Research cruise off California finds life lacking in parts of the ocean
The California Cooperative Oceanic Fisheries Investigation captures a trove of data about what the ocean is like now, and how it compares to conditions decades ago
Scripps CalCOFI scientists and technicians deploy the Conductivity Temperature Depth sensor rosette over the side of the research vessel, Bold Horizon. (Natalya Gallo)
In parts of the California Current this summer, the ocean was clear, azure, and almost empty.The high water clarity, and low biological productivity, were some of the defining features that struck scientists returning from a cruise with the California Cooperative Oceanic Fisheries Investigation (CalCOFI) program, a 70-year study of West Coast waters.Although the lack of life sounds ominous, scientists said it’s neither good, nor bad, but an interesting observation that will add to their knowledge of the California Current.“I have never seen the water so blue in my life,” said Dave Griffith, a fisheries biologist with the National Oceanic and Atmospheric Administration. “It was beautiful. It looked like Lake Tahoe out there. You don’t have upwelling, which is what brings the nutrients up to the surface.”A joint venture of Scripps Institution of Oceanography, the National Oceanic and Atmospheric Administration, and the California Department of Fish and Wildlife, CalCOFI was launched in 1949 as a way to understand the collapse of the once prolific sardine industry in California.It soon expanded to become an exhaustive catalogue of fisheries, marine ecosystems and water chemistry. Its quarterly research cruises capture a trove of data about what the ocean is like now, and how it compares to conditions decades ago.The ocean serves as a vast factory for manufacturing life, with plankton nourishing crustaceans and small fish, which in turn support marine mammals, seabirds, sharks and tuna. This summer, that production system seemed to be on pause, researchers said.“Productivity conditions were very low, we weren’t capturing high biomass in any of our nets,” said Natalya Gallo, a postdoctoral researcher with the program, who volunteered on the cruise. “Marine mammal observations were low. That makes sense, because you have more animals when you have more food.”Without the churning of nutrients from the ocean floor, the system stalls and ocean productivity -- the amount of life produced at all those levels -- declines.That’s normal in the summer, when warmer water slows up-welling of nutrients from the sea floor, but researchers said ocean productivity seemed lower than usual, even for the season.
NOAA scientists and Scripps scientists work together to bring the Manta net back onboard, following a 15-minute sampling period of the ocean surface. Manta net samples often contained gelatinous organisms, copepods, and fish eggs and larvae. (Natalya D. Gallo)
NOAA fisheries scientist, Dave Griffith, prepares to attach the Pairovet, a vertically sampling net, to the winch wire before its deployment. The Pairovet net is primarily used to sample anchovy eggs. (Natalya D. Gallo)
NOAA fisheries scientist, Dave Griffith, holds a newly preserved zooplankton sample up to the light to get a better look at the amphipods and euphausiids in the sample. (Natalya Gallo)
Chief scientist, Dan Schuller, prepares the Conductivity Temperature Depth sensor rosette for deployment as the crew leaves San Diego Bay and heads towards the first sampling station of CalCOFI Cruise BH1907. (Natalya Gallo)
The ability to observe, measure and compare ocean chemistry and biology from year to year is the chief benefit of CalCOFI, which scientists said is the longest running set of marine data in the world.“There was very little biomass at all, at all tropic levels, from (plankton) all the way up to marine mammals,” said CalCOFI Director Brice Siemons. “That is an observation, and we can put that in perspective in our time series, and compare it to all of the last 70 years.”That’s why the 70-year time series of the California Current is so valuable, they said. The ability to maintain a running tally of ocean measurements allows researchers to sort out whether an event, such as this summer’s biological scarcity, is a short-time curiosity, or a long-time trend.Over a 16-day cruise of the Southern California Bight and California Current, researchers took samples of water chemistry, plankton, fish eggs, marine mammal and seabird sightings, and other variables, at 70 research stations in a grid off the coast. Scientists with Scripps, in charge of oceanographic testing, lowered a device fitted with metal cannisters that measures water temperature and chemical properties at depth.NOAA researchers study fisheries by sampling fish eggs and larvae, using four different types of nets. This time, it was slim pickings, particularly in the sea beyond the California Current -- the open waters that scientists refer to as an “ocean desert.”