Hilborn Study Redifines Forage Fish Predator Relationships; Suggests Fishing Pressure Lesser Factor
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New research published today in the journal Fisheries Research finds that fishing of forage species likely has a lower impact on predators than previously thought, challenging previous studies that argued forage fish are more valuable left in the ocean.In 2012 a Lenfest study got wide play claiming that models showed fishing pressure on prey species had big impacts on the abundance of predator species, such as cod and tuna. However, some of the authors of the original model have now joined with other researchers to say it is out of date.A team of seven respected fisheries scientists, led by Prof. Ray Hilborn, Ph. D., of the University of Washington, found that predator populations are less dependent on specific forage fish species than assumed in previous studies including a 2012 study commissioned by the Lenfest Ocean Program is managed by The Pew Charitable Trusts. The Lenfest Forage Fish Task Force argued that forage fish are twice as valuable when left in the water to be eaten by predators, and recommended slashing forage fish catch rates by 50 to 80 percent.For fisheries management, such a precautionary approach would have a large impact on the productivity of forage fisheries. As groups such as IFFO (The Marine Ingredients Organisation) have noted, these stocks contribute strongly to global food security, as well as local and regional social and economic sustainability.However, the new research found multiple omissions in the methodology of the Lenfest study. “When you review the actual models that were used [by Lenfest], there are a few key elements on the biology of these animals that were not represented, ” said Dr. Ricardo Amoroso, one of the study’s co-authors. He added that one of the authors’ approaches was to “look for empirical evidence of what is actually happening in the field. ” Previous studies relied on models which took for granted that there should be a strong link between predators and prey.Specifically, the Lenfest study and another study using ecosystem models ignored the natural variability of forage fish, which often fluctuate greatly in abundance from year to year. It also failed to account for the fact that predators tend to eat smaller forage fish that are largely untouched by fishermen. Because of these oversights, the new study concluded that the Lenfest recommendations were overly broad, and that fisheries managers should consider forage species on a case-by-case basis to ensure sound management.“It is vital that we manage our fisheries to balance the needs of the ecosystem, human nutrition and coastal communities, ” said Andrew Mallison, IFFO Director General. “These findings give fishery managers guidance based on science, and update some of the inaccurate conclusions of previous reports. ”The Lenfest findings were largely based on a model called EcoSim, developed by Dr. Carl J. Walters, one of the co-authors of the new paper. Dr. Walters found that the EcoSim models used in earlier studies had omitted important factors, including natural variability, recruitment limitations and efficient foraging of predators.Dr. Walters noted that there were “very specific” issues with previous uses of the EcoSim model. “It was predicting much higher sensitivity of creatures at the top of the food webs to fishing down at the bottom than we could see in historical data, ” he said.This is not the first time ecosystem models used in earlier studies have been questioned. One year after the Lenfest study was completed, two of its authors, Dr. Tim Essington and Dr. Éva Plagányi, published a paper in the ICES Journal of Marine Science where they said, “We find that the depth and breadth with which predator species are represented are commonly insufficient for evaluating sensitivities of predator populations to forage fish depletion. ” The new study reaffirmed this finding, noting “several reasons to concur with the conclusion that the models used in previous analysis were insufficient. ”In addition to its critiques of previous research, the researchers found further evidence of the lack of fishing impact on forage fish. Their research indicated that environmental factors are often much more important drivers of forage fish abundance. They also found that the distribution of forage fish has a greater impact on predators than simply the raw abundance of forage fish.The authors concluded by noting the importance of forage fish as a part of human food supply chains, praising their high nutritional value, both through direct human consumption and as food in aquaculture, as well as the low environmental impact of forage fishing. Cutting forage fishing, as recommended by the Lenfest group, would force people to look elsewhere for the healthy protein and micronutrients provided by forage fish – likely at much greater environmental cost, the authors wrote.“Forage fish provide some of the lowest environmental cost food in the world – low carbon footprint, no water use, ” Dr. Hilborn said. “[There are] lots of reasons that forage fish are a really environmentally friendly form of food. ”It is also well-established that forage fisheries provide substantial health benefits to human populations through the supply of long chain omega-3 fatty acids, both directly through consumption in the form of fish oil capsules, and indirectly through animal feed for farmed fish and land animals.The paper was authored by Dr. Ray Hilborn, Dr. Ricardo O. Amoroso, and Dr. Eugenia Bogazzi from the University of Washington; Dr. Olaf P. Jensen from Rutgers University; Dr. Ana M. Parma from Center for the Study of Marine Systems -CONICET, Argentina; Dr. Cody Szuwalski from the University of California Santa Barbara; and Dr. Carl J. Walters from the University of British Columbia.
