Saving Seafood

Fisheries Managers Face Mixed Forecast For Northwest Salmon, Concerns Over Endangered Orca

March 12, 2019 — About this time every year, the Pacific Northwest gets a report card from the natural world. It comes in the form of salmon run forecasts and gives us an indication of how healthy the Pacific Ocean and our rivers and streams are.

The grades are in, and here’s what you need to know about our scores.

How’d we do this year?

It’s definitely looking like we’re in for a “there’s room for improvement” kind of year.

Every spring, a group called the Pacific Fishery Management Council gets together and look at the salmon forecasts from the Puget Sound all the way down to the Sacramento River in California. They use this data to decide at a week-long meeting in April what overall catch limits will be. This catch allowance is then split between commercial, recreational and tribal fishermen in the Pacific Northwest. The goal is to make sure we don’t catch more salmon than the numbers can actually support.

Read the full story at KLCC

These Chinook almost went extinct during California’s drought. Can this $100 million plan save them?

March 9, 2018 — During the worst of California’s five-year drought, thousands of eggs and newly spawned salmon baked to death along a short stretch of the Sacramento River below Shasta Dam.

The winter-run Chinook, already hanging by a thread, nearly went extinct.

Hoping to avoid a repeat of that dire scenario, fisheries officials announced Thursday the launch of a plan — nearly 20 years and $100 million in the making — they say would expand the spawning range of the fish to include a cold-water stream called Battle Creek. The idea is that the stream could keep the fragile winter-run alive as California’s rivers get hotter because of a warming climate.

The stakes are high and go well beyond the fate of the fish. Concerns about this run of salmon have a major impact on how water is distributed to farms and cities across California.

During the drought, for example, farmers experienced cuts to their water supply as dam managers held water in Shasta, the state’s largest reservoir, in a frantic effort to ward off extinction of the Chinook.

Read the full story at the Sacramento Bee

Forecast shows California salmon fishermen in for another year of sharp limits

March 2, 2018 — A third straight year of low king salmon runs is expected to deliver another blow to one of the North Coast’s most iconic and lucrative fisheries, wildlife managers indicated Thursday, as both regulators and fishermen faced the prospect of a federally mandated plan to reverse the trend and rebuild key stocks.

The grim news comes amid a dramatic, yearslong decline in the state’s commercial salmon landings, which are down 97 percent last year from their most recent peak, in 2013, when they hit 12.7 million pounds.

The full picture for commercial and sport seasons won’t be clear for several more weeks, but spawning projections show Sacramento River salmon — historically the largest source for the state’s ocean and freshwater harvests — have fallen so low that they’re now considered by regulators to be “overfished.”

Wildlife officials acknowledged that term minimizes the many factors that have led to this point, including shifting conditions in the ocean and years of low river flows during the drought, all of which have pummeled stocks.

The outlook is dire enough to mandate development of new regulations expected to further limit where and when anglers can drop their lines and what their size and catch limits will be.

Read the full story at The Press Democrat

 

California faces another bleak salmon-fishing season, a holdover from the drought

March 6, 2017 — California salmon anglers are looking at another bleak fishing season, despite the remarkably wet winter – a lingering impact from the state’s five-year drought.

This week, state and federal fisheries regulators released their estimates for the numbers of adult fall-run Chinook salmon swimming off California’s coast. The news was even more grim than the drought-weakened numbers of fish last year.

An estimated 54,200 adult fall-run Chinook salmon reared in the Klamath River are swimming off the Pacific Coast – among the lowest number on record and down from 142,000 in 2016. Of the adult fish reared in the Sacramento River and its tributaries, biologists estimate there are 230,700 in the Pacific Ocean – 70,000 fewer than last year.

The reason for the declines? The adult fish set to return to Central Valley rivers to spawn were hatched two to four years ago, during the peak of California’s record-breaking drought when river and ocean conditions were abysmal.

