‘Blob’ research shows ecological effects that halted fishing and hiked whale entanglements

Unprecedented environmental changes inspire new online tools to better spot them next time

NOAA Fisheries West Coast Region

An ecological pileup of unprecedented changes in the ocean off the West Coast beginning about 2014 led to record entanglements of humpback and other whales, putting the region’s most valuable commercial fishery at risk, new research shows.

The findings reflect a new management challenge brought about by a changing climate, recovering whale populations, and fishing pressure, according to the new research published in Nature Communications. The situation calls for new measures to alert fishermen to the risk of entanglements and help managers adjust to more rapid and frequent changes in the marine environment.

“We need to put information in the hands of those who can use it, at a time when it can make a difference,” said Jarrod Santora, a research scientist at NOAA Fisheries’ Southwest Fisheries Science Center (SWFSC) in Santa Cruz, California, and lead author of the research. “We are seeing changes coming at us in ways they never have before.”

Santora and his colleagues are developing a website that will use oceanographic data to forecast the areas where whales are most likely to be feeding off the West Coast. Crab fishermen could then use the information to help decide where–and where not–to set their traps. It may also help managers decide where and when to open–or close–fishing.

The new research teases out the ecological causes and effects that contributed to the spike in reported whale entanglements. Many involved traps set for Dungeness crab, said Nathan Mantua, a research scientist at the SWFSC and coauthor of the research. Reported entanglements have since dropped off but remain higher than before the increase.

“We had all these things that weren’t part of anyone’s experience come together in this remarkable three-year period,” he said.

Conflict Prompts Improved Communication

The entanglements have also prompted environmental lawsuits that threaten to restrict crab fishing. At the same time, though, the focus on entanglements has led to better communication and conversation between fishermen, environmental groups, and managers. Collaborative working groups have also developed tools to better anticipate and avoid entanglement risk.

“If the working group knew then what we know now, it wouldn’t have happened,” said John Mellor, a crab fisherman from San Francisco, referencing the increased entanglements. “The more we understand the whole picture, the better chance we have to mitigate the impacts.”

The driver behind many of the environmental changes was an unprecedented marine heatwave that took hold in 2014. It became known as “the warm Blob,” because of the large expanse of unusually high temperatures that dominated waters off the West Coast. The warm temperatures attracted subtropical species rarely seen in the region. The krill that humpback whales typically feed on grew scarce.

The whales switched to feed instead on high concentrations of anchovy that the warm, less productive waters had squeezed into a narrow band near the coast.

At the same time, the higher temperatures fueled a record bloom of toxic algae. It shut down crabbing on the West Coast from November 2015 through March 2016. When toxin levels eased and the Dungeness season finally opened, fishermen set multitudes of crab traps in that same narrow band where many whales were feeding.

NOAA Fisheries’ West Coast Region confirmed a then-record 53 whale entanglements in 2015 and 55 in 2016.

The scientists developed a new measure for ocean conditions called the Habitat Compression Index. It tracks the width of the productive band and how tightly species are coalescing there.

Whale Numbers Reflect Unprecedented Change

Research Biologist Karin Forney, also from the SWFSC and a coauthor of the research, lives in Moss Landing, California. She has a view of Monterey Bay and has long seen occasional humpback whales feeding just offshore. During the “the Blob” years, she would regularly see 30 to 40 whales from her front windows. Local whale watch boats made two to three trips a day to keep up with the demand.

Some 300 whales were counted at once in Monterey Bay.

“In our lifetimes living here, that was unprecedented,” she said. “We knew something dramatically different was pulling these whales closer to shore.”

She is also part of a NOAA team trained to free entangled whales.

“We were on call every day for weeks, with simultaneous reports of two or three entangled whales, so we could respond if they were sighted again,” she said. The team disentangled a few, while others were never seen again.

The lesson of the research, Forney said, is that scientists and fishermen must share information. They can help each other understand how complex environmental connections affect marine species and fisheries. Communication may be one of their most important tools as environmental changes come ever faster.

“Things are dynamic, and things are changing,” she said. “That is not going away.”

