1793-1805. https://doi.org/10.1007/s12237-018-0391-x

Whaley, S. D., Shea, C. P., Santi, E. C., & Gandy, D. A. (2023). The influence of freshwater inflow and seascape context on occurrence of juvenile spotted seatrout Cynoscion nebulosus across a temperate Estuary. PLOS ONE, 18(11), e0294178.
November 10, 2025
The Moonlit Assassin: The Stealth of the Atlantic Moon Snail
On a stroll along the damp sand of the tide line, just after dusk under the soft glow of the moon over Topsail or North Topsail Beach, you might spot a round, glossy shell that looks more like a polished marble than a living creature. This little orb belongs to the Atlantic moon snail or Shark Eye (Neverita duplicata) — smooth and innocent-looking by day, but by night the script flips. It becomes a stealthy predator disguised in plain sight, turning the quiet sand into a midnight hunting ground.

A Shell with a Secret

To the casual beachcomber, the moon snail’s shell looks harmless — a perfect spiral polished smooth by the tide. But that rounded shape is built for stealth and movement beneath the sand. Moon snails bury themselves under the flats and inlets of sandy shores, waiting to pounce. Their favorite prey? Soft-bodied bivalves — clams, coquinas, and other shelled animals that live partly buried in sand.

The moon snail doesn’t wait for prey to drift by; it actively hunts. Using its broad, muscular foot, it glides unseen beneath the surface, sensing vibrations of hidden clams. Once it finds a meal, it envelops the prey in its foot like a slow-moving trap — then the drilling begins.

A rough tongue called a radula rasps the surface while secreted acid softens the calcium shell. Hours later, a single round hole opens a doorway to dinner. Every drilled shell that washes up tells the same story. These beveled, countersunk holes are so distinctive that scientists can identify the species of moon snail just by the shape of the bore (Grey & Bounding, 2005; Dietl & Kelley, 2006).

That neat, circular hole — the hallmark of moon snail predation — is what beachcombers often discover without realizing the drama that unfolded beneath their feet.

Have you seen shells with a perfect hole in them? This is evidence of predation by moon snail.

Hunting Under the Sand

Unlike many beach creatures you spot on the surface, the moon snail is mostly hidden. During low tide, it may creep near the edge of the exposed flats; at other times, it lies just beneath the surface. When it finds a buried bivalve, it uses a combination of mechanical drilling (via the radula) and acidic secretions to bore through the shell until it can reach the soft tissues inside (Visaggi, Dietl, & Kelley, 2013).

In experimental trials, moon snails were observed to prefer drilling over suffocating their prey, even when the prey was buried at different sediment depths (Visaggi et al., 2013). That means whether the sand is shallow or deeper, the snail still goes for the drill rather than waiting for the prey to weaken.

But that’s not all — stable-isotope studies, which measure chemical fingerprints of diet, show that the moon snail’s feeding habits may be more flexible than once thought. It appears to feed not only on animal prey but occasionally on other resources, hinting at omnivory (Casey, Fall, & Dietl, 2016). In other words: it’s a predator, yes — but one with a backup plan when food runs low.

Why It Matters (and Why It’s Cool)

1. Predator and Prey in One
The moon snail helps regulate bivalve populations, preventing a single species from dominating the sand flats. In doing so, it maintains habitat diversity. At the same time, it transfers energy upward in the food chain by becoming prey for larger predators — fitting neatly into the middle of the coastal food web.

2. Ecosystem Engineer
Burrowing, hunting, and leaving behind drilled shells change the physical landscape of the beach. Each empty shell, each “crime scene” hole, becomes part of the microhabitat for small invertebrates, microbes, and future shell-seekers. In this way, the moon snail contributes to sediment health and biodiversity.

3. The Hidden Drama Beneath Your Feet
From a beachcomber’s perspective, the moon snail is a perfect spooky-season protagonist. Picture it: a “moon” shell glinting under moonlight, a buried assassin beneath your feet, and a perfect little hole in a clam shell — the evidence of a tiny midnight crime.