“This was exceptional,” Griffith said. “We weren’t seeing many eggs in the water, which is not uncommon, but there were areas where we were not seeing anything. It was pretty sparse.”It’s unclear why the samples were so scanty as the ocean’s physical conditions didn’t seem out of the norm, said Dan Schuller, chief scientist for the cruise.“There was nothing crazy anomalous in any of the parameters we were looking at,” he said. “Physical parameters -- temperature, salinity, oxygen, chlorophyll -- were pretty standard for a Southern California trip.”Researchers said they’ll have to test their observations of low productivity against the data they get from analyzing their samples in the lab. It may turn out that there was more abundance of life than it appeared at first glance. And even if the ocean was less productive this summer, that could be part of cycles of boom and bust in marine populations.Warm waters in recent years have suppressed some fish populations, but also led to favorable conditions for other species popular with fishermen.“Fishes, especially near-shore commercial fishes -- kelp bass, rock bass, the marine species that everybody likes to catch -- they can’t particularly pick up and leave,” Siemens said.Other migratory fish, such as yellowfin and bluefin tuna, are drawn to the balmy, near-shore waters, to the delight of San Diego fishermen.“Somewhat counter-intuitively, when the water’s warm, and production is low, you get some of the best commercial fisheries, which is really good for our economy,” he said.Although their biological samples were low overall, scientists did find creatures, including small crustaceans called copapods, as well as euphausiids, or krill, a shrimp-like crustacean. They pulled up chaetognaths, a transparent predatory worm that “should probably be featured in the next “Aliens” movie,” Gallo said.They also found pyrosomes, a bizarre, colonial organism made up of many small tunicate worms, stitched into a translucent tube that can grow to an imposing 60 feet in length. Gallo said CalCOFI researchers found many smaller ones in their bongo nets -- circular nylon nets shaped, as their name suggests, like bongo drums. The apparent abundance of these otherworldly creatures is exactly the sort of thing that CalCOFI data can put in perspective.“Talking to some of the NOAA fisheries scientists, they said that pyrosomes used to be quite rate, and they didn’t see many,” Gallo said. “So that’s one of the things we can do with our data, and compare to (data from) the 1950s.”Despite high waves, strong winds, storms and seasickness, the cruises are indelible experiences for the scientists on board. For Gallo, the chance to help write a chapter in a one of the most enduring stories of marine science was a professional milestone.“I was out at sea with NOAA scientists who have been doing CalCOFI cruises since before I was born,” she said. “It’s almost three whole (generations of scientific) careers that have been dedicated to this time series that gives us this phenomenal understanding of the dynamics of the ecosystem off the West Coast, and how it has changed in the past, and how it may change in the future with climate change.”For Griffith, a veteran of the CalCOFI cruises, the hard work and long hours are the price of perpetual wonder.“The ocean is a very powerful thing,” he said. “It’s a very resilient source. It’s just a curiosity. We’ll see something different next year. We see fish populations explode and then collapse, but they never go away.... It’s fascinating to watch.”
Scripps CalCOFI scientists and technicians deploy the Conductivity Temperature Depth sensor rosette over the side of the research vessel, Bold Horizon. (Natalya Gallo)
At the nearshore station off San Pedro, NOAA fisheries scientist Amy Hays (left), prepares to recover the Bongo net while Scripps CalCOFI researchers take water samples from the Conductivity Temperature Depth sensor. (Natalya Gallo)
During transit between stations, NOAA fisheries scientists collect fish eggs and larvae and count and identify them to examine fish spawning patterns across the CalCOFI grid.
Angela Klemmedson, research associate for the Scripps CalCOFI group, runs at test to measure the oxygen concentration in discrete water samples collected with the CTD rosette.
Original post: https://www.sandiegouniontribune.com/news/environment/story/2019-08-04/calcofi-cruise-california-current-marine-science-anniversary-warm-ocean-scripps-ucsd-noaa
How much U.S. Seafood is Imported?
According to the latest science, 35-38% of seafood consumed in the U.S. is produced domestically, meaning 62-65% is imported.
