University of Washington Study: Pacific "Blob" Likely to Return in Five Years Time
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SEAFOODNEWS.COM [Peninsula Daily News] By Chris McDaniel - April 22, 2016The so-called “warm blob” that emerged in 2013 and 2014 off the Pacific Northwest and just recently dissipated is a recurring phenomenon — known as a marine heat wave — expected to return in five-year intervals, according to a recently released University of Washington study.Unusually warm oceans can have widespread effects on marine ecosystems, scientists say.Warm patches off the Pacific Northwest from 2013 to 2015, and a couple of years earlier in the Atlantic Ocean, affected everything from sea lions to fish migrations to coastal weather.The study — published in March in the journal Geophysical Research Letters — reviews the history of such features across the Northern Hemisphere.Happen at sea surface “We can think of marine heat waves as the analog to atmospheric heat waves, except they happen at the sea surface and affect marine ecosystems,” said the study’s lead author Hillary Scannell, a doctoral student in oceanography.“There are a lot of similarities.”Co-authors of the study are Andrew Pershing and Katherine Mills at the Gulf of Maine Research Institute, Michael Alexander at the National Oceanic and Atmospheric Administration and Andrew Thomas at the University of Maine. The study was funded by the National Science Foundation.Land-based heat waves, Scannell said, are becoming more frequent and more intense due to climate change.Scannell and her collaborators’ work suggests this also might be happening in the north Atlantic and Pacific oceans.Marine heat waves Their study found that marine heat waves have recurred regularly in the past but have become more common since the 1970s, as global warming has become more pronounced.The new paper looks at the frequency of marine heat waves in the North Atlantic and the North Pacific since 1950.Scannell did the work as a student earning a master’s degree at the University of Maine, where she was inspired by the 2012 record-breaking warm waters off New England.“After that big warming event of 2012 we keyed into it and wanted to know how unusual it was,” Scannell said.Warm blob The study also analyzes the “warm blob” that emerged in 2013 and 2014 off the Pacific Northwest.The authors analyzed 65 years of ocean surface temperature observations, from 1950 to 2014, and also looked at how these two recent events stack up.In general, the results show that the larger, more intense and longer-lasting a marine heat wave is, the less frequently it will occur.The study also shows that the two recent events were similar to others seen in the historical record, but got pushed into new territory by the overall warming of the surface oceans.An event like the northwest Atlantic Ocean marine heat wave, in which an area about the size of the U.S. stayed 2 degrees Fahrenheit above normal for three months, is likely to naturally occur about every five years in the North Atlantic and northwestern Pacific oceans, and more frequently in the northeast Pacific.The blob in the northeast Pacific covered an even larger area, with surface temperatures 2.7 degrees Fahrenheit above normal for 17 months, and is expected from the record to naturally happen about once every five years off the West Coast.El Niño years In the northeast Pacific, the record shows that marine heat waves are more likely during an El Niño year and when the Pacific Decadal Oscillation brings warmer temperatures off the west coast of North America.The blob likely got an extra kick from a possible transition to the favorable phase of the Pacific Decadal Oscillation, as well as from the overall warming of the ocean.“The blob was an unfortunate but excellent example of these events,” Scannell said.“As we go into the uncharted waters of a warming climate, we may expect a greater frequency of these marine heat waves.”Scannell also is a co-author of an earlier study published in February in which the authors define the term “marine heat wave” and specify the duration, temperature change and spatial extent that would meet their criteria. That study was led by researchers in Australia, who were curious about a warm event from 2010 to 2011 in the Indian Ocean.Streamlined definition “We’re working towards a more streamlined definition so we can more easily compare these events when they occur in the future,” Scannell said.Better understanding of marine heat waves could help prepare ocean ecosystems and maritime industries, she said.At the University of Washington, Scannell currently works with Michael McPhaden, an affiliate professor of oceanography and scientist at the National Oceanic and Atmospheric Administration looking at air-sea interactions along the equator and other factors that might create marine heat waves.
