1/28/15 1/28/15

California sea lions in trouble

In mid-December, when moms were raising pups down south, 700-pound males hauled out onto the Moss Landing Harbor visitor dock. One fell asleep with its face in the water. (Leslie Willoughby Contributed) right).

MOSS LANDING -- When baby sea lions are healthy, the curious and bright-eyed creatures sit up on their front flippers and take in the world around them. When humans approach, they skedaddle and leave nothing behind except a fishy, musky smell.But along the Central Coast, sea lion pups in recent years increasingly have been found stranded -- and they're down to skin and bones. "Sometimes they could barely lift their heads, and they were reluctant to move, even when approached," said Claire Simeone, a conservation medicine veterinarian at the Marine Mammal Center in Sausalito. "I could see the outlines of their hipbones and their shoulders."Even in a good year, a sea lion pup has only a 70 percent chance of reaching its first birthday. But in 2013 only 30 percent survived. And by May of that year, almost 1,500 were stranded along the California coast -- up to 10 per day along the Monterey Bay shoreline.To marine biologists, the deaths were the clearest sign yet that California sea lions, whose numbers skyrocketed for decades, are now smacking up against the limits of their environment.The stranded pups should have been with their mothers, but the mothers apparently couldn't get enough nutrition to support them, said Sharon Melin, a researcher with the National Oceanographic and Atmospheric Administration.One reason was that the California Current, which flows south along the coast, moved farther offshore, making sardines and anchovies less available. Working harder to find food, the moms ate more market squid and rockfish, Melin said, and this change in diet may have reduced the quality of their milk.The number of pups rescued from Sausalito to San Luis Obispo by the Marine Mammal Center, which has a facility in Moss Landing, jumped from 35 in 2012 to 111 in 2013. And last year that number increased to more than 239."We're seeing another year of low weight and small body size," Melin said. "We're telling everyone to brace for more sea lion pups on your beaches."Although California sea lions have never been considered endangered, they have been hunted throughout history. Early Californians killed them for food; in the mid-19th century the mammals were hunted for their oil and hides. And from the 1930s to 1950s, they were turned into pet food.According to UC Santa Cruz scientists, the Montrose Chemical Corp. from 1949 to 1970 manufactured DDT and dumped thousands of tons of the insecticide residue through sewage outfalls near the Channel Islands, the main sea lion breeding area in the U.S. During the late 1960s, scientists found hundreds of premature sea lion pups at the islands, and one year half of all pups died. Tests showed that moms that miscarried their pups had at least eight times more DDT in their tissue than did moms that gave birth to fully developed pups.Two key events, however, soon improved the sea lions' fate.Montrose stopped releasing DDT into the breeding area in 1970, and two years later Congress passed the Marine Mammal Protection Act. The number of pups, which had hovered around 11,000 during the mid-1970s, doubled by 1993 and exploded to 60,000 by 2009, according to the National Marine Fisheries Service.But the population is now leveling off.Anticipating more starving pups this winter, the Marine Mammal Center has been ordering medications and training rescue volunteers, Simeone said.In addition to the pups, the center rescued 180 adult sea lions in 2013 and 420 last year. Some were afflicted by hookworm or another parasite, Toxoplasma gondii, which is carried by cats. Others had contracted diseases such as leptospirosis, a bacterial infection that affects their kidneys. And some were poisoned by a nerve toxin called domoic acid, which is found in increasingly widespread blooms of a particular type of algae, according to NOAA. Sea lions eat fish that eat the algae.Domoic acid also sickens humans if they eat shellfish that have eaten the toxic algae. When the Marine Mammal Center finds sea lions poisoned by domoic acid, the staff works with health departments to locate the algae and ban people from collecting shellfish nearby.Marine scientists say that sea lions are the ocean's canaries in a coal mine. "They tell us so much about the health of the ocean," Simeone said.Many fishermen and harbormasters, however, aren't as enamored with the species."If sea lions are around, a salmon sports fisherman doesn't stand a chance," said Roger Thomas, the president of the Golden Gate Fishermen's Association. "A sea lion will tear a fish right off the line and the angler is left with just a head."Thomas has been involved in recreational salmon fishing since he started in Monterey Bay in the 1950s. He has observed the sea lion population boom and wonders whether that may be contributing to pup strandings, he said.At Moss Landing Harbor, the 700-pound mammals cause roughly $100,000 damage each year, said Linda McIntyre, the harbor's general manager.Between 200 and 2,000 sea lions vie for dock space around Monterey Harbor, said Harbormaster Steve Scheiblauer. One year they sank five vessels.When someone tries to get to a boat, the animals usually move out of the way, but they leave vomit and excrement behind. And, he said, because there are so many of them, they are entering places they would ordinarily avoid."Most people love the sea lions and want to protect them," Scheiblauer said. But when he thinks about their future, he said, "I worry that nature will take its course through disease and famine. That would be a tragedy for the animals."

