Biological Projects
Fish Research
To learn more about the tools of fisheries research, such as sonar, counting towers, weirs, and aerial surveys, click here.
Alaska fisheries research reports are available at the following websites:
U.S. Fish and Wildlife Service
Alaska Department of Fish and Game
Anadromous Species Projects
Resident Species Projects
Anadromous Species Projects:
Anadromous fish found on Togiak National Wildlife Refuge include smelt and eulachon, Dolly Varden, and five species of Pacific salmon. Salmon returning from the sea, spawning, and dying in Togiak Refuge rivers and lakes provide a major source of nutrients for both aquatic and terrestrial ecosystems. The U.S. Fish & Wildlife Service works with the Alaska Department of Fish and Game Commercial Fisheries Division to balance the needs of subsistence, sport, and commercial user groups, and to focus on the common concern to maintain healthy fisheries resources. Togiak Refuge staff take part in several projects to ensure that the needed number of salmon are allowed to enter the rivers and spawn.
Reconstruction of prehistoric salmon runs
In 2006 Togiak Refuge and the University of Washington Fisheries Research Institute began a project to investigate changes in salmon abundance within and among watersheds on Togiak Refuge over a time frame that includes the commercial harvest, but extends far enough back in time to capture much of the range of natural variation caused by non-human factors. This project will relate the abundance of salmon to the commercial harvest and other factors that affect it. It will also relate changes in prehistorical salmon abundance to changes in aquatic productivity, and determine how these relationships change across the landscape of the Togiak Refuge. We are using paleolimnology to reconstruct historical dynamics of sockeye salmon populations and related changes in lake production rates. Thus far, we have collected and partially analyzed sediment cores from 16 lakes.
Salmon Spawning Grounds Surveys: (1985-present)
Since 1985, Togiak Refuge has worked with the Alaska Department of Fish and Game (ADF&G) to conduct aerial counts of peak spawning abundance of 5 species of salmon (king, chum, sockeye, pink, and coho) in 13 drainages along the Togiak Refuge coast.
Kanektok River Weir: (2001 - present)
Counting salmon escapement in the Kanektok River has been attempted by biologists since the 1960s, by use of sonar, a counting tower and now more recently a weir. All previous attempts have failed, partially due to the high water flow and unstable gravel banks of the Kanektok.
For these reasons, the new floating weir installed in 2001 is located approximately 42 river miles upstream of Kuskokwim Bay, in an area where the riverruns in a single channel and has relatively stable banks. Although this project is still in the research stage, biologists from the ADF&G, the U.S. Fish & Wildlife Service (USFWS), and the Native Village of Kwinhagak hope to accurately count the number of salmon and Dolly Varden returning to the river each year.
Successfully doing this will provide the information necessary to determine minimal salmon escapement needs for the upper Kanektok River and manager the commercial fishery to achieve those goals. Beginning in 2008, this project was not longer operated during the coho salmon run to avoid high water issues which have resulted in complete replacement of the weir panels due to damage.
Visit the ADFG Commercial Fisheries management Division web site to find in-season project updates and the end of the season summaries.
Goodnews River Weir: (1980 - present)
Salmon have been counted in the Middle Fork of the Goodnews River (MFGR) since 1980 by first using a counting tower and air surveys. In 1990 a rigid weir replaced the tower and provided a more accurate count of the various species. Unfortunately, during periods of high water the weir would get washed away.
In 1996 Togiak Refuge provided ADF&G with the materials for a new floating weir. The new weir design has lower operations and maintenance costs and allows ADF&G to operate the weir through the coho run, typically the high water season. This is one of the few projects in western Alaska that provides accurate coho salmon escapement numbers.
Because the MFGR escapement project has been consistently operated for several life cycles of salmon there are actually escapement goals (ranges) established for Chinook salmon (1,500 to 2,900); sockeye salmon (18,000 to 40,000); chum salmon (>12,000) and coho salmon (>12,000).
Visit the ADFG CFMD web site for more information and project reports for the Kanektok and Goodnews management areas:
Squaw Creek Fish Passage Barrier Removal:
In an effort to restore fish travel in Squaw Creek, which flows through the Dillingham area, steps have been taken to remove some of the barriers that currently encumber migrating salmon. Two culverts were replaced in 2001. A third culvert was replaced in 2003. This project is a cooperative effort between the Dillingham Chamber of Commerce, Nushagak Cooperative (utilities), Bristol Bay Economic Corporation, USFWS, and ADF&G.
