Fast facts about snook:
● Common snook are hermaphrodites: Each one is born a male, and then switches sexes to female at about 12-35 inches in length.
● They commonly spawn, or lay eggs, in coastal rivers and inlets during new and full moons. Spawning occurs from April to October.
● Snook commonly eat smaller fish, like pinfish, and invertebrates, like shrimp.
● Anglers are likely to find snook near inshore areas, mangroves, creeks and inlets.
● The 2010 cold kill event decimated snook populations statewide. Since then, the fishery has managed to rebound with great success, including the expansion in the Gulf northward.
Twenty-five years ago, it was rare for Heath Davis’s father to catch snook in the Gulf of Mexico near Cedar Key.
Davis, the town’s former mayor, first remembers seeing him reel in one of the feisty sport fish with its characteristic sleek, black stripe that runs from cheek to tail. That was 1996, and for the previous century and a half that his family had lived on the island, they had never documented catching a snook.
Now, they’re not an uncommon visitor offshore and in freshwater springs, where they keep warm.
University of Florida and Florida Fish and Wildlife Conservation Commission researchers have studied the common snook for more than a decade, tracking their movements and recent invasion into the waters near Cedar Key, a town with fewer than 700 residents an hour southwest of Gainesville. That’s about 100 miles north of the fish’s historical range, said Micheal Allen, a UF fisheries scientist who co-authored a recent study analyzing the snook’s expansion north as a result of climate change.
Parts of the Gulf that used to be too cold for the fish — namely, anything north of Tampa — are now warm enough in winter months. The study also reports that snook have moved into the estuaries of the Suwannee River and north central Florida’s freshwater springs, which act as a warm refuge for the temperature-sensitive species that can’t survive in water below 50 degrees Fahrenheit.
Using data from a National Oceanic and Atmospheric Administration buoy near Cedar Key, the researchers observed the number of days each year below about 53 degrees Fahrenheit. The number of such cold days steadily declined over the past two decades, helping to explain the snook’s ability to reproduce and survive in the area.
The snook is an angler’s dream: a lean, tan-colored sport fish easily identified by its black racing stripe that runs from gills to tailfin. It’s sneaky, too. Snook are often found winding through the maze of mangrove roots, where they dwell in the muddy, shaded seafloor. If you’re lucky enough to catch one on your line, you’ve got a fight.
“It’s a beautiful fish, it’s very tasty and it’s a great battle on the fishing pole,” said Denny Voyles, a recreational fishing guide in Cedar Key.
Voyles said he has over the past decade caught juvenile snook in estuaries and inlets, indicating that a breeding population has started to establish in the area. He said he’s caught more and more of them each year, but he mostly catches them by accident in areas where he fishes for mullet, which are food for snook and other local fish predators.
“It’s good to see that they’re reproducing and starting, maybe, a sustainable fishery, depending on if we get a hard winter or not,” he said.
The Florida Fish and Wildlife Conservation Commission documents a cold kill event in winter 2010 that decimated several species of fish, including the common snook. It prompted the agency to temporarily close harvest for three years on the Gulf Coast before it reopened. Data show that populations have steadily increased ever since.
“That 2010 cold event, which killed snook all the way down to the Everglades, really happened before there were snook here, and the expansion northward of snook has happened since that time,” Allen said.
The probable reason? Climate change.
This year alone has seen record-breaking temperature highs in Florida. Data for January through October indicate the warmest year on record for the state, according to state climatologists and data from the NOAA National Centers for Environmental Information.
Despite the recent trend of warmer winters, the changing climate might also mean harsher cold winters, when they come. Allen added that another abnormally cold winter could again decimate snook populations. Florida State University’s Climate Center explains that “cold air outbreaks can produce below-freezing temperatures and are usually accompanied by strong winds that can produce bitterly cold wind chills.”
The area has also seen an expansion of black and red mangroves, which provide rich habitat for snook and other marine species.
“Snook are not the only thing changing in this region,” Allen said. “Mangroves are not a bad habitat for fish and wildlife, so it’s not like you can say the expansion of mangroves is a bad thing, but it is replacing salt marsh.”
While the trend is pushing marine species like snook and their mangrove habitat further north, Allen notes that not all climate change effects are necessarily bad for humans or individual species.
Mangroves provide habitat for more species than just snook, and increased snook might mean more opportunities for local fishing guides like Voyles to entertain clients for their charters. As of mid-November, Voyles said he was already booked through early 2021.
“Climate change and sea level rise is going to be a challenge for people on many fronts, but not all the impacts of that are going to be bad for humans,” Allen said. “It’ll create some fishing opportunities in the case of snook.”
Still, the snook’s arrival could also threaten the balance of the local ecosystem. The fish’s diet overlaps with that of spotted seatrout and red drum, two other medium-sized sport fish that are longtime inhabitants along Cedar Key’s shoreline. Increased competition among the three species for food could have impacts on the food web, Allen said.
State regulations for snook fishing vary for each coast. On the Gulf of Mexico near Cedar Key, licensed fishers are allowed to catch snook from Sept. 1 through Nov. 30 and March 1 through April 30. Anglers are allowed to keep just one snook per day per person, and only if the fish measures between 28 and 32 inches. During the off-season and in some parts of Florida year-round, people are required to release the fish back into the water if they catch one.
“It’s a well-managed fishery, not considered overfished, you know, not under threat,” Allen said.
Allen explained that if groundwater recharge and freshwater flows are down — meaning less thermal refuge, or warm waters — that could affect the viability of snook populations to persist in the Suwannee River and its tributaries. He said he and the other researchers on the study are working with the Suwannee River Water Management District to better understand how water flows might impact the local population.