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CFOOD: New Study Sheds Light on Relationship Between Forage Fish, Predators, and Fishing

April 18, 2017 -- The following was published by CFOOD. Founded by Dr. Ray Hilborn from the University of Washington, CFOOD is a network of scientists formed to study the science of fisheries sustainability, and to correct erroneous stories about fisheries in the mainstream media:A paper published earlier this month shows a new understanding of how commercially fishing forage fish impacts forage fish predators like sea birds, marine mammals, and pelagic finfish.Forage fish are small, silvery, bottom-of-the-food-chain fish that eat plankton and small invertebrates. They are eaten by seemingly everything in the ocean, providing “forage” for many other animals—you’ve probably heard of the two most common forage fish: sardines and anchovies. If asked their favorite marine species, not many people would choose a forage fish, but many would choose a forage fish predator: Penguins and puffins are endearing, dolphins and seals are adorable, and tuna and swordfish are delicious. Forage fish help sustain these populations, but are also favorite foods for many cultures.With a high oil and protein content, forage fish are also the perfect species for conversion to fishmeal and fish oil. The largest fishery in the world, Peruvian anchovy, is such a fishery. Fish oil provides essential fatty acids and is sold in drugstores as a nutritional supplement. Fishmeal is food for several of our favorite edible animals. It is especially important in farmed fish production (like most of the salmon eaten in the US), but is also fed to terrestrial livestock like cows and pigs. Essentially, forage fish fisheries take a renewable resource and turn them into protein that people eat.But how do these fisheries affect the marine predators that feed on forage fish? This is an important question that has only recently been investigated. A paperpublished in 2012 used mathematical models to estimate the impact of fishing forage fish populations on their predators and recommended that commercial reduction fishing be cut by 50-80% to ensure forage fish predators get enough food. However since then, several papers—including some by the authors of the original—have recognized that the models used in the 2012 research were not suitable for the questions asked, and further studies are needed.The latest, Hilborn et al. (2017) published earlier this month (open access), shows that environmental variability, left out of the original models, is actually the most important factor affecting forage fish populations. Commercial fishing often has little effect on forage fish populations and their predators. Instead, ocean conditions and nutrient cycles (things humans have no control over) dictate how many forage fish survive each year.The new paper also suggests that the relationship between forage fish and their predators is complicated by several factors. Forage fish predators often rely on specific, high-density locations where the abundance may be largely unrelated to the total abundance of the population. Basically, instead of predators relying on the total number of forage fish, they rely on forage fish appearing in certain locations, such as near breeding areas. Predators are also not singularly reliant on commercially harvested forage fish to survive—most consume a wide variety of prey. Indeed, Hilborn et al. (2017) found no link between larger forage fish populations and increases in predator populations.Forage fish provide a wonderful service to humans. They are tasty, nutritious, and their harvest provides food for animals that we enjoy and eat, both above and below the surface. Understanding their ecological role is important to ensure sustainability.


Read the story at CFOOD | Watch a video about the study here

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Study of Central Coast marine reserves finds signs of fish recovery

Researchers say more time is needed for fish populations to flourish

MorroBayFishermensWharfTourists stop to watch fish being unloaded at the Morro Bay Fishermen's Wharf.DAVID MIDDLECAMP — dmiddlecamp@thetribunenews.com

 Fish populations have shown signs of rebounding in state marine protected areas off California's Central Coast, but more time is needed for them to flourish, according to a recent study conducted by Cal Poly and the California Sea Grant.The study was published in March in Plos One, a peer-reviewed journal by the Public Library of Science.The study examined the first seven years of monitoring of fish within four marine protected areas (MPAs) between San Francisco and Morro Bay.Fishing within MPAs is generally prohibited or severely limited to allow refuges for fish species that are harvested commercially.MPAs make up about 18 percent of the state water territory.“These marine reserves are going to work, but they’re not a short-term solution for commercial fisheries,” said the study’s lead author, Rick Starr, director of the California Sea Grant’s Extension Program.Starr said that fish populations go up and down based on environmental conditions, and they’ve not detected much difference in populations inside and outside the protected areas.“In the seven years of data examined, we didn’t see much change that could be attributed to the MPA status,” Starr said.That could be partly due to reduced fishing pressure through regulations in non-protected areas, the scientists said.However, Starr believes more time is needed to assess the newer MPAs.In comparison, the much older Point Lobos State Marine Reserve, protected since 1973, is thriving with an abundance of fish.Cal Poly biological resources researcher Dean Wendt, a co-author of the study, said about 20 fish per hour can be caught recreationally in Point Lobos near Monterey — compared to about seven fish per hour in the MPAs Año Nuevo (north of Santa Cruz), Piedras Blancas (between Morro Bay and Monterey) and Point Buchon (near Morro Bay). That’s an indicator that the Point Lobos zone is far more populated.

