Long baleen whale mothers are more likely to have female calves than males, according to a new study led by the 天美影视传媒. The findings contradict a popular evolutionary theory postulating that strong mammals benefit more from birthing males.

In 1973, that fit female mammals can improve their odds for grandchildren by having males. Large strong mothers will raise large strong offspring that, if male, can outcompete other males for mates.聽But, according to the theory, female fitness is less consequential. The studies backing this argument focused on land mammals, such as deer and elk, and often included just tens or hundreds of animals.

UW researchers tested the theory in marine mammals by comparing maternal length and fetal sex in more than 100,000 baleen whales. They found that the fetal sex ratio skews female for longer 鈥� and thus more fit 鈥� rorqual whales, the predominant baleen whale family that includes humpbacks and blue whales. The findings, on Sept. 24, suggest that female calves benefit more from heritable fitness than males do.

Carrying and caring for young is exhausting, and whales often breed far from food sources. They must rely on stored fat to sustain themselves and their young during and after pregnancy.

鈥淭he question we wanted to answer was: if you are in good condition, if you鈥檙e big and fat and you鈥檙e going to have a big fat calf that will survive and reproduce 鈥� do you want that calf to be a male or a female?鈥� said , a UW doctoral student of quantitative ecology and resource management.

To answer this question, the researchers turned to historical whaling data.

Back in the early 1900s, when people hunted whales, a group from Norway began collecting data on their catch. The practice was codified into a law that required all Norwegian hunters to record the whale鈥檚 length, sex and pregnancy status, as well as the sex and size of a fetus. In the 1930s, the Norwegian regulation became international law.

鈥淲hen they hunted whales, there were often biologists around who were knee-deep in the carcasses, measuring and collecting samples,鈥� Rand said. in 1986 to protect dwindling populations from further decimation. The IWC data, however, is a treasure trove for researchers.

鈥淲e have this enormous data set with hundreds of thousands of data points that doesn鈥檛 exist for almost any other wild population,鈥� said , a UW professor in the School of Aquatic and Fishery Sciences. In 2023, Branch and Rand helped create an interactive map depicting whale distribution from the data.

The data also gave Rand an opportunity to investigate fetal sex ratios in marine mammals. Experts argue that some animals just after conception. No one knows exactly how this works for mammals, but adapting sex ratios based on physical or environmental conditions is considered advantageous.

鈥淚 think for our mammal brains, it is a little bit confusing,鈥� Rand said, 鈥淏ut insects, and ants, have a lot of control over the sex of their offspring, so it鈥檚 not entirely surprising that mammals might have a little bit of control.鈥�

In this study, the researchers modeled maternal length against sex for fetuses measuring three feet and longer 鈥� the size at which sex becomes evident. They included seven whale species in the rorqual family, totalling more than 100,000 whales.

If the Trivers-Willard hypothesis were correct, researchers would have seen a slight increase in the number of male fetuses as maternal length increased. Instead, they observed a downward trend, indicating that fewer males were born to larger mothers. The results varied some by species: There was a 77% chance that longer female humpbacks have more female calves, and that probability increased to 99% for sei whales.

There are several possible explanations for why these findings flip the Trivers-Willard hypothesis, and the trends observed in land mammals. Some male whales compete for mates, but competition might not be as significant a pressure as female size because small female whales will likely struggle to reproduce and raise healthy young. Big whales, on the other hand, will have big female calves that will grow into long mothers with strong reproductive potential.

For baleen whale mothers, investing energy in female calves is the best way to ensure generations of grandchildren.

Research also suggests that some whale species are , which could spell trouble for future generations if females are unable to support offspring. The findings could have implications for conservation, but Rand said that this will require further research to confirm.

鈥淧reviously it was assumed that if you have male-male competition for mates, bigger mothers will have males,鈥� Rand said. 鈥淥ur paper shows that you can鈥檛 make that assumption because there鈥檚 also an advantage to being big as a female.鈥�

Other authors include , the Leader of the USGS Washington Cooperative Fish and Wildlife Research Unit and a Professor in the UW School of Aquatic and Fishery Sciences.

This research was funded by the National Oceanic and Atmospheric Administration.

Contact Rand at zrand@uw.edu for more information.

Even though they鈥檙e the , whales remain difficult to track. So experts often turn to historical whaling data to inform current research. A dataset maintained by the (IWC) contains detailed information on commercial whale catches 鈥� more than 2.1 million records, predominantly from 1880 until the IWC banned whaling in 1986. Yet for researchers, distilling that data can prove its own challenge.

A team at the 天美影视传媒 has created an online interactive map called WhaleVis, which lets whale researchers visualize the IWC鈥檚 data on global whale catches and whaling routes. From this, researchers can estimate the animals鈥� spatial distribution and the effort whalers put into hunts.

By comparing historical data and its trends with current information, scientists can better understand how populations of whales have changed over time, where they鈥檝e been, and how to better protect those still living.

