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Fisheries Projects of Juneau Ranger District

Berners Bay Eulachon Population Estimate

Moose Lake Outlet Habitat Restoration

Dredge Creek Coho Enhancement with JDHS

Fish Video Capture Weir

Berners Bay Eulachon Mark/Recapture Population Estimate

Eulachon (Thaleichthys pacificus) is an important food fish for indigenous peoples in Alaska and the Pacific Northwest, as well as an important prey species for Steller sea lions (Eumetopias jubatus). The USFS conducted research on eulachon in Berners Bay from 1995-1999 and from 2002-2003. Little is known about eulachon habitat requirements and they are only found in a limited number of rivers throughout Alaska. A proposed mine expansion and road construction project in the immediate area encouraged us to learn more about their ecology. In a continued effort to monitor population trends, the Antler River was selected as an index stream for developing baseline abundance data. Starting in 2004, a mark-recapture study was implemented to estimate population size. Our goal is to establish a simplified data collection effort that occurs during the main upstream migration and can be repeated on an annual basis.

Mark-recapture techniques were used to establish a population index (a way to accurately estimate numbers of fish). Trap locations were chosen based on the following: eulachon preference for traveling upstream in slower water and to ensure that eulachon mix adequately for equal probability of being trapped. Fish were marked with a tag at the lower trap and then released into calm water. New aluminum box traps were built in March of 2005. The design of these traps improved durability, ease of assembly, and increased efficiency due to their ability to continue fishing during high water events and tidal influence.

Traps were operated from April 21 to May 10. Just over 10,000 fish were marked and approximately 36,000 fish were captured in the upper two traps. Of the 36,000 fish captured, 187 were recaptures (had tags). The population estimate for the Antler/Gilkey system based on this data was 2.1 million eulachon. In addition to the mark/recap project, samples were taken for genetic analysis. Performance of the newly constructed floating box traps exceeded all expectations. The traps captured and held fish well and the ease of adjusting trap positions in changing water levels aided in the success of the project.

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Moose Lake Outlet Habitat Restoration

Moose Lake is located within the Mendenhall Glacier Recreation Area (one of the most popular recreation sites in Juneau ). Approximately 75 feet of stream bank between Moose Lake and the Holding Pond have completely eroded and required restoration efforts. Woody debris, control structures, and vegetation have been lost. In addition, bikers, hikers, and dogs continue to run through this area, increasing disturbance along the banks and in the water. The objective of this project is the restoration of damaged stream banks at the outlet of Moose Lake.

A John Deere tractor was used to move soil and sand to the site. Debris from a nearby beaver dam was also used in stream bank construction. Willow, cottonwood, alder, and grass plugs were used to vegetate the stream banks. This work will improve the quality and quantity of spawning habitat available to both resident and anadromous fish in the system.

Roughly 12-15 cubic yards of material was brought in to reconstruct the banks of the stream. Sticks and organic material were interspaced in the soil/sand material. Banks were heavily vegetated with willow shoots and grass plugs as well as whole cottonwood and alder saplings. We will monitor the establishment and growth of plant starts to ensure success of the project.

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Dredge Creek Coho Enhancement with JDHS

The goals of this cooperative project are to enhance fishing opportunities at an easily accessible site on the Juneau Road system and teach high school students about coho salmon biology, habitat management, and local hatchery operations. The students are responsible for documenting and reporting on the project and obtaining necessary permits. The Forest Service provides materials and guidance in collecting fish, offers field instruction on fish biology and land-use management, helps set up the incubator, and assists with fry release.

High school students capture adult salmon using seine nets with the assistance of Forest Service personnel. Sperm and eggs are then collected from ripe male and female coho salmon. Students are instructed on proper collection techniques and then transport the gametes to the local DIPAC fish hatchery where the eggs are fertilized and placed into an incubator. The students observe egg development during the rearing process. Once eggs have developed for a period of time, they are transported to an established remote incubator site on Dredge Creek where final rearing and imprinting occurs.

Six high school students participated in this year’s project by collecting eggs and milt from wild coho in Dredge Creek. Two females and three males were selected for their eggs and milt. The males were milked and released while the females were sacrificed and disinfected before the eggs were removed. The milt and eggs were then brought to DIPAC for fertilization. A successful transfer was made from the hatchery to the incubator box the following February. Over 3,500 coho fry were released into Dredge Creek in early April. This was the second highest total since the project was started. This project helps contribute to the coho run in this small Mendenhall River tributary while helping to educate local students on current fish biology management practices.

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Fish Video Capture Weir

The objective of this project is to accurately count adult coho salmon with a fish video capture system. Our goal is to eventually replace a traditionally operated weir. The video system can decrease operational costs and the need for manpower as well as eliminate or reduce the amount of fish handling. This has the potential to match the accuracy of a weir, save money, and reduce occurrence of fish mortality due to handling stress.

The camera system involves a laptop computer using specialized motion sensing software. An underwater camera is installed in the stream at a location where fish are directed to pass within a few feet of the camera. Images are analyzed by the software and those with movement are recorded to a hard drive. The system can run 24 hours a day and only requires fish to pass close to the camera. Two solar panels were integrated into the system, and a new HID light was installed this year to light the area better than the previous LED lights.

The camera is operated from mid-September through October. A majority of the footage has been reviewed and preliminary results indicate the system is performing well. Very few "dead frames" (no fish in the frames) recorded to the hard drive. Usually dead frames are recorded when in the fall of 2005, bubbles, debris, or shadows trip the motion sensor off. Over 200 adult coho salmon have been counted using this system.

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