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A director with the Morro Bay Commercial Fishermen’s Organization, Jeremiah O’Brien, said that he has appreciated the collaboration between fishermen and scientists in the research.But O’Brien said he’s skeptical about the type of ocean management that blocks off large areas off the coast from fishing.“These MPAs were mandated by many who know nothing about fishing and less about ocean issues,” O’Brien said. “There are many management tools available, and this is a poor choice. Seven years and there is no difference — one would think that there would be some noticeable change no matter how small.”O’Brien, however, added that “we have a lot of respect for Dean Wendt, and he always tries to include commercial fisherman in his work.”

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Starr and Wendt, who is dean of research in Cal Poly’s biological sciences department, coordinated with a team of marine researchers and more than 700 volunteer fishermen to sample fish within and outside of the protected areas.The scientists attribute the study results to several factors, including the longer life and reproductive cycles of cold-water California fish, including some that live to be more than 50 years old and can take several years to reproduce.However, lingcod, which take 3 to 5 years to mature, have seen increases in population within the MPAs, Wendt said.Fish recruitment — meaning how well local juvenile fish are surviving — is another factor.In some years, conditions can be right for juvenile fish to significantly add to the population, while in other years ocean currents channel them farther out to sea, where they die. In El Niño years, juvenile fish don’t have enough to eat.Rockfish recruitment is particularly sporadic, meaning it can be more difficult to gauge how well the MPAs are working.The idea behind the MPAs is that eventually the protected zones will contribute to a “spillover” effect in which species move from the protected areas to surrounding ocean vicinities to help grow populations.


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Sardine Assessment Shows Cyclic Decline in Population