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Sardine numbers remain low, 2016 fishing remains closed
Stock assessment finds sardine biomass below cut-off level for directed fishing this yearLast weekend scientists and managers at the Pacific Fishery Management Council weighed the results of a new stock assessment of sardine populations off the West Coast. This new assessment, which was approved and adopted as best available science for management of sardine in the 2016-2017 fishing year, shows that sardine numbers remain low, and remain below the cut-off level where directed fishing for the species could again be allowed.
Based on this information, and the management framework in place for this stock, the Council voted to keep fishing for sardine closed for the second year in a row. As occurred last year, the Council voted to allow for small amounts of sardine taken (up to a total of 8,000 metric tons) as live bait harvest, Tribal harvest, incidental catch in other fisheries (such as mackerel and anchovy), and for scientific research studies.Directed commercial fishing for Pacific sardine is not allowed because the assessment estimated the spawning biomass to be approximately 106,000 metric tons. This is below the cut-off level of 150,000 metric tons, the lowest level at which directed fishing is allowed. This cut-off threshold, included in the Coastal Pelagic Species fishery management plan, is set three times greater than the level at which sardines are considered overfished. This approach limits fishing as the stock declines to help maintain a stable core population of sardines that can jump-start a new cycle of population growth.The stock biomass is the size of the adult sardine population of reproductive age (a year old and older) as measured by offshore surveys conducted by NOAA Fisheries in the last year. The estimate does not include very young fish that are not yet part of the spawning population.There are some indications of stronger sardine reproduction in the last year that could eventually lead to improvements in West Coast sardine numbers, scientists said. For example, surveys in 2015 counted increased numbers of small sardines off central California and similarly found young sardines along the Oregon-California Coast that would not be included in overall stock biomass estimates, and as such, would not be represented in the stock assessment. That indicates that sardines spawned along the West Coast last year and, if the young fish survive, they could add to the adult population in coming years.Although sardines usually spawn off central California in the spring, last year they apparently spawned farther north, off Oregon. That suggests that sardine spawning may have shifted, perhaps in response to unusual ocean conditions such as “the blob,” an expanse of warm water that dominated West Coast waters through much of 2014 and 2015, and the El Nino climate pattern now affecting the region.“The normal timing and distribution of sardine spawning has shifted dramatically as a result of warm water conditions the last three years and we did not catch them in their usual spawning areas at their regular time,” said Dale Sweetnam, deputy director of the Fisheries Resources Division at NOAA Fisheries’ Southwest Fisheries Science Center, which leads sardine surveys and stock assessments on the West Coast.Sardines are known for their wide-ranging “boom-and-bust” population cycles around the world. They have been in decline off the West Coast since a series of cool years from 2010 to 2014 reduced the survival of eggs and very young fish so that few survived to join the adult spawning population. The question now is whether recent warmer conditions may boost the survival of the large numbers of young fish so that more survive long enough to join the adult population.Two annual stock assessment surveys, one currently underway this spring and another one planned for this summer will help to answer that question.“We have had a few years of very unusual conditions on the West Coast, and we’re still learning what that means for sardines and many other species,” Sweetnam said. “Our best sources of information are the surveys that tell where the fish are and how well they’re surviving. Preliminary results this spring suggest that we did have good recruitment last year; however, the magnitude and extent of that recruitment will have to wait until we have completed the surveys.”
Read the original post: http://www.westcoast.fisheries.noaa.gov/
NOAA issues La Niña watch as tropical Pacific temperatures tank
El Niño is quickly fading. Sea surface temperatures are coming down in the tropical Pacific, and winds in the region have weakened. History tells us, and forecast models predict, that La Niña conditions will be quick on its heels.Seeing the writing on the wall, NOAA issued a La Niña watch on Thursday. “Nearly all models predict further weakening of El Niño, with a transition to ENSO-neutral likely during late spring or early summer 2016,” NOAA’s Climate Prediction Center wrote. “Nearly all models predict further weakening of El Niño, with a transition to ENSO-neutral likely during late spring or early summer 2016. Then, the chance of La Niña increases during the late summer or early fall.”La Niña is El Niño’s cooler counterpart in the tropical Pacific Ocean. Whereas El Niño exhibits abnormally warm ocean temperatures and a strong atmospheric circulation across the equator, La Niña represents abnormally cold water. The cooler sea surface temperature pattern enhances the circulation in the tropics, called the Walker circulation.The Walker circulation tends to dominate the weather across the equatorial Pacific. Air flows west toward Indonesia, where water is typically the warmest, and rises. This creates lots of thunderstorms and rain. During El Niño, this circulation is disrupted. The warmest water sloshes to the eastern side of the Pacific near South America. Air ends up rising closer to South America, and it sinks over Indonesia.