Salmon from the Sacramento and Klamath river systems account for the vast majority of salmon caught by anglers in California’s rivers and along the coast. They’re considered critical to the state’s commercial and recreational salmon industries, which account for an estimated $1.4 billion in annual economic activity.

Scientists Improve Predictions of How Temperature Affects the Survival of Fish Embryos

December 7, 2016 — The following was released by NOAA:

Scientists closely tracking the survival of endangered Sacramento River salmon faced a puzzle: the same high temperatures that salmon eggs survived in the laboratory appeared to kill many of the eggs in the river.

Now the scientists from NOAA Fisheries and the University of California at Santa Cruz have resolved the puzzle, realizing new insights into how egg size and water flow affect the survival of egg-laying fish. The larger the eggs, they found, the greater the water flow they need to supply them with oxygen and carry away waste.

The results of the study were published in the scientific journal Ecology Letters. NOAA Fisheries is using the findings to improve protection of fish in the Sacramento River.

“Our model, based on a literature search of laboratory studies, predicted that temperatures in the upper Sacramento River since 1996 almost never got warm enough to cause mortality of salmon embryos,” said Benjamin Martin, NOAA Fisheries researcher and lead author of the study. “But data from field studies in the Sacramento River indicated that in some years, temperature-related mortality exceeded 75 percent, for example, in 2014-2015.”

Scientists often use laboratory studies to estimate how species will respond to elevated temperatures. The results from this study reveal that fish may respond to temperature differently in the field than in the lab. Understanding the causes for this difference may help researchers improve their predictions of how temperature affects fish eggs across different environments.

“We wanted to know why these salmon eggs have a much lower thermal tolerance in the field compared to the lab,” said Martin. “We hypothesized that the reason salmon eggs die in the river is because they don’t get enough oxygen.”

External temperatures govern the biological processes of salmon eggs and the embryos inside. As the water gets warmer their metabolism increases, demanding more and more oxygen. Unlike juvenile and adult fish, eggs cannot move and don’t have a developed respiratory or circulatory system. Instead they rely on flowing water to supply oxygen and carry away waste products.

Winter-run Chinook salmon are especially challenged when it comes to warmer water temperatures because their eggs are atypically large and require more oxygen exchange. Their egg size evolved to take advantage of cold water above Shasta Dam where they once spawned. However, the salmon now spawn in the warmer Sacramento River below the dam.

After further analysis of field data, scientists found a fundamental difference between conditions in the laboratory and conditions that effect eggs in the wild.

Laboratory studies estimating the temperature tolerance of the Chinook eggs included water flowing over the eggs at about two to three times faster than salmon eggs typically experience in the wild. The faster moving water provided more oxygen to the eggs in the laboratory, allowing them to survive higher temperatures.

The researchers borrowed concepts from physics to develop a model to determine how much oxygen flowing water can supply to fish eggs, depending on its velocity. The model predicted that the slower flowing water in the river would not supply the oxygen needed for egg viability in elevated temperature conditions. Field studies found that the slower flow in the river equated to about a 3 °C difference in the temperature tolerance of eggs, exactly what the model predicted.

This new model also provides an explanation for why fish species produce larger eggs in colder water. In general, the oxygen demand of eggs is proportional to their volume, while oxygen supply is proportional to the surface area of the egg, where the oxygen diffuses into the egg from the surrounding water. The surface area to volume ratio of an egg decreases with increasing egg size, which sets a limit on how large eggs can be and still get enough oxygen to survive. Since oxygen demand increases with temperature, fish species in warm water must make smaller eggs to match oxygen demand with supply. However this model also predicts that fish can produce larger eggs in warm waters when they are in high flow environments.

The researchers compiled data on 180 fish species and found that eggs in high flow environments, such as rivers, consistently produce larger eggs than expected for a given temperature. Some fish have even adapted to produce larger eggs in warm waters by using their tail to fan water over their eggs, which comes with a significant cost in terms of energy, time and risk of predation.

One important implication of this model is that warming conditions and declines in oxygen levels in aquatic systems may create evolutionary pressure for fish to produce smaller eggs in the future.