The UW team presented Oct. 25 at the in Melbourne (Narrm), Australia. The tool is online, but users must have permission from the IWC to access it.

鈥淪cientific data is a really important aspect of big data, but scientists all over the world have access to completely different hardware and software. Maybe they can鈥檛 use big servers to process huge data sets quickly,鈥� said senior author , a UW assistant professor in the Paul G. Allen School of Computer Science & Engineering. 鈥淪o when creating WhaleVis we had to ask: How do we design a tool that can visualize millions of data points, but that doesn鈥檛 rely on super beefy servers?鈥�

The team approached this in a couple of ways. First, instead of trying to render more than 2 million points on a global map at once, taxing the computer processor and creating a 鈥渉airball visualization鈥� 鈥� an illegible mess of lines and dots 鈥� the researchers aggregated whale catches in clusters. One large blue dot at South Georgia island in the South Atlantic Ocean, for example, signifies 130,611 whale catches, most of them fin whales. As researchers continue to develop the tool, they鈥檒l allow users to zoom in on parts of the map to access greater detail.

Second, they built the tool for web browsers, instead of as a standalone app, to make it function on different computing platforms.

鈥淚t was important to make this data accessible so it can easily be used to generate actionable insights,鈥� said lead author , a UW doctoral student in the Allen School. 鈥淭ools like this make information more tangible and comprehensible.鈥�

WhaleVis came about through the UW鈥檚 , an initiative bringing together computer and climate scientists to collaborate. , a co-author on the paper and UW professor in the School of Aquatic and Fishery Sciences, had been working with the IWC data set and wanted help visualizing it, especially in such a way that would estimate how much effort had gone into each whale catch. Battle and Patil were seeking a project that combined environmental science with data visualization, and the IWC data set fit the bill.

鈥淏eing able to visualize the data like this helps us answer a huge number of questions,鈥� Branch said. 鈥淔or example, it is difficult to separate two of the subspecies of blue whales 鈥� massive Antarctic blue whales and pygmy blue whales that are about 20 feet shorter. Visualizing the expeditions that caught big whales versus pygmies lets us clearly and quickly see the boundary between those two subspecies.鈥�

In its current iteration, WhaleVis uses the density of expeditions in certain areas to let scientists approximate the effort whalers put into each hunt. If researchers can quantify this effort 鈥� that is, the time and distance between catches on these expeditions 鈥� it gives a better sense of size, density and location of historical whale populations.

In the future, the team plans to refine the methods of estimating whalers鈥� efforts, normalizing for factors such as time between catches on each expedition. The researchers also intend to add interactive prediction modeling for different scenarios and to apply the methods used on WhaleVis to other animal populations.

鈥淔rom a researcher point of view, what鈥檚 already online is very, very cool,鈥� Branch said, 鈥渁nd way past anything that鈥檚 been available up to now. Only when you start playing with the data in a nice visualization do you discover some of the anomalies and surprises in it.鈥�

, a doctoral student in quantitative ecology and resource management, was a co-author on this paper. This research was funded by the 天美影视传媒 Computing for the Environment Initiative and the National Science Foundation.

For more information, contact Patil at ameyap2@cs.washington.edu, Battle at leibatt@cs.washington.edu, and Branch at tbranch@uw.edu.

Fish populations tend to do better in places where rigorous fisheries management practices are used, and the more measures employed, the better for fish populations and food production, according to a new paper published Jan. 11 in Nature Sustainability.

The , led by of the 天美影视传媒鈥檚 School of Aquatic and Fishery Sciences, draws upon the expertise of more than two dozen researchers from 17 regions around the world. The research team analyzed the management practices of nearly 300 fish populations to tease out patterns that lead to healthier fisheries across different locations. Their findings confirmed, through extensive data analysis, what many researchers have argued for several years.

鈥淚n general, we found that more management attention devoted to fisheries is leading to better outcomes for fish and shellfish populations,鈥� Melnychuk said. 鈥淲hile this won鈥檛 be surprising to some, the novelty of this work was in assembling the data required and then using statistical tools to reveal this pattern across hundreds of marine populations.鈥�

The research team used an international database that is the go-to scientific resource on the status of more than 600 individual fish populations. They chose to analyze 288 populations that generally are of value economically and represent a diversity of species and regions. They then looked over time at each fish population鈥檚 management practices and were able to draw these conclusions:

• In regions of the world where fish and shellfish populations are well studied, overall fisheries management intensity has steadily increased over the past half century
• As fisheries management measures are implemented, fishing pressure is usually reduced toward sustainable levels, and population abundance usually increases toward healthy targets
• If fish populations become depleted as a result of overfishing, a rebuilding plan may be implemented. These plans tend to immediately decrease fishing pressure and allow populations to recover
• If strong fisheries management systems are put in place early enough, then overfishing can be avoided and large, sustainable catches can be harvested annually, rendering emergency measures like rebuilding plans unnecessary

The study builds on previous work that found, by using the same database, that nearly half of the fish caught worldwide are from populations that are scientifically monitored and, on average, are increasing in abundance. The new paper takes a closer look at specific management actions and how they have impacted fishing pressure and the abundance of each population examined, Melnychuk explained.

