This paper was written as part of the 2006 Alaska Oceans Sciences Bowl high school competition. The conclusions in this report are solely those of the student authors.

Haa Shagoon: An ecosystem–based fisheries management plan for sockeye salmon (Oncorhynchus nerka) in the Taku Watershed

Authors

Devon Kibby
Erika O'Sullivan
Hillary Buck
Katie Conway
Eva Ceder

Team Juneau Zissou

Juneau–Douglas High School
10014 Crazy Horse Drive
Juneau, Alaska 99801

Introduction

Ecosystem based management plans (EBMP) have been recommended by notable reports including the Pew Oceans Commission, U.S. Oceans Commission and the Magnuson–Stevens Fisheries Act (MSFA). However, the idea of responsible stewardship of resources is not a new idea. The Tlingit people, who have inhabited and used the resources of the Taku Watershed for centuries, express this idea as haa shagoon. Haa shagoon describes their obligation to care for and protect land for future generations. Our goals are to maximize productivity of the system around the lucrative sockeye salmon, Oncorhynchus nerka, by maintaining biodiversity and habitat integrity while involving all stakeholders in an inclusive and transparent management process. Sockeye salmon are the focus of this report because of their value economically, culturally, and as an indicator of the overall health of Taku ecosystems.

The Taku Inlet and watershed area has many stakeholders representing many aspects of use. Stakeholders include commercial fishers, Taku Tlingit, subsistence users, sport fishers, tourists, landowners, mining interests and recreational users. Managing salmon harvest levels, pollutants, human activities and wildlife populations are just the beginning of what must be addressed to regulate the Taku watershed ecosystem. Certain human restrictions are necessary to sustain the health of the ecosystem.

The Taku is a dynamic and complex system including multiple habitats on both sides of the American–Canadian border. The areas of diverse ecosections and biogeoclimactic subzones must be studied and addressed within the context of their own biological and physical interactions.

Cooperative international relations between the U.S. and Canada and the adoption of a unified, integrated management plan will be beneficial for the future of the ecosystem and to all people who use and enjoy the Taku area. A panel approach to management of the Taku is an effective way to respond to the needs of both the ecosystem and the associated stakeholders. Diverse needs can be best met by a panel of stakeholders speaking for their interests in an open forum. Communication between the public, stakeholders, panel members and government regulators is crucial if management goals are to be met.

Physical and biological data should be sufficient to inform discussions between stakeholders as well as to guide the ultimate policy decisions. Historical data of fires, flooding, logging and other succession types should be studied to better understand habitat in the present and future. Archived climate and other physical data are also important in understanding and drawing conclusions about ecosystem changes.

Physical characteristics

Located approximately 16 km southeast of Juneau, Alaska, the mouth of the Taku watershed system is the largest unprotected wilderness system on the west coast of North America. The system (Figure 1) covers 4.5 million acres and is drained by the 160 km–long Taku River (McDowell Group, 2004).

The Taku watershed is situated on the Taku terrane which "is a well–mixed hodgepodge of strata that has been deformed, intruded, and metamorphosed several times" (Connor, 1988). Rock types in the terrane include: metamorphosed marine shales, basalts, rhyolite lavas, and muddy sandstones. Rock types found in smaller amounts include marble, limestone and other rocks that have been accreted onto the terrane. Geographically, the Taku terrane is separated by thrust faults to the north and east, and the Chatham Strait fault to the west (Connor, 1988).

Two hundred thousand years ago, Southeast Alaska was covered in 1600 m of ice. The desolate landscape of ice and snow revealed only barren mountain peaks of rock. Ten thousand years ago, the ice had partially melted, raising the sea almost 160 m while the land slowly rebounded. For the next ten thousand years, the land continued to rebound as glaciers slowly receded from marine influence. Glacial melt and weathering eroded away mountains and sediments filled in bays and valleys (O'Clair, 1997).

