A NW EnerNet News Service of Energy NewsData
NW FISHLETTER
NWF.020/OCT.22.1996
***Fish News***
[1] Scientists Share Signals for Clues to Ocean Abundance
[2] Columbia Estuary Birds Go For Salmon In a Big Way
[3] Hatchery Supplementation- an Idaho Perspective
[4] Fall Gillnet Catches Up, Prices Down
[5] Barge Funding Hits Snag, Decision Promised Soon
[6] Fish Passage Center Operations Scrutinized

[1] SCIENTISTS SHARE SIGNALS FOR CLUES TO OCEAN ABUNDANCE :: Researchers around the Pacific Rim are looking at everything from satellites to sea lion whiskers for clues to one of the greatest global puzzles--what makes the ocean tick?

They count tree rings, study baleen from bowhead whales, pick through mud from the bottom of Alaska lakes and study sediments off Santa Barbara where one scientist has discovered a 1,500 year record of past fish populations. Others have scanned historical wind records and found that since the turn of the century, summer is now two months longer off the West Coast.

These are just a few of the fascinating facts presented before a group of scientists at a week-long conference in Nanaimo, B.C., the fifth annual meeting of PICES, the North Pacific Marine Science Organization.

Soft-spoken Seattle oceanographer Curtis Ebbesmeyer told the group the transition from winter to spring off the mouth of the Columbia River occurs a month sooner than it did around 1900. The transition comes about when winds switch from prevailing southerlies to northerlies and the coast-hugging fresh water plume from the river discharge fans out and moves towards the southwest in summer. The record shows that fall now comes a month later, when winds switch back to southerlies and the river plume again hugs the coast.

Ebbesmeyer and co-authors Rich Hinrichsen, and James Ingraham Jr., looked at the implications of this phenomenon for the Columbia region. Since juvenile fish feed in the area around the river plume (it's where nutrient-rich, deeper saline waters are transported into the photic zone), they think it is important to document the timing of these transitions since the intensified food chain is so important to the health of young salmon.

If fish emerge from the river before the spring transition has occurred, the authors expect juvenile mortality to be increased. This could have major implications for hatchery releases and fish barging schedules. Fish barged downstream in the spring reach the estuary three weeks ahead of their river riding counterparts.

But a longer summer could mean good news for salmon. The upwelling season would last longer, affecting circulation of estuarine water bodies like Georgia Strait and Puget Sound.

Prof. James Anderson from the University of Washington addressed that issue in a separate paper, noting that hatchery fish could exhibit more variability in year-class strength than a wild stock because they arrive downstream in such a narrow window of time compared to a wild stock's traditionally protracted migration.

Anderson said tag studies have found that late migrating juveniles (barged), had a two-fold increase in survival over early migrating fish. He cited a 1996 study (Deriso, Marmorek, and Parnell) that attempted to separate hydrosystem effects from year-to-year effects, and showed that the mortality rate of spring chinook exhibited a pattern tied to the Pacific Northwest Index (PNI), a group of temperature and precipitation measurements that reveals a pattern of alternating warm/dry and cold/wet climate regimes approximately 20 years long. In 1976 the region moved out of a cold/wet regime that correlates with lower salmon mortality rates into a warm/dry period that has not been kind to West Coast salmon. The region may soon be cycling back again.

In that vein, J.J Polovina of the NOAA Honolulu Laboratory told the group of his work studying the biological effects of the strong/weak atmospheric oscillations over the ocean . He reported that the strong current gyres in both the subarctic and subtropics started to weaken after 1988-89 . By using historical data on sea level height that goes back nearly 100 years, he has figured that the North Pacific gyres have spun-up and spun-down four times between 1910 and 1995.

Satellite altimetry suggests that circulation of the gyres has been stronger the past couple of years, which, according to Polovina, "could signal the beginning of a shift to a decadal period of strong ocean circulation." The subtropical gyre is a downwelling gyre that could provide the West Coast with the nutrient base responsible for improved fish abundance.

Japanese researchers have evidence of cycles from their vantage point, too. Shoshiro Minobe of Hokkaido University reported on a 50- to 60-year oscillation he has detected over the North Pacific, and others reported on important changes in fish stocks off Japan after 1976.

The group was awed by Bruce Finney's results from core sediments from Alaska lakes. He used them to trace variations in sockeye salmon abundance back 500 years, by sampling the cores for Nitrogen-15, an isotope that comes only from the ocean, that is brought back to the lakes in salmon when they return to spawn. Finney 's work has mapped periods of abundance and decline from systems on Kodiak Island--peaks in the late 1800s, and declines in the early 1800s and mid-1900s that correspond to periods of colder temperatures.