Read original post Contra Costa Times.

1/27/15 1/27/15

Atlantic, Pacific Fish Face Mixing as Arctic Warms

The gradual warming of the Arctic Ocean over the next century will weaken a natural barrier that has separated fish from the Atlantic and Pacific Oceans for millions of years, leading to a mixing of species that could make life difficult in fishing communities from Alaska to Norway.A new study by scientists in Denmark combined current models of climate change, and the biological water temperature and food requirements for 520 fish species native to the two oceans. The report forecast changes in the range of these fish in five-year increments from now until 2100, when the world’s oceans are expected to heat up globally by an average 4 degrees Celsius (7 degrees Fahrenheit)."There will be an interchange of the fish communities between those two seas," beginning as soon as 2050, said Mary Wisz, lead author on the report in Nature Climate Change and a senior ecosystem scientist at Aarhaus University in Denmark. "We know from historical examples that this kind of interchange, when biotas have been separated over long evolutionary time scales, can have huge consequences."In this warmer future, fishermen based in Kodiak, Alaska, could be pulling up Atlantic cod, a prized species normally caught off New England and Northern Europe. A similar change has already started off the coast of Greenland, where fishermen in the last five years have been catching larger numbers of Atlantic mackerel, which prefers more temperate water.Wisz and colleagues say that by 2100, up to 41 species could enter the Pacific and 44 species could enter the Atlantic, through Arctic water passages over Canada or Russia. This interchange will have ecological and economic consequences to ecosystems that at present contribute 39 percent to global marine fish landings.While some fishermen may benefit from the new catches, scientists warn that it's hard to predict exactly what kind of fish will take over, and which will be driven away by the newcomers. It's also possible that several kinds of fish could compete for the same food source – smaller fish, marine shrimp or larvae, for example, leading to a big reshuffling of the existing marine food chain."Some species when they come together they get along," said Peter Moller, curator of fishes at the Natural History Museum of Denmark and another author on the new report. "But of course the Atlantic cod has the potential to become extremely numerous and dominating if it has the right conditions. There is speculation if it gets to a new place, it can be a real game-changer."Moller said the cod is an especially voracious predator of smaller fish, and could impact commercial landings of Alaska Pollock, for example. Around 3 million tons of Alaska pollock are caught each year in the North Pacific from Alaska to northern Japan. Alaska pollock is the world's second most important fish species in terms of total catch.Jason Link, senior scientist for ecosystem management at the National Oceanic and Atmospheric Administration, agreed that the mixing of species will cause changes in the food web in both oceans, but it's hard to predict exactly how it will shake out."Another issue not noted in this paper is what happens in the ecosystem that these fish move out of, do they remain there or do other species replace them from the south?" Link said via e-mail.Another thorny issue is how to manage fishing boats who will likely be plying the rugged Arctic Ocean once commercial harvests become feasible."This work raises important ramifications for fishes in response to changes in sea ice," Link said.Wisz and Moller say their next task is to look at realistic scenarios of predators and prey in the new warmer Arctic ecosystem.

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1/26/15 1/26/15

Monterey Bay Aquarium testing the waters with open source camera

Mercury News | By Samantha Clark, Santa Cruz Sentinel

Rockfish researchers recover a frame carrying a small SeeStar system and a larger, older camera system after a deployment in Monterey Bay. (Francois Cazanave -- MBARI)