Glaciers in the Taku watershed still play a defining role; cooling the local climate, and in some cases, altering a river's course. The Juneau Ice Field covers approximately 1820 km2. Of that total area the Taku Glacier covers approximately 800 km2. The Taku Glacier is the largest and southern most glacier on the Juneau Ice Field. The Taku Glacier is unique because it has advanced 7.3 km since 1890 while other glaciers in the area have receded considerably. The advancing trend however, is far from the norm for the Taku Glacier. In 1890, the Taku Glacier recession uncovered a deep glacial fjord with depths in front of the glacier at 102 m (Post, 1995). Over time the Taku River sediments filled in the fjord and the Taku Glacier began to advance. By 1937 the Taku Glacier had advanced 3.7 km. The average tidewater depth at the terminus of the glacier was 6.7 m (Post, 1995). By 1980 the glacier had pushed up glacial silt from previous recessions into a moraine that halted calving into tidewaters (Figure 2). There were concerns that if the advancing continued, it could dam the Taku River. The Taku Glacier continues to advance today, but its growth is more in volume than length. Experts such as Roman Motyka believe that it is unlikely that the Taku Glacier will dam the Taku River in the near future (pers. comm.).

The low flow of the Taku River during the winter months varies greatly from the flow during the summer due to glacial melt. The unique jökulhaup events of its tributaries, such as the Tulsequah River, occur when the Tulsequah Glacier harbors a seasonal glacial lake that is dammed by the glacier and is drained by a periodic dramatic release of water (Figure 3). Large releases of water occur when the lake fills and the hydrostatic pressure on the base of the ice dam becomes greater than downward forces and the dam floats. This causes a large release of water, flooding the Tulsequah River and lower Taku River. On average, the flow of the Taku during the winter is under 100 m3/s while during the summer the average is around 700 m3/s (Murphy, 1989). During jökulhaup events, the Taku River's flow can be as high as 2000 m3/s (Host, 1999).

Seasonal temperatures of the Taku area are moderated by its proximity to the Pacific Ocean and are comparable to temperatures in Juneau, Alaska. Average winter temperatures are below 0° C in the colder months, November through March, and on average are 5°C colder than Juneau (Figure 4). However in the warmer months, May through September, the temperature is usually close to or warmer than temperatures recorded in Juneau (Ministry of Environment Lands and Parks of Canada, 2001).

Precipitation in the area is also comparable to Juneau, Alaska. Precipitation data gathered in 2001 at the Tulsequah Chief Mine shows similar precipitation levels to that in Juneau during the spring and summer, but in the months from September to March the Tulsequah watershed receives significantly more precipitation than Juneau (Figure 5). While precipitation in the Southeast area is considerable, most of the Taku River's flow comes from glacial melt.

The Taku River flows into the marine ecosystem at Taku Inlet, creating a large mixing zone (Figure 6). Data collected at the entrance of Gastineau Channel, adjacent to Taku Inlet, during the fall of 1995 shows a mean surface temperature of 7.99°C declining to 5.04°C near the bottom, 110 m. Temperatures steadily declined through the winter; in January though February of 1996 the mean surface temperature was 2.40°C and 2.87°C near the bottom. Salinity was also measured; September through November of 1995 the mean surface salinity was 29.48 ppt and 33.06 ppt near the bottom. January through February of 1996, the mean surface salinity was 30.36 ppt and 32.96 ppt near the bottom. The combination of temperature and salinity equate to overall density. During the period of September though November, the mean surface density was 1.0229 g/cm3 and 1.0267 g/cm3 near the bottom. Compared to the period of January through February, the density was 1.0254 g/cm3 at the surface and 1.0268 g/cm3 near the bottom. The decreased winter flow of the Taku River combined with cold winter winds increases the density of the surface waters, aiding upwelling and mixing (Paulson, pers. comm.).