La Niña is the exact opposite. It sends the circulation into overdrive.“During La Niña events … when waters in the western Pacific are even warmer than normal and waters in the eastern Pacific are even colder, it is like someone turned the normal Walker Circulation ‘up to 11,'” writes climate.gov’s Tom Di Liberto. “Warm, moist air rises even more over the Maritime Continent and South America leading to above-average rainfall. In the eastern Pacific, where colder than average waters exist, an enhanced downward branch of the Walker Circulation helps to further reduce the region’s already small rainfall totals.”
In its forecast, Columbia University’s International Research Institute for Climate and Society has increased the likelihood of La Niña to 65 percent by early fall, and a 70 percent chance by next winter. This is up from 50 percent last month.NOAA will “declare” a La Niña when temperatures across the eastern side of the Pacific have cooled to a temperature departure of 0.5 degrees Celsius below normal, and when the Walker circulation strengthens like we would expect it to during a true La Niña.
Read the original post: https://www.washingtonpost.com/
Federal regulators: Don’t even think about fishing for these forage species
Fishing boats line the dock along Timms Way in San Pedro. West Coast fishery managers banned the take of any forage fish (pelagic squid, herring), in a decision ratified by federal officials with a final rule issued this week, in state waters. The species aren't fished currently, and this is a move to protect them, in the event their numbers increase and become enough to sustain a productive fishery. (Chuck Bennett / Staff Photographer)
Read the original post: http://www.dailybreeze.com/
Research Shows Global Warm Water "Blobs" Have Grown in Intensity Over Last Forty Years
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In late 2013, a portion of the North Pacific Ocean off the coast of Washington, British Columbia, and Alaska became unusually warm. Parts of it five to six degrees Fahrenheit warmer than normal.This continent-sized patch quickly became known as "The Blob." Its ability to warm the air above is blamed for two record fire seasons in Washington state in 2014 and 2015, a drought, and record low snowpack in the winter of 2014/2015.Nick Bond, Washington State's climatologist, says while the blob has pretty much dissipated, we are still feeling some of the hangover effects, as the water along the West Coast is still one to two degrees above normal.Turns out “The Blob” isn't that rare. And unlike another ocean phenomenon known as El Nino, it's not just found in the Pacific Ocean.In a new research paper published in the journal Geophysical Research Letters, University of Washington oceanographer and doctoral student Hillary Scannell looks back through 65 years of warming events in both the North Atlantic as well as the North Pacific oceans."They're becoming more extreme,” said Scannell from her campus office.Scannell is the lead author of "Frequency of marine heatwaves in the North Atlantic and North Pacific since 1950.” At the University of Maine, she studied a 2012 blob or heatwave that, among other things, affected the lobster fishery.The research finds that the number of longer term, deeper events started in the 1970s. Before that, “they weren't occurring at such a high-temperature average, so the range of variability was much smaller and lower than it is now,” said Scannell.
