Lake Erie Walleye
Spring 2004 Issue
Lake Erie and all the other Great Lakes have been put through a lot of stress due to human activity. We have
dumped chemicals, sewage, and over harvested the fish. Lake Erie in the sixties was considered almost dead. We began to recognize the damage we were doing and passed laws to reduce pollution and set limits on the amount of fish we could harvest. However, we failed to recognize the most serious threat to the Great Lakes' ecosystem, exotic species. We had clues over one hundred years ago as to how serious the threat could be but we failed to recognize the signs.
When the Erie Canal was built in 1812, it opened a path to Lake Erie and the upper Great Lakes for the sea lamprey. The lamprey invasion was slow but by the
early 1900's, it became well established and it decimated the lake trout in the upper Great Lakes, in Lake Erie, lake trout became extinct. Sea lamprey not only decimated the lake trout, the lake white fish, and lake sturgeon were greatly impacted by this invader.
The Welland Canal was built in 1829; it opened another doorway for lamprey, and other non-native fishes, such as the smelt, and the alewife to expand their ranges into the Upper Great Lakes. We are now so used to seeing smelt and alewives we have become to accept them as native fish, however their appearance has been to the detriment to the ecosystem. The smelt and alewife replaced native forage fish. Smelt are not as nutritious and actually have had a negative impact on the spawning success of walleye and any other freshwater game fish that feed on them. Smelt are rich in the enzyme, thiaminase, which breaks down the B vitamin essential for the larval development of walleye, lake trout and other fry. The fry are less robust and more likely to die from environmental stresses and diseases.
If you are old enough to remember the shad die offs during the 1960's, you will also remember that we introduced salmon (another exotic species) into the lake to remedy the problem. The margined madtom, a small baitfish, was accidentally released into the lakes as bait. So we not only have exotics entering the ecosystem by canals, some are being introduced by us intentionally or accidentally. Every time this happens and the animal becomes established they are here forever; and their presence displaces a native animal.
The invaders who came through these doorways into the upper Great Lakes were serious and should have awakened us to the problem of exotic invaders but it didn't. With the globalization of trade, another vector for species introduction was opened. Ships carrying cargo
need ballast water onboard to optimize the ship's displacement to keep it from being top heavy when traveling empty. When a ship loads up with cargo,
(grain or, steel) it dumps the ballast. Ships trading between ports in Europe, the United States and Canada are constantly filling their ballast tanks and then emptying them. Every time the tank is filled from a harbor, the pumps suck in some of the creatures that live there. When the ballast is dumped usually in another port, the creatures are dumped with the water. If the conditions are okay for the new arrivals, they flourish. Usually the transferred creatures into a new ecosystem have no natural enemies thus increasing their odds for successful survival.
The wake up call for the Great Lakes came in the late 1980's when zebra mussels were discovered near Toledo Ohio. When they were discovered they already were well established now they are every where. Since that time 160 new exotic species have been identified in the Great Lakes and it is estimated that a new species is introduced every six months. The list of exotics continues to grow.
Since the introduction of sea lamprey, we have spent hundreds of millions of dollars trying to combat it and to undo the damage it has done to the lake trout. The sea lamprey control started in 1958 the US. Fish and Wildlife Service (USFWS) started treating lampreyspawning sites. The initial treatments cost about $6
million per year and the cost is rising. The USFWS last year spent over $36 million for lamprey control in the Great Lakes, one treatment on the Marquette River last year cost $500,000. It has cost millions of dollars to
treat power stations along the lakes for zebra mussels that plugged their water intakes. It has cost companies using water directly from the lakes or Niagara River millions of dollars because zebra mussels clogged heat exchangers and plumbing. The cost of these two exotics on our economy is staggering; we have spent hundreds of millions of dollars and because it will never go away the cost will have to be borne by our children and generations to come. Sea lampreys are here forever as well as the zebra mussel, and 159 other exotic species.
After the walleye rebounded in the early 1980's from overharvest and pollution earlier in the last century again in the walleye population is in decline. Exotic species continue to affect the ecosystem and are contributing to the sharp decline in the fishery. Fishery managers are struggling to keep the walleye and other native fish populations from collapse. The spiney and fishhook water fleas, which have been introduced in just the past few years, are displacing native zooplankton creating an imbalance in the lower level of the food chain to the detriment of our native fish. Once an exotic species gets
a foothold they are here to stay there is nothing we can do.
