|
Bringing back the river fish By Anna Eleria/ Special To The Tab Wednesday, January 5, 2005 When clean water activist Christopher Swain swam the length of the Charles River recently, he not only came across shopping carts, refrigerators, cars and trash, but he also shared the river with almost 30 different fish species including carp, trout and sunfish. If he had swam in the late spring, he would have encountered the Charles River herring run, one of the largest river herring runs in Massachusetts Bay, one that serves as a donor population for restoration efforts in the Neponset and Ipswich Rivers. Or he could have possibly encountered striped bass as large as 20 pounds, near the mouth of the river, a prime sport-fishing location. Because of watershed protection efforts between environmental organizations, government agencies, institutions, businesses, and the public, water quality and habitat conditions of the Charles River have improved tremendously over the past 15 years, therefore leading to more fish in the river. Twenty-three years ago, state biologists collected only 12 fish species types compared to almost 30 species identified decades later in 2002 and 2003 by the Massachusetts Division of Fisheries and Wildlife and Charles River Watershed Association. DFW and CRWA assessed the Charles River watershed fish community at 14 Charles River sites and eight tributaries and determined that the most abundant fish species are Bluegill, Redfin Pickerel, Largemouth Bass, American Eel, and Redbreast Sunfish. Unfortunately, these types of fish are indicative of a degraded riverine system. Known as macrohabitat generalists, these fish species do not require free-flowing waters for any part of their life cycle, are pollutant-tolerant, and are well-suited for lakes, ponds and reservoirs. Macrohabitat generalist species dominate the river and tributaries, comprising 95 percent of the fish collected. The amount of fluvial, or "river," fish species - those needing free-flowing waters during a portion or all of their life cycle - fell quite short of the goal that at least 70 percent of the fish population be comprised of fluvial fish. This assessment work has revealed that low flows in the Charles River, especially during the dry summer months, combined with the 20 dams which have created pond-like, slow moving waters along the 80-mile river length, have had a profound effect on the type of fish living in the river and their ability to swim its length. According to US Fish and Wildlife Service, only 20 percent (as compared to a desired 90 percent) of the river herring that migrate up the river make it past Watertown Dam, located nine miles upstream of the mouth of the river at the New Charles River Dam, to spawn. Now that there exists a solid understanding of the effects of low flow on fish type and population and of dams on fish habitat and passage, the next step is to develop the target fish community for the Charles River watershed, which will ensure the ecological integrity of the watershed. When completed in 2005, the project, which is funded by the US Environmental Protection Agency's Watershed Initiative Program, and will be led by CRWA and state fisheries experts, will specify which fish species would be expected to exist in a healthy Charles River ecosystem, in terms of water quality, flow and habitat. The results of this study will provide the basis for clearly defined restoration goals for the watershed and help guide the development of future restoration projects. We are also working to improve fish passage at several other dams. CRWA and a local Stream Team have advocated for the repair of the fish ladders at Cordingly Dam in Newton, Mass. The Cordingly Dam fish ladder, the last fishway upriver, which has been impassable for the past ten years, became fully operational this year when DMF installed new stop logs, which regulate flow into the ladder, and baffles, which control water flow within the fishway. Because of these significant fish passage improvements, fish can now swim twenty river miles upriver from the New Charles River Dam, passing through Watertown, Bemis, Bleachery, Moody Street, Finlay, and Cordingly Dams, to the Circular Dam in Newton Upper Falls. With the progress made so far and the keen interest and energy from many groups to improve fisheries and their habitat in the Charles River watershed, we move one step closer to attaining the Environmental Protection Agency's Clean Charles 2005 initiative goal of a swimmable, fishable river by Earth Day 2005. The Charles River Watershed Association headquartered in Waltham, leads in major clean-up and watershed protection efforts, working with government officials and citizen groups from 35 watershed towns along the Charles River. Since 1965 there has been dramatic improvement in the quality of water in the watershed and approaches to water resource management in the area. Anna Eleria is an Environmental Scientist at the Charles River Watershed Association. |