What factors play a role in analyzing forage fish fishing regulation?
The interaction of predators, fishing and forage fish is more complicated than previously thought and that several factors must be considered, says researcher.The group of researchers was evaluating the interaction after results from an earlier report found that fishing of forage species had a large effect on predator population, said the Marine Ingredients Organization (IFFO). Those harvested fish are used in several areas including as feed ingredients.The new study was initiated because there were some questions regarding the methods used in the initial project, said Ray Hilborn, with the school of aquatic and fishery sciences at the University of Washington and corresponding author.“When the original Lenfest [Forage Fish Task Force] report came out, a few of us said it seemed that the methods they were using were not up to the questions they were asking,” he told FeedNavigator. The report also offered several policy recommendations, he added.“It was on our radar screen,” he said. “And one of the things I’ve been interested in looking at is the intensity of natural fluctuation in populations, and forage fish are notable for how much they vary naturally.”The interaction between forage fish populations and predators is more complicated than may have been suggested by earlier studies tracking that relationship, and several factors need to be considered when analyzing the role that fishing plays on that relationship, he said. “The key point isn’t that there isn’t an impact, but that you have to argue case-by-case,” he added.Several factors need to be considered when assessing the interaction among predators, forage species, and fishing of those forage species, the researchers said in their study. “We show that taking account of these factors generally tends to make the impact of fishing forage fish on their predators less than estimated from trophic models,” they added.
Study response
The results from Hilborn’s group have seen responses from groups including IFFO.Previous research based on models suggested that forage fish were more valuable when left in the ocean and recommended reducing forage fish collection rates by 50% to 80%, said IFFO. However, the new paper presents an argument for a more case-by-case basis for management.“For fisheries management, such a precautionary approach would have a large impact on the productivity of forage fisheries,” the organization said. “As groups such as IFFO have noted, these stocks contribute strongly to global food security, as well as local and regional social and economic sustainability.”It is important that fisheries are managed with an effort to balance requirements from the ecosystem, coastal communities and human nutrition, IFFO said. The new results provide additional guidance and update conclusions from past reports.“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 organization said.
Study specifics
Fishing of low trophic or forage fish has generated interest in recent years, the researchers said. These fish include small pelagic fish, squid and juveniles of many species.The evidence and theory suggest that fishing can limit the abundance of some fish stocks and can affect predators’ reproductive success by the density of their prey, they said.“Although it would therefore seem obvious that fishing forage fish would have a negative effect on the abundance of their predators, the empirical relationships between forage fish abundance and predator abundance, or population rates of change, have not been examined in a systematic way,” they said.In the study, the group examined 11 species of forage fish in the US, including what animals eat them and the role the species play in their predators’ diets, they said.Species’ predators were identified, estimated fish abundance was analyzed and several models were fit to the data being assessed, they said. A simulation model also used information from fisheries regarding six different species of forage fish to evaluate the potential reduction in food for predators given a 5,000-year timespan.“The question that they were asking is an important question, but to ask it properly you need to have analysis that includes the important biology,” said Hilborn of earlier evaluations. “We’re just doing a more detailed look at the biology, which you need to do to understand fishing forage fish and what happens to their predators.”
Research findings
The goal of the study was to identify the key factors that should be considered by analyzing the effect of fishing on forge fish, said the researchers. The group found, overall, that the models previously used were “frequently inadequate” for determining the role the fishing of forage fish plays on their predators.“The most important feature that needs to be considered is the natural variability in forage fish population size,” they said. “Their abundance is highly variable even in the absence of fishing, and creditable analysis of the fishing impacts must consider how the extent of fishing-induced depletion compares with that of the natural variability.”The research results did offer some unexpected results, said Hilborn.“I was really surprised that we didn’t see any empirical data showing the relationship between predators and prey,” he said. “We only looked at American fisheries, but didn’t find at any correlation with fish and the predators.” The majority of cases did not offer an obvious relationship between prey and predator abundance, the researchers said. The size of the fish eaten by predators may play a role.“While some predators selectively eat small fish (usually not selected by the fishery), others prey on a large range of forage fish sizes,” they said. “The degree of overlap between fisheries and predators is highly variable.” However, work on the subject is not complete, said Hilborn. Several groups of researchers interested in the area are addressing different elements of the analysis.“We’re doing more detailed analysis of several of the components,” he said. “A more detailed model of specific places.”The work includes looking more closely at the interaction of key predators and some of the larger forage fisheries around the world, he said. “I expect in some of these that we’re going to find some impact – overlap between what the fishery takes and the predator takes,” he added.