What other invaders could be in the ballast water? What about harmful pathogens, could a new epidemic be in the hold of some ship's ballast water? Recent studies of ship ballast water have found hepatitis A virus, Vibrio cholerae, salmonella spp, E. Coli, cryptosporidium spp, giardia and enteroviruses. Through DNA, testing it was shown these pathogens did not originate in the Great Lakes but they were from places like India, and Eastern Europe. Some of the pathogens were resistant to common antibiotics. In Third World countries, there is less control of the use of antibiotics and "germs" have evolved and developed resistance to many drugs.
We have seen the damage that chemical pollution can do to our waterways. In the 1960's, Lake Erie was declared dead because it was chemically polluted with industrial waste and from untreated sewage run off. When scientists figured what was causing the decline of the fishery and water quality, there were a multitude of regulations and laws passed to correct the problem before the lake actually died. Phosphates in soaps, a fertilizer in the aquatic environment were banned, sewage treatment plants constructed eliminating septic system runoff into the lake, legislation was enacted stopping industries dumping their chemical waste into our waterways and the list goes on. It did not take long to see the results of the actions taken. When the chemical pollution was stopped, the water almost immediately started to improve. Even the most dangerous chemicals like PCBs and mercury would get chemically bound up in the sediments and be removed from the food chain if left undisturbed.
The invasion had been going on since the Erie Canal was built however more recently it has accelerated with the worldwide trade and larger ships. The unfortunate thing about this biological pollution is that if you were stop any further non-native species introductions the lake will not return to what it was before. Unfortunately, with this form of pollution, the damage is permanent. The exotic species invasion is the single greatest threat to the Great Lakes ecosystem. Now that we have identified the paths for the exotic invasion, it is time to plug the holes.
So what do we do? We can not let the status quo continue the risks are too great. It is estimated that a new species becomes established every six months. The ecosystem could collapse, we could lose many of our native fish, or hazardous pathogens could be introduced with the potential of causing epidemics. The solution is simple, stop the exchange of ballast water in the Great Lakes. In the New York St ate Senate there is a bill S02567 (already passed unanimously by the Assembly) which needs to be passed and signed into law. This bill will not solve the problem completely but it will call attention to the issue and that New York wants federal legislation that will stop the invasion. In the Congress the National Aquatic Invasive Species Act of 2003 is stuck in committee. This act will address some of the concerns, it needs to be voted on and passed. However I feel it is weak and if we want to solve this problem, the final solution will be to ban all exchanges of ballast.
The solution is rather simple. Much like what the Federal Government did for automobile emissions. They established a standard and set the timetable to reach it. The Government did not legislate what technology nor did they engineer the solution, it was left to the auto manufacturers. The standard for our Great Lakes should be "no tolerance for exotic species introductions". All ships entering the Great Lakes system will have their ballast tanks sampled at the point of entry whether they have ballast water or not. We need to keep samples of ballast water or the tank sludge form each ship traveling the Great Lakes. The samples of ballast water and sludge will be available for university research and study. A portion of the samples will also be available if needed for evidence in litigation in the event damages are claimed due to the introduction of invasive species. There are only a couple shipping companies running the ships on the Great Lakes, and Lloyds of London insures all of them. Once the insurance company realizes the potential settlement damages they could have to pay, (the Tobacco Settlement was billions of dollars) the shippers will be forced to keep ballast out of the lakes by their insurer.
The exchange of ballast water directly with the Lakes could be banned altogether. No exchange in this case means "no dumping into or no drawing water ITom" the Great Lakes or tributaries. This will insure no exotics via ballast water will be introduced, thus protecting the environment. We could provide the infrastructure for ships to get ballast and a means to dump without exchanging any water with the lake. The ballast has to be isolated from the ecosystem. Again this is simple all that is required is a couple tanks similar to what is located at any oil refinery to store crude oil be made available at each port. In the ballast situation, a ship would exchange ballast water with water in the storage tank at each port. The water could be treated with a biocide so that if there were accidental leakage no exotic species would be introduced.
Lake Erie and the Great Lakes ecosystem are unique there is no other and it can not be reproduced or replaced. Every time a new exotic species is introduced, we loose forever a part of this priceless ecosystem. Finally, the only way to get the action required is to write our elected officials and tell them our concerns.
This article is reprinted from the December issue of the FISHLINE, a publication of the Southtowns Walleye Association, the largest walleye club on the North American Continent