MOSS LANDING -- Ocean research can be a costly voyage. Scientists often need expensive, high-tech, complex equipment, which some research institutions might lack the funds to build or buy.So engineers at the Monterey Bay Aquarium Research Institute designed a simple underwater camera and lighting system that is made mostly of hardware store materials. And all for $3,000.Most oceanographic camera systems cost $5,000 to $20,000 and require ships and cranes to carry the heavy equipment.Any researcher can find the directions online to build the camera system themselves. It takes stills and video and operates as deep as 1,000 feet for months at a time."There is a movement to have open source oceanographic equipment," said Chad Kecy, lead designer and MBARI engineer. "Anyone could take our designs and modify them for specific needs they have. It's just a less expensive and easier way of getting cameras in the water."The project began in 2012 when MBARI marine biologist Steve Haddock wanted a cheap and easily deployable camera for researchers around the world to document jellyfish blooms. He also wanted versatility. A lightweight system needed to attach to a pier, be mounted on the seafloor and carried by a robotic submarine.The SeeStar's relatively simple design met Haddock's criteria. It's a GoPro camera with longer battery life and controllable lights all housed inside standard PVC pipe with commercially available electrical cables."We chose materials intentionally that people would be able to purchase at a local hardware store," Kecy said. "The mechanical parts, we tried to get them off the shelf. We were thinking about cost at every step of the way."Researchers have begun testing the waters with the SeeStar system. Instead of using their bulky and expensive cameras, scientists with the Nature Conservancy and Moss Landing Marine Laboratories opted for multiple SeeStar cameras to capture video in Rockfish Conservation Areas along the west coast and seafloor animals under the ice in Antarctica.The California Wetfish Producers Association used SeeStar to photograph the eggs and larvae of market squid. While the squid make up a large and economically important fishery in California, scientists don't know much about what they do when they're not spawning or the best conditions for spawning."If you were to charter at ROV (remotely operated vehicle), I've heard it's like $10,000 a day, which is outrageous and beyond our budgeting," said Diane Pleschner-Steele, executive director of the nonprofit. "Putting together our own SeeStar camera is going to give us a lot of opportunity to understand what's going on within their life cycle. Just by looking at a photograph, we were able to tell which eggs were about to hatch."However, the designers want camera to be even more accessible. The circuit board that controls the system is still complex enough leave non-engineers scratching their heads, so Kecy is looking to replace it with the popular Arduino microcontrollers this year."The camera system could have uses beyond marine research and could be used for monitoring anything long term," Kecy said. "Because it's open source, inexpensive and really easy, it just presents an opportunity for more researchers to cameras out in the water."

1/26/15 1/26/15

Stanford Researchers Strap ‘Crittercam’ Onto Squid

Stanford Researchers Strap ‘Crittercam’ Onto Squid, Discover How They Speak, Hide Themselves

Camera strapped onto a Humboldt squid. (Stanford University)

STANFORD (CBS SF) – Researchers at Stanford University strapped cameras on squid off the coast of Mexico and found the sea creatures likely use visual patterns to communicate and to hide themselves from predators, according to a study released this week.Their study, published in the Journal of Experimental Biology, found Humboldt squid rapidly change their body colors from red to white to red again, in what researchers called “flashing.” They believe the behavior could be a way the squid speak with each other.“The frequency and phase relationships [synchronization] between squid during flashing can be changed and this suggests that there is some information being conveyed that makes minute control over these details important to the squid,” Stanford researcher Hannah Rosen told the journal.The researchers made their findings with the help of so-called “Crittercams” from National Geographic that were strapped onto the squid using Lycra-like “sweaters.”Another behavior found by researchers is called “flickering,” where the squid produce waves of red and white across their bodies, likely to camouflage themselves from predators near the surface. They also observed what could be mating behavior of the squid.Researchers plan to outfit more squid with cameras.

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1/22/15 1/22/15

New SeeStar camera system allows researchers to monitor the depths without sinking the budget

Note: CWPA is now planning to use this camera system in our squid research.

SeeStar camera system mounted on a tripod beneath the Antarctic ice near McMurdo Station. Image courtesy of Stacey Kim, Moss Landing Marine Laboratories.

To build equipment that can operate reliably in the deep sea, MBARI engineers must often use expensive, high-tech materials and complex electronic-control systems. This makes it difficult for researchers at other institutions to build similar equipment, and thus for MBARI to fulfill its goal of sharing its technology with researchers around the world. However, MBARI engineers recently designed a new underwater camera and lighting system which they hope will be simple and inexpensive enough so that almost any researcher could build one.The SeeStar project, as it is called, began as the brainchild of marine biologist Steve Haddock and Electrical Engineer Chad Kecy. Haddock, an expert on jellies, wanted a cheap and easily deployable camera that researchers around the world could use to document jellyfish blooms. He also wanted a system that was versatile enough to be attached to a pier, mounted on a tripod on the seafloor, or carried by a robotic submarine.In designing SeeStar, Kecy worked closely with Mechanical Engineer François Cazenave and Software Engineer Mike Risi. They ended up with a system that costs just under $3,000 in parts, but can operate as deep as 300 meters (almost 1,000 feet) for months at a time.

