Results from a multi-year study of four lower Kenai Peninsula salmon streams show the water quality of the fish spawning grounds is high, but human activity, nevertheless, may be having negative impacts on the popular fishing spots, according to a study to be released today by Cook Inlet Keeper and The Homer Soil and Water Conservation District.
The report, entitled "A Preliminary Water Quality Assessment of Lower Kenai Peninsula Salmon-bearing Streams," assessed the water quality of the Anchor River, Stariski Creek, Deep Creek and Ninilchik River. All four draw huge numbers of recreational fishers or clammers each year, and the health of those streams is critical to the local economy.
Researchers and volunteers with Cook Inlet Keeper collected assorted data in and around the streams from August 1998 through June 2002, measuring such parameters as temperature, pH balance -- a measure of the relative acidity or alkalinity of liquids -- and total phosphorous, as well as turbidity, total suspended solids, stream flow and dissolved oxygen and bacteria levels.
While the streams appear to be in good shape, some measurements of water temperature, pH balance and total phosphorous were outside ranges set for rivers and streams by the Alaska Department of Environmental Conservation and the U.S. Environmental Protection Agency.
Turbidity, suspended solids and color are difficult to relate to state standards because they are described in relation to natural conditions rather than as a specific value, the report said.
"The report's results raise some questions about stress on the peninsula's salmon streams," said Sue Mauger, a stream ecologist for Keeper and author of the report.
"Whether this is new stress or not, we do not know, but these watersheds are under increasing pressure from land-use development," she said in a press release.
According to the study, which was funded by the Department of Environmental Conservation, 31 percent of all total-phosphorous measurements taken in all four water bodies were above the level suggested by the EPA. Nearly half the phosphorous readings taken in the Ninilchik River were too high.
There are natural sources of phosphorous, such as decaying plant material, soils and the underlying geology -- volcanic and sedimentary -- but detergents, fertilizers and sedimentation from human activities contribute.
Similar natural and human-impact sources exist for other monitored parameters, such as suspended solids coming from natural erosion as well as from erosion due to road building, forest harvest, mining, grazing and wastewater discharge, the report said.
Alaska's upper limit on temperature for spawning areas and egg and fry incubation is 13 degrees Celsius, or 55.4 degrees Fahrenheit. But monitoring showed that temperature was occasionally exceeded.
According to the study, temperatures were above 13 degrees Celsius in the Ninilchik River for 56 days and above 15 degrees Celsius, Alaska's upper limit for fish migratory routes, for 35 days.
The elevated temperature and phosphorous readings "may be linked to human activity in these watersheds," according to the press release.
A few pH measurements taken in all four streams over the four-year period fell below Alaska's lower limit to protect aquatic life, but most measurements showed pH levels to be within the safe range.
While suggesting a linkage, the study carefully refrained from saying definitively that human activities are the cause of the higher readings.
The study said changes in vegetation "may" have an influence on temperatures in the streams, and certain land-use practices "may" contribute to more rapid rates of sedimentation, a condition usually accompanied by a rise in phosphorous levels.
"We are paying close attention to the temperature and phosphorous data and will continue monitoring to see if these are issues that we should be concerned about," Mauger said.
The report also said the turbidity, suspended solids and color data may prove valuable in determining what the natural conditions for the streams are, but acknowledged that some land-use changes "may already have occurred that affect these water quality parameters."
Officials with the Department of Environmental Conservation said the data already collected along with that to be collected in further monitoring will be valuable for decades.
"The work they (Keeper and the conservation district) are doing is extremely high quality," said Kent Patrick-Riley, manager of the DEC's Water Quality Program, Impairment and Protection Section.
"It is regarded as really objective and thorough. The study will be pretty helpful in understanding issues with those streams."
Like Mauger, Patrick-Riley said no one is jumping to any firm conclusions from the data, but it does help identify areas where further monitoring is needed. He said it would take several years of data to detect trends.
"This data will be used 10 to 20 years down the road," he said.
Tim Stevens, an environmental specialist who acted as project manager, said the gathering of such baseline data is important.
The report compares the current data to data collected by the U.S. Geological Survey between 1950 and 1970. However, according to the Keeper, different methods were used for certain parameters and direct comparison offers only limited help. Little change in water quality is apparent based on the limited historical information, the press release said.
A $100,000 grant from the Coastal Impact Assistance Program will fund a community-based water quality laboratory, which will allow Keeper to upgrade some of its methods to match geological survey standards, Mauger said.
"The new community laboratory will allow us to make comparisons between current and historical data," she said. "The lab will also help us continue with the additional monitoring that is needed to provide adequate baseline information to track changes in these watersheds and to make sure we are doing all we can to keep our salmon streams healthy."
Keeper and the conservation district, in collaboration with Community Rivers Planning Coalition and Coble Geophysical Service, a Homer company, have received another grant of $75,000 from EPA to study turbidity patterns in the Anchor River.
The data will help the agencies determine which land-use activities are contributing a disproportionate amount of sediment into the streams, the report said.
For the current study, Keeper workers monitored a total of 12 sites in the four rivers monthly from May through October and at least six sites were visited each month from November through April. Particular attention was spent to monitoring during high-flow events, such as spring breakup and annual fall storms, the report said.
Mauger said the main objective was to collect baseline information about the rivers to determine their current state and learn how human activity is reflected in the numbers. It is reassuring to see that the rivers are in such good shape today, despite that activity, she said.
"Monitoring is not the sexiest of things to do, but, especially here on the lower peninsula where we have such wonderfully productive systems, it is some of the most important work that can be done," Mauger said.
Future monitoring will be refined to draw even better, more relevant data from the rivers. Among the issues that will be followed will be the impact of the death and disappearance of the spruce forest and the eventual revegetation of the territory and what effect that will have on the ecology of the four rivers, she said.
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