The rate of mixing is affected by local upwelling, surface winter wind currents and tidal currents. The tide in Taku Inlet is a semi–diurnal tide with a historical maximum tide range around 10.1 m, with the lowest recorded tide at -2.44 m and the highest at 7.65 m (Kent, 2005). The primary productivity of these three systems is largely driven by the mixing of nutrient rich fresh water and upwelled coastal water.

Biological components of ecosystem

The Taku is a dynamic ecosystem supporting diverse habitats and species. Young and old growth forests, wetlands, riparian habitats, lakes, flat valleys, alpine, marine and estuary habitats are interconnected as a complex, healthy ecosystem (Figure 7).

Change in an ecosystem depends upon many different factors including biological, physical and geographical factors that affect the ecosystem as a whole. Biological factors in the Taku that can alter the balance of species include succession of plant communities, populations of various species and human interactions. Physical and geographical occurrences such as climate changes, glacial activity, flooding, forest fires and isostatic rebound affect the ecosystem as well. These changes in the watershed can have negative or positive results in terms of fish populations.

Flood plain habitats

The Taku flood plain is repeatedly disturbed; fish habitats are altered, wooded areas are washed out. However, because of the disturbances, the Taku watershed is one of the most productive forest communities in Southeast. Flooding in the Taku should be closely monitored in important fish habitats because of its potentially negative impacts on future escapement of salmon populations.

Estuary habitat

Estuaries are the world's most nutrient rich ecosystems. Rivers meeting with the ocean bring nutrients, plankton and other drift invertebrates into stream networks. Juvenile salmon feed on the insects and plankton. Probing birds feed on the worms, bivalves and crustaceans that live in the sediments deposited in the estuary. Although negligible in the short term, the effect of isostatic rebound on Taku River estuaries is slowly lifting tidal marshes out of the salt water. As the estuaries rise from the salt water, marsh areas morph into meadows and wooded areas (Carstensen, pers. comm.).

Marine habitat

According to a 2005 report by the National Oceanic and Atmospheric Administration (NOAA), nearshore habitats in Southeast Alaska are very important nurseries for a variety of important juvenile fish species. The report identified 79 species of which 50 species represented 99% of the total sampling catch. The three most abundant species were walleye pollock (Theragra chalcogramma), Pacific sand lance (Ammodytes hexapterus) and Pacific herring (Clupea pallasii). The three species are all nearshore dwellers as juveniles. Shallow waters are habitat to a broad community of fish that are important to the economy. In terms of sampling abundance, shallow water nearshore habitat of the Taku is second only to eel grass habitats. In order to sustain populations of salmon in the Taku, protection of nearshore habitats used by juvenile salmon during maturation must be made an essential part of the management plan.

Sockeye Life Cycle

More than 200 known sockeye stocks occur in Southeast Alaska, including 31 in Canadian waters. Sockeye are found to typically spawn in rivers or streams connected with lakes or along lakeshores. About 70% of the lake–spawned sockeye populations spend one to three years as juveniles. Some stocks rear for a short period, one to two months, in rivers and estuaries then migrate to ocean. Fry from river–type stocks that winter in fresh water typically rear in sloughs, off–channel pools, beaver ponds or tributaries to the main river where spawning occurs. Sea–type sockeye often rear in estuarine habitats where warmer temperatures and abundant food contribute to their rapid growth. In the Taku River over half of the mainstream fish spawned in side–channel habitats while a smaller percentage spawned in slough and tributary habitat. Of the Taku River habitats, it was found that areas of upwelling groundwater are preferred for spawning (United States Department of Commerce, 2000).

Socioeconomic profile

The Taku watershed is located near two communities; at its headwaters, Atlin, British Columbia, and near its mouth, Juneau, Alaska. Located on the eastern shore of Atlin Lake, the settlement of Atlin is home to approximately 450 year–round residents, about half of whom are Taku River Tlingit (McDowell, 2004). Juneau has a total population of about 32,000. Within the city of Juneau there is a Tlingit population of approximately 3,500 (United States Census Bureau, 2000). Both indigenous people and other residents of Juneau use the Taku River's tributaries and surrounding area for commercial, recreational and cultural activities. There are approximately 40 private cabins and 3 public–use Forest Service cabins along the U.S. banks of the Taku River.