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Video: Leading Fisheries Scientists Challenge Lenfest Research that Recommended Cutting Catch of Forage Fish
Clockwise from top left: Dr. Ray Hilborn, Dr. Ricardo O. Amoroso, and Dr. Carl J. Walters
WASHINGTON (NCFC) -- April 3, 2017 -- A new study by a team of respected fisheries scientists from around the globe is challenging previous forage fish research, most notably the 2012 Lenfest Oceans Program report "Little Fish, Big Impact," which recommended leaving more forage fish in the water to be eaten by predators.Dr. Ray Hilborn of the University of Washington was the lead author on the paper, which will be published later today in the peer-reviewed journal Fisheries Research. The study concludes that fishing of forage species likely has a lower impact on their predators than previously thought.You can learn more about this important research right now by watching the seven-minute video below. In the video, Dr. Hilborn and two of the paper’s co-authors, Dr. Carl J. Walters and Dr. Ricardo O. Amoroso, discuss the paper’s findings, and their implications for forage fish management.
The Lenfest Oceans Program was established in 2004 by the Lenfest Foundation and is managed by the Pew Charitable Trusts
Look for further updates, and the complete research paper, from Saving Seafood's National Coalition for Fishing Communities throughout the day.
Copyright © 2016 Saving Seafood
New methods further discern extreme fluctuations in forage fish populations
Anchovy, sardine, and hake scale deposition rate from AD 1000 − 1500 derived from a recent, age-calibrated sediment core from Santa Barbara Basin, California. Representative fish scales and the respective fishes are shown on the right. Image credit: I.L. Hendy, University of Michigan; S. McClatchie, NOAA Fisheries; NMFS image library
ANN ARBOR—California sardine stocks famously crashed in John Steinbeck's "Cannery Row." New research, building on previous since the late 1960s, shows in greater detail that such forage fish stocks have undergone boom-bust cycles for centuries, with at least three species off the U.S. West Coast repeatedly experiencing steep population increases followed by declines long before commercial fishing began.Natural population fluctuations in Pacific sardine, northern anchovy and Pacific hake off California have been so common that the species were in collapsed condition 29 to 40 percent of the time over the 500-year period from A.D. 1000 to 1500, according to the study published online Feb. 9 in Geophysical Research Letters.Using a long time series of fish scales deposited in low-oxygen, offshore sedimentary environments off Southern California, researchers from the National Oceanic and Atmospheric Administration and the University of Michigan described such collapses as "an intrinsic property of some forage fish populations that should be expected, just as droughts are expected in an arid climate."The findings have implications for the ecosystem, as well as fishermen and fisheries managers, who have witnessed several booms, followed by crashes every one to two decades on average and lasting a decade or more, the scientists wrote. Collapses in forage fish—small fish that are preyed on by larger predators for food—can reverberate through the marine food web, causing prey limitation among predators such as sea lions and sea birds."Forage fish populations are resilient over the long term, which is how they come back from such steep collapses over and over again," said Sam McClatchie, supervisory oceanographer at NOAA Fisheries' Southwest Fisheries Science Center in La Jolla, Calif., and first author of the paper."That doesn't change the fact that these species may remain at very low levels for periods long enough to have very real consequences for the people and wildlife who count on them," he said.Downturns in sardine and anchovy linked to changing ocean conditions have contributed to the localized stranding of thousands of California sea lion pups in recent years.
