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 2018

Market 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, 2019

Paralarval 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

Arctic Report Card Shows ‘Most Unprecedented Transition in History’

Arctic Report Card: Update for 2018 – Tracking recent environmental changes, with 14 essays prepared by an international team of 81 scientists from 12 different countries and an independent peer-review organized by the Arctic Monitoring and Assessment Programme of the Arctic Council. See https://www.arctic.noaa.gov/Report-Card

 

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/

Alterations to seabed raise fears for future

The ocean floor as we know it is dissolving rapidly as a result of human activity.

Normally the deep sea bottom is a chalky white. It’s composed, to a large extent, of the mineral calcite (CaCO3) formed from the skeletons and shells of many planktonic organisms and corals. The seafloor plays a crucial role in controlling the degree of ocean acidification. The dissolution of calcite neutralizes the acidity of the CO2, and in the process prevents seawater from becoming too acidic. But these days, at least in certain hotspots such as the Northern Atlantic and the southern Oceans, the ocean’s chalky bed is becoming more of a murky brown. As a result of human activities the level of CO2 in the water is so high, and the water is so acidic, that the calcite is simply being dissolved.

The McGill-led research team who published their results this week in a study in PNAS believe that what they are seeing today is only a foretaste of the way that the ocean floor will most likely be affected in future.

Long-lasting repercussions

“Because it takes decades or even centuries for CO2 to drop down to the bottom of the ocean, almost all the CO2 created through human activity is still at the surface. But in the future, it will invade the deep-ocean, spread above the ocean floor and cause even more calcite particles at the seafloor to dissolve,” says lead author Olivier Sulpis who is working on his PhD in McGill’s Dept. of Earth and Planetary Sciences. “The rate at which CO2 is currently being emitted into the atmosphere is exceptionally high in Earth’s history, faster than at any period since at least the extinction of the dinosaurs. And at a much faster rate than the natural mechanisms in the ocean can deal with, so it raises worries about the levels of ocean acidification in future.”

In future work, the researchers plan to look at how this deep ocean bed dissolution is likely to evolve over the coming centuries, under various potential future CO2 emission scenarios. They believe that it is critical for scientists and policy makers to develop accurate estimates of how marine ecosystems will be affected, over the long-term, by acidification caused by humans.

How the work was done

Because it is difficult and expensive to obtain measurements in the deep-sea, the researchers created a set of seafloor-like microenvironments in the laboratory, reproducing abyssal bottom currents, seawater temperature and chemistry as well as sediment compositions. These experiments helped them to understand what controls the dissolution of calcite in marine sediments and allowed them to quantify precisely its dissolution rate as a function of various environmental variables. By comparing pre-industrial and modern seafloor dissolution rates, they were able to extract the anthropogenic fraction of the total dissolution rates.

The speed estimates for ocean-bottom currents came from a high-resolution ocean model developed by University of Michigan physical oceanographer Brian Arbic and a former postdoctoral fellow in his laboratory, David Trossman, who is now a research associate at the University of Texas-Austin.

“When David and I developed these simulations, applications to the dissolution of geological material at the bottom of the oceans were far from our minds. It just goes to show you that scientific research can sometimes take unexpected detours and pay unexpected dividends,” said Arbic, an associate professor in the University of Michigan Department of Earth and Environmental Sciences.

Trossman adds: “Just as climate change isn’t just about polar bears, ocean acidification isn’t just about coral reefs. Our study shows that the effects of human activities have become evident all the way down to the seafloor in many regions, and the resulting increased acidification in these regions may impact our ability to understand Earth’s climate history.”

“This study shows that human activities are dissolving the geological record at the bottom of the ocean,” says Arbic. “This is important because the geological record provides evidence for natural and anthropogenic changes.”

McGill University (via SienceDaily), 29 October 2018. Article.

Originally posted: https://news-oceanacidification-icc.org/

Startling new research finds large buildup of heat in the oceans, suggesting a faster rate of global warming

The findings mean the world might have less time to curb carbon emissions.

A post-sunset swimmer at Moonlight Beach in Encinitas, Calif., this month. (Mike Blake/Reuters) (MIKE BLAKE/Reuters)

The world’s oceans have been soaking up far more excess heat in recent decades than scientists realized, suggesting that Earth could be set to warm even faster than predicted in the years ahead, according to new research published Wednesday.

Over the past quarter-century, Earth’s oceans have retained 60 percent more heat each year than scientists previously had thought, said Laure Resplandy, a geoscientist at Princeton University who led the startling study published Wednesday in the journal Nature. The difference represents an enormous amount of additional energy, originating from the sun and trapped by Earth’s atmosphere — the yearly amount representing more than eight times the world’s annual energy consumption.

In the scientific realm, the new findings help resolve long-running doubts about the rate of the warming of the oceans before 2007, when reliable measurements from devices called “Argo floats” were put to use worldwide. Before that, differing types of temperature records — and an overall lack of them — contributed to murkiness about how quickly the oceans were heating up.

The higher-than-expected amount of heat in the oceans means more heat is being retained within Earth’s climate system each year, rather than escaping into space. In essence, more heat in the oceans signals that global warming is more advanced than scientists thought.

“We thought that we got away with not a lot of warming in both the ocean and the atmosphere for the amount of CO2 that we emitted,” said Resplandy, who published the work with experts from the Scripps Institution of Oceanography and several other institutions in the United States, China, France and Germany. “But we were wrong. The planet warmed more than we thought. It was hidden from us just because we didn’t sample it right. But it was there. It was in the ocean already.”