Kulukak River Counting Tower: (1994 - 1996)
Counting towers were successfully used to give fisheries observers an improved vantage point from which to view and count the salmon passing up river. Passage of all 5 species of salmon traveling upstream was estimated. Comparisons were made between tower counts and aerial survey estimates to determine the accuracy of aerial surveys.
Togiak River Sonar: (1984, 1987, 1988 and 1990)
Sonar was utilized in the Togiak River for several seasons. Sonar transducers fixed to the riverbed detected and counted fish as they passed through the sound waves. Biologists found it difficult to proportion the counts to the various species, since several species of salmon as well as Dolly Varden and whitefish all run up the Togiak River during the months of July and August.
A report on the 1987 – 1990 project can be found at the USFWS Fisheries web site (pdf): The 1984 project was conducted by the ADFG Commercial Fisheries Management Division in Dillingham.
Togiak River Dolly Varden Life History: (1998 - 2003)
In an effort to learn more about the life history of Togiak Refuge Dolly Varden, in 1998 staff began a long-term study of Dolly Varden in the Togiak River drainage. Main purposes of this study were to determine when and for how long the Dolly Varden travel to saltwater, where and when they spawn, and to identify overwintering areas in the Togiak drainage.
Fisheries Biologists captured several thousand fish in 1998 and 1999. Most fish were marked with external tags and released, while 97 fish were surgically implanted with radio transmitters. Radio-tagged fish were tracked until October 1999; collection of information from external tags is ongoing.
Tagged fish that have been captured again have exhibited some remarkable movements. Fish tagged in the Togiak River have been recaptured in the Egegik, Yukon, Kuskokwim, Kanektok, and Eek rivers. For more information on results of this study, click here. For more information on reporting tagged fish, or why tagging is done, click here.
Reports available that summarize the Togiak River Dolly Varden studies:
- Lisac & Buchholtz (2001)
- Crane, et al. (2003)
- Lisac & Bromaghin (2007)
Additional hard copy reports available from the Togiak Refuge office include:
- Lisac and Moran (1999), Lisac and Nelle (2000), and Reynolds (2000).
Goodnews River Dolly Varden Life History (2001)
and Run Timing Studies (2003 to present)
Biologists captured Dolly Varden at the Middle Fork Goodnews weir (2001) and in the main Goodnews River (2005) to collect biological information and to surgically implant several fish with radio transmitters. The radio-tagged fish were tracked aerially from throughout the year. Tracking results have indicated important spawning and overwintering areas. One thing we learned from these Dolly Varden studies is that these fish can travel great distances between river drainages. It appears that many of the fish seen in the annual Dolly Varden runs may not be in their home waters.
Dolly Varden tagged in the MF and main Goodnews Rivers have been recaptured in the Aniak (Kuskokwim River tributary), Kulukak (Bristol Bay drainage) and north of the Yukon River. It is suspected that these fish may have entered the Goodnews drainage to feed and spend the winter and were recaptured when they returned to their home waters to spawn.
Reports available that present the results of the Goodnews River Dolly Varden studies:
- Lisac (2004a)
- Lisac (2007a)
- Lisac (2008a)
Kanektok River Dolly Varden Life History (2002) and run Timing (2002 to present)
Biologists captured Dolly Varden at the Kanektok River weir to collect biological information and to surgically implant several fish with radio transmitters. The radio-tagged fish were tracked using aircraft to locate important spawning and overwintering areas.
One Dolly Varden tagged in the Kanektok River was recaptured in the Kwethluk River (Kuskokwim River tributary) It is suspected that this fish may have entered the kanektok drainage to feed and spend the winter and was recaptured when it returned to the Kwethluk River to spawn.
Reports available that present the results of the Kanektok River Dolly Varden studies:
- Lisac 2004b
- Lisac 2006
- Lisac 2007b
- Lisac 2008b
Togiak River Smelt Life History (2002, 2007-2008)
Biologists captured rainbowsmelt in the Togiak River to collect biological data and describe life history attributes. Prior to this study, no biological information existed on this species present in the Togiak River.