The Perfect Crime

When a clam is finished, only the perfect circular hole remains — a tiny signature in the sand. Moon snails rarely suffocate their prey; they almost always drill, no matter how deep the clam is buried (Visaggi, Dietl, & Kelley, 2013). This ancient behavior has marked shells for millions of years — the same holes appear in fossils that predate the Carolina coastline.

And when food runs low, the story turns darker. In crowded flats where competition is fierce, moon snails have been observed turning their drills on each other. Cannibalism, rare in most mollusks, becomes a desperate survival strategy in the world beneath the sand (Gould, 2010).

Drilled Atlantic moon snail shell shows cannibalism | Photo credit: iNaturalist, plawrynpx

The Ripple Beneath the Sand

The moon snail’s creeping movements do more than tell tales of horror. Its trails of mucus — left behind as it slides through the sand — subtly transform the beach. That film of slime “primes” the sediment, helping microbes break down organic matter faster and releasing nutrients back into the ecosystem (Hannides & Aller, 2016).

Atlantic moon snail in the sand | Photo Credit: D. Bray

So while it’s a killer to clams, it’s also a quiet caretaker. Its hunting churns the sand, its slime fuels the microbes, and its discarded shells shelter the next wave of tiny life.

The Balance of the Hunt

Every act of predation keeps the beach in balance. Moon snails are secondary consumers, feeding on clams that filter plankton from the water. In doing so, they prevent any single species from overrunning the flats. And they, in turn, become prey for blue crabs, rays, and drum fish that patrol the shallows.

Each neat hole in a shell is a record of that balance — energy passed from clam to snail to crab to ocean. Nothing wasted. Everything connected.

For Beachwalkers in Onslow County

If you’re exploring the sands of Onslow County — Topsail Island, North Topsail, Surf City, or the New River Inlet — here’s what to watch for:
- Round, glossy shells washed up on the tide flat — the moon snail’s shell is distinct, almost like a little orb.
- Sand collars: doughnut-shaped, jelly-like structures found after storms or low tide. These are the moon snail’s egg masses, eerie “rings” that crumble when dry.
- Drilled bivalve shells: clams or coquinas with a neat circular hole — the aftermath of a moon snail meal.
- Time and place: Visit during low tide, especially after a storm that exposes more of the flat. The sand will tell its stories. Wear shoes, tread lightly, and remember — much of the life here remains hidden.
Atlantic moon snail sand collar | César Andrés Castillo (c) 2019

Final Thought

It’s easy to write off a pretty shell as just another beach find. But every shell, hole, and collar tells a story of life beneath the waves. The moon snail wears the moon’s name well — luminous, secretive, and always working in the dark. Its beauty hides its appetite; its predation hides its purpose.

In its own way, it keeps the beach breathing — a tiny engineer of life and death that turns sand, shell, and shadow into an endless cycle. The next time you find that round shell glinting in the surf, you’re not just finding a souvenir — you’re finding the ghost of a hunter in the sand.

References

Casey, M. M., Fall, L. M., & Dietl, G. P. (2016). You are what you eat: Stable isotopic evidence indicates that the naticid gastropod Neverita duplicata is an omnivore. Frontiers in Ecology and Evolution, 4, 125. https://doi.org/10.3389/fevo.2016.00125

Dietl, G. O., & Kelley, P. H. (2006). Can naticid gastropod predators be identified by the holes they drill? Ichnos, 13(2), 103–113. https://doi.org/10.1080/10420940600842979

Gould, E. S. (2010). Unexpected rates of cannibalism under competitive conditions by the naticid gastropod Neverita duplicata. Marine Biology, 157(10), 2341–2349. https://doi.org/10.1007/s00227-010-1505-8

Grey, M., & Bounding, E. G. (2005). Shape differences among bore holes drilled by three species of naticid gastropods. Palaeogeography, Palaeoclimatology, Palaeoecology, 221(3–4), 245–260. https://doi.org/10.1016/j.palaeo.2005.02.003

Hannides, A. K., & Aller, R. C. (2016). Priming effect of benthic gastropod mucus on sedimentary organic matter remineralization. Marine Ecology Progress Series, 545, 77–88. https://doi.org/10.3354/meps11587

Visaggi, C. C., Dietl, G. P., & Kelley, P. H. (2013). Testing the influence of sediment depth on drilling behaviour of Neverita duplicata (Gastropoda: Naticidae), with a review of alternative modes of predation by naticids. Journal of Molluscan Studies, 79(4), 310–322. https://doi.org/10.1093/mollus/eyt023
October 27, 2025
A Phantom on the Sand: The Mysterious Atlantic Ghost Crab

When the sun sets behind the dunes and the surf begins to whisper, pale shapes flicker across the sand. Their movements are quick, darting, and silent – like apparitions under moonlight. These aren’t the spirits of shipwrecked sailors but the true “ghosts” of our Carolina coast: Atlantic ghost crabs (Oxypode quadrata).

