The crystal clear waters of Lake Benzeman, South Baranof Wilderness
Back in late January a crew from the Sitka Conservation Society took a short float plane ride down to the South Baranof Wilderness Area. The team flew into Secluded Bay, situated on the West side of Baranof Island just off the head of Necker Bay. South Baranof is a Federally protected wilderness area that covers over 300,000 acres of picturesque glacially carved fjords, scarred granite mountain tops, hanging lake valleys and old-growth temperate rainforest.
The SCS team arrive at the foot of the Lake Benzeman falls, Mary Wood,
Sophie Nethercut and Scott Harris.
The goal of the expedition was to conduct wilderness monitoring and install stream temperature gauges into the falls flowing from Lake Benseman into Secluded Bay. Wilderness monitoring involves collecting valuable data on invasive species, human impacts on wilderness, and wildlife abundance. The human impact data includes reporting evidence of camps, fires, trash (picking it up as well of course) and recording the level of solitude (e.g. the number of planes and boats in the area).
Conservation Science Director Scott Harris anchors the stream temperature
gauge to two large logs.
Lake Benzeman supports a large sockeye salmon run and a special one at that as these are smaller than other sockeyes. Researchers believe that these fish evolved to be a smaller size in order to be able to swim up the long fast flowing falls to Lake Benzeman. This system is unique and SCS determined Lake Benzeman Falls to be an important site to install water temperature gauges.
View of the long rapids draining from Lake Benzeman to Secluded Bay.
So, why monitor stream temperatures at all? Salmon are sensitive to water temperature, with eggs and fry often not able to survive in warm waters. Alaska has just experienced its warmest winter on record and there is a concern that climate change could seriously impact our salmon stocks. Across the whole of Southeast Alaska there is a large data gap on how our streams and lakes are being affected by climate change. Therefore, SCS is helping to fill in this gap by installing a series of stream temperature gauges around the Sitka area.
The stream temperature gauge is housed in the plastic tube, weighed down
with the metal chain and anchored in placed by the wire.
The temperature data is then fed into the Southeast Alaska Long-term Monitoring Network (SALMoN), with the stream monitoring program being a collaboration between several partners including: the University of Alaska Anchorage, University of Alaska Southeast, the United State Forest Service and of course, SCS. With the addition of the Lake Benzeman falls temperature gauges the SALMoN now maintains 11 sites in and around the Sitka area.
It is very important we monitor the temperature of our sockeye salmon runs
so we can understand the impacts of climate change.
Without monitoring stream temperatures we will not know how our changing climate is impacting our region’s most valuable resource: salmon! To find out more about the project and see what other streams we are monitoring check out the SALMoN website.
The crew takes a break from wilderness monitoring to admire the view over
Checkout the complete photo album of this trip on our Facebook page.