Sharks of Onslow County

Category: Estuarine Predators

The Fish That Follows the Tide: American Eels Along the Waters of Onslow County

Most people who see an American eel (Anguilla rostrata) for the first time do not think they are looking at a fish at all.

They appear suddenly in shallow blackwater creeks, beneath dock lights, beside culverts after rain, or slipping through spartina grass at dusk. Long and muscular, they move more like a snake than something belonging to a river. In muddy water they are usually seen only in fragments — a curve disappearing beneath tannin-dark current, or a ripple crossing the surface where something alive passed moments earlier.

Along the coast of Onslow County, American eels have likely moved through these waters longer than the marshes themselves have held their present shape. They pass through tidal creeks, estuaries, freshwater streams, flooded ditches, cypress swamps, and inland rivers, connecting habitats that often seem separate to us but function together as one living system.

And almost no one realizes that every eel seen here began life far out at sea.

Born Beyond the Horizon

The American eel’s life cycle spans thousands of miles, linking the Sargasso Sea, Atlantic coast, estuaries, marshes, rivers, and inland lakes through a single migration that can last decades. | Image credit: U. S. Fish and Wildlife Service

Far offshore, beyond the continental shelf and beyond the visible horizon of North Carolina’s beaches, lies the Sargasso Sea — a warm, rotating gyre of Atlantic water bordered by ocean currents rather than land. This is where American eels spawn, though much of their reproduction still remains one of the great biological mysteries of the Atlantic Ocean (Béguer‐Pon et al., 2015).After hatching, eel larvae drift for months within the Gulf Stream. At this stage they do not yet resemble eels. They are thin, transparent, leaf-shaped organisms called leptocephali, nearly invisible against the open ocean (Wang & Tzeng, 2000).

Leptocephali, the larval stage of the American eel, drift within the Atlantic Ocean currents for months before transforming into glass eels and entering coastal estuaries. | Image credit: hunterefs, iNaturalist

As they approach the coastline, their bodies begin to transform. The broad leaf-like shape narrows into the familiar eel form. Their organs reorganize. Their muscles strengthen. By the time they arrive in estuaries along the Atlantic coast, they have become what scientists call glass eels — small, transparent juveniles that move into tidal rivers and marshes under the cover of darkness (Starks, 2026).

Glass eels, the transparent juvenile stage of the American eel, gather along coastlines before moving inland through estuaries, marshes, and rivers. | Image credit: W. O’Connor

At night in late winter and spring, these glass eels enter coastal waters by the thousands. Most people never notice them. But beneath bridge lights and along quiet marsh edges, tiny transparent bodies gather against the current, moving inland on tides that have repeated for thousands of years.

Some settle into estuaries. Others continue far upriver into freshwater creeks and reservoirs. A single eel may spend decades there before returning once again to the open Atlantic.

As they continue growing, American eels pass through a series of color changes that reflect different stages of their life cycle. Newly arrived glass eels are nearly transparent. Within months they develop pigmentation and become elvers, often showing olive, brown, or yellowish coloration. During the longest phase of their lives they are known as yellow eels, displaying yellow-brown to olive sides with lighter undersides while feeding and growing in estuaries, rivers, and wetlands for years or even decades (ASMFC, 2017; Haro et al., 2000). As they mature and prepare for their return migration to the Sargasso Sea, they transform into silver eels. Their bodies darken along the back, their sides become silvery, and their eyes enlarge — adaptations that help prepare them for life in the open ocean and their final spawning migration (Haro et al., 2000; Tesch & White, 2008).

American eels change dramatically throughout their lives, from transparent leptocephali and glass eels to yellow eels in estuaries and rivers before developing the silver coloration of spawning adults returning to the Sargasso Sea. | Image credit: C. Bowser & R. Papish

The Marsh at Night

American eels are largely nocturnal, which means many people living along the coast rarely realize how common they are.

After sunset, they emerge from submerged roots, oyster reefs, marsh undercuts, rock piles, and mud-bottom channels to feed. In tidal creeks around Onslow County, they move through habitats that shift constantly with salinity, rainfall, temperature, and tide.

Unlike many fish that specialize in one narrow environment, eels are remarkably flexible. They can tolerate freshwater, brackish estuaries, and saltwater marsh systems throughout different stages of life (Able, 2005).

This flexibility makes them important ecological connectors between habitats.

An eel feeding in an estuary may consume shrimp, small fish, crabs, worms, insect larvae, and carrion. Larger eels become predators capable of feeding on nearly anything they can overpower. In turn, they become prey themselves for river otters, wading birds, striped bass, sharks, alligators, ospreys, and larger coastal predators (MacGregor et al., 2009).

