Half of the fish species in a new study are now inhabiting different areas of the East Coast.

Research Need

Unlike humans, which are warm-blooded, fish are cold-blooded and cannot regulate their body temperatures. This means they need to move to hotter or cooler water to maintain the right level of warmth. 

The unpredictability of longer-term changes in fish locations hinders fisheries management. Due to cost and practicality, most scientific surveys only cover small regions or specific habitats, use select fishing gears, and follow different sampling designs — all of which yields inadequate data for understanding where fish are moving. 

The growth of saltwater angling, however — with the total number of East Coast marine recreational fishing trips ranging from 135 to 155 million each year over the past 20 years — presents an opportunity to examine movements of important recreational fish species. 

What Did They Study?

Since 1981, the National Marine Fisheries Service (NMFS) has collected information from saltwater anglers, first through the Marine Recreational Fisheries Statistics Survey and then, beginning in 2006, with the replacement Marine Recreational Information Program. 

Over this time, the core data coming from each angler interview have remained largely unchanged. From Maine to Florida, trained staff conduct in-person surveys with marine recreational fishers at public fishing access sites, recording what species were caught and kept or released. 

NMFS researcher Erik Williams thus focused on the 80 most-caught species. He also further categorized these species by where they live: coastal versus offshore, and near the surface versus near the bottom.

The study used landing locations as a reasonable estimate of where anglers caught fish, because most recreational fishing trips are relatively short. Williams then calculated the locations where most catches occurred. 

What Did They Find?

About half of the fish species showed clear shifts in location. Species shifting southward included bluefish, king mackerel, vermilion snapper, red snapper, and gafftopsail catfish. 

However, northward movement was much more common among species than southward movement. Northward-moving species included black sea bass, Spanish mackerel, sheepshead, cobia, northern kingfish (sea mullet), bluefin tuna, Atlantic bonito, and Atlantic cutlassfish (ribbonfish). The Atlantic cutlassfish had the quickest change in movement northward.

Coastal and bottom-dwelling species were more likely to shift northward or southward than offshore species, suggesting that nearshore waters are changing especially quickly. Sheepshead provided a clear example, with catches steadily moving northward while the population appears to remain healthy.

So What?

The movement of fish species up and down the East Coast requires fisheries management that is rapidly adaptive. Traditional population forecasts, typically from stock assessment models, cannot accurately account for the locations of species and may lead to management decisions based on incorrect information. 

This research shows that recreational fishing data are essential for understanding long-term changes in the ocean. Every dockside interview contributes to a record that helps scientists track how fish populations shift or remain in place over time.

The study highlights the important role recreational anglers play in fisheries science. By participating in surveys, anglers can help shape future management and conservation efforts.

Reading

Williams, E. H. (2025). Marine fish distribution shifts inferred from a recreational fishing survey along the U.S. East Coast. North American Journal of Fisheries Management, 45(3), 456–469. https://doi.org/10.1093/najfmt/vqaf030

Funding was provided by the U.S. Department of Commerce, National Oceanic and Atmospheric Administration, National Marine Fisheries Service, Southeast Fisheries Science Center.

The text from Hook, Line & Science is available to reprint and republish at no cost, but only in its entirety and with this attribution: Hook, Line & Science, courtesy of Scott Baker and Sara Mirabilio, North Carolina Sea Grant.