The commonly quoted statistic that “90% of seafood consumed in the United States is imported” is out of date and should stop being cited. In this post, I explain the origins of the 90% myth, the scientific paper that produced the updated numbers, and the implications for U.S. trade and seafood markets.Where did the 90% statistic come from and why is the new estimate more accurate?A lot of seafood farmed or caught in the United States is sent overseas for processing, then sent back. Due to varying trade codes that get lost in the shuffle of globalization, these processed seafood products are often mistakenly recorded as ‘imported,’ despite being of U.S. origin.For example, pollock, the fish used in McDonald’s Filet-o-fish sandwich, is caught throughout U.S. waters near Alaska. Once onboard, a significant portion is sent to China (the U.S.’s largest seafood trade partner) to be cleaned, gutted, and processed into filets. After processing in China, the fish is sent back to the U.S. and sold in restaurants and grocery stores. Pollock is not a Chinese fish, but the trade codes used when sending them back from China signify them as Chinese-origin and they are recorded as imported or foreign seafood.Recording fish caught in the U.S. but processed in China has led to a significant overestimation of Americans’ so-called ‘seafood deficit’, or the ratio of foreign to domestic seafood consumption in the U.S.Unfortunately, the misleading 90% deficit statistic has become commonplace, mostly due to coverage of Oceana’s seafood fraud campaign that stoked consumer anxiety about imported seafood. Distorted import data had been taken at face value for several years because no one had pieced together the conversion factors that account for processing and return export/import—until three scientists, Jessica Gephart, Halley Froehlich, and Trevor Branch, published their work in PNAS in May 2019.Knowing the conversion factor for seafood products caught or farmed in the U.S. is the key to accurately estimating the amount of domestic seafood processed abroad. Froehlich describes a conversion factor as a number that can be used to back-calculate a processed seafood item to its pre-processed weight. Basically, when pollock are sent back to the U.S. after being processed in China, a conversion factor can be applied to estimate how much fish was originally sent and domestic seafood statistics can be corrected. When U.S. seafood is processed abroad but consumed in the U.S., it should be counted as domestic seafood consumed domestically.Scientists compiled live weight conversion factor data from NOAA, FAO, and CEPII; then, along with estimates for the amount of seafood processed abroad and imported again, an accurate percentage of domestic seafood consumed domestically was derived. The updated number (35-38%) is over three times higher than commonly reported.
Allison Horst (University of California, Santa Barbara, CA)
The vexing 90% statistic + Twitter = paperThe story of how this paper came to be is different than most other scientific collaborations. Both Gephart and Froehlich had tried to reconcile the 90% statistic in the past, but “neither of us completely followed the breadcrumbs because it was never a primary focus of our typically global research,” according to Froehlich.“I first heard this statistic while working on my PhD and studying global seafood trade. The data I was looking at did not agree with this statistic, but I assumed I must be missing something and pushed it off,” said Gephart.Years later, a discussion on twitter reignited their curiosity and got the researchers in touch. Froehlich explains, “It started with an article posted on Twitter around US imports and what should seemingly be a quite simple question from Trevor about the percent of exports. After all three of us engaged on Twitter (along with several other scientists in the mix), it was clear none of us seafood scientists in fisheries or aquaculture could really, fully trace the numbers completely.”After connecting on Twitter, Gephart reached out to Froehlich and Branch and the three of them began working together to find the correct seafood consumption numbers. Twitter, for all its faults, is still valuable as a connector of people. You can still read through the original discussion from last year that led to the collaboration. Academic conversations that lead to published papers usually happen in hallways, closed meetings, and private conferences; ‘Science Twitter,’ a community of scientists sharing and conversing online, functions like a multidisciplinary scientific conference that everyone can attend. Twitter can stoke collaboration among scientists, but it also makes science more accessible to the public—an important feature when the science has significant political implications.United States Seafood TradeMisleading statistics in fisheries and marine conservation usually circulate with the ebb and flow of the news cycle, but the ‘90% imported seafood’ statistic has unique political implications. Gephart, Froehlich, and Branch noted in their paper:
In recent years, the former US Secretary of State, current US Secretary of Commerce, and members of Congress have all cited the number to call for new policy measures addressing seafood sustainability and dependence on foreign seafood