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CFOOD: Molly Lutcavage's Atlantic Tuna Findings Should be Embraced, Not Discredited as Industry Spin
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Copyright © 2016 Seafoodnews.com
Dr. Molly Lutcavage wrote a piece last week on Medium titled, Environmental Bullies, how conservation ideologues attack scientists who don’t agree with them. Though a summary follows, we encourage you all to read the article.Lutcavage discusses her paper published this month in the journal Proceedings of the National Academy of Sciences that has been making headlines in NPR, but also on smaller online platforms (like Medium).The paper presents evidence for a new spawning ground for Western Atlantic bluefin tuna that may suggest the species matures earlier and may be more resilient to harvesting than previously thought. The authors suggest that earlier age at maturity and additional spawning grounds likely means the stock biomass and sustainable exploitation rate are both higher than previously thought. Carl Safina and others have painted this finding as “controversial.”Dr. Lutcavage maintains this “news” should not have been considered controversial. As long ago as the early 1990’s Lutcavage and other scientists working with the New England Aquarium had counted up to one hundred thousand adult bluefin tuna from spotter planes, a total much higher than other estimates of the total stock size. Such findings contradicted Safina and his 1992 push to have Atlantic bluefin listed as Appendix I endangered because as he has said, bluefin is like, “the last buffalo, on the brink of extinction.”Dr. Lutcavage felt Safina and other NGOs like Pew Oceans have maligned her and her peers for their research because it would, “get in the way of fund-raising campaigns, messages to the media, book sales, rich donors, and perhaps the most insidious – attempts to influence US fisheries and ocean policies.”Comment by John Sibert, an emeritus professor at the School of Ocean and Earth Science and Technology at the University of Hawaii.I, like many other scientists, practice my profession with the expectation that my work will be used to improve management policies. However, scientists who choose to work on subjects that intersect with management of natural resources sometimes become targets of special interest pressures. Pressure to change or “spin” research results occurs more often than it should. Pressure arrives in many forms— usually as phone calls from colleagues, superiors, or the media; the pressure seldom arrives in writing.I have had a long career spanning several fields and institutions and have been pressured to change my views on restriction of industrial activities in intertidal zones in estuaries, on the necessity of international tuna fisheries management agencies, on the limited role of commercial fishing in the deterioration of marine turtle populations, on the lack of accuracy and reliability of electronic fish tags, and on the inefficacy of marine protected areas for tuna conservation.My most recent experience with pressure came from a stringer who writes for Science magazine. Some colleagues and I had just published a paper that analyzed area-based fishery management policies for conservation of bigeye tuna. Although the paper was very pessimistic about the use of MPAs for tuna fishery management, this particular stringer contacted me about MPAs. We had an exchange of emails in which he repeatedly tried to spin some earlier results on median lifetime displacements of skipjack and yellowfin tuna into an argument supporting creation of MPAs. We then made an appointment to talk “face to face” via Skype. His approach was to play word games with my replies to his questions in order to make it seem that my research supported MPAs. I repeatedly explained to him that our research showed that closing high-seas pockets had no effect whatsoever on the viability of tuna populations and that empirical evidence showed that the closure of the western high seas pockets in 2008 had in fact increased tuna catches. We hung up at that point, and I have no idea what he wrote for Science.When critics run out of fact, some resort to personal attack. During discussions about turtle conservation in the early 2000s, an attorney for an environmental group told a committee of scientists that we were in effect a bunch of fishing industry apologists with no knowledge of turtles or population dynamics. More recently, my friend and collaborator, Molly Lutcavage was recently subject of a personal attack by Carl Safina after she and her colleagues published an important discovery of a new spawning area for Atlantic Bluefin Tuna. This discovery ought to push the International Commission of the Conservation of Atlantic Tuna to abandon its simplistic two stock approach to management of ABFT. (Whether ICCAT will actually change its approach is another question.) Safina made the outrageously false assertion that the authors’ “… main concern is not recovery, not conservation, but how their findings can allow additional exploitation.” Instead of attacking the messenger and implying that Lutcavage and her colleagues are industry tools, Safina should have embraced the science, supported tuna conservation, and applied pressure in ICCAT to change its antiquated management. By attempting to smear Lutcavage and her NOAA colleagues, he demeans science in general and those of us who try to apply scientific approaches to resource management in particular.
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Ocean acidification takes a toll on California's tide pools at nighttime
A new study, based on the most extensive set of measurements ever made in tide pools, suggests that ocean acidification will increasingly put many marine organisms at risk by exacerbating normal changes in ocean chemistry that occur overnight. Conducted along California's rocky coastline, the study shows that the most vulnerable organisms are likely to be those with calcium carbonate shells or skeletons.Ocean acidification is occurring as the oceans absorb increasing amounts of carbon dioxide from the atmosphere, where carbon dioxide concentrations are steadily rising due to emissions from the burning of fossil fuels. Absorption of carbon dioxide changes seawater chemistry, pushing it toward the lower, acidic end of the pH scale, although it remains slightly alkaline. A small decrease in pH affects the chemical equilibrium of ocean water, reducing the availability of carbonate ions needed by a wide range of organisms to build and maintain structures of calcium carbonate, such as the shells of mussels and oysters.Kristy Kroeker, assistant professor of ecology and evolutionary biology at UC Santa Cruz, is a coauthor of the new study, published March 18 in Scientific Reports. "There is a lot of concern about how ocean acidification is going to affect marine species in the future, but most of our understanding comes from laboratory studies where a single organism is exposed to acidified seawater under very controlled conditions for a short period of time," Kroeker explained. "In reality, every organism is embedded in a complex community that experiences dynamic environmental conditions that will gradually change over time."