NOAA Fisheries has incorporated the new findings into agency guidance regarding the temperatures needed to support endangered Chinook salmon in the Sacramento River.

“This science helps us understand how seemingly small changes in river conditions can make a big difference for the salmon we’re trying to protect,” said Maria Rea, Assistant Regional Administrator for the California Central Valley Office. “This is a reminder that as much as we can learn in the laboratory, we have to always check that against what we see in the wild.”

Farmers Pitted Against Fishermen in House

July 13, 2016 — The plan to buoy historically low salmon populations imperiled by California’s historic drought made for a contentious hearing Tuesday on Capitol Hill. House Republicans accused federal agencies of depriving farmers of water while the Golden State’s reservoirs sit full.

The U.S. Fish and Wildlife Service and the National Maine Fisheries Service teamed up for the drought proposal debated at this morning’s hearing of the House Subcommittee on Water, Power and Oceans.

Though recent El Nino storms have left the state’s largest reservoirs full, the contentious plan calls for less water to be pulled from California’s largest reservoir, Shasta Lake, to preserve cold-water supplies needed to keep the Sacramento River at or below 56 degrees this fall.

Warm water in the Sacramento River has contributed to devastatingly high mortality rates of juvenile winter run Chinook salmon over the last several years, but the U.S. Bureau of Reclamation has complained that the plan could block federally contracted water deliveries without much warning.

Jeff Sutton, manager of the Tehama-Colusa Canal Authority in Northern California, told Congress the move would cripple harvests.

This year’s wet winter encouraged the planting of additional crops, Sutton said, with farmers expecting to receive their full-contracted water allotments for the first time in several years.

Read the full story at Courthouse News

California temporarily curbing water to spare vanishing fish

January 15, 2016 — SAN FRANCISCO (AP) — Saying current water conditions pose particular peril for the state’s tiny, disappearing Delta smelt, federal officials moved Thursday to temporarily reduce water deliveries for farmers and millions of other Californians.

Especially muddy water from winter storms is among the factors that risk sweeping some of the world’s few remaining Delta smelt off course and into giant water pumps that draw water from the Sacramento-San Joaquin river deltas, U.S. Fish and Wildlife officials said.

The pumps are part of federal and state water projects that provide water for up to 25 million Californians. Wildlife experts believe the pumps are one of the main threats to native fish, including the once-plentiful Delta smelt, now nearly extinct, and endangered runs of native salmon.

The federal wildlife service’s determination on Thursday means federal authorities will reduce water flows temporarily starting Friday, the U.S. Bureau of Reclamation said.

Read the full story from the Associated Press at the New Jersey Herald

Big Trouble Looms For California Salmon — And For Fishermen

November 6, 2015 — The West Coast’s historic drought has strained many Californians – from farmers who’ve watched their lands dry up, to rural residents forced to drink and cook with bottled water. Now, thanks to a blazing hot summer and unusually warm water, things are looking pretty bad for salmon, too – and for the fishermen whose livelihoods depend on them.

Preliminary counts of juvenile winter-run Chinook are at extreme low levels. These are salmon that are born during the summer in California’s Sacramento River and begin to swim downstream in the fall.

Unusually warm water in recent months has caused high mortality for the young salmon, which are very temperature sensitive in their early life stages. Most years, about 25 percent of the eggs laid and fertilized by spawning winter-run fish survive. This summer and fall, the survival rate may be as low as 5 percent, according to Jim Smith, project leader with the U.S. Fish and Wildlife Service’s Red Bluff office.

“That’s not good,” Smith tells The Salt.

Worse, it’s the second year in a row this has happened. Most Chinook salmon live on a three-year life cycle, which means one more year like the last two could essentially wipe out the winter run. To protect them, fishing for Chinook in the ocean may be restricted in the years ahead, when winter-run fish born in 2014 and 2015 have become big enough to bite a baited hook. The hope is that the few young fish that survived the recent warm-water die-offs will make it through adulthood and eventually return to the river to spawn.

Read the full story at New York Now