Perhaps the most unusual work was presented by D.M. Schell of the University of Alaska who has examined whale baleen and sea lion whiskers for trace isotopes of carbon that he hypothesizes may show a 40-percent reduction in basic plankton production in the Bering Sea during the past 20 years.

The most all-encompassing study is Tim Baumgarnter's work with sediments from the Santa Barbara Basin which contain enough fish scales to estimate alternating sardine and anchovy abundance back nearly 2,000 years. Baumgarnter's sediment analysis shows evidence of an approximate 60-year cycle--sardines like warm phases, anchovies like cold--that may reflect interdecadal fluctuations in climate on a scale never before seen by fisheries-oriented researchers. He speculated that overall, there has been a large decrease in upwelling over the past 2,000 years.

Just what mechanisms may run these cycles is the subject of much speculation. Super-computer modellers have tried to corral the basic energy interactions between the ocean and the atmosphere. One such model has come up with a predicted 20-year time frame for a southern ocean heating event to circulate around the Pacific Basin.

What these findings and speculations tell salmon biologists is a lesson in humility. As University of Washington researcher Nate Mantua, along with co-authors Steven Hare, Juan Zhang, John M. Wallace, and Robert Francis, put it in a paper presented at the Nanaimo proceedings, "Management goals, such as the current legislative mandate to double Washington State salmon production may simply not be attainable when environmental conditions are unfavorable. Conversely, in a period of climatically-favored high productivity, managers might be well-advised to exercise caution in claiming credit for a situation that may be beyond their control" [Bill Rudolph].

[2] YOUNG SALMON FEED BIRDS IN A BIG WAY :: Birds in the Columbia estuary may be pecking away at a salmon smorgasbord of gigantic proportions. An experiment with radio-tagged fish has shown that 20-30 percent of the tagged juvenile chinook that reached the estuary were taken by piscivorous birds, primarily cormorants and terns.

Carl Schreck of Oregon State University cautions that these are preliminary results. The OSU scientist led the research group that released groups of radio-tagged fish from transport barges on six dates over the 1996 outmigration. Comparison groups of tagged run-of- river fish were released concurrently on the last three dates and on an additional date following the barge releases.

From 77-96 percent of the radio-tagged fish were monitored at Jones Beach, about 86 miles downstream from the release site. Fish locations were determined throughout the estuary using aircraft.

Over the course of the study, Schreck's group observed no obvious trend in survival to the estuary over the course of the migration season and no clear difference between barged and run-of-river fish.

The researchers found that the rate of bird predation of barged fish increased late in the season, but no trend was evident for run-of-river fish. In an abstract of the study, the biologists wrote, "There was no clear difference in predation rate between barged and run-of-river fish and relatively high rates of predation were common to both groups late in the season." The predation rates ranged from 7-39 percent. The study also found that the fish increased speed during the course of their outmigration, and that run-of-river fish generally moved faster than barged fish, and appeared to be more tightly grouped.

The radio-tagged juveniles were often observed in or near the shipping channel, but some were detected in side channels. The migrants did not appear to hold in the estuary for extended periods of time (days).

Schreck said the high predation rates of young salmonids may be occurring because there are no "buffers" left, other species like lampreys that birds had preferred in their diet.

In another effort that points to high bird predation, the Columbia River Inter-Tribal Fish Commission discovered around 400 Pit-tags on Sand Island in the lower estuary. Some were visible on the surface on the sand, and sifting revealed large numbers of tags as well [Bill Rudolph].

[3] HATCHERY SUPPLEMENTATION - WILL IT BAIL OUT DECLINING SALMON RUNS? :: Hatchery supplementation of wild salmonid populations has been advanced by some agencies and Native American tribes as the way to restore salmon runs. This restoration option has been evaluated in a 1995 article by Ed Bowles of Idaho Fish & Game and published by the American Fisheries Society. (Supplementation: Panacea or Curse for the Recovery of Declining Fish Stocks. American Fisheries Society Symposium 15:277-283).

Bowles addressed the theoretical benefits and risks of using hatchery fish to supplement wild native salmonids and put these into perspective with other recovery options. "Any attempt to rebuild anadromous runs," he says, "must recognize the importance of naturally reproducing populations to enable sustainable recovery."

Bowles states that recovery efforts are shortsighted if they do not maintain or enhance the natural diversity of native populations, since they represent the source of genetic diversity that provides the foundation for adaptation and persistence in a changing environment.