Pacific sardines are known for wide swings in their population: the small, highly productive species multiplies quickly in good conditions and can decline sharply at other times, even in the absence of fishing. Scientists have worked for decades to understand those swings, including a decline in the last few years that led to the Pacific Fishery Management Council's The previous link is a link to Non-Federal government web site. Click to review NOAA Fisheries Disclaimer recommendation on April 13th to suspend commercial sardine fishing off the West Coast for the first time in decades..An updated stock assessment The previous link is a link to Non-Federal government web site. Click to review NOAA Fisheries Disclaimer by NOAA Fisheries’ Southwest Fisheries Science Center (SWFSC) was the basis for the Council's action. Stock assessments are research tools that estimate the status and size of the sardine population. The Council uses the assessments to set fishing quotas.Models that support the sardine assessment combine NOAA data on past and current abundance of sardine eggs, larvae and mature fish with other data on sardine biology and fishery catches. The data on sardine abundance come from two SWFSC research vessel surveys conducted off the West Coast each year.These surveys employ two methods to estimate the current size of the sardine population. They use underwater acoustic equipment (like sonar) to estimate the size of fish schools, followed by the use of trawl nets to verify the species comprising the schools. Additionally, the surveys employ devices that measure the density of sardine eggs in the water as a gauge of sardine spawning. Scientists can then calculate how large the spawning population must be to produce the measured density of sardine eggs.These data feed a computer model to estimate sardine population trends and provide the foundation for projections of the total population of sardines off the West Coast in the next fishing year.“The assessment produced this year suggests that cool ocean water temperatures off the West Coast beginning around 2007 may have reduced the survival of juvenile sardine resulting in a population decline”, said Kevin Hill, a fisheries biologist who oversees the stock assessment for the SWFSC. The number of surviving young fish appears to have dropped to the lowest levels in recent history and has likely remained low in 2014. This has led to a steady decline in the fishable sardine stock biomass, which is defined as the total volume of sardines at least one year old. This is the measure the Council relies on when setting fishing quotas.“The environment is a very strong driver of stock productivity. If ocean conditions are not favorable, there may be successful spawning, but fewer young fish survive to actually join the population,” Hill said. “Small pelagic fish like sardine and anchovy undergo large natural fluctuations even in the absence of fishing. You can have the best harvest controls in the world but you’re not going to prevent the population from declining when ocean conditions change in an unfavorable way.”The current decline adds to a series of ups and downs that illustrate the boom-and-bust nature of sardine populations. The sardine biomass rose from about 300,000 metric tons in 2004 to a high point of more than 1 million in 2008 and is predicted to decrease to an estimated 97,000 metric tons by this coming July.Because of these swings in sardine populations, the Council’s management framework for sardines includes built-in mitigation measures and safeguards to exponentially reduce fishing pressure as the stock declines.  One of these Council measures is a cessation in directed fishing on sardines when the biomass falls below 150,000 metric tons. “The fishing cutoff point is included in the guidelines adopted by the Council and is designed to maintain a stable core population of sardines that can jump-start a new cycle of population growth when oceanic conditions turn around,” Hill said.In the course of reviewing the 2015 updated assessment, it became evident that the final model used in the 2014 assessment did not correspond to the best fit to the data. The data were reanalyzed and a better fit to the 2014 model was achieved. This re-examination resulted in a lower 2014 biomass estimate of 275,705 metric tons, down from the previous estimate of 369,506 metric tons, which is still above the fishing cutoff value of 150,000 metric tons.The revised model applied to the 2015 assessment resulted in a biomass estimate of 97,000 metric tons, which is below the fishing cutoff.  As a result, the Council decided to close the 2015-2016 sardine fishing season and requested that NOAA Fisheries close the remainder of the 2014-2015 sardine fishing season. The sardine population is presently not overfished and overfishing is not occurring; however, the continued lack of recruitment observed in the past few years could decrease the population, even without fishing pressure.The NOAA Ship Bell M. Shimada is currently conducting a new sardine survey off the West Coast to collect updated information on the size and location of the sardine stock. In addition, a large-scale 80-day survey this summer will collect data on sardine and whiting (hake) populations from the Mexican border to Canada. This new information will support the next stock assessment SWFSC prepares for the Council and NOAA fisheries managers.Learn more:Pacific sardine stock assessmentExecutive summary The previous link is a link to Non-Federal government web site. Click to review NOAA Fisheries Disclaimer Full report  The previous link is a link to Non-Federal government web site. Click to review NOAA Fisheries Disclaimer In the Field: Spring Sardine Survey 2015Pacific Fishery Management Council Coastal Pelagic Species The previous link is a link to Non-Federal government web site. Click to review NOAA Fisheries Disclaimer California Cooperative Oceanic Fisheries Investigations (CalCOFI)Video – Coastwide Sardine SurveyGreen Seas Blue Seas – Interactive Guide to the California Current For more information, please contact: Michael.Milstein@noaa.gov or Jim.Milbury@Noaa.gov (West Coast Regional Office Public Affairs), Dale.Sweetnam@noaa.gov (Southwest Fisheries Science Center) and Joshua.Lindsay@noaa.gov (West Coast Regional Office)


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Trawling has “negligible” effect on soft-bottom

petralesolePetrale sole, a flatfish caught by trawling on soft-bottom seafloor. Credit: The Nature Conservancy