鈥淎ll fish populations have their own unique contexts that might dictate what management tools would be most helpful and promising to use,鈥� he said. 鈥淒espite the great diversity in their management objectives and various strategies to meet those, we focused on key management tools in common to many fisheries around the world.鈥�

The international research team chose to look at a spectrum of fish populations, such as hakes in South Africa and Europe, orange roughy in New Zealand, tuna species on the high seas, anchovies in South America and scallops off the Atlantic coast of North America. Most of the populations they examined had a history of being depleted at some point, usually due to historical overfishing.

For example, with U.S. mid-Atlantic population of black sea bass, a rebuilding plan instituted in 1996 brought fishing rates down from three times the sustainable level to below this mark, which led to a steady rebuilding of the fishery and full recovery by 2009.

“Fishers targeting black sea bass in the northeastern U.S. are finally reaping the rewards of harvest caps that allowed the population to rebuild,鈥� said co-author of the University of Wisconsin鈥擬adison. 鈥淭he 2020 catch limit of more than 6,000 tons is the highest since catch limits were first imposed more than 20 years ago.”

This analysis omits fisheries that lack scientific estimates of population status, even though these account for a large amount of the world鈥檚 catch. These include most of the fish populations in South Asia and Southeast Asia 鈥� fisheries in India, Indonesia and China alone represent 30% to 40% of the world鈥檚 catch, most of which is essentially unassessed. Although fisheries in these regions could not be included in the analyses, the paper鈥檚 authors conclude that lessons learned can equally apply to data-limited fisheries: Greater investment in fisheries management systems is expected to lead to better outcomes for the fish populations upon which our fisheries are based.

Other UW co-authors include , , , Maite Pons, Daniel Hively, Charmane Ashbrook, Nicole Baker and Ricardo Amoroso. A full list of paper co-authors is .

This research was funded by The Nature Conservancy, The Wildlife Conservation Society, the Walton Family Foundation and a consortium of Seattle fishing companies.

For more information, contact Melnychuk at mmel@uw.edu.

The global pandemic is hurting the seafood industry, and American fishmongers may flounder without more government aid, according to the largest study of COVID-19鈥檚 impacts on U.S. fisheries.

The new , published Nov. 23 in the journal Fish and Fisheries, found that monthly fresh seafood exports declined up to 43% compared to last year, while monthly imports fell up to 37%, and catches dropped 40% in some months.

Additionally, over the first six months of 2020, total U.S. seafood exports were down 20% and imports were down 6%, compared to the same period last year. Further losses are likely as restrictions increase to address COVID-19.

鈥淪eafood has been hit harder than many other industries because many fisheries rely heavily on restaurant buyers, which dried up when the necessary health protocols kicked in,鈥� said lead author of the University of Vermont. 鈥淩estaurants represent about 65% of U.S. seafood spending, normally.鈥�

For context, over one million U.S. seafood workers regularly produce more than $4 billion in annual exports, much of which is processed overseas and imported back to the U.S.

While seafood data often takes several months 鈥� or longer 鈥� to compile, the research team, including of the 天美影视传媒, used pioneering methods to quickly determine the pandemic鈥檚 impacts on fisheries. U.S. Congress received in September.

The researchers found that in January 2020, demand for American imports plummeted as lockdowns began in China. Starting in March, web searches for U.S. seafood restaurants fell over 50%, and foot traffic at seafood markets decreased 30%.

Aid for fisheries has been slow, partly because pandemics are not currently considered valid reasons for a fishery failure or disaster under current law. The CARES act has authorized $300 million for the sector.

Even with increased demand for seafood delivery, which surged 460% for Google searches from March to April, some producers may not be able to recover without government assistance.

鈥淪eafood is a seasonal business,鈥� said White. 鈥淚f you have a March to June season, and can鈥檛 get funds until next year, you might have to quit. Support from policymakers will decide which producers can survive.鈥�

Aid should target regions where fisheries make up a disproportionate share of the economy, including in Maine, Alaska, Louisiana and Washington, as well as tribal fisheries, the researchers said.

鈥淐OVID-19 is a huge risk to the big factory boats that both catch and process fish in our waters 鈥� this combines the worst risks of cruise ships and meat plants. Their workers need priority access to the new vaccines,鈥� said Branch, associate professor in the UW School of Aquatic and Fishery Sciences.