An extensive set of measurements recorded daily swings in the chemistry of seawater in tide pools.
Calcifying organismsIn the new study, researchers closely monitored conditions in tide pools along California's rocky coast, which are isolated from the open ocean during low tides. During the daytime, photosynthesis—the mechanism by which plants use the sun's energy to convert carbon dioxide and water into sugar, giving off oxygen in the process—takes up carbon dioxide from the seawater and acts to reverse ocean acidification's effects. At night, however, photosynthesis stops, while the respiration of plants and animals takes up oxygen and releases carbon dioxide. This adds carbon dioxide to the seawater and exacerbates the effects of ocean acidification, increasing the risk to calcifying organisms."Tide pools are home to lots of different species that regularly experience daily swings in chemistry," Kroeker said. "Tide pools can experience particularly corrosive seawater during nighttime low tides, when all of the animals are 'exhaling' carbon dioxide into the water that has been cut off from the ocean."The research team, led by scientists at the Carnegie Institution of Science, used these natural nighttime spikes in corrosive conditions to examine how entire communities of marine species respond to natural acidification. Observing a variety of California's natural rocky tide pools near the Bodega Marine Laboratory, they found that the rate of shell and skeletal growth was not greatly affected by seawater chemistry in the daytime. However, during low tide at night, water in the tide pools became corrosive to calcium carbonate shells and skeletons. The study found evidence that the rate at which these shells and skeletons dissolved during these nighttime periods was greatly affected by seawater chemistry."Unless carbon dioxide emissions are rapidly curtailed, we expect ocean acidification to continue to lower the pH of seawater," said lead author Lester Kwiatkowski of the Carnegie Institution of Science. "This work highlights that even in today's temperate coastal oceans, calcifying species, such as mussels and coralline algae, can dissolve during the night due to the more acidic conditions caused by community respiration."These results highlight the vulnerability of marine species in even the most dynamic conditions to the global process of ocean acidification, Kroeker said.According to coauther Ken Caldeira of the Carnegie Institution, "If what we see happening along California's coast today is indicative of what will continue in the coming decades, by the year 2050 there will likely be twice as much nighttime dissolution as there is today. Nobody really knows how our coastal ecosystems will respond to these corrosive waters, but it certainly won't be well."The study was a collaborative effort by the Carnegie Institution for Science, UC Davis, and UC Santa Cruz. This work was funded by the Carnegie Institution for Science, UC Multi-campus Research Initiatives and Programs, and the National Science Foundation.