What appears at first to be a strange solitary fish is actually woven through multiple levels of the food web.

American eels help transfer energy through the ecosystem, linking marsh invertebrates, small fish, and larger predators with the waters of Onslow County. | Image credit: A. Mitchell

Ancient Currents and Modern Coastlines

And in a much deeper sense, eels also connect modern coastal ecosystems to ancient worlds that existed long before humans reshaped shorelines. Their lineage stretches back tens of millions of years, surviving repeated shifts in sea level, climate, and continental geography. Long before beach renourishment projects, before the Outer Banks existed in their present form, and even before many modern mammals evolved, ancestral eels were already moving between oceans and coastal rivers (Inoue et al., 2010).

That timeline overlaps surprisingly well with the broader environmental history explored in my earlier posts. During the Carboniferous Period over 300 million years ago, vast swamp forests covered portions of what would eventually become eastern North America, laying down the organic material that later formed coal deposits (Sahney et al., 2010). The world looked entirely different then, but the shallow coastal environments that support migratory fish today evolved from ancient marine systems shaped across those immense spans of geologic time.

By 66 million years ago — around the end-Cretaceous extinction that eliminated non-avian dinosaurs — early eel relatives already existed in ancient seas (Near et al., 2012). Modern American eels evolved much later, but their migratory strategy reflects something extraordinarily old: the continual exchange between ocean currents, estuaries, rivers, and wetlands.

Fossil eels resembling modern species appear in the geologic record tens of millions of years ago, reflecting a lineage that has persisted through changing oceans, shifting coastlines, and repeated cycles of environmental change. | Image credit: Fossil Forum

Beach renourishment, by contrast, exists on an almost microscopic timescale geologically. Most projects reshape shorelines over years or decades, temporarily altering sediment movement, inlet dynamics, turbidity, and nearshore habitat. Eels are resilient enough to survive natural coastal change — hurricanes, shifting barrier islands, overwash events, and migrating inlets that have continually transformed the Atlantic coast. But human-driven shoreline modification can compress those disturbances into shorter, more frequent intervals that affect how juvenile eels enter estuaries and move inland.

So while beach renourishment itself is modern, the habitats it alters are part of a coastal system assembled over millions of years — one that species like the American eel have been navigating since long before the present coastline existed.

Their ecological importance is recognized even within local fisheries. In many areas, crab pots are now designed with eel escapement openings that allow smaller American eels to exit traps rather than become unintended bycatch. These modifications help reduce eel mortality while acknowledging the species’ role in maintaining healthy estuarine ecosystems.

The Animal That Connects Rivers

Many coastal species remain tied to a single environment. Oyster reefs remain fixed in estuaries. Marsh periwinkle snails cling to grass stems. Flounder shift between nearshore and estuarine waters but remain marine fish.

American eels move between worlds.

A juvenile eel may travel from offshore Atlantic currents into a coastal marsh creek, then into freshwater rivers hundreds of miles inland before eventually returning to the Sargasso Sea years later to spawn. Very few animals along the Atlantic coast connect ecosystems across such enormous distances.

American eels connect ecosystems across the Atlantic Ocean, beginning life in the Sargasso Sea before dispersing into estuaries, rivers, lakes, and wetlands throughout eastern North America. } Image credit: L. Poirier

Because of this, eels transport energy and nutrients between habitats that otherwise remain loosely connected. Predators feeding on eels receive marine-derived nutrients that originated far offshore. When adult eels migrate back toward the Atlantic, they carry inland energy back toward the ocean system (Jessop et al., 2020).

Even freshwater mussels depend upon them.

Several mussel species release microscopic larvae called glochidia that temporarily attach to fish hosts while developing. Research in Mid-Atlantic rivers has shown that American eels are one of the most successful hosts for some native mussel species, helping sustain mussel populations throughout eastern river systems (Schwalb et al., 2013).

So beneath the surface, the eel is doing more than surviving for itself. It is helping move life through the watershed.

What Happens When Eels Decline

Globally, the American eel is listed as “endangered, but stable” on the IUCN Red List because of long-term population declines across much of its range (IUCN, 2023). In the United States, however, the U. S. Fish and Wildlife Service has concluded the species does not currently require federal protection under the Endangered Species Act. The Atlantic States Marine Fisheries Commission determined that their populations are largely depleted in U. S. waters and have recommended continued monitoring of their populations because their life cycle depends upon the health and connectivity of both freshwater and marine environments (ASMFC, 2026).

For centuries, rivers along the Atlantic coast held far larger eel populations than they do today.

In many parts of the eastern United States, dams and hydroelectric turbines block migration routes and kill adults moving back downstream toward the ocean. Those barriers have severely reduced eel access to inland habitat across major river systems (Haro et al., 2000).