Humpback whales feed on anchovy off the Coast of California. New research shows that warm ocean temperatures pushed whales into the same water as crab fishermen, and whale entanglements increased. CREDIT: John Calambokidis/Cascadia Research Collective

Original post: https://www.eurekalert.org/

Dungeness crab larvae already showing effects of coastal acidification

This infographic shows the location of larval Dungeness crab sampling in 2016, examples of impacts from ocean acidification, as well as photos of a larval (left) and adult (right) crab. Credit: Nina Bednarsek, SSCWRP.

A new NOAA-funded study has documented for the first time that ocean acidification along the US Pacific Northwest coast is impacting the shells and sensory organs of some young Dungeness crab, a prized crustacean that supports the most valuable fishery on the West Coast.

Analysis of samples collected during a 2016 NOAA research cruise identified examples of damage to the carapace, or upper shell, of numerous larval Dungeness crabs, as well as the loss of hair-like sensory structures crabs use to orient themselves to their surroundings.

The study was published in the journal Science of the Total Environment.

Impacts to wild crab mirror results of laboratory study

Prior to this study, scientists thought that Dungeness crab were not vulnerable to current levels of ocean acidification, although a laboratory study conducted on Dungeness crab larvae by NOAA’s Northwest Fisheries Science Center in 2016 found that their development and survival suffered under pH levels expected in the future.

“This is the first study that demonstrates that larval crabs are already affected by ocean acidification in the natural environment, and builds on previous understanding of ocean acidification impacts on pteropods,” said lead author Nina Bednarsek, senior scientist with the Southern California Coastal Water Research Project. “If the crabs are affected already, we really need to make sure we start to pay much more attention to various components of the food chain before it is too late.”

What is ocean acidification?
Ocean acidification refers to a reduction in the pH of ocean water, primarily caused by the uptake of carbon dioxide from the atmosphere over long time spans. When CO2 is absorbed by seawater, a series of chemical reactions occur resulting in the increased concentration of hydrogen ions. This increase causes the seawater to increase its acidity and causes carbonate ions to be less abundant.

Carbonate ions are an important building block of structures such as sea shells and coral skeletons that rely on using calcium carbonate for structural growth. Decreases in carbonate ions can make building and maintaining shells and other calcium carbonate structures difficult for calcifying organisms such as oysters, clams, sea urchins, crabs, corals, and some kinds of shelled plankton, such as pteropods.

Close examination reveals patterns of damage
In this study, examination under a high-magnification, scanning electron microscope revealed that the corrosive conditions of coastal waters had affected portions of the fragile, still-developing external shell and legs of the tiny, almost translucent post-larval Dungeness crabs, leaving tell-tale features, such as abnormal ridging structures and scarred surfaces. This could, in turn, impair larval survival by altering swimming behaviors and competence, including the ability to regulate buoyancy, maintain vertical position, and avoid predators.

One of the more important findings of this study was that crabs showing signs of carapace dissolution were smaller than other larvae. This was disconcerting, scientists said, because the damage during the crab’s larval stages could cause potential developmental delays that could increase energy demands and interfere with maturation.

Sensory organ damage seen for the first time
In a surprising discovery, the team found that the low pH water in some coastal areas damaged the canals where hair-like bristles called mechanoreceptors stick out from the shell. These receptors transmit important chemical and mechanical sensations to the crab, and may help crabs navigate their environment. Examination showed that carapace dissolution destabilizes the attachment of the mechanoreceptor anchor, resulting in them falling out in some individuals.

This is a new aspect of crustacean sensitivity to ocean acidification that has not been previously reported. The team hypothesize that the absence or damage of mechanoreceptors within their neuritic canals may in part explain potential aberrant behavioral patterns, such as slower movement, less tactile recognition, and prolonged searching time, as well as impaired swimming, that have been observed in various crustacean species exposed to low pH conditions in laboratory settings.

“We found dissolution impacts to the crab larvae that were not expected to occur until much later in this century,” said Richard Feely, Senior Scientist with NOAA’s Pacific Marine Environmental Laboratory and one of the co-authors of the study.

Combining observations and modelling work, the research team, which included scientists from JISAO, NOAA’s cooperative institute at the University of Washington, from the University of Connecticut, and from Quebec, Britain and Slovenia, demonstrated that the impacts of dissolution were the most severe in the coastal habitats, where crabs grow and mature.

