If the itty bitty cod are a seal’s favorite meal, and the seals continue to provide gourmet fodder for the Great White sharks, well, someone’s going to need a bigger boat.
Numerous scientists and fishermen have been equating the plethora of shark sightings this summer with the plethora of seals – which sharks crave – as well as with the perplexing absence of cod, which seals chow down in astounding amounts.
The unintended consequence of protecting mammals such as seals and porpoises could mean even more of an imbalance in the food chain this fall, fishermen fear. Fishermen will be banned by federal law, starting in the autumn, from catching fish in an area where mammals – and groundfish – abound.
As previously reported, the ban will not affect Cape Cod, where the bycatch rate of porpoises is less than here, according to a study by the National Atmospheric and Oceanic Administration, which regulates fishing. NOAA also charged that the Gloucester boats use “pingers” to scare off mammals only about two-thirds as regularly as the Cape Codders, though local fishermen soundly dispute that.
While the unprecedented overpopulation of seals is mostly around Cape Cod – where an estimated 25 Jaws-like creatures up to 18 feet are having a day at the beach – both species are summering here as well. Capt. Dave Jewell of the Lady J said he is seeing many more seals.
“They’re brutal,” he said, “sneaking in under the net, ripping open the bellies of the cod; stealing lobsters right out of the pots. They opened 140 doors on my tarps in one day lat week.”
Jewell said he spotted a 12-foot great white about 10 feet from his boat last week — just about “a half mile off Gloucester Harbor,” he said, “by Braces Cove.”
Some seals get caught in the nets, when they show up to eat the trapped cod, fishermen and the government agree, but Teri Frady of the NOAA Science Center in Woods Hole said she had no statistics either on the local seal population, how many become bycatch, or how the forthcoming ban on gillnetting might affect them.
In a Canadian study of the Nova Scotia waters in 1985, when cod there were beginning to decline, the seal count was way up, said Brian Rothschild, Montgomery Charter Professor of Marine Science at the University of Massachusetts Dartmouth.
“There were unheard of levels of seals,” said Rothschild, “like now, here, especially in Buzzards Bay. We don’t know exactly what’s going on with the cod, but some say the two are interacting in the food cycle. And we do know white sharks eat seals. Even one Great White is a scary thing.”
As Rothschild noted, the case of the mysteriously diminished cod count – NOAA says stocks are down by 22 percent in three years – is a matter of dispute between government and academic scientists.
Come October and November — prime groundfishing time – more than 2,000 square miles of the Gulf of Maine will be off limits to Gloucester’s 32 gillnetters, about half the local fleet, in order to protect what the government says are threatened numbers of porpoises. Protection of seals will be a side effect, experts admit.
The gillnetters are usually small boats, not trawlers, that use finely sized monofilament to catch fish.
“A properly tended stand-up gill net targets specific size fish,” said Mark Godfried, a Gloucester-based longtime fisherman, fish auction grader and corporate consultant. “Hooks are not discriminatory. They can catch little fish that should not be caught.”
Under the 40-year-old Marine Mammal Protection Act, high mortality rates can mean “consequence closure” in coastal waters, which is what is being invoked in and around Gloucester this fall. Yet, says Godfried, look at these consequences:
According to the Canadian study, approximately 7 million seals in the broadly defined Gulf of Maine ate an average 11 pounds of fish a day, or 77 million pounds in all.
Some 65 percent of those were herring or the like, Godfried said the study found, and about 17 percent were juvenile cod, for a total 12 million to 13 million pounds of young cod consumed daily.
Nancy Gaines is a regular Times correspondent, and a longtime writer and editor of a number of Boston-based and national publications.