The Steelhead of the Tongass National Forest: A Brief Overview of Habitat, Life Histories, and Management
By: Mark Hieronymus, Trout Unlimited Alaska
At nearly 17 million acres, the Tongass National Forest in Southeast Alaska is the country’s largest national forest. This complex landscape of western hemlock, Sitka spruce, western red cedar and yellow cedar is part of the world’s largest remaining intact temperate rainforest. The Tongass comprises thousands of mist-covered islands, deep fjords, tidewater glaciers and soggy muskegs that host some of the rarest ecosystems on the planet. It is ideal habitat for a wide array of plant and animal species, including all five species of North American Pacific salmon, resident trout and char, brown and black bear, Sitka black-tailed deer, bald eagles, and wolves, among many others. The Tongass includes more than 15,700 miles of clean, undammed streams and 4,100 lakes and ponds that provide optimal spawning and rearing conditions for the region’s abundant wild steelhead and salmon.Each year as hundreds of millions of wild salmon return to Tongass streams to spawn and die, they bring nutrients from the North Pacific Ocean to the forest. Enriched by this annual salmon return, the Tongass literally is a “salmon forest” with unique ecosystems found nowhere else on Earth. Among the beneficiaries of the salmon-based marine derived nutrient cycle is the steelhead (O. mykiss), an oceangoing phase of the rainbow trout.
Photo Copyright: Earl Harper
Steelhead are “officially” found in over 300 Tongass streams, according to the Alaska Department of Fish and Game (ADF&G) Anadromous Waters Catalog (AWC), a database of the extant institutional observations concerning anadromous fish populations in Alaska. Although the AWC is considered the last word on anadromous populations, it is by no means a complete survey, and should be thought of as a work in progress in terms of steelhead stream identification. Anecdotal data and empirical observations seem to suggest that steelhead occur in many more streams than indicated by the AWC; there are some that believe steelhead are present in 450 or more of the close to 5,000 streams in the Tongass.
The average Pacific Northwest steelhead river can be generally described as a large, long, and meandering flow. The flow of this river is in thousands of cfs, its fishable habitat numbering in the tens to hundreds of miles, and it is most likely classified as low-gradient. This river has tributary rivers, and many feeder streams of these tributaries. By way of comparison, most of the steelhead streams in the Tongass are fairly short affairs, averaging about 3-5 miles in total length of spawning and rearing habitat, and their tributaries, although of critical importance in terms of their contributions to the riparian ecosystem, are often too high gradient to be of value as spawning or rearing habitat. There are only a handful of steelhead streams over 15 miles in length and these are predominantly located on the eastern mainland section of the Tongass. Another shared attribute of many Tongass steelhead streams is their small size. While there are a relative handful of larger rivers, most of the steelhead flows in the Tongass are less than 750 cubic feet per second (cfs) in size, and it is not unusual to find fish in a stream of less than 100 cfs. Taken as a whole, the island and coastal mountain drainages of the Tongass could be described as a set of tributaries to the Inside Passage waterways, which in turn flow into the Pacific Ocean.
The combination of short, small rivers and limited spawning and rearing habitat within them has the effect of limiting steelhead run sizes in the Tongass. There are rivers that have seen recent single-year counts of over 15,000 steelhead, and a relative handful of other streams in the Tongass that may have escapements numbering over a thousand fish – however, the majority of the streams in the Tongass host fewer than 200 spawning adults.
Photo Copyright: Bryan Gregson
There are 3 distinct run components in the steelhead streams of the Tongass – the spring, summer, and fall runs. The largest component in terms of population is the spring run with the bulk of the fish entering freshwater in April and May, but starting as early as March in some watersheds. Spring run fish account for approximately 80% of the steelhead in the Tongass, and enter the river as sexually mature fish, ready to spawn. Fall run steelhead make up between 15 and 20% of the steelhead population of the Tongass, and are most often found in streams with anadromous-accessible lakes. These fish enter the river in a sexually immature state and mature as they overwinter. The fall run starts in September and continues through November, and with a few exceptions occurs mainly south of the 57° N latitude. Summer-run steelhead are rare but not unheard of in the Tongass, and they enter freshwater in July and early August and mature as they overwinter. Regardless of when the steelhead of the Tongass enter fresh water, they all spawn in the spring, with an occasional flurry of activity as early as April but the bulk of the spawn occurring in the second week of May. As a result, some fall fish may spend up to 8 months in freshwater before spawning, whereas late spring fish may have a residence time of as little as 48 hours.