Onslow County is different.

The New River estuary is not fed by large mountain rivers or controlled by dams upstream. It is a relatively closed coastal watershed shaped instead by rainfall, groundwater springs, blackwater creeks, tidal exchange, runoff, and low-gradient streams winding through wetlands and forests. Here, eel movement depends less on navigating massive river barriers and more on the health and connectivity of marshes, culverts, floodplains, tidal creeks, and shallow estuarine habitat.

That makes local environmental changes especially important.

Wetland loss, shoreline hardening, stormwater runoff, dredging, declining water quality, and altered tidal flow can fragment the smaller pathways eels rely upon throughout the watershed. Even undersized culverts or poorly designed drainage structures can interrupt movement between creeks and flooded wetlands during critical migration periods.

Barrier islands also shape the system eels enter.

Along the Onslow coast, shifting inlets, overwash events, and beach renourishment projects continually reshape the boundary between ocean and estuary. In some cases, renourishment can temporarily increase turbidity, bury nearshore habitat, or alter tidal exchange patterns affecting juvenile eel recruitment into estuarine creeks. At the same time, healthy barrier islands and functioning marsh systems help buffer salinity extremes, reduce erosion, and maintain the sheltered estuarine habitat young eels depend upon once they arrive from the Atlantic.

Because eels use so many habitats, their decline spreads outward through the ecosystem in ways people may not immediately notice.

River otters lose an important prey source in some waterways. Mussel reproduction declines where host fish disappear. Predators that once relied seasonally on eels shift toward other prey. The disappearance of a species that connects marshes, rivers, estuaries, and offshore currents weakens the ecological ties between those environments.

And unlike species that reproduce quickly, eels recover slowly.

An eel living beneath a dock in coastal North Carolina may already be older than the child fishing above it. Some females remain inland for decades before ever returning to spawn (Haro et al., 2000). Every interruption between inland waters and the sea disrupts a migration pattern older than modern coastlines themselves.

The Fish Most People Never See

On warm summer nights in coastal North Carolina, much of the estuary moves unseen.

Shrimp rise into the water column. Rays cross shallow mudflats beneath darkness. Juvenile fish gather around dock lights. Crabs emerge from oyster beds to forage with the tide.

And somewhere below that shifting water, an eel moves silently between habitats, carrying the Atlantic inland and returning inland waters back toward the sea.

Most people standing along the shoreline will never know it is there.

But the marsh still holds the traces of its passage. So do the river otters weaving through flooded reeds and the herons stalking the quiet creek edges at dusk.

The tidal creeks of Onslow County continue shaping themselves around an animal whose life still stretches beyond much of human observation — from blackwater rivers to the open Atlantic, and back again.

Hidden beneath dark water and shifting tides, American eels remain one of the Atlantic coast’s most remarkable connections between ocean, estuary, and river. | Image credit: E. Smith, iNaturalist

References

Able, K. W. (2005). A re-examination of fish estuarine dependence: Evidence for connectivity between estuarine and ocean habitats. Estuarine, Coastal and Shelf Science, 64(1), 5-17. https://doi.org/10.1016/j.ecss.2005.02.002

ASMFC. (2026). American Eel. Atlantic States Marine Fisheries Commission. https://asmfc.org/species/american-eel/

Béguer-Pon, M., Castonguay, M., Shan, S., Benchetrit, J., & Dodson, J. J. (2015). Direct observations of American eels migrating across the continental shelf to the Sargasso Sea. Nature Communications, 6(1). https://doi.org/10.1038/ncomms9705

Haro, A., Richkus, W., Whalen, K., Hoar, A., Busch, W., Lary, S., Brush, T., & Dixon, D. (2000). Population decline of the American eel: Implications for research and management. Fisheries, 25(9), 7-16. https://doi.org/10.1577/1548-8446(2000)025<0007:pdotae>2.0.co;2

Inoue, J. G., Miya, M., Miller, M. J., Sado, T., Hanel, R., Hatooka, K., Aoyama, J., Minegishi, Y., Nishida, M., & Tsukamoto, K. (2010). Deep-ocean origin of the freshwater eels. Biology Letters, 6(3), 363-366. https://doi.org/10.1098/rsbl.2009.0989

Jessop, B. M. (2020). Oceanic environmental effects on American eel recruitment to the east river, Chester, Nova Scotia. Marine and Coastal Fisheries, 12(4), 222-237. https://doi.org/10.1002/mcf2.10121

