Anoxia in the Central Basin of Lake Erie
Testimony of Gary Isbell
Ohio Department of Natural Resources
To the U.S. Senate, Committee on Environment and Public Works
August 5, 2002
On behalf of the State of Ohio and particularly the Department of Natural Resources, I want to express appreciation for the Committee's willingness to seek input on this serious issue affecting Lake Erie. It is great that there is such recognition of the value of Lake Erie to Ohio by our Congressional delegation, and especially Senator Voinovich. When Senator Voinovich was our governor, I personally had the opportunity to share with him our common concern for the lake and our common appreciation for the fantastic yellow perch and walleye fishing. As we examine and discuss the current issue, let's not allow people to erroneously conclude that the lake is dead or that the fisheries are not outstanding. This truly is one of the top fisheries in the country. While the rampant pollution problems of the 1960s and the images of the burning Cuyahoga River are gone, there are new challenges to the integrity of the lake's ecosystem and we must collectively address them.
The problem of the anoxic zone in Lake Erie is not that it exists, but that its size, frequency, and duration are changing. The anoxic zone is a naturally occurring phenomenon, but can be a serious detriment to the ecosystem if it gets too large, thereby limiting the potential of the lake to produce the benefits we enjoy. The real problem about the anoxic zone is that just when we thought we had it figured out and managed, it is behaving in ways that we do not fully understand. We are unsettled by the observation that the reduction in nutrient loading, brought about by pollution controls over the last 30 years, appear to be trumped by something mysterious. A leading hypothesis is that zebra mussels are at the heart of the mystery, perhaps recycling nutrients that contribute to the development of a larger anoxic zone than we would expect.
What should be done?
First, we must be aware that there may not be a reasonable cure or fix to the current problem. However, we think that the collaborative study sponsored by the USEPA is a step in the right direction. Levels of nutrients in the lake and their effects on microorganisms were monitored fairly comprehensively in the past through a similar USEPA sponsored study. However, recent monitoring has not been funded sufficiently to help us detect problems or devise solutions. As a result, comprehensive phosphorus monitoring was discontinued in 1994. While sampling was resumed in 1996, it has not been consistent from year to year and coverage of the lake has been mostly limited to offshore sites. A stronger and more robust monitoring effort is justified and fundamental to the development of sound management strategies for the lake. This is an effort that is appropriate for federal funding and leadership. We must have solid long-term data about the basic features of the lake in order to detect problems and prescribe solutions.
Second, this mystery about the anoxic zone is yet another wake up call about the seriousness of invasions of aquatic nuisance species. Each new invader brings with it a random box of mostly negative effects. Some of the effects are not so subtle, such as the predator-prey interactions of the sea lamprey that devastated fisheries in the last century. Sea lamprey control in the Great Lakes is a success story, thanks to Congressional support of the Great Lakes Fishery Commission. Although difficult, these types of effects are much easier to model and to control than the ultimate effects of nutrient recycling on populations of walleye or yellow perch off Cleveland. It has been 12 years since passage of the first comprehensive
federal law regarding aquatic nuisance species. Even so, each year there are still more alien species that find their way to the Great Lakes. This is biological pollution that has the potential to permanently devastate many of the lakes' beneficial uses. A legacy we should strive to leave is a solid federal policy that shuts the door to future invasions of the Great Lakes.
The anoxic zone mystery is just part of a larger, complicated set of issues. It is encouraging to us at the state level to see Congress taking an interest and being willing to act. We urge you to do so quickly by funding more comprehensive monitoring within the lake. Lake Erie, given its hydrology can change very quickly. Quick action may avert some significant and lasting negative effects. Also, we urge you act with a response that is appropriately scaled to the size of the problem. This is a huge resource; therefore, investigations and solutions will not be cheap. Water quality programs, lamprey control measures, electric fish barriers, and ballast water management systems may be very expensive. However, the billions of dollars of resource values that are generated in the Great Lakes are worth it. Finally, we urge you to act comprehensively. The anoxic zone problem is not an isolated issue within the Great Lakes ecosystem. It is critical for development of long-range solutions to address the influx of invasive species into our waters, as well. Therefore, I would encourage Congress to support a re-authorization of NISA and work collaborately in strengthening the monitoring and survey efforts necessary. With proper funding, numerous state, federal and private entities could be utilized to partner in the effort to conserve and protect this resource.
Thank you again for the opportunity to provide input to the Committee on Environment and Public Works. Please feel free to call upon the state agencies for additional information or review of strategies that may evolve from your initiatives.