“I kept hearing this number [90%] repeated and it started to bother me that I couldn’t figure out where the number came from. Then, under the current administration, reducing the seafood trade deficit became a priority and this statistic was being used to support a range of policy changes. If this number was going to be used as support for proposed policies, it felt important to know where the number came from, whether it was right, and whether it is even a good indicator for sustainable fisheries policy,” Gephart told me.Essentially, the misleading 90% statistic has been used to justify recent nationalist/protectionist shifts in U.S. foreign policy: President Trump has lamented the U.S.’s trade deficit with China since he began running for president in 2014. Now in power, he has escalated a trade war that has hit the seafood industry especially hard. For example, Maine lobster (a popular seafood item in China) is now at a 45% price disadvantage compared to Canadian lobster due to the U.S. and China raising tariffs on each other’s imports. Many in the Maine lobster fishery have been laid off as a result.The most mind-numbing implications are the tariffs on “foreign” seafood from China. Remember the pollock example above? It is now potentially tariffed twice, “once going to China and another when it enters back into the states as a processed good,” explained Froehlich. “It’s a bit of cutting off the nose to spite the face for the U.S., which is not helping fishers, farmers, or consumers.”Although it has received less attention and relief efforts than agriculture, US seafood is front and center in the trade war.NOAA has said the U.S. will not tax domestic seafood on the way back from China, but there is currently no way it can differentiate it from other seafood. China has exempted seafood for processing and export, but a retaliatory tariff is a card they still hold.We haven’t seen a misleading fishery statistic taken quite so far politically, but with correct statistics available now, hopefully the Trump administration will flout their history and work towards a policy that benefits working class people like those in the U.S. seafood industry.
Original post: https://sustainablefisheries-uw.org/fact-check/how-much-seafood-is-imported/
Squid Research Update 2018-19
Methodological Overview
The California Wetfish Producer's Association (CPWA) in collaboration with NOAA's Southwest Fisheries Science Center (SWFSC) and the California Department of Fish and Wildlife has been conducting a long-term data collection program targeting California Market Squid paralarvae in Southern California since 2011, and in Monterey since 2014. Sampling sites occur at fixed and known squid spawning and aggregation sites and were selected through a collaborative process involving the squid fishing community, government managers, and independent scientists. These sites are in shallow waters, generally between 40-100 meters, over sandy substrate and often within one km from shore. Sampling effort targets the winter hatching season in southern California, sampling occurs in December, January, and February. Summer surveys are also conducted in SC and Monterey. Depending on funding availability, additional surveys are conducted in spring and autumn. To date, over 1,000 net tows have been collected during 42 survey efforts spanning nine years. Sampling is done on chartered fishing vessels and paralarvae are captured via bongo nets with a 505-micron mesh. Zooplankton volume and preservation, paralarval sorting and identification and other lab work are conducted at the SWFSC. Paralarval ageing is conducted with SWFSC personnel in an on-going project. Paralarval condition is measured by obtaining an average weight for paralarvae at a given station location, as well as measuring lengths of all individuals at a station location, or from 10 randomized individuals if >10 individuals occur at a station.
Overview – Early Winter 2018Market squid paralarval abundance in Southern California (SC) during the winter of 2018 remained very low compared to the long-term mean, and especially compared to paralarval densities found during previous La Niña time periods (prior to 2015), indicating lingering effects from the historic 2015-16 El Niño. The 3-month mean SC paralarval density index (PDI) for the December 2018, and January and February, 2019 winter paralarval hatching season was 3.17 paralarvae per 1,000 m3 of filtered sea-water (± 19 SD). This is down from 7.43 (± 46.9) the previous hatching season (2017-18). The long-term SC winter mean PDI is 51.3 (± 342). Measurements of productivity, both zooplankton displacement volume (ZPDV) and surface chlorophyll (SCHL) declined from the previous year. ZPDV has steadily declined since the onset of the strong El Niño in 2014. Surface chlorophyll concentrations have recovered slightly from the El Niño, but are lower than last year, and still much lower than the previous period of high productivity (Fig. 1). Local sea surface temperature (SST) and the Ocean Niño Index (ONI) both saw cooling periods in 2017, but have warmed slightly during 2018 and 2019. Late Winter Hatching Season, 2019Paralarval abundance, temperature, and ocean productivity began the 2018-19 winter hatching season similarly to previous years, marked by very low abundance, warmer ocean temperatures, and reduced productivity. However, February, 2019, marked a dramatic change. A series of strong winter storms drove coastal upwelling, which cooled surface waters, increased ocean mixing, nutrient availability, zooplankton abundance, and yielded a significant increase in paralarval abundance (Table 1, Fig. 2). Zooplankton biomass and availability seems to be particularly important for market squid, likely due to the high energetic demands required by squids (O'Dor 1982). General Additive Models were used (also see Van Noord & Dorval 2017) to evaluate the importance of oceanographic variables on determining variability in paralarval density for the 2018-19 season. Sea surface temperature, ZPDV, SCHL, and four geographic variables (separating the coast from the Channel Islands and north from south at Santa Monica Bay) explained 48% of the variability in paralarval abundance. Sea surface temperature and ZPDV were particularly important in the model (Fig. 3). Greater paralarval density was associated with lower SST and moderate to high ZPDV.