"Successful recovery is thus dependent upon two key factors: (1) recovery must enhance the number of naturally reproducing fish and; (2) this enhancement must not reduce the natural genetic diversity and fitness... of fish living in the wild."

The Snake River spring and summer chinook stock complex or metapopulation is composed of 38 distinct and locally adapted populations. This population structure is vital to keep the whole complex viable. Bowles warns that the species unit represented by this population structure is only as strong as its diversity and productivity. This stock complex is likewise dependent upon the diversity and productivity of each of the populations that compose it. Since the locally adapted populations are all connected, to recover the endangered spring and summer chinook, each population must be recovered.

However, recovery options are often selective and do not benefit all the natural populations and the diversity they represent. Therefore, selective recovery options cannot promote sustainable recovery. This is true even if fish abundance is increased by management actions but diversity has declined. This is an example of the production hatchery where the goal has been to increase the supply of salmon for harvest but has not addressed the issue of maintaining the diversity of the species in the many watersheds where they have evolved.

Bowles claims that mainstem passage problems for juvenile salmonids is the overriding factor in native salmon decline, and solving them is the best way to increase salmon numbers, specifically, native spawners in each of the distinct populations found in the Snake River basin. By adding a 0.3% to the survival rate from smolt to adult, all populations could be increased by 50% after one generation Habitat and hatchery supplementation could have that effect on only the target population. With regard to harvest, Bowles wrote that recovery efforts will be hampered without continued harvest restrictions on mixed stock fisheries. However, harvest restrictions alone are not enough to recover upriver natural populations.

On habitat, he pointed out that low numbers of adult chinook spawners limit utilization of the habitat to less than 20% of its potential. While he supports strong habitat protection and recovery measures, he again states that habitat measures only benefit the targeted population and cannot provide recovery for all natural population components of the species.

"The optimal scenario for supplementation would be to increase the number of naturally produced fish without reducing their ability to survive in the wild," says Bowles. But without evidence that supplementation can increase the abundance without altering fitness of those same populations, Bowles recommends that it be used sparingly.

Supplementation can increase adult returns because fish are protected in the hatchery environment, but exposure to that environment impairs survival in nature by negative hatchery influences of genetic and behavioral changes and exposure to pathogens. Consequently, the increased number of naturally produced fish is not self-sustaining and the reduced natural fitness puts the population in more serious risk of extinction.

Hatchery supplementation, Bowles says, "can potentially enhance only targeted populations. Obviously, supplementation of every population within all stocks is unrealistic. Thus supplementation can benefit only a portion of the population diversity or structure necessary for sustainability."

Some managers have suggested pooling populations so that supplementation of the entire stock becomes manageable. Bowles says, "This misdirected approach could greatly reduce the sustainability of the stock by diluting among population diversity, even if the number of naturally produced fish increases."

Furthermore, he says, "Supplementation cannot be considered a recovery alternative for addressing the causes of decline for upper Columbia River salmonids." He maintains that recovery must be approached as a package of of options, with the major emphasis being placed on resolving mainstem mortality for juvenile and adult salmonids due to the hydrosystem [Bill Bakke].

[4] GILLNETTERS KEEP FISHING DESPITE LOW PRICES :: Columbia River gillnetters have kept on fishing as the fall chinook season wound down and terminal fisheries opened near the mouth of the river.

Tribal fishers above Bonneville have taken 61,000 fall chinook, both upriver brights destined for the Hanford Reach and tules produced from Bonneville pool hatcheries. They have caught 19,000 steelhead as well. The salmon catch has weighed in around 925,000 pounds, but low prices triggered by a glut of salmon from Alaska and fish farms has dropped the value of the catch to about $230,000. The last year of the Celilo Falls tribal dipnet fishery in 1956 produced a harvest of 910,000 pounds.

By Oct. 10, non-tribal fishermen caught 10,600 chinook and were fishing the lower river terminal areas where netpen fisheries have been developed at Youngs Bay, Big Creek, Blind Slough, Tongue Point and Deep River. The lower river netters have also caught 2,800 cohos, 5,700 white sturgeon, and 600 green sturgeon.

Many non-tribal fishermen returned from Alaska and were surprised to find their backyard was open for business. But it was nothing like the glut up north, where nearly 170 million salmon were landed this year, actually down about 25 percent from last year's catch.

Landed value of the Alaska catch was worth $360,330,000, the lowest value in the past four years, still less than the amount the Northwest has committed to Columbia Basin fish and wildlife mitigation annually for the next five years [Bill Rudolph].