- Reports on Togiak smelt
- Dion and Bromaghin 2008
Resident Species Projects:
Resident fish within the Togiak Refuge are valuable resources for subsistence and sport anglers. To better manage resident fish populations, Togiak Refuge staff are working to gain knowledge on the population health, stock identification, age, and general life history attributes of resident species.
Lake trout stock structure (pdf - 1.4mb)
Togiak Refuge and the U.S. Fish and Wildlife Service Conservation Genetics Laboratory conducted an investigation of the genetic relationships and length structure of lake trout throughout Togiak Refuge in 2004-2008. Lake trout were found in 15 lakes, including North Middle Fork, Middle Fork, Canyon, Kagati, Hole, Arolik, Goodnews, Tikchik, Kanuktik, Ohnlik, Nenevok, Salmon, Heart, Little Swift, Chikuminuk Lakes. Each lake contains a distinctly different population. There is little evidence of recent genetic exchange between populations, although populations within watersheds are more similar than they are between watersheds. Colonization and genetic exchange is best explained by glacial history following the last glacial maximum (~20,000 years ago). However, we documented one example of a non-glacial geologic process providing a mechanism for gene flow across watershed boundaries (a lake outlet stream re-routed itself from one watershed into another watershed).
Rainbow trout was chosen as an indicator species of system health. Because rainbow trout are highly sought after by sport anglers, studying rainbow trout allows Togiak Refuge staff to better understand human influences on resident fish and area river systems.
Kanektok River Rainbow Trout: (1985, 1993, 2000)
In response to fishing pressure, shifts in the size and age composition of fish populations can often be observed. As part of a long term monitoring plan, staff from the USFWS King Salmon Fisheries Resources Office (KSFRO) and Togiak Refuge have conducted surveys to assess the age and size structure of the Kanektok River rainbow trout. Managers use the information collected from these surveys to help insure that the historic length and age composition of the trout population is maintained.
Goodnews River Rainbow Trout: (1988-89, 1993-95)
Surveys were conducted to collect data on the age and size structure of rainbow trout populations in the Goodnews River watershed. Seasonal movements of rainbow trout were monitored by surgically implanting radio tags and following the fish throughout the year. From these studies, biologists suspect that the rainbow trout from the North Fork and the Middle Fork of the Goodnews River may be isolated spawning populations with distinct age and growth characteristics.
Arolik River Rainbow Trout: (1991-97)
Rainbow trout have been sampled on the Arolik River as part of Togiak Refuge's inventory and monitoring of rainbow trout populations since 1991. Length and age data are collected because they provide information on the health of the population(s) and overall health of the system. Information on the Arolik River rainbow trout is particularly valuable, due to the limited human impacts on this river prior to 1999.
Negukthlik/Ungalikthluk River Rainbow Trout: (1989, 1990, 2003)
Rainbow trout were sampled for the first time in 1989 and 1990 from the Negukthlik and Ungalikthluk Rivers to collect useful baseline information on the size structure and the seasonal movement of rainbow trout within the watershed. Rainbow trout were radio-tagged during the summer of 1989 in the Negukthlik River and followed into the next spring. In 2003 rainbow trout were again sampled to collect information on the size structure and to aid managers in maintaining the historical size composition of the population(s).
Togiak River Rainbow Trout: (2000-2001)
To address the seasonal movement and distribution of rainbow trout populations in the Togiak River watershed, rainbow trout were radio-tagged in two tributary creeks. The goal was to track rainbow trout movements throughout the year and identify critical seasonal habitat locations. Information from this study supports previously collected genetic data that indicate that rainbow trout from these two creeks do not interbreed and constitute discrete populations. Natal homing during spawning has been suggested as the mechanism that continues to separate these populations since no geographic barriers exist at the present time. For more information on how to report tagged fish, or why tagging is done, click here.
Baseline Stream Inventories: (ongoing)
Fisheries biologists conduct inventories on previously undocumented streams to gather baseline information and define distributions of Pacific salmon and resident fish on the Togiak Refuge.
Lake Surveys: (ongoing)
Fisheries biologists have collected baseline data on water quality, fish species, and productivity for many lakes throughout the Togiak Refuge. This information is valuable in understanding the impacts of resource use on Togiak Refuge. Population characteristics of previously undocumented rainbow trout, Arctic char, lake trout, and northern pike have been recorded from the lake survey studies. These studies provide, in some cases, the only information on lake health and organisms that reside there.
Last updated: April 21, 2010
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