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The winter of 2001-2002 marked the best return of salmon to the Mattole River since the 1987-1988 season when an estimated 1500 chinook salmon returned. This year, it was estimated that 1400 chinook and 600 coho salmon returned to the Mattole. Furthermore, there was a strong steelhead run this season for the fourth year in a row, possibly exceeding 10,000 spawners. These figures were based on the following surveys:
? The number of redds/mile (shallow troughs scooped out in the river bed by the female for nesting purposes) was the highest documented in fourteen years particularly in the upper mainstem Mattole, Thompson Creek, upper Bridge Creek and the middle reaches of South Fork Bear Creek.
? By far the largest number of salmon carcasses was found since the 1987-1988 season.
? Number of live fish seen was greater then in any year since the 1987-1988 season.
Factors that contributed to this great year for fish include a succession of moderate storms that kept the river flows up with no destructive flooding allowing adult spawners unrestricted access to key spawning reaches throughout the watershed. The lack of flooding resulted in beneficial river bottom conditions without scouring of spawning areas or silting-in of gravels. Good ocean conditions (temperature and food resources) resulted in the overall large size and robustness of returning adults in the Mattole, particularly chinook. The average size of adult chinook was about 36 inches long and over 20 pounds, which is about 3 inches longer and a few pounds heavier than in ?normal? years on the Mattole. Surveyors saw two very large female chinook whose carcasses were 50 inches long with an estimated weight of 45 pounds.
While the Mattole Salmon Group is unable to take full credit for the moderate storms and good ocean conditions that were instrumental in producing this salmon and steelhead bonanza on the Mattole, the group has played an important part in documenting all of this fish activity. Furthermore, the Mattole Salmon Group has a number of programs in place that may have positively affected this year?s excellent fish return. These include two types of salmon rearing projects.
Rescue Rearing Projects focus on trapping down migrating chinook salmon who are doomed if they remain, after the mouth of the river closes, in a shallow and warm inhospitable lagoon. By trapping these fish and maintaining them in fish tanks, they are able to survive until the mouth opens, usually in the fall. Before release, the fish are marked allowing us to obtain information on returning chinook.
The Hatchbox Program is a rearing project that depends upon artificial propagation of chinook salmon. This season two females and a number of male spawning salmon were trapped. The eggs were expressed and fertilized with the milt from the males, which led to approximately 5000 fry (baby chinook) that are being carefully raised upriver near Whitethorn. These genetically wild chinook salmon are scheduled to be marked in late May and will be released into the river when the mouth is open.
Members of the Mattole Salmon Group are often asked how effective is our work in restoring the salmon to the Mattole watershed. There has been a general upward trend in the last four years and based on this year?s numbers we are quite successful. However, it will take a number of other years to determine if this is part of a general upward trend or is merely a fluke.
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TOC for Forest & River News, Spring 2002