MacGregor, R., Casselman, J. M., Allen, W. A., Haxton, T., Dettmers, J. M., Mathers, A., LaPan, S., Pratt, T. C., Thompson, P., Stanfield, M., Marcogliese, L., & Dutil, J. D. (2009). Natural Heritage, Anthropogenic Impacts, and Biopolitical Issues Related to the Status and Sustainable Management of American Eel: A Retrospective Analysis and Management Perspective at the Population Level. American Fisheries Society Symposium, 69, 713-740. https://www.thelandbetween.ca/wp-content/uploads/2014/06/Anacat_Final_Final-reprint_-macgregor.pdf

Near, T. J., Eytan, R. I., Dornburg, A., Kuhn, K. L., Moore, J. A., Davis, M. P., Wainwright, P. C., Friedman, M., & Smith, W. L. (2012). Resolution of ray-finned fish phylogeny and timing of diversification. Proceedings of the National Academy of Sciences, 109(34), 13698-13703. https://doi.org/10.1073/pnas.1206625109

Pike, C., Casselman, J., Crook, V., DeLucia, M. B., Jacoby, D., & Gollock, M. (2023). Anguilla rostrata. The IUCN Red List of Threatened Species. https://dx.doi.org/10.2305/IUCN.UK.2023-1.RLTS.T191108A129638652

Sahney, S., Benton, M. J., & Falcon-Lang, H. J. (2010). Rainforest collapse triggered Carboniferous tetrapod diversification in Euramerica. Geology, 38(12), 1079-1082. https://doi.org/10.1130/g31182.1

Schwalb, A. N., Cottenie, K., Poos, M. S., & Ackerman, J. D. (2011). Dispersal limitation of unionid mussels and implications for their conservation. Freshwater Biology, 56(8), 1509-1518. https://doi.org/10.1111/j.1365-2427.2011.02587.x

Starks, C. (2026). Interstate Fisheries Management Program Overview: American Eel (May 2026). Atlantic States Marine Fisheries Commission. https://asmfc.org/wp-content/uploads/2025/11/4.AmericanEel_May-2026.pdf

Tesch, F. W., & White, R. J. (2008). The eel (5th ed.). John Wiley & Sons.

Wang, C., & Tzeng, W. (2000). The timing of metamorphosis and growth rates of American and European eel leptocephali: A mechanism of larval segregative migration. Fisheries Research, 46(1-3), 191-205. https://doi.org/10.1016/s0165-7836(00)00146-6

May 29, 2026
Fish That Break the Rules: Unusual Anatomy Along the Edge of Onslow County

Where Expectations Begin to Slip

There are stretches of shoreline in Onslow County where the water looks simple.

A low wind flattens the surface just beyond the breakers. The sand underfoot is firm, packed by a falling tide. Small schools of baitfish turn in unison at the edge of visibility, their bodies catching light and then disappearing again as if nothing had moved at all.

From here, fish seem predictable. They swim. They are streamlined. They slip through water in ways that feel consistent, almost mechanical.

A school of juvenile fish swim in the Surf City sound. | Photo credit: A. Mitchell

But that impression doesn’t hold for long.

A few steps into the surf, something crunches beneath your heel—a shell, or what remains of one.. Offshore, a shape drifts that doesn’t seem built for movement at all. In the shallows, something settles to the bottom and then, impossibly, walks.

The closer you look, the more the pattern breaks apart. Along this stretch of coast—from the swash zone to the deeper water of Onslow Bay—some fish are not built like fish are “supposed” to be.

And once you notice them, the rules start to feel less like rules at all.

Teeth built for stone: Sheepshead

The rule broken: fish are supposed to have simple teeth

On calm mornings near New River Inlet, when the tide is just beginning to push in, the water around pilings and rock edges clears enough to see movement below the surface. Dark vertical bands appear and disappear as fish turn sideways to feed, their bodies angled tightly against pilings and rock.

If you get a close look—often only when one is caught—you notice the teeth.

Flat. Squared. Set in rows that look more like something borrowed from a mammal than a fish.

Sheepshead fish have mammal-like teeth used for scraping and crushing hard shells and barnacles. | Photo credit: Jeannette’s PIer

The sheepshead (Archosargus probatocephalus) feeds primarily on hard-shelled organisms—barnacles, oysters, mussels, and crabs attached to pilings, jetties, and natural hardbottom (Sedberry, 1987). These prey items are abundant in estuarine and nearshore environments where salinity fluctuates and structure concentrates life.

Instead of pointed, uniform teeth, sheepshead possess incisiform front teeth for scraping and strong molariform teeth set further back for crushing (Deang et al., 2018; Hernandez & Motta, 1997). Bite force measurements and stomach content analyses show they are capable of breaking calcareous shells that would resist most coastal fishes (Hernandez & Motta, 1997).

They are most active in waters typically ranging from 60–80°F (15–27°C), often within just a few feet of structure in depths from less than a meter to roughly 10 meters (Sedberry, 1987).