Commercial Fishing

Gillnetting is the only type of commercial fishing method permitted in Taku Inlet. According to Albert McDonnell, a local commercial fisherman, the number of gillnet vessels fishing in Taku Inlet may exceed 80 at the peak of sockeye season. Commercial fishermen gillnetting in Taku Inlet sell to several different processors. On average most Taku gill–netters earn a gross annual income ranging from roughly $20,000 to $30,000. Commercial fishing is the third largest industry in Juneau, after tourism and government. Sockeye is the most valuable commercial harvest of the Taku, bringing in some $2 million every year from 1994 to 2003 (Table 1) (McDowell, 2004). On the Canadian side, the estimated ten year average ex–vessel value for all salmon species harvested by Canadian commercial fishermen is $545,400 (Table 2). Sockeye salmon accounted for 83% of this income (McDowell, 2004).

Sport fishing

Sport fishing in the Taku is popular with tourists and local anglers. In 2001, $100 million was spent on sport fishing in Southeast Alaska, including the rapidly growing charter sport fishing industry that accounts for an increasingly larger share of the sport take of salmon. "The annual average of sport caught fish attributable to the Taku River was 2,669 Chinook and 8,345 Coho" (McDowell, 2004). During the month of July, area residents obtain subsistence permits from the Alaska Department of Fish and Game to gillnet salmon for personal use. An estimated 130 permits are awarded annually to harvest sockeye for personal use. Tributaries of the Taku River offer additional sport fishing opportunities—both Moose Creek and Yehring Creek are popular because of their accessibility. The creeks host both dolly varden, and cutthroat trout. The majority of salmon in Yehring Creek are sockeye, though there are small runs of silver, pink and dog salmon (McDowell, 2004).

Tourism

With more than 600,000 cruise ship passengers visiting Juneau annually, tourism is the second largest economy in Juneau after government. The Taku River area is one of the most popular destinations for visitors to Juneau because of its undeveloped wilderness. Transportation to the Taku is primarily airborne. The commercial flight industry, both helicopter and fixed–wing, provides on average, 150 jobs, $5.5 million in labor income and $18 million in total economic output. Over 60,000 visitors participated in flight seeing in the Taku River area in the year 2003 with an average ticket price of $220 (McDowell, 2004). Taku Glacier Lodge was established in 1923 and became a tourist destination in 1978. Visiting season begins in early May and lasts until late September, bringing more than 14,000 people to the Taku Lodge each summer (Ward, pers. comm.).

Recreational use

Relatively few locals from Juneau and Atlin take full advantage of the numerous recreational resources the Taku offers, due in part to its limited accessibility. The only reliable way to reach the area during the winter is by ski plane or helicopter. During the spring, summer and autumn months, the river is accessible by water, but sandbars and other obstacles make it difficult to navigate. Residents of Juneau and Atlin use the Taku area for a variety of activities. During the summer boating, fishing, hiking, canoeing, kayaking, camping, sightseeing and swimming in warm–springs near the Twin are among the favorite activities of people who visit the Taku. During the winter, activities such as snowmobiling, cross–country skiing, snow shoeing, hiking, hunting and trapping are enjoyed in the Taku area.

First nation traditional use

According to Rosita Worl, a professor of Anthropology at University of Alaska, president of Southeast Alaska Native Corporation and vice chair of the Sealaska corporate board of directors, Tlingit are traditionally a fishing people, using both fish wheels and nets to harvest salmon on the Taku River. The Taku watershed also provides abundant wild game—bear, moose, goat, grouse and ptarmigan to name a few. The Taku watershed is also home to many types of useful plants including: black currants, blueberries, soapberries, watermelon berries, wild strawberries, nagoon berries, devil's club and most abundantly highbush cranberries (Worl, pers. comm.).