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Mysterious 'sea pickles' invade the West Coast
Warming waters may be the cause
Pyrosomes are usually found in more tropical waters, but started to appear on the West Coast in 2014. They are made of many small multicellular organisms, "linked together in a tunic to form a tubelike colony that is closed on one end," according to a release from the Northwest Fisheries Science Center.A research trip by NOAA in May showed large populations of pyrosomes stretching from approximately 40 to 200 miles off the Oregon coast.Aaron Baldwin, a fishery biologist for the Alaska Department of Fish and Game, said fishermen were seeing pyrosomes "every few inches.""They were reporting them everywhere," he said.
Pyrosomes off the Oregon coast in May, 2017.Fishing nightmare
Milstein said the beauty of the creatures can be startling. "When looking at underwater pics of these guys, it's kinda like looking at the stars."Not only are pyrosomes large in numbers, they can also be more than two feet long, leading to complications for fishing boats. Milstein said he's heard of fishermen towing a net for five minutes and picking up 60,000 pyrosomes. "We've heard stories of some nets breaking under the weight of these things."According to Baldwin, the pyrosomes first appeared this February, stopping some fishermen in their tracks. "People were not fishing," Baldwin said, "just returning to port."While the number of pyrosomes is down in Alaska from where it was earlier in the year, Baldwin said people are still feeling the impact they had. "Some of these seasons are pretty short," he said. "So delays like this can have a big impact."
Originally posted: http://www.cnn.com/
TWO IMPORTANT WEST COAST GROUNDFISH STOCKS REBUILT
PORTLAND, OREGON – Two important West Coast groundfish stocks that were formerly overfished have now been rebuilt.Bocaccio and darkblotched rockfish, which are managed by the Pacific Fishery Management Council, were under strict rebuilding plans that have constrained West Coast fisheries for more than a decade. Bocaccio was declared overfished in 1999, and darkblotched rockfish in 2000; both were rebuilt well before their original target dates.The Pacific Fishery Management Council is one of eight regional fishery management councils that manage ocean fisheries in the United States. Altogether, the Pacific Council manages more than 100 species of groundfish.Managing groundfish fisheries under rebuilding plans has been an immense challenge for the Council and the National Marine Fisheries Service (NOAA Fisheries). These plans required sharp reductions in commercial and recreational fisheries targeting groundfish, which included widespread fishing closures through the establishment of Rockfish Conservation Areas off the West Coast and other measures. Since 2003, managing overfished species through area closures such as the Rockfish Conservation Areas has helped to reduce fishing impacts and rebuild overfished groundfish species. In addition, the groundfish fleet has had to limit fishing for other more abundant species to avoid unintentional catch of the overfished stocks.“The rebuilding strategies used to achieve this conservation success, coupled with favorable environmental conditions for groundfish productivity, have paid huge dividends in rebuilding our overfished groundfish stocks and resurrecting West Coast groundfish fisheries,” said Council Chair Herb Pollard.The successful rebuilding of these species reflects the support and sacrifice of West Coast ports and fishermen who recognized the difficult actions and fishing cutbacks necessary to restore the stocks. The rebuilding of bocaccio and darkblotched rockfish will lead to increased harvest opportunities beginning in 2019.“By working together, we’ve brought bocaccio and darkblotched rockfish back to where they will again be part of a sustainable West Coast groundfish fishery that creates renewed opportunity for the fishing fleet, as well as more options for seafood consumers,” said Barry Thom, Regional Administrator of NOAA Fisheries West Coast Region.Between 1999 and 2017, ten West Coast groundfish stocks were declared overfished, as surveys documented their declining numbers. Pacific whiting, for example, was declared overfished in 2002. The Council, working with NOAA Fisheries and the fishing industry, reduced commercial harvests. Combined with strong reproduction and recruitment, the fishing cutbacks led to the rapid rebuilding of Pacific whiting by 2004. The Council and NOAA Fisheries developed rebuilding plans for the other nine overfished stocks—bocaccio, darkblotched rockfish, lingcod, canary rockfish, cowcod, Pacific ocean perch, widow rockfish, petrale sole, and yelloweye rockfish.Lingcod was declared rebuilt in 2005, and widow rockfish in 2012. Both petrale sole and canary rockfish were declared rebuilt in 2015. Rebuilding plans remain in place for three remaining overfished species: cowcod, Pacific ocean perch, and yelloweye rockfish. New assessments for Pacific ocean perch and yelloweye rockfish will be reviewed this summer and may be adopted in September. Cowcod is expected to be rebuilt by 2019.