Atlantic ghost crab (Oxypode quadrata) | From iNaturalist

Living Between Worlds

Ghost crabs live in that liminal zone between land and sea – not quite aquatic, not quite terrestrial. They spend most daylight hours deep inside burrows up to four feet long, spiraling down in the cool, moist sand where they can keep their gills damp (Lucrezi & Schlacher, 2014).

Architecture types of ghost crab burrows. | From Silva & Colado, Burrow architectural types of the Atlantic ghost crab, Ocypode quadrata (Fabricius, 1787) (Brachyura: Ocypodidae), in Brazil (July 2014)

At night, they emerge to feed and patrol their territories. Their footprints – delicate, zigzagging tracks across the high tide line – are often the only sign they’ve been there. Scientists describe O. quadrata as a “semi-terrestrial” species, adapted to breath air while still depending on water for respiration (Lucrezi & Schlacher, 2014). Each burrow is unique, shaped like a J or L., with a single opening and a smooth rim that the crab maintains meticulously (Strachan et al., 1999). It’s both a refuge from predators and a fortress against the summer sun.

Ghost crab footprints | From UF/IFAS Extension Escambia County

Predators and Predators’ Prey

Despite their spectral charm, ghost crabs are voracious predators. They scavenge for dead fish, clams, and organic debris but will actively hunt small invertebrates and even sea turtle hatchlings (Wolcott, 1978; Call et al., 2024).

In many coastal ecosystems, ghost crabs are top invertebrate consumers, linking marine and terrestrial food webs by recycling nutrients back into the sand (Wolcott, 1978). Yet their own lives are precarious – shorebirds, raccoons, and even humans are a constant threat. A study in Virginia found that burrow abundance correlated with temperature and habitat type, showing how these crabs respond to subtle environmental shifts (Call et al., 2024). They’re not just scavengers – they’re indicators of a beach’s health.

The Science of the “Ghost”

There’s a reason they earned their spectral reputation. Their translucent shells and lightning-fast reflexes make them appear and vanish like spirits. In low light, the fine grains of sand reflecting off their bodies amplify that effect – a built-in camouflage evolved for moonlit hunting. Can you spot them in the images below?

Ghost crabs also possess 360-degree vision from their elevated eye stalks, allowing them to spot threats in any direction (Lucrezi & Schlacher, 2014). And if the idea of “haunted sounds” intrigues you, here’s a Halloween twist: they “growl” by grinding their internal stomach plates – a process called stridulation – to warn off intruders. The sound, faint but distinct, echoes eerily under the dunes.

Ghosts of Onslow County

If you’ve ever walked Topsail Beach under a full moon, you’ve probably seen them: glowing white blurs racing sideways across your flashlight beam. (It’s best to use red or blue light as you search for ghost crabs and sea turtles.) Locally, these crabs are essential dune engineers. Their burrows aerate sand, help control organic decay, can reduce erosion, and maintain the delicate balance between dry and wet zones of the shore.

Ghost crab at night | From iNaturalist

You might wonder: since ghost crabs dig deep into the sand, do their burrows stabilize the beach and help fend off erosion? The answer is – sometimes, but not always.

You don’t even need to see a ghost crab to know it’s there – just look for the telltale burrow holes scattered along the upper beach. Each one marks a crab’s hiding place, and scientists often estimate ghost crab populations by counting burrow openings rather than the crabs themselves (Call et al., 2024; Lucrezi & Schlacher, 2014). The more holes you find, the healthier the local population – assuming the beach hasn’t been compacted or disturbed by human traffic.

