Lower Kenai Peninsula salmon streams are running hot, and not the kind of "hot" that should send anglers and commercial fishers running to cast their lines and nets.
In a report released this week entitled "A Preliminary Water Quality Assessment of Lower Kenai Peninsula Salmon-bearing Streams," the Homer Soil and Water Conservation District said that during parts of the past few years, the Anchor River, Ninilchik River, Stariski Creek and Deep Creek frequently were too warm, at times contained too much phosphorus, occasionally tested too acidic and are showing increased levels of sediment none of which is healthy for salmon fry.
In part, the study sought to document the recovery of rivers and steams following the 2002 floods. But data that's been collected over six years also has revealed threats to the salmon habitat.
In a press release announcing the availability of the new report, the conservation district said water temperatures in the summer months often exceeded the Alaska standard for spawning areas of 13 degrees centigrade, or 55 degrees Fahrenheit.
While no state standard exists for phosphorus, the waterways frequently contained amounts exceeding the federal Environmental Protection Agency recommended level. Similarly, pH measurements an indication of the relative acidity of water occasionally fell below the state's lower limit meaning the water was acidic. The study also found increased sedimentation.
"These changes have raised concern about the surrounding watersheds, which recently are experiencing dramatic increases in land-use activities," the district said.
Shirley Schollenberg, district manager of the conservation district, said she was particularly concerned "about the continuing evidence that water temperatures and phosphorus levels exceed state standards and federal recommendation for rearing healthy salmon fry."
According to the study, in 2002, the Anchor River water temperature exceeded the state limit for spawning and fry incubation on 54 days through the summer. In 2003, that figure jumped to 60 days. Preliminary data collected by Cook Inlet Keeper, which has conducted the water data collection for the district, shows temperatures exceeded the upper limit on 86 days in 2004. Similar situations were found in the Ninilchik River and Stariski and Deep creeks.
"We placed temperature loggers, which take readings every 15 minutes, throughout all four watersheds to gain a better understanding of the frequency and extent of the elevated temperatures," said Sue Mauger, Keeper's stream ecologist. "We should take note of this increasing trend and consider the implications of climate change in our land and fish management decisions."
Proper water temperature is important to salmon egg and fry incubation, their resistance to disease, and the availability of oxygen and nutrients in the water, the district said.
According to the study, there is little historical temperature data available, so there is no way to be certain whether or not the high temperatures are typical of the systems. A recent U.S. Geological Survey cited by the district's report suggests that Cook Inlet Basin streams may experience a water temperature change of 3 degrees centigrade (5.4 degrees Fahrenheit) in coming years, a change considered significant in terms of increased incidents of disease in fish populations.
The USGS study based its conclusions on a model using air temperature to predict water temperature, and accounted for climate warming.
Phosphorus, while crucial for aquatic life, is a contaminant at high levels, and thus, a threat to fish.
"Significant concentrations can result in dramatic decreases in dissolved oxygen, which is essential for the survival of all fish," the district said.
According to the study, during the six-year data collection period, phosphorus in the Anchor River exceeded the EPA's suggested level 22 percent of the time. The Ninilchik River exceeded the mark 47 percent of the time.
There may be logical geological reasons for the higher phosphorus levels, including volcanic deposits and sedimentation. However, according to the district's report, there are studies showing phosphate levels being unrelated to geology, but rather a reflection of the impact of land uses that increase sediment inputs to rivers and streams, "such as urban development, logging, mining, road construction, all-terrain vehicle use and wetland development."
Whether sediment levels are actually rising is more difficult to determine. For one thing, there are no baselines for those waterways against which to measure the collected data. But that makes the turbidity monitoring stations like those on the south and north forks of the Anchor River all the more important, the district said. Those stations are deployed and maintained by Community Rivers Planning Coalition and Coble Geophysical Services. Cook Inlet Keeper and the conservation district have been monitoring water quality on the four waterways since August 1998.
District Project Coordinator Lindsay Winkler said she believes it may be time for the state to reconsider its water quality standards for salmon streams.
"For land managers to ensure the protection of these salmon streams as the economic and cultural engines they are, wouldn't a stronger commitment to collecting baseline data allow them to develop quantitative state standards that would improve their ability to evaluate water quality?" Winkler said.
The full report can be downloaded from the Cook Inlet Keeper's Web site at www.inletkeeper.org/monitor ing.htm, or by contacting the Homer Soil and Water Conservation District or Cook Inlet Keeper.
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