Tuesday, August 31, 2010
We implanted PIT tags in 933 fish that were over 65 mm (2.55 inches) in length. The purpose of this tagging is to compare fish survival at the two sites over the next couple of months. We plan to return to the sites in September to conduct a habitat survey, perform a fish survey to look for the fish we just PIT tagged, and determine the total number of fish in both sites.
On August 11, approximately 30 people from the Nisqually Land Trust, Nisqually Tribe, Washington Department of Fish and Wildlife, U.S. Fish and Wildlife Service, Stream Stewards, Washington Conservation Corps and Mason County Conservation District gathered for a fish rescue operation at Ohop Creek near Eatonville, WA.
We restored 1.2 miles of Ohop Creek to its natural condition through a concerted effort from the agencies listed above.
We started collecting fish in the 1/3 of a mile of the ditch using electroshockers, dip nets and seines, then transferring the fish to a large holding tank. Once the fish were collected they were taken to the restored creek where the fish were identified, enumerated, measured and released. We found Coho fry, lamprey, dace, crawfish, sculpins, fresh water mussles, large scale sucker, and some non-native warmwater fish.
Thursday, August 26, 2010
Since my last blog update I have had the pleasure of assisting with three different monitoring and research projects with the USFWS. I have worked with colleagues on the Duwamish Estuary, Issaquah Creek and the Hoh River. Participating in these projects as a STEP student has been a great opportunity for me to diversify my field experience.
My first field work opportunity with the USFWS was a habitat mapping event on the Duwamish Estuary, located in Seattle, Washington. This is a restoration monitoring project that focuses on two species of sedges - Lyngbye's sedge ( Carex lyngbyei) and Soft Stem Bulrush (Scirpus validus). I became familiar with the morphological features and life histories of these two sedges and it was my first experience collecting field data in an estuary.
The sampling events I assisted with at Issaquah Creek are part of the Water Resource Inventory Area (WRIA) 8 project. Under the Watershed Planning Act (WA State - ESHB 2514), WRIA 8 is monitored to ensure that the best possible management practices are implemented to protect Washington’s water resources. Our USFWS sampling crew teamed up with King County employees to conduct habitat surveys and fish population surveys via electroshocking. This was a great example of how different agencies can work together to practice fisheries conservation.
I am currently focusing on the sampling events on the Hoh River and they have proved to be amazing adventures! I have learned new skills such as beach and herd seining, minnow trapping and surgically inserting PIT tags into juvenile salmonids (trout, whitefish and salmon). Some of this work included night sampling which was a new and exciting experience. For more information on this project, be sure to visit the Hoh River Project page on this site.
Monday, August 16, 2010
Both approaches have been used to stabilize eroding banks, especially when infrastructure such as roads and houses is threatened. Several reports, however, suggest that the more commonly used method of stabilizing river banks, rock riprap, negatively impacts fish habitat complexity and aquatic communities including fish. Additionally, several reports suggest that wood is an important ecological component of aquatic systems, and fish and other aquatic life often occur in greater densities and diversity at locations associated with wood. As a result, large wood complexes, such as engineered logjams, are viewed as an alternative tool for bank stabilization and stream restoration. Therefore, bank stabilization with engineered logjams may provide the dual benefit of protecting infrastructure and conserving aquatic natural resources, such as fish populations, when compared to alternative stabilization techniques.
USFWS and WSDOT are conducting the Hoh River study to compare fish habitat diversity, fish density, growth, survival, movement, and species diversity in Hoh I and Hoh II. Fieldwork started in August 2009 with two study components. Fish survival in both Hoh I and Hoh II was estimated and compared between sites by capturing, tagging, and recapturing fish at a later date. A total of 495 fish were tagged with passive interrogated transponder (PIT) tags between the two sites. The second study component relied upon acoustic tagging technology to provide spatial information in order to identify how fish utilize the engineered logjams at the Hoh I site. In this second effort, USFWS technicians and biologists deployed a series of sound recorders called hydrophones on the river bottom. Twenty-nine fish were captured and surgically implanted with an acoustic tag. The hydrophones passively tracked the location and movement of the tagged fish over a couple of weeks. Preliminary results from Hoh River study indicate that engineered logjams are a valuable technique for bank stabilization projects and can provide favorable habitat for juvenile salmonids when compared to sites utilizing other bank stabilization methods.
In August 2010, we plan to PIT tag more fish at both sites. We are also preparing to collect habitat information in order to describe differences in the habitat quality and quantity from the perspective of fish in the study areas. Check back for postings of our upcoming fieldwork!