Former University of Michigan graduate student Karla Knudsen, left, and former U-M undergraduate Athena Eyster sample deep-sea sediment collected in 2009 with a coring device beneath the Santa Barbara Channel in California. The sediments were used in a fish-scale analysis. Image credit: Ingrid Hendy
Scientists traced the historic abundance of sardine, anchovy and hake by examining deposits of their scales collected on the floor of the Santa Barbara Channel from A.D. 1000 to 1500. While previous studies had shown that forage fish exhibited collapses prior to commercial fishing, the new research used methods developed by climatologists to examine the frequency and duration of the fluctuation in finer detail."The Mediterranean climate of California, with wet winters and dry summers, produces a sediment layer we can pull apart like pages in a book," said U-M paleoceanographer and study co-author Ingrid Hendy. "Although these sediments have been studied before, we are using new technology to examine them in unprecedented detail."Hendy and members of her lab collected the California sediments in 2009 using a coring device that allowed them to sample large portions of the sea floor beneath the Santa Barbara Channel. Hendy is an associate professor in the U-M Department of Earth and Environmental Sciences.In the lab, fish scales from the core were identified under a binocular dissecting microscope by comparing them to reference specimens from the U-M Museum of Zoology collection. Anchovies in the collection were bought at the San Pedro Fish Market, near Long Beach, Calif., in 1922. The sardines came from Barkley Sound, on the west coast of Vancouver Island, and were collected in 1933.
From left to right: Former University of Michigan undergraduate Athena Eyster, former U-M graduate student Karla Knudsen, Ingrid Hendy and former U-M graduate student Meghan Wagner examine a sediment core collected in the Santa Barbara Channel, California, in 2009. Image credit: Arndt Schimmelmann
The fish-scale analysis was performed by former U-M undergraduate Alexandra Skrivanek, who is now a graduate student at the University of Florida. Hendy's lab has also helped to advance techniques used to date the layers within marine sediment cores. Those advances involve improved radiocarbon dating of organic materials in the sediments and better ways to count the annual layers, Hendy said.The scientists described a collapse as a drop below 10 percent of the average peak in fish populations, as estimated from the paleorecord. Anchovy took an average of eight years to recover from a collapse, while sardine and hake took an average of 22 years.
The record also showed that sardine and anchovy fluctuated synchronously over the 500-year study period. Combined collapses may compound the impact on predators and the fishery, the scientists said. The finding runs counter to suggestions that the two species' cycles alternate.Sardine and anchovy have at times been the most heavily harvested fish off Southern California in terms of volume. Hake, also known as Pacific whiting, spawn off California but are harvested in large volumes off the Pacific Northwest and Canada.The new study concludes these forage fish are well-suited to variable fishing rates that target the species in times of abundance, "while recognizing that mean persistence of fishable populations is one to two decades, and that switching to other target species will become a necessity."Collapses last, on average, "too long for the industry to simply wait out the return of the forage fish."The study authors concluded that "well-designed reserve thresholds" and adjustable harvest rates help protect the forage species, the fishery and nonhuman predators for the long term. However, they added that "reserve thresholds only protect the seed stock for recovery, and cannot prevent collapses from occurring."Funding for the study was provided by NOAA and the National Science Foundation.
Read the original post: http://www.ns.umich.edu/
Omega 3 Health Benefits, Nutrition Facts And Sources
October 31st, 2016 — According to a lot of research, omega 3 benefits each of the body’s systems in its own way. The greatest benefits can be found in the heart and the brain.In places where other fats clog the arteries and contribute to heart disease, the omega 3 fatty acids helps to fight off the heart disease in many ways.Here I have contributed a list of the things that omega 3 can do for your heart:
- Anti-Coagulant Activity – helps prevent the formation of clots in the blood
- Antioxidant Activity – they help to prevent oxidation of the fats that are found in the bloodstream. When the fats become oxidized, they can stick to the artery walls and harden atherosclerosis
- Relax Smooth Muscles – the help reduce the blood pressure, which can reduce the risk of stroke and heart attack
- Improves The Levels Of Cholesterol – Cholesterol isn’t all bad. Most individuals who have problems with cholesterol have high levels of LDL and low levels of HDL. The particles of LDL are most
- likely to stick to the walls of the arteries and create clots. HDL is what helps remove the particles of LDL from the blood. Omega 3 supplements have been known to increase the amount of HDL.