Monterey Bay Area and Summer Sampling
The Monterey Bay Area was sampled in June, 2018 (n=15) and the paralarvae density index was 10.5 (± 7.18). This was the highest paralarvae abundance measured during the 2018-19 season. Southern California was sampled in June, 2018 and the PDI measured 0.45 (± 0.04). This was the second consecutive year that Monterey PDI values were the highest recorded in a given fishing year, indicating the population's center of distribution may still be north following the anomalous warm water event during 2015-16, indicating that squid are seeking cooler ocean waters and greater food availability.
Understanding Ocean Acidification Impacts to California’s Living Marine Resources – Ocean Science Trust
Helping the State visualize what’s at stake as oceans acidify
Now Available: http://www.oceansciencetrust.org/wp-content/uploads/2019/01/OST-OA-Impacts-Infographic-Final.pdf
OVERVIEW: UNDERSTANDING OA RISKS TO CALIFORNIA’S LIVING MARINE RESOURCES
VISUALIZING IMPACTS OF OA TO LIVING MARINE RESOURCES IN CALIFORNIA
WORKSHOP: DEFINING OCEAN ACIDIFICATION HOTSPOTS IN CALIFORNIA
- Help identify research and data gaps to understanding OA impacts to California’s fishery resources
- Inform species selection for a modeling exercise to identify species vulnerability thresholds
- Provide the groundwork for a quantitative OA or climate vulnerability assessment for California or the West Coast
Originally posted: http://www.oceansciencetrust.org/
Arctic Report Card Shows 'Most Unprecedented Transition in History'
Those are two takeaways from the 2018 Arctic Report Card, which was released Tuesday at the American Geophysical Union conference in Washington, D.C. The 13th year of this peer-reviewed report card features 14 essays by 81 scientists from 12 countries.
Few places will feel the blight of climate change as hard as the Arctic. Our upper pole is warming faster than any other region on Earth, a trend that may be tied to erratic weather patterns across the northern hemisphere.
For the first time, the report card includes a warning about red tide and harmful algal blooms, which are expanding due to a lack of ice and warming ocean temperatures. Toxins from these micro-organisms are threatening marine wildlife and coastal fisheries, imperilling communities that depend on these species.
This year will also enter the record books as the second warmest for the Arctic since 1900, said Emily Osborne of the NOAA Arctic Research Program.
“The only warmer year occured in 2016,” Obsorne said, adding that Arctic air temperatures for the past five years have exceeded all records since the beginning of the 20th century. “The Arctic is experiencing the most unprecedented transition in history.”
Here are three things you need to know about the Arctic Report Card.
Red tide
When you hear about harmful algal blooms, the mind typically wanders to Florida, where thick scums of blue-green algae and clouds of red tide have floated in the state’s warm waters for more than a year.
Due to a warming Arctic Ocean, at least five families of these harmful micro-organisms are now present in other northern waters, like the Chukchi and Bering seas.
“The vast majority of the Arctic ocean has experienced clear long- term trends of warming,” said Karen E. Frey, a geographer and biogeochemist at Clark University in Worcester, Massachusetts. Microscopic creatures are thriving in these waters. Near St. Lawrence Island, for instance, west of the Alaska mainland, aquatic biomass in 2018 increased between 275 and 500 percent relative to the average over the last 14 years.
These harmful algal blooms produce a range of toxins, which can poison other plankton, fish, shellfish, birds and humans. One study of stranded marine mammals — like whales and seals — found the algal toxin domoic acid in all species tested.