Fish are often imagined as generalized swimmers feeding on soft prey. But along the Onslow coast, hard surfaces—oyster beds, submerged debris, pilings—create entire microhabitats built on calcium carbonate (Grabowski & Peterson, 2007).

Sheepshead are not exceptions to the system; they are shaped by it. Their teeth are a direct response to a landscape where food remains locked inside a shell.

Most fish don’t have teeth like this because most environments don’t require it. Here, where geology and biology meet in layers of shell and structure, the rule changes.

The fish that walks: Bluespotted and Northern searobin

The rule broken: fish move by swimming

On a falling tide along the edges of Topsail Island, the water pulls thin over the sand flats. What remains is a shifting surface—ripples, shadows, and the occasional sudden burst of motion.

Then something moves without swimming.

It doesn’t dart or glide. It advances in short, deliberate steps, stopping and starting again, as if testing the ground before each movement.

For a moment, it looks wrong—like something moving through air instead of water.

The bluespotted searobin (Prionotus roseus) and the Northern searobin (Prionotus carolinus) do not rely on their fins for propulsion in the way most fish do. Instead, three detached rays from each pectoral fin extend downward, contacting the bottom and supporting the body as it moves. These rays function both as supports and as sensory structures, probing the sediment and detecting chemical cues—effectively allowing the fish to “taste” the seafloor as it moves (Bardach & Case, 1965).

Across these shallow flats, often just inches to a few feet deep, the water warms into the upper 60s and 70s as the tide recedes. Prey is rarely exposed. Worms, small crustaceans, and buried mollusks remain hidden beneath the surface. Vision alone is not enough here. The searobin moves slowly, stepping and pausing, tracing the bottom until something beneath the sand gives itself away.

Movement in water is usually about efficiency—minimizing drag, maximizing speed.

But the seafloor is a different environment entirely.

Here, visibility narrows, prey disappears beneath the surface, and swimming can carry you past what you’re trying to find. Walking—slow, deliberate, sensory-driven—becomes the better strategy.

Most fish don’t have “legs” because most fish don’t live where walking is more useful than swimming. Along the shallow bottoms of Onslow waters, this rule no longer applies.

The fish that swells: Northern puffer

The rule broken: fish don’t change shape

In late summer, when the water just beyond the breakers settles into the upper 70s, small shapes begin to move just offshore—slow, almost indifferent to the motion around them.

One drifts closer than expected, rounded in a way that doesn’t quite match the others. It hovers, turning slightly, its movement controlled but unhurried.

Then, without warning, the body changes.

It expands outward, the outline swelling until the fish no longer resembles something built to move through water at all.

The Northern puffer (Sphoeroides maculatus) does this by rapidly drawing water into a highly elastic stomach, a process that allows the body to expand far beyond its resting shape (Brainerd, 1994). Without rigid skeletal constraints like ribs or pelvic bones, that expansion can happen quickly, transforming the fish into something difficult for a predator to grasp or swallow.

A Northern pufferfish skeleton is made up of spiny modified scales (not bones) that expand like a balloon when threatended. | Photo credit: The Fossil Forum

In these nearshore waters—where predators move quickly and encounters happen at close range—there is little time to outrun what’s coming. Most fish rely on speed to escape. This one changes shape instead.

Speed isn’t part of the solution here.

The fish that locks itself in place: Gray triggerfish

The rule broken: fish don’t anchor themselves

Farther offshore, where the bottom begins to break into scattered hardbottom and reef patches, movement slows in a different way.

Shapes hold just above the structure, adjusting position in small increments, never straying far from the surface below them.

When disturbed, they don’t flee into open water.

They turn downward.

The gray triggerfish (Balistes capriscus) moves into crevices and tight spaces within the structure, where a set of dorsal spines can be raised and locked into place. The first spine lifts, and a smaller second spine holds it there—an arrangement that gives the fish its name and allows it to anchor itself firmly in place (Tyler, 1980; Lobel, 1980).

Its body is built for this kind of movement: deep and laterally compressed, with tough, abrasive skin and strong incisor-like teeth capable of breaking into hard-shelled prey (Tyler, 1980; Lobel, 1980). These are not features meant for speed. They are features meant for contact—pressing into structure, resisting removal, holding position when movement would fail.

In waters often 50–120 feet deep off Onslow County, where reefs and wrecks break the seafloor into pockets and edges, escape doesn’t always mean distance (Bellwood et al., 2004).

Sometimes it means holding ground.

Most fish survive by staying in motion.

This one survives by becoming fixed in place, turning the structure around it into part of its defense.

