Conference Report on Water Ecology Workshop –Afternoon Talks

Roger Johnson and Bill Soucie, West Shore Water Producers Association

More than 40 drinking water plants in four states draw on Lake Michigan as a water source. All of the plants have water intakes that extend from about 900 feet (40 m) to upwards of 15,000 feet (4.5 km) into the lake. The intake structures typically rest in 10 -50 feet (5-15 m) of water.

High- and low-water levels affect water plants differently. However, most water plants are designed to withstand 100-year historic high and low lake levels. Some water plants built in the late 1800s have actually persevered through these extremes and continue to pump water today. High water levels pose the greatest challenge to shoreline water plants. The combination of elevated lake level and wave action makes these facilities particularly vulnerable to flooding. In contrast, lower lake levels would provide increased protection for these utilities. Lake levels below 100-year historic lows may decrease the ability of some water producers to draw enough water from the lake to meet customer demand. Deeply submerged intakes facilitate water conveyance through intakes to pumping stations. Shallow water limits water withdrawal. If customer demand then exceeds the ability to withdraw water, some intakes may require extension.

Water quality changes during high and low lake level extremes are difficult to identify. The major water quality factors that treatment plants work with today are water temperature, turbidity (suspended solids), and microbiological quality factors. These factors also change more often than other water quality factors. New water temperature extremes may pose a few challenges. Colder winter water may lead to increased ice formation on intakes and a decreased ability to supply water. Warmer summer water may lead to increased algal blooms and the resulting taste and odor events. Taste and odor problems would increase treatment costs. Turbidity and microbiological changes already fluctuate greatly during the year, especially for near-shore shallow intakes. Although water plants are designed specifically to handle these extremes, slightly increased usage of coagulants and disinfectants may be anticipated.

Changes in climate also may affect public water demand. Water production typically increases by more than a factor of two during the hot summer months. Extended dry and hot weather results in maximum water demand since irrigation increases. If treatment plants are unable to produce sufficient quantities of water, demand will have to be reduced or water supply increased. Increasing the supply would most likely involve increases in water rates.

Overall, water providers are cautiously confident that the climactic changes anticipated for the 21st century will not dramatically affect our ability to supply drinking water to the communities we serve. However, we will continue to monitor lake levels and water quality closely to assure production of high-quality water in sufficient quantities.

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Chubs, whitefish, lake trout, yellow perch, and rainbow smelt are important commercial fishes harvested in the Great Lakes. Species are harvested at various depths and times of the year, using a variety of gear types and techniques. Gill nets, trap nets, and pound nets are the most common gear used in the region, though trawls and trap nets are still used by some. Historically, natural cycles cause variability in fish populations, but invasive species have caused the most significant changes to local fish populations. Whether climate change will affect Great Lake fisheries for better or worse is unknown.

Climate change will bring warmer water, which will affect species composition and lead to a greater introduction of exotic species. Depending on the market value of the fishes that thrive under warmer conditions, climate change will either hurt or help the fishing industry. Changes in water clarity also will affect fishing practices and catch levels, if nets become more visible at shallower levels. Improved water quality from zebra mussels has allowed whitefish to detect gill nets and swim deeper in order to avoid them. Because gill nets can go no deeper than 150 to 180 feet, problems could result if climate change produces a significant further increase in water clarity. In addition, greater water clarity allows predatory birds, such as cormorants, to hunt more fish and create added competition for fishermen. Other possible changes include lower lake levels that could lead to dredging in order to maintain the use of existing docks, and shifts in prevailing winds, which could affect fishing dramatically (with more easterly winds resulting in decreased fish catches and more westerly winds resulting in increased catches). On a positive note, reduced ice cover would facilitate fishing during the winter months. How the fishing industry will change and adapt under climate change remains to be seen.

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Eric Skindzelewski, President, Lake Shore Fishermen Sports Club

The Lake Shore FishermanÕs Sports Club has worked to achieve greater public access to lake shores and clean water for about 20 years. After confronting countless barriers and eventually paying high costs for legal representation without achieving results, the club decided to embark on a major outreach campaign to win public support. The club conducted workshops and educational seminars about public access, and conducted a successful campaign to inform government at various local, state, and national levels about the need for greater public access.

After 15-20 years of this outreach, the club prevailed. A state park was established and a boardwalk constructed; public access to piers and many lakefronts was awarded; children now are allowed to ice fish in county parks; and laws were passed to ensure that there are enough fish for the public to enjoy. Other notable accomplishments of the club include improvement of boat ramps and the provision of fishing pole holders and other amenities for the public, all paid for by the local government and donations from the public. Today, the club supplies videos on water safety to children and holds educational workshops in parks twice each year, fostering the enjoyment and care of water resources and the natural environment. Approximately 80,000 children and 40,000 elderly have attended the seminars.

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As greenhouse gases accumulate in the atmosphere and alter the climate, rising temperatures, changes in precipitation, and changes in other weather patterns are likely to affect ecological processes and ecosystem services. Among the systems and organisms affected may be a variety of fish species. The potential negative impacts on fish species and the popularity of recreational fishing led to an EPA-sponsored research project that examined the potential impacts of climate change on fish species survival and the consequent impacts on future recreational fishing opportunities. The study modeled the effect of temperature changes on habitat conditions in various geographic areas and the subsequent effect on the ranges of fish species. An economic model in the second step of the analysis projected changes in recreational fishing behavior based on measures of habitat changes and fishes estimated by the thermal model. Results were expressed as changes in total days spent fishing for each class of fish (cold, warm/cool, rough). The annual damages represented by lost fishing opportunities were calculated using values per day spent fishing for each class of fish developed from a series of recreational fishing valuation studies.

The modeling results showed that 21 of 48 states would lose at least one of the 31 fish species studied in the analysis. More than 75 percent of the scenarios that were modeled resulted in economic costs associated with climate change being significantly larger than benefits (on the order of about $239 million in losses per year), indicating that the costs will likely outweigh any benefits for recreational fishing. Using very conservative assumptions, cold water fishing losses were estimated at $1.3 to 3 billion per year (1993 dollars). This modeling exerciseÊis a first attempt to characterize and assess the economic impacts of climate change in the Great Lakes region and provides a sense of the magnitude of the problem.