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There were four Michigan State Legislators in the Muskegon, Michigan, town-hall meeting on Asian carp May 20, 2011. I’ve learned from experience that when that many politicians are in a room it is wise to sniff the air for smells, in this case the stink of a dog and pony show. Under pressure from state politicos to do something to respond to constituent concerns about Asian carp (note: this is not the same as actually doing something about Asian carp ... thank god, as we shall see), the Michigan Department of Natural Resources and the Michigan State University Extension developed a document entitled the Michigan Cap Control Plan, a 60-page document that in my estimation does a good job in addressing a limited, self-admitted goal: "(to) develop a draft plan for Michigan to address potential monitoring and assessment needs for Asian carp."
So what we have is a draft of a draft plan that I think does a thorough job of covering the issues, calls for lots of coordination-communication-cooperation, but is short on action steps. And maybe, at this point, that's for the better.
I raised the objections outlined by some prominent researchers that most of the Great lakes are too cold, and have too little phytoplankton to support a breeding Asian carp population, although the fish might do well in select Great Lakes tributary rivers. The presenters acknowledged that indeed Asian carp may not do well in the Great Lakes. However, they also said you never can tell about these things with invasive species, and we must be prepared to respond should the carp get a foothold in the Great lakes and its many tributaries. Everybody also admitted that in all likelihood the carp are already here, but not in numbers large enough to form a breeding population.
A charter boat captain pointed out that we have a far bigger problem with the quagga mussels in that they have cleared the water to such an extent that boats now have to fish in water 100 feet deeper than previously, using entirely new equipment, to catch the popular chinook salmon (which are light averse).
The DNR people admitted there are more than a trillion quagga mussels in Lake Michigan alone. There is no quagga mussel control plan, nor any effective way to control the mussels. The situation made me think of an army fighting an invader (carp) while all the soldiers were dying of smallpox. The quagga mussel is changing the Great Lakes in profound and enduring ways, much more so than any other invader to date. They clear the water of phytoplankton, which means there will be no bait fish, which means the salmon fishery is doomed. Since Asian carp also eat phytoplankton, it likely means they will also not survive.
The DNR people were ominously quiet about what the captain had to say about quagga mussels, and it suddenly struck me why the dog and pony show over Asian carp: we've already lost the battle to quagga mussels. The Great lakes are irreversibly changing — our artificial salmon fishery's days are numbered, so we are seeking some modicum of redemption by taking on Asian carp. It's understandable; we're acting out of a combination of helplessness and irritation; it's like kicking the dog because of something your boss has done. The problem is that reacting this way yields stupid, self-destructive results.
There are a limited number of things that can be done to clear a river, where Asian carp have a chance at reaching reproductive numbers:
- They can be netted. This is not effective because it doesn't catch enough carp to make a difference, and because it doesn't get the small carp.
- They can be poisoned. Rotenone is used and it kills everything in the water. This may not be effective because when done it leaves a pristine body of water with no predators. Should Asian carp get into it after the poisoning, they will have free rein.
- Their reproductive habitat can be disrupted. Asian carp need a minimum of 60 continuous miles of fast flowing river in order to spawn because their eggs need to be suspended in the water column until they hatch. A river can be dammed to prevent rapid flow for long stretches. This is impractical because dams change a river's fundamental ecology, and because they're so damned expensive to build.
- Predator numbers can be increased. The DNR folks said this needs to be done just at the right time when an Asian carp population is forming because, though very vulnerable to predation when young, carp grow very fast and use size as they main defense against predation.
When asked what the DNR would do with a specific body of water infested by carp — say, Muskegon Lake, right outside our meeting-room window — the DNR head guy didn't want to answer. After being pressed, he said the two main responses would be netting (which he had previously said was not effective) and poisoning.
Think of it! Poisoning Muskegon Lake, a 12-square-mile body of water used by tens of thousands of people. The very idea is lunacy. A member of the audience identified herself as a public health nurse and asked if Rotenone posed a hazard to other animals and people. The DNR guy said that animals that ate the dead fish such as dogs, cats, birds, otter, mice, rats, snakes, etc., would also die, but that it wouldn't harm people as long as they don't eat the poisoned fish.
I consulted the Rotenone MSDS sheet, which states the chemical compound is toxic to unborn children, harms women's reproductive systems, and targets your liver and kidneys. People handling Rotenone are advised to wear a self-contained breathing apparatus and protective clothing to avoid inhalation and skin contact. Rotenone is sensitive to light and air and releases carbon monoxide when it decomposes.
Exposure causes stomach pains, vomiting, and diarrhea, as well as convulsions and central nervous system depression. The MSDS sheet also states the chemical, physical, and toxicological properties of Rotenone have not been thoroughly investigated. And the DNR guys said it'll take $750,000 to get the job done. Holy cow! Given the cheap price of Rotenone, that's a shitload.
The alarm has been sounded and Great Lakes states are developing plans to deal with real or perceived Asian carp threats. At this point it’s fair to ask if there are any precedents that can inform the development of Asian carp control plans, and it happens that there is one: The Sea Lamprey Control Program.
Sea lamprey are aquatic vertebrae that resemble eels. They used the Welland and Erie canals to gain access to the Great Lakes in the early twentieth century; found in all the Great Lakes, they kill fish by using their sucker mouths to attach themselves to fish, rasping a hole in their victims with circular rows of teeth, then sucking out the victim’s body fluids. They are so predatory that by 1960 lampreys reduced the annual catch of lake trout in Lakes Huron and Superior from 15 million pounds to 300,000 pounds.
Poison is the most effective way of controlling Sea Lamprey numbers. About 175 Great lakes streams are regularly treated with Lampricide TMF to kill larval lamprey. This has reduced the number of lamprey by 90 percent, and does not hurt fish (the physiology of the lamprey is very different from that of fish) or humans, but is very expensive. Consequently, other control methods are being attempted, including laying barriers that prevent Lamprey migration, and trapping, where females are destroyed and males are sterilized and released to happily shoot blanks.
To date, both poisoning and barriers have been used to control Asian carp populations outside of the Great Lakes. No Asian carp-specific poison has been developed and probably none will be, given the similarities between the physiologies of carp and other fish, so it will be interesting to see what alternatives are planned for Great lakes Asian carp control.
I left the town meeting as the mid-morning sun dissipated what had been a dense fog shrouding Muskegon Lake and its channel to Lake Michigan. I walked the channel break wall where men were net-casting for bait. Families were readying their boats for launch; kids were tentatively toe-testing water still too cold to swim; fishermen were already out after the Northern pike and Muskellunge this venerable lake is noted for. Just think how much we stand to lose if our alarm is false and our response intemperate.