SeeStar has three parts—a camera, a battery pack, and LED lights—each contained in its own pressure housing. The pressure housings are made of relatively inexpensive PVC pipe with plastic end caps. Kecy said, “We tried to choose parts that you could buy at almost any hardware store—standard PVC tubing, stainless-steel rods and bolts… nothing too exotic.”The three pressure housings are connected using commercially available flexible electrical cables. This modular construction makes SeeStar easy to attach to a variety of platforms. The team selected a camera made by GoPro because it was relatively inexpensive and easy to use. Kecy then designed a custom circuit board to control both the camera and the LED lights.From the beginning, SeeStar was conceived as an open-source project. Kecy explained, “Our goal is to put enough information on the web for someone to build an entire system. There are written instructions, mechanical drawings, electrical schematics, circuit-board build files, and controller code up there on our website. It’s still a work in progress, but at least it’s up there… and we’ll be updating it as we improve the system.”Kecy continued, “One of our biggest challenges was designing a general device that different people could use in different ways, rather than a specific device for a specific task. Doing open-source hardware required a different mindset from our normal engineering development process. We also wanted to keep costs down.”Although SeeStar began as a system for counting jellies, it soon became apparent that the system could be used for all kinds of underwater research. By the end of 2013, other marine researchers began to hear about Kecy’s project. Soon he was being approached by a variety of organizations wanting to try out the camera.

Photograph taken by SeeStar of rockfish and anemones on the seafloor of Monterey Bay. By taking many such images over time, researchers hope to be able to monitor changes in fish populations. Image: (c) 2014 MBARI

One of the first outside groups to show interest in SeeStar was a group of researchers from the Nature Conservancy and Moss Landing Marine Laboratories (MLML), who were studying fish in Rockfish Conservation Areas along the US West Coast. As Kecy put it, “They had an existing camera system, but it was and bulky and expensive, and they were looking for one that was smaller and easier to use. They also wanted multiple cameras, which they could deploy in a number of locations simultaneously.”Working with Cazenave, the researchers used SeeStar to collect short videos at 12 different locations on the seafloor of Monterey Bay, about 100 meters (330 feet) below the surface. They then used these videos to identify and count different types of fish. The group is presently evaluating SeeStar cameras as a tool for monitoring marine protected areas all along the US West Coast.Another group, the California Wetfish Producers Association, used SeeStar to photograph the eggs and larvae of market squid. These squid support one of the most economically important fisheries on the California Coast, yet many aspects of their life cycles are still unknown.Several MBARI researchers have also used SeeStar in their research. One group attached SeeStar to an underwater robot (an autonomous underwater vehicle or AUV) so that they could observe and count jellyfish in the open ocean.Another MBARI group used a SeeStar-equipped AUV to follow a second robotic vehicle as it traveled across the ocean surface. Video from SeeStar confirmed that the AUV was able to track the surface vehicle closely, like a white shark stalking a sea lion. A third MBARI group is using SeeStar to document wear and tear on a buoy that generates electrical power from the ocean waves.The most ambitious SeeStar project is currently under way in Antarctica, where researchers from MLML are using two SeeStar systems to study seafloor animals under the ice near McMurdo Station. In order to deploy the camera in this challenging environment, the researchers must first drill a 25-centimeter (10-inch) hole in the ice, then lower the camera on a folding tripod through the hole and down to the seafloor.In December 2014, one of the Antarctic SeeStar systems successfully recorded still images of the seafloor every 20 minutes for an entire month. As of this writing, two SeeStar systems were just recovered from 200 meters (660 feet) beneath the ice. If this second deployment is successful, the team hopes to return next season to deploy SeeStar beneath the Antarctic ice for an entire year.

Even though the current version of SeeStar is relatively inexpensive, it still uses circuit boards and controllers that may be difficult for non-engineers to build. During 2015, the team will be addressing these issues in several different ways. They will investigate alternative cameras that could provide higher resolution still images and more control of exposure, as well as commercially available underwater lighting systems.Kecy also hopes to replace his existing camera controller board with a new board that works with the popular Arduino microcontrollers. This would make the system as a whole cheaper and easier to use, as well as providing more flexibility in operating the camera. Because an Arduino camera-controller board would have many uses beyond marine research, Kecy hopes that an open-source hardware company might be willing to manufacture and sell his board on line.Once Kecy has the Arduino controller system completed, he plans to take it to “Maker Faires” and similar hobbyist gatherings to generate interest from other potential users. This way, if the project takes off, the user community will come up with improvements of their own.Looking back on the evolution of the SeeStar project, Kecy said, “The most satisfying thing has been getting the camera out there and having people use it. I love it when researchers come back from a deployment and see the videos and are happy with them. It’s great to make something that people not only can use, but also something they get useful results from.”Even though it is still in development, SeeStar is already letting marine researchers see things underwater that they’ve never seen before. It’s also helping MBARI in its continuing efforts to share its high-tech tools with the rest of the world.