Light written into skin: Atlantic midshipman

The rule broken: fish don’t carry light in their skin

On warm summer nights near quiet stretches of marsh and inlet edges, the water sometimes carries sound before anything else. A low, continuous hum. It’s easy to miss unless you stop moving.

The Atlantic midshipman (Porichthys plectrodon) produces that sound through specialized sonic muscles vibrating against the swim bladder, creating a sustained hum that can carry through shallow coastal water (Sisneros, 2009; Bass & McKibben, 2003).

If you listen carefully during a quiet evening, the sound of a male midshipman trying to court a female might be heard. | Audio credit: SanctoSound – Integrated Ocean Observing System (IOOS)

Along the sides of the body and across the head are rows of small organs—photophores—set into the skin, giving the fish its name and marking it as something unusual among coastal species found in these waters (Schwartz, 2013). When seen out of the water, those rows catch the light in a very particular way—small, round points that flash gold in direct sunlight, spaced with a regularity that makes them look almost set into the surface, like buttons fixed into the skin.

The Atlantic midshipman has photophores that dazzle when out of the water, and used in seeing in darkened burrows and structures in limited light. | Photo credit: North American Native Fishes Association

Midshipman inhabit shallow coastal environments, often in burrows or beneath structure along muddy or sandy bottoms, typically in depths less than 20 meters.

Light in fish is often associated with deeper water, where darkness is constant and illumination becomes necessary (Haddock et al., 2010). But along the Onslow coast, those conditions can exist in smaller, shifting pockets. Light narrows quickly with depth, suspended sediment moves with the tide, and visibility can collapse even in water shallow enough to stand in.

Not all fish in these waters experience the bottom the same way. A flounder rests exposed on the sand, relying on camouflage and stillness. The midshipman, by contrast, spends much of its time within burrows, beneath structure, or pressed close to the substrate, where light is already limited and often disappears entirely.

In those spaces, the rules of visibility begin to resemble something closer to deeper water, even though the surface is only a few feet above.

The presence of photophores here does not follow the pattern most people expect.

Not all light comes from above.

The deep blade: Long-snouted lancetfish

The rule broken: fish are dense, muscular swimmers

From the beach, the horizon feels like a boundary—beyond the sandbars, beyond the nearshore currents—about two miles out, where the surface lifts just enough to hide what comes after. But beyond that line, the water doesn’t simply continue. It changes.

Depth increases quickly. Layers begin to form. Light fades long before the bottom is reached.

And in those deeper waters off Onslow Bay, some fish are not built to chase anything at all.

The long-nosed lancetfish lives in the middle depths of the ocean where body density is less desirable for a drifting fish. | Photo credit: ML – some rights reserved (CC BY-NC)

The long-snouted lancetfish (Alepisaurus ferox) lives in the midwater column, often hundreds of meters below the surface. Its body is long and thin, almost blade-like, with muscle reduced and tissue that is less dense than most active predators, appearing almost soft in the water (Drazen & Seibel, 2007).

It does not move with the steady, powered swimming most fish rely on. Instead, it drifts, adjusting position and taking prey as it comes within reach. Stomach analyses show a wide range of prey—fish, squid, and even other lancetfish—suggesting opportunism rather than pursuit (Kubota & Uyeno, 1970).

In these deeper layers, energy becomes harder to acquire and more costly to use.

Building and maintaining dense muscle comes at a cost. Chasing prey demands more of it (Sutton, 2013).

Here, that balance shifts.

The lancetfish represents a different solution—one that reduces the cost of movement and relies instead on encounter.

Most fish are built to swim.

This one is built to wait.

The armored survivor: Atlantic sturgeon

The rule broken: fish are supposed to have scales

In cooler months, when water temperatures drop into the 50s and 60s, large shapes move along the bottom of estuaries and nearshore waters.

They do not flash or turn sharply. They move steadily, close to the sediment.

At times, that movement reaches the surface. A back breaks through, arcing briefly before slipping under again, the shape unfamiliar enough that it doesn’t immediately read as a fish.

The Atlantic sturgeon (Acipenser oxyrinchus oxyrinchus) retains an older form—rows of bony scutes instead of the flexible scales seen in most fishes (Bemis et al., 1997). Along the underside, a protrusible mouth extends downward, drawing in prey from the bottom through suction rather than pursuit (ASSRT, 2007; Bemis et al., 1997).

An anadromous fish, they move between river systems and coastal waters, passing through estuaries and along the nearshore edge, often in depths ranging from shallow channels to over 100 feet offshore (Dunton et al., 2015; ASSRT, 2007).

This design is not new. It has persisted for tens of millions of years, carried forward through changing coastlines, shifting sea levels, and the rise of entirely different groups of fishes (Bemis et al., 1997).