Previous research has indicated that Dungeness crab may also be vulnerable to future declines due to lack of availability of prey – including bivalves such as clams and other bottom-dwelling invertebrate species.

More research needed
Bednarsek emphasized that more research will be needed to determine whether the external dissolution seen in crabs at this early life stage could carry over into later life stages, including the reproductively active adult stage, and what the potential consequences may be for the population dynamics.

“If these larval crab need to divert energy to repair their exoskeletons, and are smaller as a result, the percentage that make it to adulthood will be at best variable, and likely go down in the long-term,” she said.

Ocean acidification is a major concern for West Coast fishery managers, said Rich Childers, Washington Department of Fish and Wildlife’s ocean acidification policy lead. “These data and results give state and tribal fishery managers and policy makers information that’s vital for harvest and conservation planning.”

The research was supported by the NOAA’s Ocean Acidification Program and NOAA’s Pacific Marine Environmental Laboratory.

NOAA Research News, 23 January 2020. Article.

Original post: https://news-oceanacidification-icc.org/

Fish populations around the world are improving

Fish populations around the world are improving

January 16, 2020 — The following was released by Sustainable Fisheries UW:

Let’s enjoy some unequivocal, inarguable good news: a paper published today in PNAS, Hilborn et al. 2020, shows that on average, scientifically-assessed fish populations around the world are healthy or improving. And, for fish populations that are not doing well, there is a clear roadmap to sustainability. With Australia on fire and scares of World War III, the start of 2020 and the new decade has been awful; hopefully Hilborn et al. 2020 can kickstart a decade of ocean optimism.

Hilborn et al. 2020 counters the perception that fish populations around the world are declining and the only solution is closing vast swaths of ocean to fishing. Instead, Hilborn et al. 2020 argues that increasing scientific, management, and enforcement capacity will lead to more abundant and sustainable oceans. The major takeaway of the paper is that fishery management works—when fisheries are managed, they are sustained. The key is following the science-to-management blueprint. Scientific data collection and fishery assessment comes first, then fishing regulation and enforcement of fishing policies. With the blueprint in place, most fisheries around the world are sustainable or improving.

The paper uses updates to the RAM Legacy Stock Assessment Database, a decades-long project to assemble data on fish populations that are scientifically assessed. As of 2019, the database contains data on 882 marine fish populations, representing about half of reported wild-caught seafood. In 2009, the database contained data on only 166, representing a much smaller proportion of global seafood. Researchers have spent the last 10 years adding to the database, and with today’s publication, update the global status of fish stocks. They found that, on average, fish populations are above target levels. Not every stock is doing well, but on average, things are much better than they were 2 decades ago. How nice: an environmental story where things are better now than they were in the past!

The paper describes the global status of fish stocks, but it also tells the story of fishery sustainability from the past 50 years.

Read the full story at Sustainable Fisheries UW

Original post: Copyright © 2020 Stove Boat LLC, All rights reserved.
Saving Seafood | 202-595-1212 | savingseafood.org

Release — Fisheries management is actually working, global analysis shows

FROM: Michelle Ma
University of Washington
206-543-2580
mcma@uw.edu
(NOTE: Researcher contact information at end)

EMBARGOED BY THE PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES
For public release at 12 p.m. Pacific / 3 p.m. Eastern on Monday, Jan. 13, 2020

Fisheries management is actually working, global analysis shows

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 University of Washington to compile and analyze data from fisheries around the world. The results 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 — and it’s totally wrong,” said lead author Ray Hilborn, 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 — or distinct populations of fish — 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 Ana Parma, 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.”

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 Christopher Costello, 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 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’ International Symposium on Fisheries Sustainability in Rome.

The research was funded by the National Center for Ecological Analysis and Synthesis Science for Nature and People Partnership. 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.

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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 Sustainable Fisheries UW, an effort to communicate the science, policies and human dimensions of sustainable fisheries.

Earth’s oceans are hotter than ever — and getting warmer faster

The world’s oceans hit their warmest level in recorded history in 2019, according to a study published Monday that provides more evidence that Earth is warming at an accelerated pace.