Read the original post: http://news.ucsc.edu/
Dungeness Crab Fishery
Recreational Dungeness Crab Fishery Open South of Sonoma/Mendocino County Line, Commercial Fishery to Open in Seven DaysClosure of the recreational Dungeness crab fishery south of the Mendocino/Sonoma county line has been lifted, and opening of the commercial Dungeness crab fishery - delayed since November - is set for March 26 in the same region.Recent test results show that domoic acid levels in crabs off the California coast south of the Mendocino/Sonoma county line no longer pose a significant human health risk, according to notice given today to the California Department of Fish and Wildlife (CDFW) and the Fish and Game Commission (Commission) by the director of the Office of Environmental Health Hazard Assessment (OEHHA), after consultation with the Director of the California Department of Public Health (CDPH).As a result, the director of OEHHA recommends opening the Dungeness crab fishery in this area. Under emergency closure regulations, CDFW will provide commercial Dungeness crab fishermen at least seven days' notice before the re-opening of the commercial fishery south of the Mendocino/Sonoma county line. The fishery will open at 12:01 a.m. Saturday, March 26. The presoak period, during which commercial fishermen may begin setting gear in place, starts at 6:01 a.m. Friday, March 25.Closures remain in place north of the Mendocino/Sonoma county line for the Dungeness crab commercial and recreational fisheries. The commercial and recreational rock crab fisheries are closed north of Piedras Blancas Light Station near San Simeon, and in state waters around San Miguel, Santa Rosa and Santa Cruz islands.The unusually high domoic acid levels off the coast this fall and winter wrecked a Dungeness crab fishery worth as much as $90 million a year to California's economy. Domoic acid is a potent neurotoxin that can accumulate in shellfish, other invertebrates and sometimes fish. At low levels, domoic acid exposure can cause nausea, diarrhea and dizziness in humans. At higher levels, it can cause persistent short-term memory loss, seizures and may even be fatal."This has been a very difficult season for hardworking Californians who have suffered significant financial hardship due to this natural disaster," said Charlton H. Bonham, Director of CDFW. "We thank the affected communities for their patience and fortitude as we have worked with our partners at CDPH and OEHHA to open a portion of the commercial fishery along a traditional management boundary as recommended by the industry."Both the commercial and recreational Dungeness crab seasons are scheduled to end June 30 in the newly opened area, although the CDFW director has authority to extend the commercial season.In February, Governor Edmund G. Brown Jr. sent a letter to U.S. Secretary of Commerce Penny Pritzker seeking federal declarations of a fishery disaster and a commercial fishery failure in response to the continued presence of unsafe levels of domoic acid and the corresponding closures of rock crab and Dungeness crab fisheries across California. Should a federal determination be made to declare a disaster and failure, the state and federal agencies will work together to determine the full economic impact of the disaster and, upon appropriation of funds from Congress, provide economic relief to affected crabbers and related businesses.Despite several weeks of test results that showed crab body meat samples below alert levels, one sample of viscera was slightly above the alert level. Because of this, CDPH and OEHHA strongly recommend that anglers and consumers not eat the viscera (internal organs, also known as "butter" or "guts") of crabs. CDPH and OEHHA are also recommending that water or broth used to cook whole crabs be discarded and not used to prepare dishes such as sauces, broths, soups or stews. The viscera usually contain much higher levels of domoic acid than crab body meat. When whole crabs are cooked in liquid, domoic acid may leach from the viscera into the cooking liquid. This is being recommended to avoid harm in the event that some crabs taken from an open fishery have elevated levels of domoic acid.With the upcoming partial opening of the commercial fishery in the state, CDFW recommends that all people fishing for crab refer to the Best Practices Guide, a resource providing tips on how to use crab trap gear in a manner that reduces incidences of whale entanglements. This guide was produced collaboratively by commercial crabbers, agency staff and staff from non-profit organizations during two meetings of the Dungeness Crab Fishing Gear Working Group that took place late last year.Pursuant to the emergency regulations adopted by the Commission and CDFW on November 5 and 6, 2015, respectively, the current open and closed areas are as follows:Areas open to crab fishing include:• Recreational Dungeness crab fishery along mainland coast south of Sonoma/Mendocino county line - 38° 46.1' N latitude, near Gualala, Mendocino County• On March 26, 2016 commercial Dungeness crab fishery along mainland coast south of Sonoma/Mendocino county line - 38° 46.1' N latitude, near Gualala, Mendocino County• Commercial and recreational rock crab fishery along the mainland coast south of 35° 40' N latitude (Piedras Blancas Light Station, San Luis Obispo County)Areas closed to crab fishing include:• Recreational Dungeness crab fishery north of Sonoma/Mendocino county line - 38° 46.1' N latitude, near Gualala, Mendocino County• Commercial Dungeness crab fishery north of Sonoma/Mendocino county line - 38° 46.1' N latitude, near Gualala, Mendocino County• Commercial and recreational rock crab fisheries north of 35° 40' N latitude (Piedras Blancas Light Station)• Commercial and recreational rock crab fisheries in state waters around San Miguel, Santa Rosa and Santa Cruz Islands.CDFW will continue to closely coordinate with CDPH, OEHHA and fisheries representatives to extensively monitor domoic acid levels in Dungeness and rock crabs to determine when the fisheries can safely be opened throughout the state.
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