First nation traditional values

The Taku Tlingit feel a strong spiritual connection to the land because their ancestors first inhabited the land over 10,000 years ago. This relationship is described as haa aani; this literally translates to our land. Haa shagoon is another Tlingit concept, similar to haa aani. This belief conveys the obligation felt to protect the land for future generations out of reverence for their ancestors. Tlingit people take pride in their ability to cultivate and harvest resources in a responsible manner. Traditional Tlingit values do not permit waste; therefore, they are concerned with non–consumptive use. Both local and regional Tlingit are apprehensive about increasing tourism on the Taku River. A major point of concern includes visitor disturbance of sacred burial sites and removal of artifacts. Tlingit today are struggling to preserve their culture and traditional values. "We know times are changing and we are trying to deal with that... we are trying to figure out how to keep our traditions and our culture with the changing times and technology" (Worl, pers. comm.).

Related management policies

Management of marine ecosystems is not a new idea, but only within the last few decades have there been significant steps made toward preserving the sustainability of our oceans and marine habitats. The framework for most international ocean management plans and conservation measures is the 1982 Law of the Sea. The Law of the Sea compels all nations to enact measures to protect and manage the marine environment this includes protection and prevention of pollution, overharvesting of resources and adverse effects on the food web (Division for Ocean Affairs and the Law of the Sea, 2005). Other international conventions on marine management include the 1992 United Nations (UN) Conference on Environment and Development, 1992 Convention on Biodiversity, 1995 Food and Agriculture Organization Code of Conduct for Responsible Fishing and the 2001 Reykjavik Declaration on Responsible Fisheries in the Marine Ecosystem (Kruse, pers. comm.).

The United States has enacted several conservation acts applicable to fisheries management. Major U.S. policies include the Marine Mammal Protection Act of 1972 which was a critical step in enforcing strict limits on the regulation, protection and importation of marine mammals and products into the United States. The National Environmental Policy Act, NEPA of 1969 was the first legislation in the U.S. to ensure consideration of environmental values in policy formation. The Endangered Species Act of 1976 was also an important step toward the preservation of endangered plants and animals and their ecosystems.

The Mangnuson–Stevens Fishery Conservation and Management Act of 1976, revised and extended through 2005, provides standards and protocol specific to the management of Alaska's important fisheries. The main goals of the act are to promote use of market–based management tools, to end overfishing, to ensure better collection of scientific data and better analysis of the ecosystem, to strengthen fisheries enforcement and to emphasize an ecosystem approach to fisheries management (United States Department of Commerce, 2005).

The rational for an EBFM plan is to heightened awareness of the interaction among fisheries and ecosystems as well as to recognize societal objectives for fishery resources and marine ecosystems (Kruse, pers. comm.).

Many conventional management plans fall short of their goals due to a number of overlooked factors. Flaws in management can be found mainly in single–species issues as well as entire ecosystem issues. Single–species issues that have caused problems in the past are the disproportionate harvest of one sex, underestimations and overestimations of the importance of specific age groups of fish, the disruption of the spawning behavior and habitat and ultimately loss of genetic diversity due to overfishing. Ecosystem factors influenced by humans not previously considered are bycatch mortality, competition between predators and fisheries, fishing down food webs, removal of top predators, mixing of fisheries stock with wild stock and effects of climate regimes on stock productivity. Failure of management plans in the past has forced ecosystem managers to look at our existing resources more carefully, learn from our mistakes and improve plans to sustain our ecosystems (Kruse, pers. comm.).

Management of sockeye

Sockeye have the longest history of intense commercial exploitation of all salmon species in Southeast Alaska (Figure 8). There was an open fishery 1970's and salmon stocks dwindled until an amendment was passed limiting quotas and permits. The sockeye numbers have since rebounded. The current preferred management approach of sockeye stocks is the use of escapement goals. However, most small stocks are fundamentally unmanaged and smolt immigration of sockeye is not well studied in Southeast Alaska (United States Department of Commerce, 2000).