MBARI YouTube video on this research:https://www.youtube.com/watch?x-yt-ts=1421828030&x-yt-cl=84411374&v=wZrmUTl8Z68

For more information on this article, please contact Kim Fulton-Bennett:(831) 775-1835, kfb@mbari.org

Read original story: http://www.mbari.org/news/homepage/2015/seestar/seestar.html

1/16/15 1/16/15

The Pacific Sardine Fishery: Then and Now

Sardines and giant kelp, Channel Islands

The Pacific sardine (Sardinops sagax caerulea) is a small pelagic fish found throughout the Pacific Ocean. In California, the Pacific sardine fishery has historically been one of the largest commercial fisheries in the state. The fishery began in the early 1900s, peaked in the late 1930s, and then declined rapidly in the 1940s during a well-known population downturn fueled by oceanic regime changes and fishing pressure. A moratorium was placed on the Pacific sardine fishery from 1967 to 1986. Then, beginning in the 1990s, Pacific sardine landings increased as the population recovered.Today, the Pacific sardine fishery continues to contribute to California’s economy. In 2013, the fishery for Pacific sardine was the fourth largest commercial fishery in the state of California by volume. These landings were valued at over $1.5 million dollars.

Pacific sardine

Since 2000, the commercial fishery off California, Oregon, and Washington has been managed by the Pacific Fishery Management Council under the Coastal Pelagic Species Fishery Management Plan. The commercial fishing season for Pacific sardine runs from July 1 through June 30 of the following year. The season is split up into three periods: July 1 – September 14, September 15 – December 31, and January 1 – June 30, each with an assigned harvest limit. Based on 2014 landings information to date from the second period (September 15- December 31), the preliminary harvest amount for the third period (January 1 – June 30, 2015) will be 5,084 metric tons.For more information about coastwide Pacific sardine landings, please visit the NOAA Fisheries Pacific sardine landings web page. For more information about Pacific sardine history, research, and management, please visit CDFW’s Pacific sardine web page.

Original post by Anna Holder, CDFW Environmental Scientist — CDFW file photos

12/18/14 12/18/14

Unusual Species Highlight West Coast Cetacean and Ecosystem Survey

The research ship Ocean Starr returned to San Diego Wednesday, completing NOAA Fisheries’ first comprehensive survey of whales, dolphins and porpoises and the marine ecosystem off the West Coast in six years. Highlights of the four-month survey included unusual marine mammals and birds drawn by warm ocean conditions, and the first offshore tests of an innovative new system for remotely counting marine mammals through sound.“You don’t know what you will find until you are out on the ship, which is what makes it so important,” said Jay Barlow, chief scientist of the California Current Cetacean and Ecosystem Assessment Survey that stretched from California north to Washington. “This has been a very interesting and surprising survey because we’ve seen species we wouldn’t expect, which gives us information about their distribution as well as about current ocean conditions.”The Survey led by the Southwest Fisheries Science Center identifies and counts cetaceans, seabirds and marine turtles using high-powered binoculars and towed listening arrays. The team also uses a series of specialized nets and oceanographic sampling gear to survey microorganisms that provide important clues about ocean conditions as well to monitor the physical environment through which the ship is traveling. In some cases researchers take tiny biopsies from whales and dolphins for genetic studies of population structure, foraging habits and health.Scientists use the survey results to assess numbers of whales and dolphins and trends in their abundance, which helps determine the degree of protection the species may need.Unusual species sighted included pygmy killer whales seen for the first time off California and warm-water seabirds such as band-rumped storm petrels seen for the first time in the Northeast Pacific. The survey also sighted sei, blue, fin, humpback, killer and short-finned pilot whales. In one instance the crew could hear a particularly loud chorus of singing humpback whales in the open air on deck.The abundance of sei whales was a surprise, with more sightings of this species than the last five surveys combined from 1991 to 2008.The Survey included the first offshore tests of the Drifting Acoustic Spar Buoy Recorder (DASBR), a pioneering system developed at the Southwest Fisheries Science Center to record the calls and other sounds of marine mammals while drifting the open ocean. Crews recover the DASBRs by following a GPS beacon and later acoustic analysis can distinguish the number and density of different species of marine mammals in surrounding waters.The successful launch and recovery of several DASBRs over the course of the survey helps pave the way for longer-term deployment of the devices that cost less than $5,000 each. DASBRs drift in the open ocean and avoid the engine noise of similar arrays towed behind ships. That allows them to collect more data at a lower cost, supplementing traditional surveys that require expensive ship operations.More information can be found on the Southwest Fisheries Science Center and California Current Cetacean and Ecosystem Assessment Survey web sites.View San Diego ABC Channel 10 News and CBS Channel 8 News reports on the California Current Cetacean and Ecosystem Assessment Survey.A selection of photographs from the four-month West Coast cetacean and ecosystem survey can be viewed on flickr.com.

