By Erik Baard
Easter eggs are hunted in “Eggstravaganzas” and “Eggstreme” events across the city, from the Bronx Zoo to the Queens Zoo, and south to the Leon Kaiser Playground in Brooklyn and the West Brighton Zoo on Staten Island. But the best-hidden eggs in the very center of Gotham right now may be those laid by Winter Flounder.
The mighty machinery of our industrial port city has been stayed so that the roughly million tiny eggs (the fertilized flounder eggs magnified in the photo above are from a Virginia Institute of Technology laboratory) dropped by each mature female can be deposited right on the sandy substrate, and incubate undisturbed for two or three weeks.
“From February first through the end of May for the past several years we’ve suspended dredging the shipping channels where the eggs are laid,” said William Slezak, Chief of the Harbor Operations Branch of the U.S. Army Corps of engineers. Winter flounder prefer sheltered shallows with cool water, such as you’ll find in the kills (Dutch for creek, a linguistic colonial legacy) surrounding Staten Island, Newark Bay (a main commercial hub of the mid-Atlantic region), Jamaica Bay, and Raritan Bay.
That surprising deference to a not-so-pretty bottom feeder reflects not only how far natural resources public policy has come hereabouts, but how dire the winter flounder crisis has become.
“It’s pretty amazing that winter flounder is steering dredging policy in the harbor these days. These ‘conservation windows’ are certainly very progressive, working our way around a species’ critical periods to cause as little harm as possible,” said Queens College marine biologist John Waldman, author of Heartbeats in the Muck. “But something has happened and the local stock is really crashing.”
Waldman, who grew up on the western Long Island Sound, recalls that in his youth the species was “common as hell.” Now, after a decline in population that began in the ‘70s, “You can fish all day and catch one or two.”
Waldman points to a pincer of culprits threatening the species: global climate change and “a whole suite of hungry mouths.”
The species is clearly sensitive to warmth; when water temperatures cross 73 degrees Fahrenheit (23C) they bury themselves in muddy bottoms and wait out the heat wave. A few degrees more and they are dead. Also, as Waldman pointed out, a change in water temperatures could disrupt previously reliable detritus-based food production at the microbial level before it can rain down to the flounders below.
As for all those “hungry mouths,” winter flounder certainly remain prized by local anglers, including those in New Jersey ready at this very moment to sneak out from family gatherings to hook them; fishing season for the species begins today. But natural predators, often themselves benefitting from government protection, are removing much more winter flounder, both in terms of numbers and biomass. Species like striped bass, bluefish, summer flounder and fluke, and even seals in the Gateway National Recreation Area, are feasting on winter flounder. Cormorants are a new arrival to our estuary, having expanded their range north. These extraordinarily effective fishing birds put greater pressure on an already stretched resource.
But there’s some cause for optimism about the estuary as a whole, even if winter flounder fans aren’t ready to pop the cork on the champagne. The National Oceanic and Atmospheric Administration section for Ecological Applications views the species as a maritime canary in a coal mine, signaling befouled habitats in decades past. Note this report based on data from decades past:
Winter flounder are particularly susceptible to pollution (Grosslein and Azarovitz 1982). The eggs are laid directly on the substrate and therefore any toxins in the sediment can affect their viability. This species’ close association with the benthos also potentially exposes the fish to sediment toxins. Grosslein and Azarovitz (1982) noted that few larvae survived in polluted estuaries, and that winter flounder were entirely absent from polluted sections of NY/NJ Harbor. In particular, winter flounder experience increased mortality as a result of exposure to insecticides, especially DDT (Buckley 1989).
But now, while winter flounders are scarcer than ever, their re-colonization of our bays and inlets testifies to a cleaner and healthier estuary.
“It’s interesting, a kind if dualistic situation. The Upper Bay and some of these other places in the harbor were once written off as wastelands, and now they’ve recovered so much that they are recognized as productive ecosystems,” Waldman observed. “So in a way, there’s some good news here.”
Yeah, but just try to get a flounder to see any situation from both sides.