“The Council is a transparent, science-based, inclusive approach to fisheries management,” said Council Executive Director Chuck Tracy. “Our progress in rebuilding overfished stocks shows the effectiveness of this approach. West Coast fisheries are a model of sustainable resource management, and they will continue to provide healthy seafood, jobs, and support for coastal communities, as well as access to this resource for all Americans.”Process The bocaccio and darkblotched rockfish assessments were developed by scientists at NOAA Fisheries and were reviewed by the Council’s scientific advisory bodies. NOAA Fisheries confirmed the stocks’ status as rebuilt on June 16.Council Role The Pacific Fishery Management Council is one of eight regional fishery management councils established by the Magnuson Fishery Conservation and Management Act of 1976 for the purpose of managing fisheries 3‐200 nautical miles offshore of the United States of America coastline. The Pacific Council recommends management measures for fisheries off the coasts of California, Oregon, and Washington.
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Contact:Ms. Jennifer Gilden, Communications Officer, Jennifer.gilden@noaa.gov, 503-820-2418Mr. John DeVore, Groundfish Staff Officer, John.DeVore@noaa.gov, 503-820-2280Mr. Chuck Tracy, Executive Director, 503-820-2280Mr. Jim Milbury, National Marine Fisheries Service, 310-245-7114Michael Milstein, National Marine Fisheries Service, 503-231-6268On the WebPacific Fishery Management Council: http://www.pcouncil.org Bocaccio stock assessment: http://tinyurl.com/yaycynmqDarkblotched rockfish stock assessment: http://tinyurl.com/ybzm3ob6NOAA Fisheries article on rockfish rebuilding: https://go.usa.gov/xNvCV
Two Decades Later, Focused Efforts on Reducing Entanglements in Gillnet Fishery Still Paying Off
June 2017In the early 1990s the drift gillnet fishery targeting swordfish off the U.S. West Coast took a high toll on whales, sea turtles and dolphins, with the drifting nets entangling and killing hundreds of these protected species each year. It was clear that management action was needed to reduce entanglements. 
Swordfish. Photo: copyright William Boyce
In 1996, NOAA Fisheries convened a “take reduction team,” under the Marine Mammal Protection Act. The team brought together scientists, fishermen, representatives of environmental organizations, and others to develop strategies that would reduce the entanglements. Those strategies included net modifications and sound-emitting devices.The recommendations of the Pacific Offshore Cetacean Take Reduction Team (POCTRT) quickly reduced entanglements, as documented by observers aboard fishing vessels in the late 90s. Today, some 25 years later, the drift gillnet fishery that catches swordfish, opah, and some sharks off the West Coast continues to have low impacts on protected species; it entangles very few whales, sea turtles, and dolphins.
Source: Carretta, J.V., J.E. Moore, and K.A. Forney. 2017. Regression tree and ratio estimates of marine mammal, sea turtle, and seabird bycatch in the California drift gillnet fishery: 1990-2015. NOAA Technical Memorandum, NOAA-TM-NMFS-SWFSC-568. 83p. Available online at https://swfsc.noaa.gov/publications/TM/SWFSC/NOAA-TM-NMFS-SWFSC-568.pdf
Source: Carretta, J.V., J.E. Moore, and K.A. Forney. 2017. Regression tree and ratio estimates of marine mammal, sea turtle, and seabird bycatch in the California drift gillnet fishery: 1990-2015. NOAA Technical Memorandum, NOAA-TM-NMFS-SWFSC-568. 83p. Available online at https://swfsc.noaa.gov/publications/TM/SWFSC/NOAA-TM-NMFS-SWFSC-568.pdf
“This fishery has made great improvements in the last two decades,” said Barry Thom, Regional Administrator of NOAA Fisheries’ West Coast Region. “If you look at the numbers of whales, turtles, and dolphins affected, they have all declined over the years and remain very low today.”For instance, the drift gillnet fishery killed or seriously injured almost 20 endangered leatherback turtles per year in some years in the early 1990s. Now leatherback deaths and injuries are rare, with an estimate of just one since 2009. An estimated 50 beaked whales were injured or killed in drift gillnets in some years in the early 1990s, but estimates now show just one seriously injured or killed since 2002.Humpback whales are among the most common whales off California but estimates show none have been killed or seriously injured in drift gillnets since 2008.Improvements in the fishery include pingers, which are devices that emit sounds to warn marine mammals away from the gillnets; and net extenders that lower the nets at least 36 feet beneath the surface, leaving room for surface-swimming animals such as dolphins to pass above them. In addition, the agency designated two large conservation areas off the West Coast that are off-limits to drift gillnets when endangered sea turtles are known to frequent the areas.