鈥淔oreign markets play an important role in the U.S. seafood sector, but dependence on exports leaves portions of the sector vulnerable to these global shocks,鈥� added co-author of American University. 鈥淒iversifying the sector by building local networks and consumer education campaigns can help build resilience to future shocks.鈥�

The study used traditional and novel sources of data, from NOAA fisheries reports and federal customs data, to anonymous commercial web location data made available to researchers studying COVID-19, and a comprehensive database of news and trends 鈥� created by University of Vermont students 鈥� tracking the pandemic鈥檚 impacts on fisheries, from plant closures and outbreaks to travel restrictions on seafood laborers.

While the drops in catches and international trade were stark, the researchers said some seafood producers have found ways to adapt. Community supported fisheries programs are increasing, with websites like helping consumers buy fresh seafood that might have previously been sold to restaurants or at markets.

That said, home cooking won鈥檛 replace seafood restaurant sales.

鈥淢ost people who cook at home are not likely looking to cook fresh monkfish from Maine for themselves or their family, so the types of species being consumed is changing,鈥� said co-author of University of California, Santa Barbara.

These changes in seafood consumption may be here to stay 鈥� particularly as global COVID-19 cases climb ever higher 鈥� as producers look for ways to sell more of their catches domestically.

Other co-authors are Richard Cottrell of the University of California, Santa Barbara; Rahul Agrawal Bejarano of the University of Michigan; and Julia Baum of University of Victoria.

This study was funded by from the Gund Institute for Environment at University of Vermont.

This piece was adapted from a University of Vermont .

Nearly half of the fish caught worldwide are from stocks that are scientifically monitored and, on average, are increasing in abundance. Effective management appears to be the main reason these stocks are at sustainable levels or successfully rebuilding.

That is the main finding of an international project led by the 天美影视传媒 to compile and analyze data from fisheries around the world. The were published Jan. 13 in the Proceedings of the National Academy of Sciences.

“There is a narrative that fish stocks are declining around the world, that fisheries management is failing and we need new solutions 鈥� and it鈥檚 totally wrong,” said lead author , a professor in the UW School of Aquatic and Fishery Sciences. “Fish stocks are not all declining around the world. They are increasing in many places, and we already know how to solve problems through effective fisheries management.”

The project builds on a decade-long international collaboration to assemble estimates of the status of fish stocks 鈥� or distinct populations of fish 鈥� around the world. This information helps scientists and managers know where overfishing is occurring, or where some areas could support even more fishing. Now the team’s database includes information on nearly half of the world’s fish catch, up from about 20% represented in the last compilation in 2009.

“The key is, we want to know how well we are doing, where we need to improve, and what the problems are,” Hilborn said. “Given that most countries are trying to provide long-term sustainable yield of their fisheries, we want to know where we are overfishing, and where there is potential for more yield in places we’re not fully exploiting.”

Over the past decade, the research team built a network of collaborators in countries and regions throughout the world, inputting their data on valuable fish populations in places such as the Mediterranean, Peru, Chile, Russia, Japan and northwest Africa. Now about 880 fish stocks are included in the database, giving a much more comprehensive picture worldwide of the health and status of fish populations.

Still, most of the fish stocks in South Asia and Southeast Asia do not have scientific estimates of health and status available. Fisheries in India, Indonesia and China alone represent 30% to 40% of the world’s fish catch that is essentially unassessed.

“There are still big gaps in the data and these gaps are more difficult to fill,” said co-author , a principal scientist at Argentina’s National Scientific and Technical Research Council and a member of The Nature Conservancy global board. “This is because the available information on smaller fisheries is more scattered, has not been standardized and is harder to collate, or because fisheries in many regions are not regularly monitored.”

Since the mid-1990s, catch has generally declined in proportion to decreases in fishing pressure for the fish stocks assessed in the database. By 2005, average biomass of fish stocks had started to increase.

The researchers paired information about fish stocks with recently published data on fisheries management activities in about 30 countries. This analysis found that more intense management led to healthy or improving fish stocks, while little to no management led to overfishing and poor stock status.

These results show that fisheries management works when applied, and the solution for sustaining fisheries around the world is implementing effective fisheries management, the authors explained.

“With the data we were able to assemble, we could test whether fisheries management allows stocks to recover. We found that, emphatically, the answer is yes,” said co-author , a professor of environmental and resource economics at University of California, Santa Barbara, and a board member with Environmental Defense Fund. “This really gives credibility to the fishery managers and governments around the world that are willing to take strong actions.”

Fisheries management should be tailored to fit the characteristics of the different fisheries and the needs of specific countries and regions for it to be successful. Approaches that have been effective in many large-scale industrial fisheries in developed countries cannot be expected to work for small-scale fisheries, especially in regions with limited economic and technical resources and weak governance systems, Parma said.

The main goal should be to reduce the total fishing pressure when it is too high, and find ways to incentivize fishing fleets to value healthy fish stocks.