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12/18/14 12/18/14

Climate change projected to drive marine species northward

New study predicts eastern Pacific species shifting poleward by 30 km per decade Contributed by Michael Milstein December 10, 2014Anticipated changes in climate will push West Coast marine species from sharks to salmon northward an average of 30 kilometers per decade, shaking up fish communities and shifting fishing grounds, according to a new study published in Progress in Oceanography.The study suggests that shifting species will likely move into the habitats of other marine life to the north, especially in the Gulf of Alaska and Bering Sea. Some will simultaneously disappear from areas at the southern end of their ranges, especially off Oregon and California.“As the climate warms, the species will follow the conditions they’re adapted to,” said Richard Brodeur, a NOAA Fisheries senior scientist at the Northwest Fisheries Science Center’s Newport Research Station and coauthor of the study. “We’re going to see more interactions between species and there will be winners and losers that we cannot foresee.”Climate models used to project species shiftsThe study, led by William Cheung of the University of British Columbia, estimated changes in the distribution of 28 near-surface fish species commonly collected by research surveys in the northeast Pacific Ocean. The researchers used established global climate models to project how the distribution of the fish would shift by 2050 as greenhouse gases warm the atmosphere and, in turn, the ocean surface.Brodeur cautioned that like any models, climate models carry uncertainty. While they provide a glimpse of the most likely changes in global climate, they may be less accurate when estimating more fine-scale, local changes.“Nothing is certain,” he said, “but we think we have a picture of the most likely changes.”Some species shifts are already being documented as West Coast waters are warming: predatory Humboldt squid from Central and South America have invaded the West Coast of North America in recent years, albacore have shifted to more northerly waters and eulachon have disappeared from warming waters at the southern end of their range.Effects on the marine ecosystem“Thinking more broadly, this re-shuffling of marine species across the whole biological community may lead to declines in the beneficial functions of marine and coastal ecosystems,” said Tom Okey, a Pew Fellow in Marine Conservation at the University of Victoria and a coauthor of the study. “These declines may occur much more rapidly and in more surprising ways than our expected changes in species alone.”The study anticipates warm-water species such as thresher sharks and chub mackerel becoming more prominent in the Gulf of Alaska and off British Columbia. Some predators such as sea lions and seabirds, which rear their young in fixed rookeries or colonies, may find the fish they usually prey on moving beyond predators’ usual foraging ranges.“If their prey moves farther north, they either have to travel farther and expend more energy to get to them, or find something else to eat,” Brodeur said. “It’s the same thing for fishermen. If it gets warmer, the fish they depend on are going to move up north and that means more travel time and more fuel will be needed to follow them, or else they may need to switch to different target species. It may not happen right away but we are likely to see that kind of a trend.”El Nino years, when tropical influences temporarily warm the eastern Pacific, offer a preview of what to expect as the climate warms.Shifts in marine communities may be most pronounced in high-latitude regions such as the Gulf of Alaska and Bering Sea, which the study identifies as “hotspots” of change. Cold-water species such as salmon and capelin have narrower temperature preferences than warmer water species, making them more sensitive to ocean warming and likely to respond more quickly.An intrusion of warm-water species into cooler areas could lead to significant changes in marine communities and ecosystems. The diversity of northern fish communities, now often dominated by a few very prolific species such as walleye pollock, may increase as southern species enter the region, leading to new food web and species interactions.

Albacore tuna have shifted to more northerly waters.

Eulachon have disappeared from warming waters at the southern end of their range.

Humboldt squid from Central and South America have invaded the West Coast of North America in recent years.

According to the study, thresher sharks may become more prominent in the Gulf of Alaska and off British Columbia.

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REPRESENTING CALIFORNIA’S HISTORIC FISHERY