- Lowers The Amount of Blood Triglycerides – triglycerides are the fats found in the blood. The more fats that are found in your blood, the more likely you are to develop blood clots, have a stroke, or develop heart disease. The prescription medication LOVAX used for high levels of triglycerides is really nothing but omega 3 fish oil
- Anti-Inflammatory Activity – when the oxidized fats get stuck to the artery walls, they create swelling or inflammation, which makes the arteries even narrower
Read the full report at Cooking Detective
Read the original post: http://www.savingseafood.org/
Fish oil turns fat-storage cells into fat-burning cells in mice, study finds
Photo: Neil Tackaberry/Flickr
Fish oil has long been known to confer a wide range of health benefits, including boosting the cardiovascular system and potentially even treating the effects of schizophrenia. Now a new study from Japan says it could also help people trying to lose weight.
Researchers from Kyoto University found that mice fed on fatty food and fish oil gained considerably less weight and fat than mice that consumed fatty food alone. The findings suggest that fish oil is able to transform fat-storage cells into fat-burning cells – and if the same process occurs in humans, fish oil could help us reduce weight gain, especially as we age, when our fat-burning cells are in lesser supply.
While we might think of our fat tissue as primarily a fat storage system, this isn't always so. White fat cells store fat, but brown fat cells metabolise fat to maintain a stable body temperature. Our bodies metabolise fat more easily when we're young, as we have a greater amount of brown fat cells in youth, but we start to lose them in maturity.
Scientists have also discovered a third type of fat cell – beige fat cells – which function much like brown fat cells in mice and people. Also like brown fat cells, the beige cells diminish in number as we get older, making it harder for our bodies to burn fat. This is where fish oil could come into play.
"We knew from previous research that fish oil has tremendous health benefits, including the prevention of fat accumulation," said food scientist Teruo Kawada from Kyoto University. "We tested whether fish oil and an increase in beige cells could be related."
To examine the links, the researchers fed one group of mice fatty food, and another group fatty food with fish oil additives. The results, published in Scientific Reports, reveal how the animals that consumed the food with fish oil gained less 5 to 10 percent less weight and 15 to 25 percent less fat – a significant reduction in the circumstances.
But why does this happen? The researchers say that fish oil activates receptors in the digestive tract, which fires up the sympathetic nervous system and induces storage cells to metabolise fat. In other words, the fish oil causes white cells to transform into beige cells, effectively turning fat-storage tissue into fat-metabolising tissue and leading to increased energy expenditure at the expense of weight gain and fat accumulation. This is good to know.
It's too soon to say whether these findings also apply to humans, but further studies may show just that, which the researchers believe could contribute to an effective treatment for obesity.
"People have long said that food from Japan and the Mediterranean contribute to longevity, but why these cuisines are beneficial was up for debate," said Kawada. "Now we have better insight into why that may be."