Ghost crab holes near the dunes in the Outer Banks | From OuterBanks.com

Ghost crabs don’t just dig- they reshape their sandy underworld. Their burrows loosen compacted sediments, which can lower resistance to wind and wave forces (Rinehart et al., 2024). In some species, burrowing stabilizes surface flows, but in ghost crab systems the effect is less predictable – sometimes helping, sometimes hindering.

Unfortunately, they’re also victims of human disturbance. Coastal development, trampling, beach renourishment, and nighttime beach driving can collapse burrows and disrupt populations (Costa, Madureira & Zalmon, 2018). During the COVID-19 lockdown, researchers noticed ghost crab populations rebounding on urban beaches – a reminder that these “ghosts” return quickly when given peace (Costa et al., 2022).

The Real Spirits of the Shore

So this Halloween, as you wander along the moonlit sands of Onslow County, remember that the pale forms darting ahead of your footsteps aren’t apparitions – they’re guardians of the dunes, keeping our coasts breathing and balanced.

Every footprint, every scuttle, every faint rustle beneath the stars tells a story of adaptation and resilience. Ghost crabs may look like specters, but they’re among the most living, vital spirits of the beach.

“They vanish without a trace…except for their tracks.” – A. Mitchell

References

Antunes, G. D., Do Amaral, A. P., Ribarcki, F. P., Wiilland, E. D., Zancan, D. M., & Vinagre, A. S. (2010). Seasonal variations in the biochemical composition and reproductive cycle of the ghost crab Ocypode quadrata (Fabricius, 1787) in southern Brazil. Journal of Experimental Zoology Part A: Ecological Genetics and Physiology, 313A(5), 280-291. https://doi.org/10.1002/jez.593

Call, M. N., Pongnon, R. S., Wails, C. N., Karpanty, S. M., Lapenta, K. C., Wilke, A. L., Boettecher, R., Alvino, C. R., & Fraser, J. D. (2024). Biotic and abiotic factors affecting Atlantic ghost crab (Ocypode quadrata) spatiotemporal activity at an important shorebird nesting site in Virginia. PLoSONE, 19(8), e0307821. https://doi.org/10.1371/journal.pone.0307821

Costa, L. L., Machado, P. M., Barboza, C. A., Soares-Gomes, A., & Zalmon, I. R. (2022). Recovery of ghost crabs metapopulations on urban beaches during the COVID-19 “anthropause”. Marine Environmental Research, 180, 105733. https://doi.org/10.1016/j.marenvres.2022.105733

Costa, L. L., Madureira, J. F., & Zalmon, I. R. (2018). Changes in the behaviour of Ocypode quadrata (Fabricius, 1787) after experimental trampling. Journal of the Marine Biological Association of the United Kingdom, 99(5), 1135-1140. https://doi.org/10.1017/s0025315418001030

Gül, M. R.(2019). Energetic Consequences of Human Impacts for Bioindicator Atlantic Ghost Crab (Ocypode Quadrata). (Doctoral dissertation). Retrieved from https://scholarcommons.sc.edu/etd/5460

Lucrezi, S., & Schlacher, T. A. (2014). The ecology of ghost crabs. Oceanography and Marine Biology, 201-256. https://doi.org/10.1201/b17143-5

Rinehart, S. A., Dybiec, J. M., Walker, J. B., Simpson, L., & Cherry, J. A. (2024). Effects of burrowing crabs on coastal sediments and their functions: A systematic meta‐analysis. Ecosphere, 15(7). https://doi.org/10.1002/ecs2.4927

Strachan, P. H., Smith, R. C., Hamilton, D. A., Taylor, A. C., & Atkinson, R. J. (1999). Studies on the ecology and behaviour of the ghost crab, Ocypode cursor (L.) in Northern Cyprus. Scientia Marina, 63(1), 51-60. https://doi.org/10.3989/scimar.1999.63n151

Wolcott, T. G. (1978). Ecological role of ghost crabs, Ocypode quadrata (Fabricius) on an ocean beach: Scavengers or predators? Journal of Experimental Marine Biology and Ecology, 31(1), 67-82. https://doi.org/10.1016/0022-0981(78)90137-5

October 16, 2025