A warm stretch in winter seems as good a time as any to think about fish, carp specifically. A news items came past our Twitter feed the other day about how the federal government has spent hundreds of millions on controlling the destructive fish — much of it to support efforts to keep carp out of the Great Lakes. Why does this matter here?
Well, for starters, carp have colonized several South Fork freshwater ponds, with potentially devastating effects on native fish and plants. And at another level, that local officials and environmental authorities seem not to have noticed, this provides a glimpse into how governments work — or fail in some instances.
Carp do not belong here. Yet they are now are spread across the United States, introduced in the 1960s. Their expansion has been relentless, reaching every state in the mainland. Few predators can get through the carps’ armored scales, and they are prolific procreators. A single female carp will deposit up to one million eggs at a go. On contact with water, the eggs form remarkably sticky masses, adhering to submerged rocks and aquatic vegetation and providing a food bonanza for other fish, invertebrates, and most important for this discussion, birds. In rare instances, the eggs survive long enough for a duck, goose, or wading bird to fly to another water body. This might be infrequent, but given enough time carp have shown up in places they never were seen before.
Two South Fork ponds are known to hold heavy carp populations — Fort Pond in Montauk and Hook Pond. At Hook Pond, where we have observed grass carp frequently in recent years, they can be found from the Main Beach parking lot way up past the Dunemere Lane bridge and as far as the Nature Trail, where they wait for scraps of bread to float out from under a culvert.
At least some of their impact is readily observed: They stir up the silt-mud bottom, decreasing the amount of light entering the water. They out-compete other kinds of fish and invertebrates and eliminate aquatic plants, destroying nursery habitats, which only exacerbates the problems. To give you a sense of the threat, an adult grass carp can be as long as your leg, weigh 20 pounds or more, and eat close to half its body weight in plants a day.
Worrying, too, is the fact that carp can thrive in water with low oxygen levels, levels at which native fish cannot. At least anecdotally, it seems the native bass and perch that once thrived in Hook Pond are all but gone — carp must share at least some part of the blame. So much for the problem.
The question is what are the region’s environmental stewards doing about it? The answer is not much.
Despite officials’ good-faith efforts to improve water quality, they seem unaware of this fast-growing threat. Money can now be diverted from the community preservation fund for sewage treatment projects and contaminant barriers. New construction is required to include nitrogen-reducing wastewater systems. Zoning laws are in effect to keep development away from wetlands. And yet, we can see with our own eyes that our ponds’ ecosystems are at risk. Local officials should get out there, too, and have a look for themselves.
The solutions will not be easy or inexpensive, but with dedicated effort, invasive carp can — and must — be stopped.