Read the original post: http://www.sciencealert.com/
'Ridiculously Resilient Ridge' retires, making room for rain
El Niño is expected to bring a low-pressure system, which will replace the high-pressure system that's exacerbated California's drought. nasa.gov
The high pressure system that has shunted storms away from California for much of the past four years has dissipated, possibly for a long time.The Ridiculously Resilient Ridge — as meteorologists and forecasters have dubbed the system because of its unusual persistence — has been absent for more than a month, according to a forecaster with the National Oceanic and Atmospheric Administration.“It hasn’t been like that since August really, and instead we’ve had sort of more variable weather patterns,” said Nate Mantua, a research scientist with NOAA’s Southwest Fisheries Science Center in Santa Cruz.Mantua said the ridge will likely stay away, because it will have been replaced by a low-pressure trough.“The expectations are as we get into Fall and Winter seasons more deeply, we’re going to see a lot more low pressure there, and that will be the more sort of dominant story,” Mantua said.Eric Boldt, a meteorologist with the National Weather Service in Oxnard, said low-pressure systems typically accompany El Niño events.“Lower pressure in the Eastern Pacific is a classic pattern you’d see with an El Niño setting up with the jet stream a little more to the south, and that’s were we get into our storm track coming up from the southwest across California,” Boldt said.The high-pressure ridge has created a large swath of unusually warm water off the coast. Boldt said the warm water would take months to dissipate and that its interaction with El Niño isn’t well understood. However, he said storms from strong El Niño events, which can bring heavy rains to California, could be bolstered by the warm water.“That’s the part that is a little bit unprecedented. We don’t really have a good idea about how that might impact us, but warmer ocean temperatures typically lead to fueling the atmosphere and kind of energizing those storms. So I don’t think it’s going to be a negative for us,” Boldt said.Mantua said the disappearance of the ridge and the presence of a strong El Niño is likely to produce a lot of rain in Southern California.“[The low-pressure system is] just another factor that sort of favors a more normal winter, although I don’t think it’s going to be normal. I think it’s going to be probably an exciting winter, especially for Southern California,” Mantua said.
Read/listen to the original post: http://www.scpr.org/
Researchers Keep Missing Picture on Sardines, Where there is a 1400 Year History of Boom and Bust
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Copyright © 2015 Seafoodnews.com
“Climate variations or natural boom-and-bust cycles contribute to population fluctuation in small fast-growing fish, ” Pinsky said, “but when they are not overfished, our data showed that their populations didn’t have any more tendency to collapse than other fish. ” He called these findings counterintuitive because the opposite dynamic holds true on land: “Mice thrive while lions, tigers and elephants are endangered, ” he said.While it’s common these days to blame the ocean’s woes on overfishing, the truth is Pinsky’s conclusions don’t paint a complete picture. Fortunately, we do have an accurate picture and it’s definitely better than the proverbial thousand words.The picture is a graph (adapted from Baumgartner et al in CalCOFI Reports 1992, attached) that shows sardine booms and busts for the past 1,400 years. The data were extracted from an anaerobic trench in the Santa Barbara Channel which correlated sardine and anchovy recoveries and collapses with oceanic cycles.
(Click on Image for larger Version)
It’s important to note that most of sardine collapses in this timeframe occurred when there was virtually no commercial fishing. The best science now attributes great fluctuations and collapses experienced by sardines to be part of a natural cycle.“Pinsky has never been a terrestrial biologist or naturalist or he would have known that small rodents have boom and bust cycles brought about by combinations of environmental conditions and the mice's early maturity and high fecundity rates, ” says Dr. Richard Parrish, an expert in population dynamics now retired from the National Marine Fisheries Service, .“All fish stocks show boom and bust cycles in recruitment unrelated to fishing, ” says Dr. Ray Hilborn, internationally respected fisheries scientist from the University of Washington. “Sardines in particular have been shown to have very great fluctuations and collapses long before commercial fishing. Fast growing, short-lived species will be much more likely to decline to a level called "collapse" when recruitment fluctuates because they are short lived -- longer lived species won't decline as much. ”As a further poke in the eye to the truth, Pinsky cites sardines off the coast of Southern California as a species that has seen fluctuations for thousands of years, but “not at the levels that they’ve experienced in recent decades due to overfishing. ”Again, this simply is not true.Since the fishery reopened in 1987, Pacific sardines have been perhaps the best-managed fishery in the world – the poster fish for effective ecosystem-based management. The current harvest control rule, updated to be even more precautionary in 2014, sets a strict harvest guideline that considers ocean conditions and automatically reduces the catch limit as the biomass declines.If the temperature is cold – which scientists believe hampers sardine recruitment – the harvest is reduced. And if the population size declines, both the harvest rate and the allowable catch will automatically decrease, and directed fishing will be stopped entirely when biomass declines below 150,000 mt.In fact, the current sardine harvest rule is actually more precautionary than the original rule it replaced. It does this by producing an average long-term population size at 75 percent of the unfished size, leaving even more fish in the water, vs. 67 percent in the original rule. The original harvest rule reduced the minimum harvest rate to 5 percent during cold periods. The present has a minimum rate of 0 percent during cold periods.Compare this to the 1940s and '50s when the fishery harvest averaged 43 percent or more of the standing sardine stock with little regulatory oversight and no limit on the annual catch. This, coupled with unfavorable ocean conditions, culminated in the historic sardine fishery collapse that devastated Monterey's Cannery Row.But that was nearly 70 years ago, not “recent decades. ” Our current fishery harvest is less than a quarter of the rate observed during that historical sardine collapse.As a scientist, Pinsky should be aware of the complex, proactive management efforts that have been in place for decades to prevent overfishing in California and the west coast. He should also be aware of the data from Baumgartner that contradicts his faulty conclusions.D. B. Pleschner is executive director of the California Wetfish Producers Association, a nonprofit dedicated to research and to promote sustainable Wetfish resources.