A groundbreaking new study recently conducted by California fishermen, The Nature Conservancy and CSU Monterey Bay indicates that bottom trawling only has a “negligible effect” on the seafloor and fish habitat in certain types of soft sea bottom.Trawling is continually criticised by environmental advocates for the damage it causes to rocky marine habitats and the long-lived animals that occur in them. However, important questions remain about the extent of any damage to sandy and muddy environments.During the three-year study, fishermen trawled patches of the ocean floor off Morro Bay. Those areas were analysed by underwater photos and video and compared with nearby areas that were untouched.Their peer-reviewed work, published in the Fishery Bulletin, found that California’s largely soft-bottom seafloor saw little lasting impacts from trawling with a small-footrope trawl.The researchers say that their study adds to a growing body of literature from around the world showing trawling impacts are context-dependent - the impacts depend on the type of gear used, the types of habitats trawled and how often trawling occurs.The scientists point out that their study does not imply that all soft-bottom habitats should be open to trawling; but, with new research and technology, "we can fine-tune our fishery regulations to protect truly vulnerable habitats."One of the researchers, Dr. James Lindholm has been studying marine ecosystems for 20 years and this autumn he will conduct a similar experiment off Half Moon Bay using trawling nets of different sizes. Commercial fishermen will also be involved.


Read the original post: www.worldfishing.net

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Dungeness landings likely down 50% in California, 40% in Oregon; lowest volumes in 8 years

Posted with permission of SEAFOODNEWS.COM | by John Sackton December 11, 2014 

The crabs are great.  Its just that there aren't that many of them.

The Oregon Dungeness fishery opened on time on December 1st, after a short season in the San Francisco Bay area, called district 10.

But boats are simply not finding many crabs.

dungeness-estimateGraph: Seafood Datasearch, based on state and federal data

One fishermen, describing the northern California / Oregon fishery which opened December 1st, said "North of District 10 was the worst opener I can remember.  We knew it would be bad, but not this bad."

Larger vessels that have the ability to move to other fisheries are now leaving the crab fishery, as the catch rates can no longer support their operations.

Meanwhile, the price at the dock has risen to $3.50, and most packers have extended that retroactively back to December 1st, when the fishery opened with an initial price of $3.10.

The upshot is that harvesters are now predicting the Oregon fishery to be down about 40% from last years 14.3 million pounds, and California is likely to be down 50%.

This means that coast wide, certainly for December and Janaury, it is looking like the lowest total landings for dungeness in the last eight years.

Hugh Link, Executive Director of the Oregon Dungeness Crab Commission, said fishermen keep records and know if they are up or down year over year, and that he definitely has the sense that there are fewer Dungeness crabs coming into pots this year, even though fish tickets are still being tallied from the first few days of the season.

Meat fill has been excellent, the fishery opened on time, and there was agreement on price. Only the crabs have not shown up.

The fishery is highly cyclical, so it is quite likely in a few years we will again be talking about heavy supplies of Dungeness.  But for this year, the section and crabmeat supplies will be very tight, and what crab is landed later in the year should be going mainly to the live market.


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Morro Bay's fishing industry reels in largest catch in 20 years

6.8 million pounds of fish landings were reported in 2013 in Morro Bay, up from low of 668,866 pounds in 2007, study of data from Department of Fish and Wildlife reveals

