BOURNE, MA, December 29, 2004 — Water temperatures in Alaska's Lower Kenai Peninsula salmon streams have been teetering above the state-mandated 55°F temperature limit, posing a substantial health risk to salmon habitat, according to a new report published by Alaska's Homer Soil and Water Conservation District.

Six-year temperature profile of Kenai streams raises concern over salmon health

According to the report, underwater temperature loggers placed in four area watersheds show that water temperatures rose above the upper limit on 54 days in 2002, 60 days in 2003, and 86 days in 2004. The data loggers, supplied by Massachusetts-based Onset Computer Corporation, sampled water temperatures every 15 minutes during the study.

The Homer district, in partnership with Cook Inlet Keeper, a watershed-based nonprofit organization, has been collecting water quality data on the region's economically important salmon streams since 1998.

"We monitored the streams to gain a better understanding of the frequency and extent of the elevated temperatures," said Sue Mauger, a stream ecologist for Cook Inlet Keeper. "To see these types of temperature increases in the streams is definitely a concern, especially when you consider that many of the communities here depend on commercial and recreational fishing and tourism."

Water temperature plays a critical role in the salmon incubation process, and warmer temperatures have been linked to a higher susceptibility to disease and a depletion of available oxygen and nutrients.

According to Paul Gannett, a spokesman for Onset Computer Corporation, stream temperature monitoring is key to understanding the impact local and global environmental changes have on stream ecosystems. "By looking at temperature profiles over time, researchers are better able to correlate specific environmental events with their impact on streams."

Mauger adds, "It's easy to blame climate change, but we also need to look closely at other things we're doing in the watersheds. For example, in recent years we've lost over a million acres of white spruce forests from a bark beetle infestation. There has also been a dramatic increase in logging, road building and real estate development. We don't know what effect this shift from a forested landscape to a more grassland-dominated ecosystem might have on stream temperatures."


Evan Lubofsky, Director of Marketing
Onset Computer Corporation
Direct Tel. (508) 743-3181
email: Evan Lubofsky


About Onset: 

Onset Computer Corporation has been producing small, inexpensive, battery-powered data loggers since 1981, and has sold over 1 Million units used throughout the world by more than 50,000 customers. Onset offers more than 60 models of data loggers to measure temperature, humidity, rainfall, wind, barometric pressure, light, AC current, carbon monoxide, 4-20 mA, voltage, on/off, open/closed, and events. Onset data loggers are used in a wide range of research, commercial and educational applications including agriculture, forestry, field biology, food production, manufacturing, transportation, and HVAC. NASA used HOBOs to measure space suit temperatures during spacewalks.