[5] BARGE FUNDING HIT SNAG, DECISION PROMISED NEXT MONTH :: On Sept. 30, state fish and wildlife agencies withdrew support for the FY-1997 funding for two new juvenile fish transportation barges, but the National Marine Fisheries Service thinks they should still be built next year. The barges had already been pushed ahead from the 1996 budget when Corps of Engineers funding was reduced last year.

Steve Petit of Idaho Fish & Game said the Corps of Engineers' reduced budget for next year requires careful screening to get the maximum benefit for the $90.2 million that Congress appropriated for the Corps' 1997 fish mitigation program. Petit also said that IDFG chinook hatchery production for 1998 will be only a third of normal, around 3.3 million fish, which means only about 2 million would survive to Lower Granite Dam. With improved spill programs, the agency said even fewer would be collected. They recommended delaying barge construction until the following year.

Oregon felt the same way, adding two more reasons for delaying construction. Citing the unclear benefits of direct loading of smolts onto barges rather than from raceways, and the fact that the potential role of transportation in recovery programs is still not clear, Raymond Boyce of ODFW's fish division told the System Configuration Team in an Oct. 2 letter "it is possible that these investments in the transportation program may be wasted if future decisions are made to emphasize in-river passage and reduce transportation."

The Columbia River Inter-Tribal Fish Commission also sent a letter to the SCT. They recommended the barges not be funded at all, citing uncertainty over transportation's future, "pending results of regional review with PATH analyses and evaluation of the existing transportation studies."

NMFS' response to the SCT was written by Jim Ceballos, who said new information would be needed to change NMFS' conclusion that survival benefits are worth the direct loading option to reduce smolt stress.

He said that NMFS did not disagree with the states' assessment about the size of the juvenile outmigration in 1998, but available information leads the federal agency to conclude that potential survival benefits to fish from reduced cumulative stress would be achieved by the addition of two new barges.

NMFS also said new barges would reduce the likelihood that excess collected fish would have to be returned to the river during peak migration periods, "especially if in-river conditions are poor."

NMFS did not buy the states' argument that lower than normal numbers of fish in 1998 are a reason to delay construction, pointing out that the number of barges now makes it impossible to direct load more than half of all juvenile fish. New barges would eliminate "avoidable crowding/loading stress" and the agency added that transportation studies of Snake River steelhead, potential candidates for listing under the ESA, "have demonstrated very positive results for these fish."

As for long-term strategy, the NMFS letter pointed out that the Corps of Engineers has estimated the earliest possibility of a Natural River drawdown would be in 2006, therefore barges built in 1998 would "contribute towards improved survival of transported fish for at least eight years."

Since the SCT could not agree on the issue, the funding decision was elevated to the Implementation Team, who will take up the question in early November, when the future of the two 75,000-gallon barges will finally be decided [Bill Rudolph].

[6] COUNCIL REVIEWS FISH PASSAGE CENTER FUNDING :: At their late October meeting in Whitefish, Montana the Northwest Power Planning Council will finalize an issue paper on the Fish Passage Center dealing with several policy matters, including the degree of policy oversight on recommendations, resident fish concerns, and accessibility of data.

The Fish Passage Center's first mission was to assist the fish managers in the collection of data on salmon migration at the dams, water quality data, and structure fish passage flows at dams to protect salmon. Oregon Council member John Brogoitti said the issue paper was long overdue and expected timelines to be met. He said, "This stalling has to stop."

Fred Olney of USFW, representing the fish managers, said the work was being completed. He said he did not know there was a deadline, but asked for this meeting with the Council to be moved up so the work could be completed. Olney said, "I do not appreciate your accusation that there is a delaying tactic."

Council member Mike Field of Idaho noted that the Columbia Basin Fish and Wildlife Authority, the coordination body for the fish agencies and tribes in the Columbia River Basin, has been in turmoil and disorganized of late and access to information and analysis has been slow.

A conflict has developed between the region over salmon recovery. The Biological Opinion by the National Marine Fisheries Service is not concerned about effects of reservoir water level management on resident fish as water is used to improve endangered salmon runs downstream. However, the Power Council must consider resident fish affected by reservoir manipulation.

Bob Lohn, fish and wildlife program manager at Bonneville Power Administration said, "I must admit BPA has a difficult time with the Fish Passage Center advocacy." He asked for direction to help decide the differences between data collection, data analysis, and advocacy. He told the Council he would like them to set guidelines for operations of the Fish Passage Center. [Bill Bakke].

***Document Annex***
Works Cited

DOCUMENTS FROM NW FISHLETTER 020 :: Below are listed available documents and links referred to in the text of NW Fishletter issue 020.

THE ARCHIVE :: Previous NW Fishletter issues and supporting documents.


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