Photo Copyright: Bryan Gregson
The steelhead of the Tongass exhibit a high rate of return spawning when compared to steelhead from other geographical areas; estimates vary from system to system, but it has been suggested that 20-25% of all spawners are repeats, and in some cases may make up close to 50% of the spawning population. The repeat spawners are typically female and most often spawning for the second time, although 4- and even 5-time spawners have been documented.
Tongass steelhead also display a wide range of both freshwater and marine residence times in their complex life history. The results of a 1994 weir study on a high-production Tongass steelhead stream showed that in one year, 22 distinct age classes and 6 separate brood years were present. The most common freshwater residence time is three years, followed closely by four and two years. Five and six year freshwater residence fish are uncommon but present in small number in several systems in the Tongass. Similarly, the residence time of steelhead in saltwater is most commonly 2 or 3 years, however, the observed range is anywhere from 1 to 5 years.
The bulk of the steelhead populations in the Tongass are composed of wild fish, but there have been historic efforts at enhancing run sizes. In the 1970’s, the ADF&G initiated a study series on multiple steelhead streams with the ultimate goal of enhancing runs to provide more angler opportunity. Similarly, there have been cases of “mitigation enhancement” of runs that have displayed anthropogenic-based habitat degradation or population depression. Steelhead stocking efforts have largely been curtailed in the Tongass due to a number of factors, including less-than-satisfactory run performance, concerns of competition potential between wild and hatchery stocks, high costs, and poor return on investment . One Tongass steelhead stocking program was discontinued in 1994, in part due to the average cost of $572 per harvested fish. The ADF&G Genetic Policy, adopted in 1985, places stringent controls on hatchery activities and emphasizes the protection of wild populations. Currently, there are no hatchery steelhead propagated for directed enhancement of Tongass populations.
Photo ©Earl Harper
The steelhead populations on the Tongass have fluctuated from an historic perspective, both when taken as a whole and on a stream-by-stream basis. Population counts and estimates are a relatively new trend in Tongass steelhead management. Prior to the 1960’s, there was very limited data on steelhead, usually found in the form of anecdotal observation. Biologists and sport fishers alike began taking an interest in steelhead in the mid-1970’s in part due to lower harvests despite increasing angler effort. Daily bag limits were restricted from 3 fish to 2 in 1975 in an effort to conserve a limited resource, and several population surveys were undertaken to better understand the scope of the issue. Steelhead populations in some Tongass streams increased after 1977, in part because of the restricted harvest limits but quite possibly the increases were more attributable to the loss of interception in foreign fisheries after the enactment of the Magnusson act in 1976.
In the late 80’s and early 90’s, steelhead populations across the Tongass took a sharp turn downward. In response to this, fisheries managers implemented a series of emergency orders prohibiting steelhead harvest and banning bait on select rivers in the Tongass. In 1994, ADF&G adopted sweeping regulation changes for the steelhead fisheries in hopes of halting and eventually reversing the population decline while still providing for recreational opportunity and limited harvest. The new regulations prohibited harvest of steelhead smaller than 36”, a measure that protects close to 95% of all Tongass steelhead and is designed to exclude first-time spawners from harvest. In addition, bag limits were sharply curtailed from the previous 2 fish a day to one fish a day with a 2-fish annual limit, to be noted on a new harvest record portion of the Alaska state fishing license. The use of bait was also banned on select rivers of the Tongass.
Photo Copyright: Bryan Gregson
In the 2000’s, close management of Tongass steelhead stocks continued, with more watersheds added to the bait ban and several high-use areas closed to the retention of steelhead. Many fall steelhead streams in the southern portion of the Tongass that had seasonal bait restrictions were closed to the use of bait year-round to more adequately protect stocks. In 2009, the watersheds crossed by the road system of Juneau (Alaska’s capital city and 3rd most populous borough) were closed to the retention of steelhead.