Possible risk factors for the sockeye salmon stocks include a lack of information about small stocks and the possibility that species of high commercial value could cause enhancement of fisheries programs that are detrimental to wild stocks. Also, heavy and poorly monitored subsistence harvests and potential development of mining interests place sockeye stocks at risk (United States Department of Commerce, 2000).

The resilience of wild sockeye salmon stocks in Southeast Alaska is directly related to the high–quality spawning and rearing habitats (Figure 8). The recent increase in commercial harvest can be sustained only if the quality of the freshwater spawning habitats continues to be maintained (United States Department of Commerce, 2000).

Management recommendations

Because of recent advances in science and technology as well as the functional value of ecosystems to humans, a revised management plan is all the more necessary. An ecosystem approach to fisheries, "...strives to balance diverse societal objectives, by taking into account the knowledge and uncertainties of biotic, abiotic and human components of ecosystems and their interactions and applying an integrated approach to fisheries within ecologically meaningful boundaries" (Kruse, pers. comm.).

The formula for developing an ecosystem assessment framework (EAF) begins with scoping the broad, key issues, gathering background information and analyzing this data. In most management plans this process must occur roughly every three to five years to accurately monitor the ecosystem. After analysis, objectives must be set, rules and regulations formulated and enforced. This is a process that must be annually monitored with assessments and reports to maintain management goals. The overarching scheme of the plan must include the consultation and cooperation of stakeholders at each level of the management process (Kruse, pers. comm.).

Panel approach to management

With a panel approach to management of the Taku, representative stakeholders, made up of the commercial fisherman, recreation and sport users, Native/subsistence users, landowners, and tourist industry representatives would be appointed according to their interests by state administration and the Canadian Government to serve for staggered terms of two years. They would serve as an advisory board to managers that implement and enforce the rules and regulations of the management plan.

Ecosystem indicators–multispecies approach

In developing a multispecies approach to management, interactions among species, the effects of fishing on relative abundance, predator–prey relationships and competitive relationships between species must all be accounted for (Leffler, 1995). For sockeye specifically it is important to find out the incidental by–catch rates in other fishing industries and compare that data to recruitment numbers to look for a connection. We recommend use of certain biological and physical indicators to inform the panel and managers in the second step of the EAF. Focal species can indirectly measure the health of an ecosystem based upon their dietary needs and seasonal habits. In the Taku, the presence of sea lions, Eumetopias jubatus, have been correlated to the abundance of certain species of fish. Sea lions are easy to track and count because of their size and their use of haulouts in the vicinity of the Taku and therefore are good indicators of ecosystem balance (Womble et al., 2005).

Populations and species of fish in the Taku determine what animals live in the ecosystem based on their diet as predators. Fish species and numbers are estimated based on catch data and in river sampling each year. Because of the quantity of data periodically gathered and the procedures already in place, salmon runs in the Taku River are the most valuable indicators of ecosystem health (Andel, 2004).

A presence of the American Dipper, or water ouzle, Cinclus mexicanus, in a stream or tributary is an indication of a healthy habitat. The dippers diet consists mainly of small fish and macroinvertebrates, both of which are pollution– and sediment–sensitive organisms. Consequently, dippers are directly affected by pollutants and other disturbances in watersheds (Feck and Hall, 2005). While dippers, sea lions and a number of other species (including but not limited beaver, bear and orca) do not necessarily have direct correlations to sockeye, they still indicate potential problems in an ecosystem.

Physical characteristics in the Taku watershed give relevant information about the system. LANDSAT images reveal vegetation and hydrologic dynamics. We also recommend monitoring, water levels and general climatological (temperature and precipitation) and oceanographic data (sea surface temperature) to recognize changes and ecosystem feedback (per the five step decision process) in both the Gulf of Alaska and the Taku watershed. To guide the panel in making more informed decisions.