“There isn’t really a one-size-fits-all management approach,” Costello said. “We need to design the way we manage fisheries so that fishermen around the world have a long-term stake in the health of the ocean.”

Other UW co-authors are , and of the School of Aquatic and Fishery Sciences. Other co-authors are from University of Victoria, University of Cape Town, National Institute of Fisheries Research (Morocco), Rutgers University, Seikai National Fisheries Research Institute Japan, CSIRO Oceans and Atmosphere, Fisheries New Zealand, Wildlife Conservation Society, Marine and Freshwater Research Center (Argentina), European Commission, Galway-Mayo Institute of Technology, Center for the Study of Marine Systems, Sustainable Fisheries Partnership, The Nature Conservancy, and the Food and Agriculture Organization of the United Nations.

Hilborn and collaborators recently presented this work at the Food and Agriculture Organization of the United Nations’ in Rome.

The research was funded by the Science for Nature and People Partnership, a collaboration between the National Center for Ecological Analysis and Synthesis at UC Santa Barbara, The Nature Conservancy and Wildlife Conservation Society. Individual authors received funding from The Nature Conservancy, The Wildlife Conservation Society, the Walton Family Foundation, Environmental Defense Fund, the Richard C. and Lois M. Worthington Endowed Professorship in Fisheries Management and donations from 12 fishing companies.

For more information, contact Hilborn at rayh@uw.edu, Parma at anaparma@gmail.com and Costello at costello@bren.ucsb.edu.

More information is available at , an effort to communicate the science, policies and human dimensions of sustainable fisheries.

A new by 天美影视传媒 scientists has found that, for dozens of fish populations around the globe, old fish are greatly depleted 鈥� mainly because of fishing pressure. The paper, published online Sept. 14 in Current Biology, is the first to report that old fish are missing in many populations around the world.

“From our perspective, having a broad age structure provides more chances at getting that right combination of when and where to reproduce,” said lead author , a UW postdoctoral researcher at the School of Aquatic and Fishery Sciences and the Joint Institute for the Study of the Atmosphere and Ocean.

In forestry, a tree farm with only 20-year-old trees may be healthy and productive, but the loss of old-growth trees should not go unnoticed. The giant trees have unique traits that support a number of animal and plant species and make for a diverse, robust ecosystem. In a similar sense, the same is true for old fish.

“More age complexity among species can contribute to the overall stability of a community,” Barnett said. “If you trim away that diversity, you’re probably reducing the marine food web’s ability to buffer against change.”

The designation of an “old fish” varies from species to species, depending on life history. Some types of rockfish might live to 200 years, while few herring live past age 10.

After female fish release eggs, many factors must align for a healthy brood to hatch and grow to adult size. Because the marine environment is so variable, species might go a whole decade between successful broods. Older fish in a population have more years to produce eggs, increasing the chance for success over time.

“In the marine world, the success rate of producing new baby fish is extremely variable,” said co-author , a UW associate professor of aquatic and fishery sciences. “I think of old fish as an insurance policy 鈥� they get you through those periods of bad reproduction by consistently producing eggs.”

In addition to having more opportunities to reproduce, older fish also behave differently than younger fish. As they age, some fish change what they eat and where they live in the ocean. They also take on different roles in the marine food web, sometimes becoming a more dominant predator as they get older, and bigger.

When you take old fish out of the mix, the diversity and stability of an ecosystem can suffer, the authors explain.

“Big fish are in a lot of ways different from smaller fish,” said co-author , a UW professor of aquatic and fishery sciences. “Having that diversity acts as a hedge against risk and helps stabilize the system a bit.”

The researchers looked at model output gathered from commercial and recreational fisheries and scientific observations that describe the status of fish populations over the years. In their analysis of 63 populations living in five ocean regions worldwide, they found that the proportion of fish in the oldest age classes has declined significantly in 79 to 97 percent of populations, compared with historical fishing trends or unfished figures, respectively. The magnitude of decline was greater than 90 percent in 32 to 41 percent of the groups.

This is mainly due to fishing pressure, the researchers say. In general, the longer a fish lives, the more encounters it has with fishing gear, and the greater the likelihood it will be caught. However, some environmental factors like disease and pollution might also contribute to the loss of old fish.

These findings could inform fisheries management, which often sets limitations based on the total weight of fish caught over a season without considering factors such as the size or age of a fish. The authors suggest fishing methods to protect young and old fish by prohibiting the harvest of fish below and above a specific size range. Other solutions include closing certain areas to fishing permanently, or rotating areas where fishing can take place each year to let fish grow older and bigger 鈥� similar to agricultural crop rotations that allow the soil to recover between planting cycles.

The paper’s other co-author is R. Anthony Ranasinghe of Virginia Polytechnic Institute and State University, who completed data analysis for the paper with the aid of a NOAA Hollings Undergraduate Scholarship.

