We would like to address three issues in our presentation: the need for ongoing research on invasive species in the Great Lakes; how to deal with the threat of the Asian carp; and the need for ballast water standards.
I'd like to share with the committee the latest research on aquatic invasive species in the Great Lakes, which was presented by U.S. and Canadian scientists at last month's Great Lakes Fishery Commission conference. The main message presented was that the ecosystem of the Great Lakes is undergoing what senior biologists call “a regime change”—that's a case in which the ecology of the fishery moves from one stable state to another stable state over a number of decades—and that the particular regime change we're going through has been brought on by the impact of aquatic invasive species.
The chart I am showing shows what the stable state in the middle Great Lakes—Michigan, Huron, and Georgian Bay, which we focus on—looked like in the 1990s. The lakes had a relatively healthy stable ecosystem, and you'll notice that invasive species dominated many of the levels of the food chain—the salmon, the alewife, zebra mussels.
Zebra mussels were introduced through ballast water in the late 1980s and had spread through the near shores of the Great Lakes, causing problems with water intake systems but not with the overall ecology of the lake. It was the later introduction of another invasive specie, the quagga mussel, also through ballast water, that precipitated the ecological change in the lakes. Unlike the zebra mussels, which only survived on rocky bottoms to maybe 30 feet deep, the quagga mussels could survive on sandy or silt bottoms down to a level of 350 feet. The quagga mussels have now replaced the zebra mussels in the near shore and have carpeted the bottom of the lakes. This quantum growth in the number of mussels filtering phytoplankton and zooplankton out of the lake water has resulted in a serious break in the food chain.
This reduction in food at the lowest level of the food chain created a domino effect up the chain. The tiny shrimp diporeia, of which within a square metre you'd find thousands, have now pretty well disappeared from the middle lakes, the issue being that they are without the phytoplankton to feed on. The alewife crashed without their main source of food, which was the diporeia, and as you move up, so did the salmon, which were the next to fall—that once-prized recreational sport fishery.
The chart titled “A Regime Change is Underway” shows us where we are now, in the midst of the regime change. The native fish of the Great Lakes—the lake trout and the walleye—have actually returned to be the top predators. Another invasive specie, the round goby, is now their main source of food. The overall energy level, however, of the once vibrant lakes has now dropped to the same level as that of Lake Superior.
The scientists at the conference have also reported on a new side effect from the introduction and spread of quagga mussels and round goby. It turns out that the round goby like to eat quagga mussels. The problem is that quagga mussels filter and retain bacteria. When they die, their bodies act like an incubator, producing botulism and toxins. When round goby eat the dying quagga mussels, they act as a conduit to carry the botulism and toxins up the food chain to all the fish and birds that now rely on these round goby as their main source of food. We're now experiencing mass die-offs of fish and waterfowl from botulism types C and E around the Great Lakes.
In order to better understand the significant ecological changes that are still taking place in the Great Lakes as a result of invasive species, it is our recommendation that more scientific research be done. With the completion of the Great Lakes Water Quality Agreement now awaiting approval by both governments, the negotiations of the Canada-Ontario agreement will soon begin. This funding is critical to support the scientists and the biologists who carry out the necessary research on the Great Lakes. We would urge the committee to support the federal government in this funding.
I'll turn the floor back over to Bob.