Atlantic sturgeon have a bony structure that has remained relatively unchanged for millions of years. | Photo credits: mdadswell – some rights reserved (CC BY-NC) (left); Steven McGrath – some rights reserved (CC BY-NC-ND) (right)

It works because the conditions it responds to have never fully disappeared.

Along the bottom, prey remains buried. Sediment still shifts with current and tide. Feeding still depends on contact more than speed. Armor still protects a body that cannot easily maneuver out of danger.

For a long time, these fish seemed to fade from local waters. In Onslow County, encounters became rare enough to feel like absence. But populations have persisted elsewhere, and in nearby systems like the Cape Fear River, they are being observed again with increasing frequency—moving through channels, returning to spawning grounds, reappearing in places where they had not been seen in years (Dunton et al., 2015; ASSRT, 2007).

Their range has shifted before. It may be shifting again.

What remains constant is the need for connection—between river and ocean, between spawning grounds and feeding habitat.

This fish does not depend on a single place. It depends on the continuity between them.

Not all designs are meant to change. Some persist because the system they belong to still exists.

The drifting giant: Ocean sunfish

The rule broken: fish are supposed to be shaped for swimming

Occasionally, especially in warmer months when currents shift, something appears offshore that barely seems to move at all.

A large, flattened body. A fin breaking the surface. Then another, held there longer than expected.

It drifts more than it swims.

At times, it lingers there, tilted at the surface, absorbing the sun before slipping back beneath the water.

The ocean sunfish (Mola mola) is one of the heaviest bony fish, reaching weights over 1,000 kg. Its body is truncated, lacking a true caudal fin, and propulsion is achieved through synchronized movements of dorsal and anal fins (Pope et al., 2010; Watanabe et al., 2009).

After diving into colder, deeper water, sunfish often return to the surface, where this slow, drifting posture allows their body temperature to rise again (Watanabe et al., 2009). Prolonged time at the surface can leave the skin visibly altered—shifting from darker grey to lighter tones, sometimes appearing pale or pinkened under sustained exposure.

Sunfish often inhabit offshore waters but can approach nearshore areas following currents and prey, particularly gelatinous organisms like jellyfish (Cartamil & Lowe, 2004).

By most expectations, this body plan shouldn’t work.

But it does—because efficiency, here, takes a different form. It is about buoyancy, drift, and feeding on abundant, slow-moving prey.

In a system where jellyfish blooms are seasonal and sometimes dense, a fish shaped like this becomes not an anomaly, but a specialist.

Answers to a layered environment

From the shoreline, the water still looks simple.

Small waves rise and fall. Baitfish turn and vanish. The surface holds its shape.

But beneath that surface, the rules have already begun to shift.

Fish move through these waters in ways that don’t match what we expect—crushing shell, stepping across the bottom, changing shape, holding themselves in place, carrying structures that catch light, drifting where others would swim, or moving through forms shaped long before this coastline took its present shape.

What appears, from the beach, to be a single environment is something else entirely. It is layered—sand, structure, depth, temperature, light—each one asking something different of the animals that live within it.

And the fish that seem unusual are not exceptions.

They are answers.

A layered system, at New River Inlet, seen from the surface. | Photo credit: A. Mitchell

References

Atlantic Sturgeon Status Review Team. (1998). Status review of Atlantic sturgeon (Acipenser Oxyrinchus Oxyrinchus). U.S. Fish and Wildlife Service. https://books.google.com/books?id=ee5MhnuurDMC&dq=+Status+review+of+Atlantic+sturgeon+(Acipenser+oxyrinchus+oxyrinchus)

Bardach, J. E., & Case, J. (1965). Sensory capabilities of the modified fins of squirrel hake (Urophycis chuss) and Searobins (Prionotus carolinus and P. evolans). Copeia, 1965(2), 194. https://doi.org/10.2307/1440724

Bellwood, D. R., Hughes, T. P., Folke, C., & Nyström, M. (2004). Confronting the coral reef crisis. Nature, 429(6994), 827-833. https://doi.org/10.1038/nature02691

Bemis, W. E., Findeis, E. K., & Grande, L. (1997). An overview of Acipenseriformes. Developments in Environmental Biology of Fishes, 48, 25-71. https://doi.org/10.1007/0-306-46854-9_4

Blake, R. W. (2004). Fish functional design and swimming performance. Journal of Fish Biology, 65(5), 1193-1222. https://doi.org/10.1111/j.0022-1112.2004.00568.x

Brainerd, E. L. (1994). Pufferfish inflation: Functional morphology of postcranial structures in Diodon holocanthus (Tetraodontiformes). Journal of Morphology, 220(3), 243-261. https://doi.org/10.1002/jmor.1052200304

