Flora and Fauna Fridays
A weekly entry about the life of our estuary and watershed.
by Erik Baard
Skinny dipping in the Newtown Creek Superfund Site might seem unwise, particularly in February, but it’s a way of life for naked gobies (Gobiosoma bosc). These very small, bottom-dwelling fish of the Eastern Seaboard and Gulf states are extremely common yet rare to see. That’s a shame because gobies — one of the most diverse families of fish, with over 2,000 species — have rich and fascinating lives packed into typically less than four inches and four years.
Ecologists for city, state, and federal agencies did encounter naked gobies in early studies to profile the life and pollutants of what became HarborLAB’s home waterway. They discovered an abundance of goby eggs at the mouth of the creek but not further in, indicating that spawning happened where cleaner East River waters swirled in with each tidal cycle. No surprise given that naked gobies and their eggs and spawn are often found in the fish-protecting screens covering intake tubes at the nearby Ravenswood Power Plant. Bear in mind, however, that this is opposite of the natural state of affairs. Fish normally lay eggs and spawn in sheltered areas outside the swift main channel of waterways. The East River is dredged, constricted by landfill, and edged with bulkheads that make for even faster currents. The slower-moving four-mile stretch of the Newtown Creek should by rights be the East River’s nursery.
As it is, only adult “gobies were prevalent in the mid-section of the Creek,” according to the Fish and Wildlife Service report linked above. Still, what a testament to this species’ hardiness, given that the creek bed (commonly described as being like “black mayonnaise”) is sedimented with toxins and stripped of naked gobies’ natural habitat of oyster beds and salt grass clusters. Females prefer to lay their amber-colored eggs into empty oyster shells. In the Newtown Creek, they make do with rock, crumbled concrete bulkheads, partly interred plastic trash, bottles, and other debris. In the winter, they bury themselves into that poisonous black mayonnaise.
Naked gobies feed on worms and small crustaceans, which concentrate in their tissue the toxins of a century of oil spills, refinery and tannery effluents, and illegal dumping. Cloaked by the muck and the murk, these “naked” prey fish for better known species like striped bass, eels, and bluefish are still taking no chances. The species is scaleless and camouflaged in green and brown blotches. Their eyes are close together, atop the head. At a glance they look like lizards. The young are translucent.
Naked goby pelvic fins have evolved to fuse into suction cups, a neat trick for anchoring themselves. Scientists have noted that gobies can remember how to navigate complicated obstacle courses for at least 40 days, and judge and remember spatial relationships, useful for hopping from tidal pool to tidal pool. Some cousin species of goby have also evolved complex behaviors and symbiotic relationships. For example, one species climbs waterfalls that to human scale is the equivalent of climbing Mt. Everest three times over — check out this video! Others groom the parasites off larger fish. Another enjoys an “Odd Couple” relationship with a large burrowing shrimp. The fish and crustacean cohabitate and deposit eggs in the same burrow. They touch each other (with tail and antennae respectively) constantly to know if the other is agitated or retreating, relying on each other’s complementary senses. And we are still discovering new species of goby!