The work was directly funded by the UW’s Joint Institute for the Study of the Atmosphere and Ocean under a NOAA cooperative agreement, with additional funding from the Richard C. and Lois M. Worthington Endowed Professor in Fisheries Management.

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For more information, contact Barnett at lewisab@uw.edu; Branch at tbranch@uw.edu; and Essington at essing@uw.edu or 206-616-3698.

Black swan events are rare and surprising occurrences that happen without notice and often wreak havoc on society. The has been used to describe banking collapses, devastating earthquakes and other major surprises in financial, social and natural systems.

A by the 天美影视传媒 and Simon Fraser University is the first to document that black swan events also occur in animal populations and usually manifest as massive, unexpected die-offs. The were published聽online March 7 in the Proceedings of the National Academy of Sciences.

“No one has really looked at the prevalence of these black swan events in animal population abundance before,” said lead author , a UW postdoctoral researcher in aquatic and fishery sciences. “People associate the phrase with financial market crashes, and being able to take that term and apply it to another system gives context about what we’re seeing in animal populations.”

The researchers analyzed data from more than 600 animal populations, including mammals, birds, fishes and insects. They found that drastic changes in populations occurred in about 4 percent of the animals they surveyed, most commonly in birds.

Almost always, these black swan events came as massive, unexpected population crashes or die-offs, instead of positive surges in population, the analysis found. Current methods to look at a species’ extinction risk don’t take into account the impact of a black swan event 鈥� and probably should, the researchers argue.

“Everyone just assumes an animal population has an equal chance of going up or down, but we’ve found that isn’t true,” said co-author , a UW associate professor of aquatic and fishery sciences. “My hope is that when people are trying to assess extinction risk, they will use different models that project into the future in a more accurate way.”

Anderson and colleagues developed a method to detect black swan events over time in different species. They found that most occurrences were driven by factors such as parasites, severe winters, predators or climate 鈥� most of which will likely get more extreme under climate change.

“I would expect climate change to make black swan events even more important,” Anderson said. “We expect an increase in the frequency and magnitude of extreme climate, and it’s quite possible we will see black swan events become more common in animal populations.”

About two years ago, more than a third of the world’s population of . Researchers later determined that a bacterial infection was behind the deaths of the endangered antelopes in Kazakhstan. It’s a classic example of a black swan event impacting animals, the authors say.

Other examples included in their analysis are England’s grey heron population crashes in the mid-1900s as the result of cold winters; European shag cormorants’ decline from a red tide event in the late 1960s; and Scotland’s red grouse collapse in the 1970s due to parasite outbreaks and fox predators. Each of these events caught managers by surprise.

The researchers say the goal is not to try to predict black swan events, but instead to prepare for them by developing management plans that help populations withstand sudden, dramatic swings. For example, managing animal populations so they remain large enough to accommodate crashes 鈥� or maintaining diversity within a population 鈥� could help buffer against black swan disasters.

The earthquake preparedness movement across seismically active regions is a good example of how to buffer against the unexpected, the researchers say. Adding a cushion for extreme events in animal populations could be the difference between a species taking a severe dive or going completely extinct.

“The question of extreme events is really hard to address, yet it’s a really interesting, relevant topic. You need a massive amount of data and a good analysis to do this in animal populations,” Branch said. “There’s no bigger dataset to look at and no better method to detect black swan events than this.”

The study’s other co-authors are and of Simon Fraser University.

The analysis relied on data from the Global Population Dynamics Database. The research was funded by a David H. Smith Conservation Research Fellowship; the Natural Sciences and Engineering Research Council of Canada; the Canada Research Chairs Program; and the Richard C. and Lois M. Worthington Endowed Professorship in Fisheries Management.

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For more information, contact Anderson at sandrsn@uw.edu and Branch at tbranch@uw.edu聽or Skype:聽trevor.branch

Recording how many fish are caught is one important requirement to measure the well-being of a fish stock 鈥� if scientists know the number of fish taken from the ocean, they can adjust management of that fishery to keep it from being overfished. Missing catch data, however, are rampant, causing concern that fisheries around the world are overfished.

A new by 天美影视传媒 scientists finds that in many cases, this isn’t true. Specifically, misreporting caught fish doesn’t always translate to overfishing. The study was published online this month in the journal .

“While quantifying total catch is important for understanding how much is removed from the system, it is possible to manage sustainably even if we don’t know those numbers,” said lead author , a UW doctoral student in aquatic and fishery sciences. “This paper shows there are some situations where, just because there is unreported catch, it doesn’t mean we are overfishing.”

The researchers modeled five different misreporting scenarios on a simulated fishery: complete reporting of catch numbers, constant over-reporting, constant under-reporting, increasing reporting rate over time and decreasing reporting rate over time. They found that in cases where misreporting was constant, the fish population could still be managed sustainably over the years because misreporting was proportional each year.

But in cases where misreporting increased or decreased year to year, those fisheries were found to be over- or under-fished.