Above: A large area of ocean off the coast of California and Oregon is off limits to drift gillnet fishing each year to protect endangered leatherback sea turtles. Another area off southern California is closed during El Nino years (as determined by NOAA Fisheries) when water temperatures are warmer than average and loggerhead sea turtles are likely to be present.
The improvements have helped the drift gillnet fishery off the West Coast provide a local and sustainable domestic source of seafood with less environmental impact than many alternatives, including swordfish from some foreign fisheries that take a greater toll on marine mammals and sea turtles. After years of adaptive management to reduce the fishery’s impacts, the drift gillnet fishery now has impacts on protected species comparable to other U.S. fisheries, including the U.S. Atlantic swordfish longline fishery, which is certified by the Marine Stewardship Council.Improvements in the fishery have been recognized by others, including the Monterey Bay Aquarium’s Seafood Watch Program that considers swordfish and most other species caught with drift gillnets on the West Coast a “good alternative” for consumers.“Although sea turtle interactions used to be an issue in this fishery, management measures put into place in 2001 have greatly reduced these incidental encounters,” Seafood Watch said in a recent update of its ratings for swordfish from the West Coast drift gillnet fishery.While the improvements have been substantial, fishery managers continue to look for additional ways to harvest swordfish with even less impact. The Pacific Fishery Management Council and NOAA Fisheries have encouraged research into new fishing methods such as deep-set buoy gear, which in early trials has proven to catch swordfish with almost no bycatch of non-marketable fish or impacts on protected species.NOAA Fisheries is also collaborating with industry and co-managers on the West Coast to reduce impacts of other fisheries on large whales off the West Coast.“We’re always looking for opportunities to reduce impacts on whales, sea turtles, and other protected species,” said Chris Yates, Assistant Administrator for Protected Species in NOAA Fisheries’ West Coast Region. “Fortunately we have built good partnerships, and we’ve made substantial progress.”LEARN MORE about the fishery and recent management actionsLEARN MORE about North Pacific swordfish harvest and sustainability at FishWatchWATCH a short movie about efforts in West Coast fisheries to protect sea turtles and marine mammals
Read the original post: http://www.westcoast.fisheries.noaa.gov/
RAY HILBORN: WORLD FISH STOCKS STABLE
June 12, 2017 — Speaking at the SeaWeb Seafood Summit on Wednesday, 7 June in Seattle, Washington, U.S.A., University of Washington fisheries researcher Ray Hilborn said the perception that the world’s fish stocks are declining is incorrect, and that fishing could sustainably be stepped up in areas with good management.Hilborn pointed to figures from the RAM Legacy Stock Assessment Database that indicate that fish stocks dipped through the last part of the 20th century, but have since recovered in many fisheries.“There is a very broad perception that fish stocks around the world are declining. Many news coverages in the media will always begin with ‘fish stocks in the world are declining.’ And this simply isn’t true. They are increasing in many places and in fact, globally, the best assessments are that fish stocks are actually stable and probably increasing on average now,” Hilborn said.The RAM Legacy Database collects information on all the stocks in the world that have been scientifically assessed, which is a little more than half of the world’s catch.“What we don’t really know about is the big fisheries in Asia, in the sense that we don’t have scientific assessments of the trends in abundance,” Hilborn said.He added that the general consensus is that the status of those stocks is poor, a result of, among other things, poor fisheries management, reinforcing surveys that have shown a direct correlation between high stock abundance and high intensity of management.“For most of the developed world fisheries’ management is quite intense, and South and Southeast Asia stand out as really not having much in the way of fisheries’ management systems, particularly any form a enforcement of regulations, if regulations exists,” he said.But in much of the developed world, Hilborn said fish stocks are robust, even when they sometimes get labeled as overfished.