By Nick Wilson | November 6, 2014

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The fishing industry in Morro Bay has regained its sea legs, bouncing back from a 20-year low in 2007 to post its largest catch by volume since 1993, according to an economic impact report released this week.Lisa Wise Consulting Inc. compiled the study, which showed a boost in earnings of more than 300 percent from about $2 million in 2007 to about $7.1 million in 2013 — the latest year of data accumulated.The report documents a rise in fish landings from a low of 668,866 pounds in 2007 to nearly 6.8 million pounds in 2013, the highest single-year landing total since the boom times of the early ’90s.The report relies on figures documented under government regulations, including information provided by the fishing industry to the Marine Fisheries Statistical Unit at the California Department of Fish and Wildlife.This is the fourth consecutive year of the report, which was produced this year with $6,000 in funding provided by the Central California Joint Cable/Fisheries Liaison Committee. The Morro Bay Commercial Fishermen’s Organization also partners in the project. “As fishermen, we have an understanding of the industry, but others often don’t,” said Jeremiah O’Brien, a member and past president of the Morro Bay Commercial Fishermen’s Organization. “We do those reports to show people what’s happening.”Lots of good newsThe latest data shows a steady trend of increased earnings and landings, although the figures haven’t yet matched peak years of the 1990s, which topped 9 million pounds of landings in 1990 and eclipsed 10 million in 1993.In 2008, the city of Morro Bay paid for an economic study that predicted a change from a once-thriving fishing industry to a primarily recreational fishing and boating area.However, the city has since recognized the recovery of the commercial fishing industry, which “should continue to play a significant role in the social and economic future of Morro Bay,” staff members wrote in a recent report.One of the factors that contributed to the decade-long decline in Morro Bay’s fishing industry — in additional to environmental closures and restrictions of fishing in certain ocean areas — occurred in 2006 with the purchase of Morro Bay’s fishing quota.The Nature Conservancy bought out Morro Bay’s entire trawl fishing industry in 2006 with the goal of protecting and growing fish populations while limiting fishing.About eight trawlers left the business, which exacerbated the decline in landings in those years, O’Brien said.Since that time, the local industry has steadily improved, and earlier this year, the Conservancy transferred the quotas to the Morro Bay Community Quota Fund, which manages the fishing quota and leases fishing permits to local fishermen, who may trawl under specified environmental restrictions such as avoiding trawling in coral reef areas.How the catch evolvedWhile the overall catch and earnings have climbed in recent years, landings of certain species have declined along with closures and regulations on uses of fishing equipment.The salmon catch, for example, dropped to 45,000 pounds in 2013, from around 200,000 pounds per year in much of the 1990s.And halibut, which must be fished outside of three miles from shore, has remained low for the past decade with a total of about 10,328 pounds landed in 2013 compared with takes of more than 40,000 pounds in the early 1990s.But other species — including Dungeness crab and squid — have spiked.Crab accounted for 17 percent of 2013 earnings in Morro Bay, climbing to a 20-year high of more than 300,000 pounds in landings.There were 170,000 pounds of crab caught in 2006, which was the previous high in the past two decades. There was little to no crab caught between 2008 and 2011.“The last couple of years we’ve seen a lot more crab,” O’Brien said. “Crab is typically cyclical, and we’ll have bigger catches usually about every six years. But they’ve been spawning in big numbers the past three in a row.”The squid catch has also swelled, with landings of more than 4 million pounds in 2013.That total hasn’t been matched since 1993, the only other year in the past two decades to top 4 million pounds of squid.O’Brien said that a couple of fishing boats have made the investment in catching large numbers of squid along the Central Coast, which has kept squid processing companies from Watsonville and San Pedro, the closest around, returning to Morro Bay because it’s worth their while.Another factor in the boom in local crab and squid fishing has been a trending preference for the seafood in China, where local buyers are shipping their products.Local fishermen including Bill Blue have seen their sales of live crab, transported to China, significantly boost income over the past few years.Like fellow anglers, Blue fishes for a variety of species, including black cod, but the high price that crab fetches in China is too lucrative to pass up.“It’s good for business, but sad in some ways because you don’t see as many local restaurants buying crab because of the high price (driven by the Chinese market),” Blue said. “That means local people can’t go and get them as easily.”


 Read original story here: http://www.sanluisobispo.com/2014/11/06/3337295/morro-bays-fishing-industry-reels.html

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Eastern Pacific bluefin tuna catch to be cut 40 percent to 3,300 tons

SEAFOODNEWS.COM [Jiji Press] - October 31, 2014posted with permission of Seafood News.The Inter-American Tropical Tuna Commission, comprising a total of 21 countries and regions, has decided to tighten controls on bluefin tuna fishing in the eastern Pacific.The decision was made at a special session of the commission in La Jolla, Calif., on Wednesday, according to Japanese officials.Bluefin tuna catches in the ocean region will be reduced by 40 percent from the 2014 level to 3,300 tons in both 2015 and 2016.The commission also set a nonbinding goal of cutting the proportion of young tuna weighing less than 30 kilograms in total catches to 50 percent.The nonbinding goal was set as a compromise after Mexico opposed a Japanese proposal for halving annual catches of young tuna in and after 2015 from the average level between 2002 and 2004. In the central and western Pacific, including waters around Japan, the halving of young tuna catches has already been agreed.Mexico has developed a tuna ranching sector dependent on capture of juvenile tuna used for growout.


 Read original article: SeafoodNews.com

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