Mounting microplastics
This explosion in tiny creatures has been paralleled by the rapid rise of microplastics in the Arctic Ocean. The Arctic Basin contains more microplastic than all other ocean basins in the world, according to a study published in June and cited in the report card, with the highest concentrations stuck in the Beaufort Sea.
These microplastics have made multiple intrusions into the food web, being found in everything from polar cod and seafloor-hugging invertebrates to Arctic birds. The plastic waste has also been found buried in sea ice, which scientists are using to study its abundance.
The major sources of these microplastics remain unclear. They could be floating to the Arctic from other oceans, but some contribution is due to waste like fishing nets and other gear from shipping activities, which have increased substantially since 2009.
The greening of the Arctic continues to gradually grow. Vegetation has expanded overall in the Arctic for the last 36 years, according to the new report card. As shrubs and grasses expand, some species of birds and mammals are thriving. Caribou and wild reindeer, both herbivores, are not part of this lucky class.
Despite growing food sources overall, caribou and wild reindeer are dying
Arctic caribou in North America and Greenland and reindeer in Russia and Norway have declined 56 percent over the last two decades, with their populations dropping from 4.7 million to 2.1 million. Why?
Increased drought and longer spans of hotter weather are causing outbreaks of infectious bacteria and parasites, said Howard Epstein, an ecologist at the University of Virginia. The caribou and reindeer populations are also declining due to a boon in predators and because extreme weather events are occasionally triggering droughts.
Wacky weather and the eviction of older ice
The Arctic pattern most pertinent to our daily lives, here in North America, revolves around warmth.
Warm air temperatures, which are increasing at twice the rate of the remaining world, continue to disrupt the polar jet stream, making it sluggish and unusually wavy. A surge of warm Arctic weather in 2017 coincided with severe winter storms in the eastern United States at the beginning of 2018 and a cold snap in Europe in March. Osborne said the jury is still out on the strength of the connection between Arctic warming and wacky weather in the mid-latitudes, but at the moment, the correlation is solid.
This atmospheric warming also drove declines in Arctic snow cover and caused melting of the Greenland ice sheet. But the biggest loser, in terms of frozen water, is Arctic sea ice. Older packs of Arctic sea ice, which used to be impervious to the annual melting cycle, are thinner and covering less area than they have in the past. The oldest ice has declined by 95 percent in the last 33 years.
“During two weeks in February, which is typically the height of ice growth, the Bering Sea lost a piece of ice the size of Idaho,” said Donald Perovich, a sea ice geophysicist at Dartmouth College in New Hampshire. March witnessed the second lowest sea ice extent in 39 years.
Perovich said this loss is being felt hardest by coastal communities, which used to be buffered by the sea ice. The loss is also exposing communities to massive storm surge and disappearing shorelines. It is also depriving coastal residents of a safe route for hunting and travel.
“In 2018, the effects of persistent Arctic warming continue to mount … pushing the Arctic into unchartered territory,” Obsorne added.
Original post: https://www.kqed.org/
CWPA CPS Nearshore Cooperative Research Survey Video
In cooperation with the California Department of Fish and Wildlife and Southwest Fisheries Science Center, CWPA is developing sampling methods to assess sardine and anchovy in nearshore waters not surveyed in NOAA acoustic trawl surveys. Both sardine and anchovy are abundant in California's coastal waters inshore of current NOAA acoustic trawl surveys; in fact, approximately 70 percent of California coastal pelagic species landings are harvested in waters not surveyed in federal stock assessments. The sharp decline reported for both sardine and anchovy in recent years is belied by our nearshore surveys, and fishermen’s observations, that find increasing populations of both species. Accurate biomass estimates and stock assessments for CPS will benefit sustainable harvest policies, fishermen and seafood processors who produce these species, as well as our fishing communities and seafood consumers.Our aerial survey samples CPS schools using aerial spotter pilots with plane and aerial camera system to fly transects near shore and photo-document schools, coupled with qualified purse seine vessels chartered to capture a subset of the schools identified while the pilot photographs the “point sets.”