Cartamil, D., & Lowe, C. (2004). Diel movement patterns of ocean sunfish mola mola off Southern California. Marine Ecology Progress Series, 266, 245-253. https://doi.org/10.3354/meps266245

Deang, J., Persons, A., Oppedal, A., Rhee, H., Moser, R., & Horstemeyer, M. (2018). Structure, property, and function of sheepshead (Archosargus probatocephalus) teeth. Archives of Oral Biology, 89, 1-8. https://doi.org/10.1016/j.archoralbio.2018.01.013

Drazen, J. C., & Seibel, B. A. (2007). Depth‐related trends in metabolism of benthic and benthopelagic deep‐sea fishes. Limnology and Oceanography, 52(5), 2306-2316. https://doi.org/10.4319/lo.2007.52.5.2306

Dunton, K. J., Jordaan, A., Conover, D. O., McKown, K. A., Bonacci, L. A., & Frisk, M. G. (2015). Marine distribution and habitat use of Atlantic sturgeon in New York lead to fisheries interactions and Bycatch. Marine and Coastal Fisheries, 7(1), 18-32. https://doi.org/10.1080/19425120.2014.986348

Fernandez, L. P., & Motta, P. J. (1997). Trophic consequences of differential performance: Ontogeny of oral jaw‐crushing performance in the sheepshead, Archosargus probatocephalus (Teleostei, sparidae). Journal of Zoology, 243(4), 737-756. https://doi.org/10.1111/j.1469-7998.1997.tb01973.x

Grabowski, J. H., & Peterson, C. H. (2007). Restoring oyster reefs to recover ecosystem services. Theoretical Ecology Series, 4, 281-298. https://doi.org/10.1016/s1875-306x(07)80017-7

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

McIver, E. L., Marchaterre, M. A., Rice, A. N., & Bass, A. H. (2014). Novel underwater soundscape: Acoustic repertoire of plainfin midshipman fish. Journal of Experimental Biology. https://doi.org/10.1242/jeb.102772

Mensinger, A. F., & Case, J. F. (1990). Luminescent properties of deep sea fish. Journal of Experimental Marine Biology and Ecology, 144(1), 1-15. https://doi.org/10.1016/0022-0981(90)90015-5

Petersen, J. C., & Ramsay, J. B. (2020). Walking on chains: The morphology and mechanics behind the fin ray derived limbs of sea-robins. Journal of Experimental Biology. https://doi.org/10.1242/jeb.227140

Peterson, D. L., Bain, M. B., & Haley, N. (2000). Evidence of declining recruitment of Atlantic sturgeon in the Hudson River. North American Journal of Fisheries Management, 20(1), 231-238. https://doi.org/10.1577/1548-8675(2000)020<0231:eodroa>2.0.co;2

Pope, E. C., Hays, G. C., Thys, T. M., Doyle, T. K., Sims, D. W., Queiroz, N., Hobson, V. J., Kubicek, L., & Houghton, J. D. (2010). The biology and ecology of the ocean sunfish mola mola: A review of current knowledge and future research perspectives. Reviews in Fish Biology and Fisheries, 20(4), 471-487. h ttps://doi.org/10.1007/s11160-009-9155-9

Schwartz, F. J. (2013). Atlantic midshipman, Porichthys plectrodon, in North Carolina. Journal of the North Carolina Academy of Science, 129(3), 111-114. https://doi.org/10.7572/2167-5880-129.3.111

Sedberry, G. R. (1987). Feeding habits of Sheepshead, Archosargus probatocephalus, in offshore reef habitats of the southeastern continental shelf. Northeast Gulf Science, 9(1). https://doi.org/10.18785/negs.0901.03

Sisneros, J. A. (2009). Adaptive hearing in the vocal plainfin midshipman fish: Getting in tune for the breeding season and implications for acoustic communication. Integrative Zoology, 4(1), 33-42. https://doi.org/10.1111/j.1749-4877.2008.00133.x

Snelgrove, P. V. (1999). Getting to the bottom of marine biodiversity: Sedimentary habitats. BioScience, 49(2), 129. https://doi.org/10.2307/1313538

Sutton, T. T. (2013). Vertical ecology of the pelagic ocean: Classical patterns and new perspectives. Journal of Fish Biology, 83(6), 1508-1527. https://doi.org/10.1111/jfb.12263

Tyler, J. C. (1980). Osteology, phylogeny, and higher classification of the fishes of the order plectognathi (Tetraodontiformes) (434). U.S. Dept. of Commerce, National Oceanic and Atmospheric Administration, National Marine Fisheries Service. https://10.5962/bhl.title.63022

March 28, 2026
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
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