The analysis, which also found that ocean temperatures in the last decade have been the warmest on record, shows the impact of human-caused warming on the planet’s oceans and suggests that sea-level rise, ocean acidification and extreme weather events could worsen as the oceans continue to absorb so much heat.

“The pace of warming has increased about 500 percent since the late 1980s,” said one of the study’s authors, John Abraham, a professor of thermal sciences at the University of St. Thomas in St. Paul, Minnesota. “The findings, to be honest, were not unexpected. Warming is continuing, it has accelerated, and it is unabated. Unless we do something significant and quickly, it’s really dire news.”

Abraham and his colleagues found that the rate of ocean warming accelerated from 1987 to 2019 to nearly 4½ times the rate of warming from 1955 to 1986.

According to the study, published Monday in the journal Advances in Atmospheric Sciences, average ocean temperatures in 2019 were 0.075 degrees Celsius (0.135 degrees Fahrenheit) above the 1981-2019 average. While that may seem minuscule, it represents an enormous amount of heat spread out across the world’s oceans, according to the study’s lead author, Lijing Cheng, an associate professor at the Institute of Atmospheric Physics in Beijing.

“The amount of heat we have put in the world’s oceans in the past 25 years equals to 3.6 billion Hiroshima atom bomb explosions,” Cheng said in a statement.

The study, conducted by an international team of 14 scientists, found that oceans have absorbed more than 90 percent of the heat trapped on Earth from greenhouse gas emissions since 1970.

“Oceans are the biggest reservoir of heat and therefore the best indicator of climate change,” Abraham said. “If you want to know how fast the Earth is warming, look at the oceans.”

Scientists are worried by the trend because warmer oceans can increase severe weather and intensify storms.

“It’s like putting weather on steroids,” Johnson said. “We did a study a few years ago that showed Hurricane Harvey in Texas passed over a very warm body of water, and that greatly increased the amount of rainfall.”

Harvey unleashed more than 60 inches of rain over southeastern Texas in 2017, and scientists have said climate change will make storms rainier overall.

Warmer oceans also expand and melt ice, speeding the rise in sea levels and increasing the risk to coastal communities and low-lying infrastructure, said Nick Bond, a professor of atmospheric sciences at the University of Washington in Seattle, who wasn’t involved with the new study. According to the U.N. Intergovernmental Panel on Climate Change, average global sea levels could rise by 0.95 feet to 3.61 feet by the end of the century.

“From Miami Beach to Bangladesh — as sea levels continue to creep up, it’s just going to become less viable to live in these places,” Bond said.

He added that there are other significant societal implications, such as the effect that warming oceans may have on the chemistry and biology of the world’s oceans.

When carbon dioxide is absorbed and mixes with ocean water, chemical reactions make the water more acidic. Some sea creatures and ecosystems, such as corals, struggle with this type of acidification, but Bond said scientists don’t yet know the extent of the potential fallout.

“There are going to be winners and losers, but we don’t know how that will all play out,” he said. “It’s a very complicated system, and we don’t fully understand which species will have to shift their range, which ones may go extinct or which ones may prosper.”

Katie Matthews, chief scientist at Oceana, an ocean conservation organization in Washington, D.C., said ocean warming could have enormous impacts on fisheries around the world, particularly in the tropics.

“The tropics are the areas that have the largest number of people reliant on fish for nutrition, food security and livelihood,” she said. “It’s really unfortunate that the most vulnerable and at-risk populations are going to be the ones most affected.”

The study, which incorporated measurements from the National Oceanic and Atmospheric Administration, used data on ocean temperatures dating to the 1950s. The measurements included recordings of temperatures extending from the sea surface to depths of more than 6,500 feet.

Average ocean temperatures over the years have followed the warming trend, but Abraham said some of the most pronounced warming has taken place in the South Atlantic Ocean, in the Pacific Ocean off the coast of Japan, and in the waters south of Australia.

Abraham said he hopes the findings will spark climate action around the world.

“This isn’t a political issue,” he said. “This is a science issue, and our measurements are telling us that this is a problem and we need to take action.”