Saildrone and NOAA team up to monitor fish populations
Video: http://www.thecwsandiego.com/story/39521848/saildrone-and-noaa-team-up-to-monitor-fish-populations
SAN DIEGO (NEWS 8) - Scientists in La Jolla are using cutting-edge technology to track schools of fish off the west coast.They’re using Saildrone vessels equipped with sonar to monitor the health of the ocean and fish populations.It may look like a sailboat but it's actually a drone, hence the name Saildrone.Five of the unmanned vessels recently completed a six-month mission to track fish populations from Vancouver to San Diego.“It works just like a sailboat and it can sail or tack in a specific corridor. We use the solar panels that you see onboard to power the sophisticated sensor suite that's inside,” said Nora Cohen, a spokesperson for Saildrone, a private company based in Alameda, California.The Saildrone has a satellite connection that allows scientists to control it using a smartphone app.It can stay at sea for up to 12 months. The only reason to bring it back to land is so scientists can download the data.“At the end of the mission we bring the Saildrone back to shore and we transmit the entire, full-resolution data to the scientists for analysis,” said Cohen.On the most recent mission, the Saildrones teamed up with a San Diego based, NOAA research ship: the 200-foot Reuben Lasker.“You can see the draft of a Saildrone is quite small, our draft on (the Reuben Lasker) is 30 feet, so we can't go nearly as close to shore as the Saildrone might be able to,” said Emily Rose, a NOAA Corps lieutenant command onboard the Reuben Lasker.The five drones and the NOAA research ship were all equipped with sonar that locates large schools of fish underwater.Back in La Jolla, researchers at NOAA’s Southwest Fisheries Science Center analyze the underwater sonar images.“That sound bounces off of the fish schools and the intensity of those echoes tells how many fish are in the ocean,” said NOAA researcher Juan Zwolinski.The scientists use NOAA’s 500,000 gallon Ocean Technology Development Tank to make sure the sonar equipment is calibrated using underwater metal targets and live fish.“With this data we estimate the abundance of fish stocks. That's all the anchovies, sardines, mackerel, and so on. We assess them year by year and over time we can track their populations and predict what they will be into the future,” said Zwolinski.NOAA verifies the sonar images captured at sea by lowering nets and actually catching sample fish from the schools detected.“Understanding the population and where the fish are really helps us understand what's going on with the fish stocks, and helps us make educated and informed decisions concerning closing a fishery or restricting fishing until the fishery rebounds,” said NOAA Corps Lt. Cmdr. Rose.
Original post: http://www.thecwsandiego.com/
Quantifying sensitivity and adaptive capacity of shellfish in the Northern California Current Ecosystem to increasing prevalence of ocean acidification and hypoxia
The severity of carbonate chemistry changes from ocean acidification is predicted to increase greatly in the coming decades, with serious consequences for marine species- especially those reliant on calcium carbonate for structure and function (Fabry et al. 2008). The Northern California Current Ecosystem off the coast of US West Coast experiences seasonal variations in upwelling and downwelling patterns creating natural episodes of hypoxia and calcite/aragonite undersaturation, exacerbating global trends of increasing ocean acidification and hypoxia (OAH) (Chan et al. 2008) (Gruber et al. 2012). The goal of these experiments was to identify thresholds of tolerance and attempt to quantify a point at which variance in responses to stress collapses. This study focuses on two species: Cancer magister (Dungeness crab) and Haliotis rufescens (red abalone). These species were selected for this study based on their economic and ecological value, as well as their taxonomic differences. Respirometry was used as a proxy for metabolic activity at four different scenarios mimicking preindustrial, upwelling, contemporary upwelling, and distant future conditions by manipulating dissolved oxygen and inorganic carbon (DIC) concentrations. Both species showed a decrease in mean respiration rate as OAH stressors increase, including an effect in contemporary upwelling conditions. These results suggest that current exposure to ocean acidification (OA) and hypoxia do not confer resilience to these stressors for either taxa. In teasing apart the effects of OAH as multiple stressors, it was found that Dungeness crab response was more strongly driven by concentration of dissolved oxygen, while red abalone data suggested a strong interactive effect between OA and hypoxia. Not only did these two different taxa exhibit different responses to a multiple stressors, but the fact that the Dungeness crab were secondarily impacted by acidification could suggest that current management concerns may need to be focus more strongly on deoxygenation.Gossner H. M., 2018. Quantifying sensitivity and adaptive capacity of shellfish in the northern California current ecosystem to increasing prevalence of ocean acidification and hypoxia. MSc thesis, Oregon State University, 104 p. Thesis.
Original post: https://news-oceanacidification-icc.org/