Originally posted at Seafood Source
Decades of data on world's oceans reveal a troubling oxygen decline
Date: May 4, 2017Source: Georgia Institute of TechnologySummary: The amount of dissolved oxygen contained in the water -- an important measure of ocean health -- has been declining for more than 20 years, reveals a new analysis of decades of data on oceans across the globe.
A new analysis of decades of data on oceans across the globe has revealed that the amount of dissolved oxygen contained in the water -- an important measure of ocean health -- has been declining for more than 20 years.
Canary in the kelp forest
The one-two punch of warming waters and ocean acidification is predisposing some marine animals to dissolving quickly under conditions already occurring off the Northern California coast, according to a study from the University of California, Davis.In the study, published in the journal Proceedings of the Royal Society B: Biological Sciences, researchers at the UC Davis Bodega Marine Laboratory raised bryozoans, also known as “moss animals,” in seawater tanks and exposed them to various levels of water temperature, food and acidity.The scientists found that when grown in warmer waters and then exposed to acidity, the bryozoans quickly began to dissolve. Large portions of their skeletons disappeared in as little as two months.“We thought there would be some thinning or reduced mass,” said lead author Dan Swezey, a recent Ph.D. graduate in professor Eric Sanford’s lab at the UC Davis Bodega Marine Laboratory. “But whole features just dissolved practically before our eyes.”SKELETONS KEYBryozoans are colonial animals, superficially similar to, but not related, to corals. They are abundant in California kelp forests and are calcareous, meaning they build their honeycomb-shaped skeletons from calcium carbonate.The scientists found that when raised under warming conditions, bryozoans altered their chemical composition by building higher levels of magnesium into their skeletons, particularly if they were also eating less food. When exposed to acidic conditions already observed off coastal California, these changes predisposed the animals to dissolve.The researchers consider bryozoans a canary in the coal mine for other marine animals that build calcareous skeletons containing magnesium. These include sea stars, sea urchins, calcifying algae and tube-building worms.The authors do not know why the bryozoans added more magnesium to their skeletons under warmer temperatures. But they conclude that marine organisms with skeletons made of high-magnesium calcite may be especially susceptible to ocean acidification because this form of calcium carbonate dissolves more easily than others.Bryozoans grow in connected colonies. During the experiments, the animals shut down parts of themselves when undergoing the stress of ocean acidification, redirecting their energy to new growth. This was somewhat like closing down units of a condominium complex while building new ones at the same time. But the moss animals could not outpace the dissolution.“They were trying to grow but were dissolving at the same time,” Swezey said.CALCIFIED ANIMALS INCREASINGLY VULNERABLEThe authors said the study underlines the increasing vulnerability of calcified animals to ocean acidification, which occurs as the ocean absorbs more atmospheric carbon emitted through the burning of fossil fuels.During the spring and summer months, deep ocean water rich in carbon dioxide periodically wells up along the California coast when surface waters are pushed offshore by strong winds. These upwelling events also push nutrients to the surface to help support kelp forests and productive fisheries. However, this deep water tends to be more acidic.Climate modeling shows that the trends of warming ocean temperatures, stronger winds and increasingly strong upwelling events are expected to continue in the coming years as carbon dioxide concentrations in the atmosphere increase. This indicates that acidic conditions will likely become more common, rather than episodic.MARINE LIFE FACES MANY CHANGES AT ONCE“Marine life is increasingly faced with many changes at once,” said co-author Sanford, a professor in the UC Davis Department of Evolution and Ecology. “For bryozoans, their response to warmer temperature makes them unexpectedly vulnerable to ocean acidification. The question now is whether other marine species might respond in a similar way.”
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The study’s other co-authors include Jessica Bean, Aaron Ninokawa, Tessa Hill, and Brian Gaylord from UC Davis. Bean is also affiliated with UC Berkeley.The study was supported by grants from the National Science Foundation and the University of California Multicampus Research Programs and Initiatives. Swezey was also supported by a NSF Graduate Research Fellowship.Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.
Originally posted: https://www.eurekalert.org/pub_releases/2017-04/uoc–cit041717.php
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.
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