Sharks of Onslow County
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.
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.
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.
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.
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.
Every feast depends on abundance. In the New River system, fall prey peaks come from several sources:
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).
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.
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.
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.
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.
