Where did all the weakfish go?
Weakfish officially became Delaware’s state fish in 1981. At the time, this species of fish was so plentiful in Delaware’s coastal waters that locals established a World Championship Weakfish Tournament, which was coordinated every year by the Greater Milford Chamber of Commerce.
As years passed, the size of weakfish catches plunged. Fisheries managers struggled to bring back their numbers and local fishermen grew increasingly upset.
Delaware Public Media’s science reporter Eli Chen explains the mysterious decline of Delaware’s state fish.
Charles Auman is a commercial waterman and the owner of That’s Right, Fresh Seafood in Slaughter Beach. He’s referring to the late 70s and early 80s when the weakfish population exploded along the Atlantic Coast.
“When I was about 12 and 13, about 40 years ago, weakfishing was one of the biggest industries, or draws for recreational and commercial fishermen in the Delaware Bay,” said Auman.
The weakfish, also called sea trout, is a shiny, silver fish known for its soft, dark meat. John Clark, the state’s fisheries administrator, remembers how crowded Bowers Beach used to get in the summertime with fishermen.
“Back in the 70s and 80s, we used to have so many people launching there, we had to hire people to direct traffic at the ramps and it was because of the weakfish,” said Clark.
But the excitement over weakfish didn’t last.
Weakfish populations were already declining when Charles Auman started his business in the mid-1990s. According to the Atlantic State Marine Fisheries Commission, the weakfish stock dropped from about 113 million pounds in 1982 to 17.6 million in 1990. Regulators implemented fishing restrictions and for a few years, it seemed like the weakfish was coming back.
“And then the stock started to crash again. And not just crash, but crash precipitously," said Clark. "Between 1998 and 2008, both our commercial and recreational landings in Delaware dropped by over 99 percent. It was just astonishing.”
And Auman can attest to that.
“It went from pallets -- thousands of pounds -- to 15 pounds this year,” said Auman.
With tight regulations on catching weakfish in place, it became clear fishing pressure wasn’t the cause of their decline. Delaware right now only allows fishermen to keep one 13 inch weakfish per day.
Clark says the 2006 stock assessment was what suggested that the drop was due to natural mortality, basically predation from other species.
“If you look in the crash in weakfish in the early 2000s, it coincides neatly with a huge increase in striped bass populations in that time,” Clark said.
But when striped bass started to decline, weakfish numbers did not come back. And Clark says the state began looking at other culprits -- from spiny dogfish to bottlenose dolphins.
“There really hasn’t been a complete smoking gun,” said Clark.
Fishermen like Charles Auman agree there are a number of predators after weakfish, but he feels regulators also played a role by protecting some predators and allowing them to flourish.
“There’s times that rockfish come in this bay so thick that if you were a trout out there, you wouldn’t stand a chance," said Auman. "And all the fish they’ve brought back, sharks, rockfish, flounder. Everything eats sea trout. Even sea trout eat sea trout.”
But with so many predators involved, it’s complicated for fisheries managers to devise a solution.
In recent years, regulators began tagging weakfish to better understand what’s happening.
In early fall, researchers from North Carolina State University visited Delaware to sample and tag weakfish. North Carolina has also seen a drop in weakfish stock, and scientists want to compare what’s happening along the Delaware and North Carolina coasts to better understand the species decline. In late September, we met very early in the morning near the Prime Hook Wildlife Refuge.
“The tide is coming in right now, we need to get in at low tide in order to sample for fish," said Jacob Krause, a PhD student at North Carolina State. He was accompanied by a recent graduate, Cameron Luck, and a DNREC staff member, Chad Betts. It’s Krause and Luck’s third trip to Delaware and even though they aimed to tag just 30 weakfish, it’s been difficult.
“Our first week, we put out five days and we caught six undersized fish,” said Krause.
Catching undersized fish is a problem for Krause’s research. Each acoustic tag is about the size of a AA battery. So the fish has to be at least 12 inches long to survive with the transmitter inside it. And their trouble catching fish large enough shows how much the weakfish population has suffered.
“So they make it to 12, 13 inches, and then after that they don’t seem to come back. So these older aged fish aren’t in the system. We don’t know why that’s the case," said Krause. "If you have successive bad years after a while, that’s when the population takes a hit and it doesn’t recover.”
That morning, I followed them onto the beach to watch the process
Ultimately, they got one proper sized weakfish, tagged it and let it loose into the water. And from that point on, that fish was on their radar. They can track it as it moves south in the winter - and if it looks like it’s been eaten by a predator or caught by a fishermen, they’ll have an idea where it happened.
“I think of the fish population as being a big pie and a lot things are taking little slivers from this pie. It’s just a matter of what’s taking the most," said Krause. "Is it bottlenose dolphin, bird predations? We don’t know at this point.”
Krause says the tagging project will help them get closer to an answer to what’s happening to the adult weakfish and a solution, if there even is one. Otherwise, the weakfish may become the one that got away.