In other words, the catch reporting trends 鈥� not the specific numbers of fish caught 鈥� are the most critical elements to consider when trying to understand a fishery’s overall status, the authors said.

“It turns out that if you know what the trend is in a fish population, it doesn’t matter as much if you don’t know the catch numbers perfectly,” said , senior author and a UW associate professor of aquatic and fishery sciences. “Now we think we know better what impact unreported catch has on fishery status.”

A massive effort is underway through the University of British Columbia’s initiative to reconstruct the catch data for fisheries worldwide. It’s clear from this work that misreporting at a constant rate happens frequently in fisheries around the world. The UW study connects with the reconstruction efforts by showing that many of these fish populations can still be well managed despite management being based on models using misreported catches.

Misreporting can happen at the dock, on the boat and in processing plants 鈥� and many fish aren’t counted due to illegal fishing, sport fishing or discarded fish.

No two fisheries are alike worldwide, and each faces its own challenges with management. Reporting what is caught is not always standard practice, and yet managers must evaluate each year the ability of a fishery to withstand fishing pressure. That, in turn, affects local economies and livelihoods.

Instead of spending exhaustive time and money on trying to count each fish, managers could instead ask locals about fishing practices over the years to try to understand whether a misreporting trend is at play. They could also complete more biomass or biological surveys to better understand the life history of the fish.

“It might not be wise to allocate all of the monitoring funds toward understanding what the total catch is because you might be able to manage sustainably without that information,” Rudd said. “Instead, if you could get a handle on the trends in each fishery, that might be a better use of funds.”

Branch saw the need for a broad look at misreporting when helping to manage southern bluefin tuna. Right before a big management change was enacted, scientists discovered there had been major under-reporting of tuna catches.

“My initial reaction was, ‘oh my goodness, we have been overfishing this whole time. When we model this, the fishery will be in a much worse state,'” Branch said.

But when scientists added the missing catch numbers back into the model, the tuna population status actually improved into the future.

“A takeaway of this study is to not be so alarmist when there are missing data, and instead understand the processes of how the data are used,” Rudd said. “Catch data don’t exist in a vacuum. To determine how the world’s fisheries are doing, you must consider the catch data with any other information available to make the management decisions.”

The study was funded by the National Science Foundation IGERT Program on Ocean Change.

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For more information, contact Rudd at mbrudd@uw.edu and Branch at tbranch@uw.edu.

The , published this week in the Proceedings of the National Academy of Sciences, also explains how the world’s fisheries could produce more seafood and increase profits for fishermen by 204 percent by the year 2050, if reforms such as secure fishing rights are implemented now.

“We’ve uncovered a really important insight: there is urgency and tremendous upside in reforming thousands of fisheries around the world,” said , a co-author and UW professor aquatic and fishery sciences.

“The research adds to the body of work that shows that most of the world’s large fisheries are doing relatively well, but it emphasizes the critical need to rebuild fisheries that millions of fishermen and their families depend on for food and livelihoods, most of which are in the developing world.”

The study is a collaboration among researchers from the University of California, Santa Barbara, the Environmental Defense Fund and the UW. , a UW associate professor of aquatic and fishery sciences, together with Hilborn, developed a database on fisheries stock status that was used in the study for both the status of individual stocks, and to tune the statistical model that was used for many of the other stocks.

According to the paper, if reforms were implemented today, three-quarters of exploited fisheries worldwide could reach population goals within 10 years, and 98 percent by mid-century. These conclusions emerged from the analysis that used a massive database of 4,713 fisheries 鈥� including most of the U.S. West Coast fisheries 鈥� that represent 78 percent of the ocean’s catch. That’s far more precise and granular than previous analyses.

The research suggests that implementing reforms, like secure fishing rights, is critical to providing the combined benefits of increased fish populations, profits and food production. Allocating fishing rights is a management approach that ends the desperate race for fish by asking fishermen to adhere to strict, science-based catch limits in exchange for a right to a share of the catch or to a traditional fishing area.

Since 2000, overfishing in U.S. federal waters has dropped 70 percent as the number of species managed with fishing rights or “catch shares” has quadrupled. In the past three years fishing-industry jobs have increased by 31 percent and fishermen revenues by 44 percent.

“Our research reveals a stark choice: manage fisheries sustainably and realize the tremendous potential of the world’s oceans, or allow status quo to continue to draw down the natural capital of our oceans,” said , the paper’s lead author and a professor of environmental and resource economics at UC Santa Barbara.

Other co-authors are Daniel Ovando, Tyler Clavelle, Steven Gaines, Cody Szuwalski and Reniel Cabral of UC Santa Barbara; C. Kent Strauss, Douglas Rader and Amanda Leland of Environmental Defense Fund; and , a UW postdoctoral researcher in aquatic and fishery sciences.

