Counting Fish | Estimating the Gulf of Maine's Fish Population
Suddenly, off the starboard bow—spouts! The arcs of humpback whales. Then the distinctive V spout of a right whale, one of the most endangered animals on earth. Then pilot whales and dolphins. We’re curling around the tip of Provincetown, passing over Stellwagen Bank, a remnant of those glaciers. Stellwagen’s fabled fishing grounds extend from the forearm of Cape Cod nearly to Gloucester, staying about 100 feet below the surface. As currents push nutrients from the bottom of the sea up this great underwater sand pile, they trigger tremendous phytoplankton growth, which in turn feeds the rest of the food web.We’re here to document that food web. The Bigelow is the most sophisticated fishing vessel in the United States. It has to be, because it’s in the eye of the storm of the most complicated, claustrophobic, controversial, and downright crazed fishery in the United States: New England groundfish, which include cod, haddock, pollock, hake, flounder, and other species caught in bottom-trawling nets. It’s NOAA’s job to determine how many of these fish there are and how many of them New England’s fishermen can safely catch. Every spring, a team of scientists from NOAA’s Northeast Fisheries Science Center in Woods Hole sets out on the Bigelow to drag a net along the seafloor for a mile at each of hundreds of randomly selected points and catalogue the fish they find. This has never made the fish geeks at Woods Hole terribly popular in New England, but since February of this year, when they slashed the quota on Gulf of Maine cod by 77 percent, throwing fishermen out of work from New Bedford to Portland, the Bigelow has been about as welcome here as the Black Pearl.
“We have a saying,” Mike Palmer, the chief author of the new cod assessment, tells me as we watch the whales. “If you’re pissing off both sides, you must be doing something right.” By that metric, NOAA is doing one heck of a job. On the same day this past spring, it was sued by the Conservation Law Foundation for setting catch limits too high and by the Commonwealth of Massachusetts for setting them too low. Fishermen have lost all faith in NOAA’s numbers. They want to know how the same agency that announced a surging population of cod in its 2008 assessment could have discerned a crashing population just three years later.
As do I. Since it began its surveys in the 1960s, NOAA has welcomed volunteers to ease the load on its scientists. So I volunteered, to see how they do it. How do you accurately estimate fish populations in a body of water as huge as the Gulf of Maine? You can’t exactly roll back the waters and count.
Now I’m starting to get an inkling. Once we clear the whales, the net plays out. Twenty minutes later the bridge calls, “Haulback!” and the seven of us on the day watch pull on foul-weather gear and head for the LED-lit “wet lab,” where we line both sides of a conveyor belt connected to the back deck, orange plastic lobster hampers around us. The catch is dumped onto the conveyor belt, and the great, glinting diversity of the sea comes wriggling past. As the only landlubber in the group, I’m wondering what I’ve gotten myself into. I sort as fast as my hands can move: herring, flounder, mackerel, dogfish, and lots and lots of “monkey dung,” an odiferous deep-sea sponge.
“Give those flounder a swirl, people!” shouts Geoff Shook, our watch chief. “There could be lots of things hiding beneath.” Alas, there are: shrimp and four-inch eel-like fishes. “Sand lance,” Palmer says, holding one up. “Big part of the cod story.”
I’d love to follow up on that, but I’m frantically sorting shrimp into one basket, sand lance into another, trying to dodge the snapping claws of the lobsters. Cold seawater pumps across the belt and the floor to keep the fishiness to a minimum.
Shook backs me up and, once the conveyor belt is bare, delivers the bad news: My basket of herring is actually a mishmash of sea herring and river herring, a.k.a. alewives. Shook shows me how alewives are stubbier and flatter than sea herring, despite the same silver coloring. “You’ll get better,” he says, unconvincingly, sorting the two species into different buckets.
But there’s no time to study before we divide into two-man teams to work up the catch. I’m partnered with Nikolai Klibansky, a grad student from North Carolina. Klibansky is our “cutter,” while I’m the “recorder.” We position ourselves at a workstation with a cutting board and several touchscreen monitors and grab a basket of fish.
Klibansky lines up the first fish on a magnetized scale and plunks down a magnet at its tail. Length and weight automatically enter the Fisheries Scientific Computer System, known as “Fiscus.” Klibansky cuts open the fish’s belly and announces its sex and maturity as I punch the data into the monitor. Klibansky cuts out the stomach and squeezes its goopy contents onto the board, picking through the mush with tweezers and calling out the names of prey species, as I tap it all into Fiscus. (In herring, the goop looks like orange Cheez Whiz, but in large fish like cod, sometimes whole herring ooze out, looking almost ready to swim away.)