Based on the limited stock status information available, steelhead abundance in the Tongass was relatively stable and slightly above average between 2003 and 2007 but has trended downward in recent years, closer to the 15-year average. Overall adult steelhead returns are below those experienced in the late 1980’s, and there are still systems in the Tongass that have not rebounded from the depressed levels observed in the late 1980’s and early 1990’s. Current regulations which restrict the harvest and incidental mortality of wild steelhead should remain in place to conserve and rebuild the naturally producing stock. Given the small populations that occur in the bulk of the Tongass steelhead streams, there is very little wiggle-room when it comes to impingement on these stocks, either in the form of harvest or habitat degradation.
To address many of the habitat issues faced by Tongass steelhead (and other salmonids), Trout Unlimited, Alaska Program has advanced a proposal called the “Tongass 77”. While most steelhead and salmon populations in the Tongass are recovering or healthy and abundant, their future is uncertain. Industrial-scale logging and road building, new mining developments, dozens of hydroelectric dam projects, and various proposals to privatize large swathes of the most productive and valuable portions of the Tongass threaten permanent damage to the region’s most valuable resource. While 35% of Tongass steelhead and salmon habitat is currently conserved at the watershed scale, many of the most important spawning and rearing streams remain vulnerable to industrial development that has the potential to negatively impact fish habitat.
The downward trend of salmonid populations in the Pacific Northwest and California, where the volume of wild steelhead and salmon once rivaled that of the Tongass, foreshadows what could occur in Southeast Alaska unless lawmakers, government agencies and the public act to make habitat conservation and restoration top priorities. In the Tongass, there is the opportunity to ensure steelhead and salmon enjoy a healthier and more stable future.
Researchers from the Alaska offices of the Audubon Society, The Nature Conservancy and Trout Unlimited used state-of-the-art GIS and conservation planning software to identify the “best of the best” from the thousands of steelhead and salmon watersheds on the Tongass that currently lack watershed-scale conservation measures. After consulting with federal and state biologists and various community and business stakeholder groups, the list was narrowed down to 77 high-value watersheds comprising 1.9 million acres that form the backbone of salmonid production in the Tongass. Of these 77 watersheds, 61 of them have populations of steelhead ranging from a few hundred to the tens of thousands.
Photo Copyright: Bryan Gregson
Based on the outstanding fish habitat in these watersheds and their contributions to local communities and economies, the highest and best use of the “Tongass 77” is for salmon and trout production. Federal legislation to permanently conserve the watersheds of the “Tongass 77” is necessary to ensure the long-term productivity of these important watersheds. Maintaining natural steelhead and salmon production and the health and function of fish and wildlife habitat should be the top management priorities. Additionally, by prohibiting commercial logging, new road building and new mining developments within the “Tongass 77”, it is possible to ensure Southeast Alaska’s wild steelhead and salmon return for generations to come and continue to fuel the region’s communities and economy.
As previously mentioned, about 35% of the steelhead and salmon spawning and rearing habitat in the Tongass is currently conserved at the watershed scale. The footprint of these watersheds represents roughly 40% of the land base of the Tongass National Forest. The “Tongass 77” would conserve an additional 23% of the steelhead and salmon spawning and rearing habitat available in the Tongass on about 12% more of the total Tongass land base – focused, fish-first conservation measures for the continued health of Southeast Alaska steelhead and salmon populations and the millions of dollars they generate in the local, Alaskan, and greater Pacific Northwest economies. For more information about the “Tongass 77”, please visit www.americansalmonforest.org. The USFS is currently in the process of amending the Tongass Land Management Plan, and the proposed amendments includeincreased conservation measures for the majority of the Trout Unlimited “Tongass 77” high value fish watersheds. While the Forest Service has proposed changes that will prioritize fish and fish habitat in our largest national forest, your comments are needed to ensure this plan is enacted. Take Action here and join the growing number of folks who are making their voices heard.
Note: This was originally printed in the May 2014 edition on the Osprey. A publication of the Steelhead Committee of the Federation of Fly Fishers