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Global Fisheries Scientists set up 'Truth Squad' to Counter Inaccurate Scientific Claims in Media
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Copyright © 2015 Seafoodnews.com
Their media partners lap up stories of doom and collapse, often uncritically. For that reason, a group of International experts in fisheries management have come together as part of a new initiative, called CFOOD (Collaborative for Food from Our Oceans Data.) The coalition will gather data from around the world and maintain fisheries databases while ensuring seafood sustainability discussions in the media reflect ground-truth science.The scientists behind the project have long pushed for accurate and clean data sources on the world's fisheries.The CFOOD project, headquartered at the University of Washington’s School of Aquatic and Fishery Sciences (SAFS), is made up of a network of scientists whose mission stemmed from a frustration with erroneous and agenda-driven stories about fisheries sustainability in the media. The CFOOD project will maintain a website and social media channels that provide a forum for immediate feedback on new seafood sustainability reports and studies.“The CFOOD website allows us to offer independent scientific commentary to debunk false claims, support responsible science, or introduce new issues based on recent research,” said Dr. Ray Hilborn, Professor at University of Washington’s SAFS and founder of the CFOOD initiative.“The ocean is a remarkably abundant source of healthy protein,” said Hilborn. “And while sustainability challenges exist, particularly in areas lacking sufficient fishery management infrastructure, many fisheries around the world are well-managed and sustainable. The message doesn’t always seem to resonate with consumers because of misinformation they continue to hear in the media.”By reviewing and providing scientific analysis on relevant studies, papers, and media reports the CFOOD network hopes to use science to set the record straight for consumers, so they can have confidence the seafood they purchase is harvested in an environmentally responsible fashion.Other scientists on the editorial board for CFOOD include Robert Arlinghaus, Leibniz-Institute of Freshwater Ecology and Inland Fisheries and Humboldt at Universität zu Berlin; Kevern Cochrane, FAO Retired, Cape Town, South Africa; Stephen Hall, World Fish Center, Penang, Malaysia; Olaf Jensen, Rutgers University; Michel Kaiser, Bangor University, UK; Ana Parma, CONICET Puerto Madryn, Argentina; Tony Smith, Hobart, Australia; Nobuyuki Yagi, Tokyo University.“Exaggerated claims of impending ecological disaster might grab attention, but they risk distorting effort and resources away from more critical issues. I hope this initiative will help provide the balance we need,” said Dr. Stephen Hall, Director General, World Fish Center, based in Malaysia.The first set of comments on the CFOOD website debunks a WWF paper claiming a 74% decline in global mackerel and tuna species. The scientists point out that the data used to support that conclusion is out of date, having not been updated since 2004, and that more robust data sources, such as the actual stock assessments of tuna and mackerel stocks around the world were not used by the WWF in creating their estimate. We explore the comments in depth in our related story.To connect with the scientists, you can use twitter, facebook, or their website.Website: Twitter: Facebook:
John Sackton, Editor and PublisherCopyright © 2015 Seafoodnews.com