This research was funded by the David and Lucile Packard Foundation, the Waitt Foundation and the Helmsley Charitable Trust. The national Center for Ecological Analysis and Synthesis provided computational support.

Read related news stories about the study in , , , and .

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This was adapted from an Environmental Defense Fund . For more information, contact Hilborn at rayh@uw.edu.

This is the only population of blue whales known to have recovered from whaling 鈥� blue whales as a species having been hunted nearly to extinction.

Blue whales 鈥� nearly 100 feet in length and weighing 190 tons as adults 鈥� are the largest animals on earth. And they are the heaviest ever, weighing more than twice as much as the largest known dinosaur, the Argentinosaurus. They are an icon of the conservation movement and many people want to minimize harm to them, according to , UW assistant professor of aquatic and fishery sciences.

聽聽聽聽聽聽聽聽聽聽聽 “The recovery of California blue whales from whaling demonstrates the ability of blue whale populations to rebuild under careful management and conservation measures,” said , a UW doctoral student in quantitative ecology and resource management and lead author of a on the subject posted online Sept. 5 by the journal Marine Mammal Science. Branch and , a UW professor of aquatic and fisheries sciences, are co-authors.

California blue whales 颅 are at their most visible while at feeding grounds 20 to 30 miles off the California coast, but are actually found along the eastern side of the Pacific Ocean from the equator up into the Gulf of Alaska.

Today they number about 2,200, according to monitoring by other research groups. That’s likely 97 percent of the historical level according to the model the co-authors used. That may seem to some a surprisingly low number of whales, Monnahan said, but not when considering how many California blue whales were caught. According to Monnahan, Branch and another set of co-authors published earlier this summer in PLOS ONE, approximately 3,400 California blue whales were caught between 1905 and 1971.

“Considering the 3,400 caught in comparison to the 346,000 caught near Antarctica gives an idea how much smaller the population of California blue whales was likely to have been,” Branch said.

The catches of blue whales from the North Pacific were unknown until scientists 鈥� in particular Yulia Ivashchenko of Southern Cross University in Australia 鈥� put on their detective caps and teased out numbers from Russian whaling archives that once were classified as secret but are now public. The numbers Russian whalers had publicly reported at one time were incomplete and inaccurate 颅鈥� something that was admitted in the late 1990s 鈥� but there wasn’t access to the real numbers until recently.

For the work published in PLOS ONE, the scientists then used acoustic calls produced by the whales to separate 鈥� for the first time 鈥� the catches taken from the California population from those whales taken in the western Northern Pacific near Japan and Russia. The two populations are generally accepted by the scientific community as being different. Places where acoustic data indicated one group or the other is present were matched with whaling catches.

In the subsequent Marine Mammal Science paper just out, the catches were among the key pieces of information used to model the size of the California blue whale population over time 鈥� a model previously used by other groups to estimate populations of hundreds of fish and various other whale species.

The population returning to near its historical level explains the slowdown in population growth, noted in recent years, better than the idea of ship strikes, the scientists said.

There are likely at least 11 blue whales struck a year along the U.S. West Coast, other groups have determined, which is above the “potential biological removal” of 3.1 whales per year allowed by the U.S. Marine Mammal Protection Act.

The new findings says there could be an 11-fold increase in vessels before there is a 50 percent chance that the population will drop below what is considered “depleted” by regulators.

“Even accepting our results that the current level of ship strikes is not going to cause overall population declines, there is still going to be ongoing concern that we don’t want these whales killed by ships,” Branch said.

Without ship strikes as a big factor holding the population back 鈥� and no other readily apparent human-caused reason (although noise, chemical pollution and interactions with fisheries may impact them) 鈥� it is even more likely that the population is growing more slowly because whale numbers are reaching the habitat limit, something called the carrying capacity.

“We think the California population has reached the capacity of what the system can take as far as blue whales,” Branch said.

“Our findings aren’t meant to deprive California blue whales of protections that they need going forward,” Monnahan said. “California blue whales are recovering because we took actions to stop catches and start monitoring. If we hadn’t, the population might have been pushed to near extinction 鈥� an unfortunate fate suffered by other blue whale populations.”

“It’s a conservation success story,” Monnahan said.

Funding for students working on the research in Branch’s lab comes through the Joint Institute for the Study of the Atmosphere and Ocean, a collaboration between the National Oceanic and Atmospheric Administration and UW.

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For more information:
–Branch, tbranch@uw.edu
–Monnahan, monnahc@uw.edu

(NOTE: Monnahan is traveling Sept. 6-20)

Blue Whale News,

Journal articles referenced in this release:
–“”
Marine Mammal Science
Co-authors: Cole Monnahan, Trevor Branch and Andr茅 Punt

–“”
PLOS One
June 3, 2014
Co-authors: Cole Monnahan, Trevor Branch, Kathleen Stafford, Yulia Ivashchenko, Erin Oleson