Funding

We propose looking to the federal government though the Magnuson Stevens Act for funding of our management approach. The annual budget for 2005 was $35 million and the projected budget for 2006 is $40 million. We expect the federal government to at least modestly fund the management and protection of this valuable resource. Any money applied would be money well spent.

Conclusion

The Taku watershed is a diverse and dynamic ecosystem that needs to be carefully managed in order to maintain the ecosystem's health. Increasing commercial, recreational and subsistence use of the ecosystem makes the need for an ecosystem management plan essential. A panel of stakeholders from the region should consider every aspect and need in the watershed and work to maximize productivity in the Taku while maintaining the health and sustainability of the resources. The idea of managing the Taku is not a new idea. Haa Shagoon and the traditions of the native people of the area is what we are attempting to fulfill with our management recommendations for the Taku watershed.

Figures

satellite image of Taku watershed

Figure 1. Satellite image showing the Taku watershed, outlined in yellow, with Juneau, Alaska starred in red to the right of the image.
Adapted by: Devon Kibby, range data from Richard Carstensen.


distance from Taku watershed

Figure 2. Longitudinal cross-section of the Taku Glacier shows the vertical and horizontal growth of the Taku Glacier during the years of 1890, 1937, and 1989.
Adapted from Motyka, Advance of a Fjord-Type glacier.


average montly flow from Tulsequah River

Figure 3. Mean mouthly flow of the Tulsequah River during the year 2001. Notice reduced flow during winter months and increased flow during summer months. Graph also indicates fish activity relative to flooding cycle.
Adapted from: Tulsequah Chief Project Report by the Canadian Ministry of Environment, Lands and Parks.


average monthly temperatures

Figure 4. Comparison of the mean monthly air temperatures of the Tulsequah, Juneau, Juneau Historical and Atlin Historical areas. Current data was taken over the time period of May 1994–June 1995.
Adapted from: Tulsequah Chief Project Report by the Canadian Ministry of Environment, Lands and Parks.


average monthly precipitation

Figure 5.Graph compares mean monthly precipitation of Juneau, Atlin, and the Tulsequah during the year 2001.
Adapted from: Tulsequah Chief Project Report by the Canadian Ministry of Environment, Lands and Parks.


LANDSAT image of Taku River mixing zone

Figure 6.LANDSAT image of the visible spectrum adjusted to highlight the mixing zone created by the outflow of the Taku River.
Adapted from: Devon Kibby, data image via Dave Albert of the Nature Conservancy Organization.


LANDSAT image of vegetation along Taku River

Figure 7. LANDSAT image showing relative vegetation of the lower Taku River. Image produced by utilizing reflections in the visible and infrared spectrums.
Adapted from: Devon Kibby, data image from Dave Albert.


annual harvest of sockeye salmon 1880-1991

Figure 8. Overfishing of sockeye salmon during Federal management resulted in about 3,500,000 fish taken in 1914. Harvest declined steadily after that to a minimum decade average of 642,000 fish per year during the 1970's. In 1977, limited entry was introduced and steady growth of the stock has occurred under Alaska Department of Fish and Game management.
Adapted from: United States Department of Commerce, NOAA, 2000.


Year

Chinook

Sockeye

Coho

Pink

Summer Chum

Fall Chum

Total

10–year average

$139,200

$2,038,700

$973,100

$231,200

$0

$51,800

$3,434,000

Table 1.Estimated First Wholesale Value of US Commercial Harvest of Taku River Salmon, 1994–2003

Year

Jack Chinook

Large Chinook

Sockeye

Coho

Pink

Chum

Steelhead

Total

10–year average

$2,300

$88,800

$545,400

$94,700

$100

$0

$2,300

$733,600

Table 2.Estimated First Wholesale Value of Canadian Commercial Harvest of Taku River Salmon, 1994–2003
Source: McDowell Group, The Taku River Economy: An Economic Profile of the Taku River Area


References

Publications

Personal communications

Electronic sources