Cold winter weather can play a key role in what
you’re allowed to fish for next spring. That point was driven home when
low temperatures in early January led North Carolina to temporarily bar
fishing for spotted seatrout (Cynoscion nebulosus), one of the most
popular targets for recreational anglers.
Stories about isolated fish kills, or “cold stuns,” of spotted sea
trout due to cold temperatures date back more than 100 years. But no
one knew just how important these cold stuns could be until 2017, when
North Carolina State University researchers published new findings on
“We had a lot of anecdotes about spotted seatrout, but in order to make
good fishery management decisions, you need quantifiable, scientific
data,” said Tim Ellis, an ecosystems analyst for the Albemarle-Pamlico
National Estuary Partnership, or APNEP, who did research on cold stuns
and spotted seatrout while a Ph.D. student at NC State.
Ellis, in collaboration with Joe Hightower and Jeff
Buckel of NC State, collected data on the spotted seatrout fisheries in
North Carolina and Virginia from 2008 through 2014, work that
ultimately led to three publications in 2017 and 2018 that address the
impact low temperatures can have on the species. And that impact can be significant.
NC State News
is published by North Carolina State University and reports breaking
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discovery.“The full extent of this month’s cold stun is not yet known,
but conditions seemed comparable to what we saw in 2010 – and that
year’s cold temperatures led to around 95 percent mortality in spotted
seatrout populations in North Carolina and Virginia,” Ellis said.
That’s a big deal, because spotted seatrout are one of the most sought-after species by recreational anglers in North Carolina – and throughout the southeastern U.S.
“In terms of dollars and cents, the N.C. Division of Marine Fisheries
estimates that the recreational fishery for spotted seatrout in North
Carolina alone, had a total economic impact of more than $54 million in
2016,” Ellis said.
The importance of this fishery, and the N.C. State findings, are likely
why the Division of Marine Fisheries announced Jan. 5 that it was
barring commercial and recreational fishing of spotted seatrout in
North Carolina waters until June 15, after the species has passed its
peak spawning season.
Most spotted seatrout overwinter in shallow, estuarine waters, where
water temperatures are strongly affected by the air temperature. That
makes the species particularly susceptible to cold snaps like those we
saw in the first weeks of 2018.
“In mild winters, spotted seatrout populations can thrive in North
Carolina waters,” Ellis said. “But high mortality during cold winters
means it could take a while for the fishery to rebound. The fishery is
being closed in North Carolina to protect the remaining spawners, in
hopes that this will help the species bounce back more quickly.”
“Until Tim decided to take a look, nobody knew how important cold
temperatures could be for spotted seatrout at the population level,”
“Ultimately, our research is making a difference,” Ellis said. “We gave
fishery managers key information they needed to make informed decisions
about how to respond to cold-stun events.”
The three relevant papers are “Relating cold tolerance to winterkill for spotted seatrout at its northern latitudinal limits,” published February 2017 in the Journal of Experimental Marine Biology and Ecology; “Winter severity influences spotted seatrout mortality in a southeast US estuarine system,” published February 2017 in the journal Marine Ecology Progress Series; and “Relative
importance of fishing and natural mortality for spotted seatrout
(Cynoscion nebulosus) estimated from a tag-return model and corroborated
with survey data,” published in January 2018 by the journal Fisheries Research.
The research was done with support from North Carolina Sea Grant (No.
08-FEG-06) and the N.C. Coastal Recreational Fishing License Fund (N.C.
Department of Environmental Quality Task Order #2226).
NC State News is published by
North Carolina State University and reports breaking news, feature
stories and reports from the forefront of education and discovery.