Wednesday’s study also could have important policy implications. If ocean temperatures are rising more rapidly than previously calculated, that could leave nations even less time to dramatically cut the world’s emissions of carbon dioxide, in the hope of limiting global warming to the ambitious goal of 1.5 degrees Celsius (2.7 degrees Fahrenheit) above preindustrial levels by the end of this century.

The world already has warmed one degree Celsius (1.8 degrees Fahrenheit) since the late 19th century. Scientists backed by the United Nations reported this month that with warming projected to steadily increase, the world faces a daunting challenge in trying to limit that warming to only another half-degree Celsius. The group found that it would take “unprecedented” action by leaders across the globe over the coming decade to even have a shot at that goal.

Meanwhile, the Trump administration has continued to roll back regulations aimed at reducing carbon emissions from vehicles, coal plants and other sources and has said it intends to withdraw from the Paris climate accord. In one instance, the administration relied on an assumption that the planet will warm a disastrous seven degrees Fahrenheit, or about four degrees Celsius, by the end of the century in arguing that a proposal to ease vehicle fuel-efficiency standards would have only minor climate impacts.

The new research underscores the potential consequences of global inaction. Rapidly warming oceans mean that seas will rise faster and that more heat will be delivered to critical locations that already are facing the effects of a warming climate, such as coral reefs in the tropics and the ice sheets of Greenland and Antarctica.

“In case the larger estimate of ocean heat uptake turns out to be true, adaptation to — and mitigation of — our changing climate would become more urgent,” said Pieter Tans, who is the leader of the Carbon Cycle Greenhouse Gases Group at the National Oceanic and Atmospheric Administration and was not involved in the study.

The oceans absorb more than 90 percent of the excess energy trapped within the world’s atmosphere.

The new research does not measure the ocean’s temperature directly. Rather, it measures the volume of gases, specifically oxygen and carbon dioxide, that have escaped the ocean in recent decades and headed into the atmosphere as it heats up. The method offered scientists a reliable indicator of ocean temperature change because it reflects a fundamental behavior of a liquid when heated.

“When the ocean warms, it loses some gas to the atmosphere,” Resplandy said. “That’s an analogy that I make all the time: If you leave your Coke in the sun, it will lose the gas.”

This approach allowed researchers to recheck the contested history of ocean temperatures in a different and novel way. In doing so, they came up with a higher number for how much warming the oceans have experienced over time.

“I feel like this is a triumph of Earth-system science. That we could get confirmation from atmospheric gases of ocean heat content is extraordinary,” said Joellen Russell, a professor and oceanographer at the University of Arizona. “You’ve got the A team here on this paper.”

But Russell said the findings are hardly as uplifting.

The report “does have implications for climate sensitivity, meaning, how warm does a certain amount of CO2 make us?” Russell said, adding that the world could have a smaller “carbon budget” than once thought. That budget refers to the amount of carbon dioxide humans can emit while still being able to keep warming below dangerous levels.

The scientists calculated that because of the increased heat already stored in the ocean, the maximum emissions that the world can produce while still avoiding a warming of two degrees Celsius (3.6 Fahrenheit) would have to be reduced by 25 percent. That represents a very significant shrinkage of an already very narrow carbon “budget.”

The U.N. panel of climate scientists said recently that global carbon emissions must be cut in half by 2030 if the world hopes to remain beneath 1.5 Celsius of warming. But Resplandy said that the evidence of faster-warming oceans “shifts the probability, making it harder to stay below the 1.5-degree temperature target.”

Understanding what is happening with Earth’s oceans is critical, because they, far more than the atmosphere, are the mirror of ongoing climate change.

According to a major climate report released last year by the U.S. government, the world’s oceans have absorbed about 93 percent of the excess heat caused by greenhouse gases since the mid-20th century. Scientists have found that ocean heat has increased at all depths since the 1960s, while surface waters also have warmed. The federal climate report projected a global increase in average sea surface temperatures of as much as nearly five degrees Fahrenheit by 2100 if emissions continue unabated, with even higher levels of warming in some U.S. coastal regions.

The world’s oceans also absorb more than a quarter of the carbon dioxide emitted annually from human activities — an effect making them more acidic and threatening fragile ecosystems, federal researchers say. “The rate of acidification is unparalleled in at least the past 66 million years,” the government climate report stated.

Paul Durack, a research scientist at the Lawrence Livermore National Laboratory in California, said Wednesday’s study offers “a really interesting new insight” and is “quite alarming.”

The warming found in the study is “more than twice the rates of long-term warming estimates from the 1960s and ’70s to the present,” Durack said, adding that if these rates are validated by further studies, “it means the rate of warming and the sensitivity of the Earth’s system to greenhouse gases is at the upper end.” He said that if scientists have underestimated the amount of heat taken up by the oceans, “it will mean we need to go back to the drawing board” on the aggressiveness of mitigation actions the world needs to take promptly to limit future warming.

Beyond the long-term implications of warmer oceans, Russell added that in the short term, even small changes in ocean temperatures can affect weather in specific places. For instance, scientists have said warmer oceans off the coast of New England have contributed to more-intense winter storms.

“We’re only just now discovering how important ocean warming is to our daily lives, to our daily weather,” she said.

Original post: https://www.washingtonpost.com/

Southern California Coast Emerges as a Toxic Algae Hot Spot

— Posted with permission of SEAFOODNEWS.COM. Please do not republish without their permission. —

Copyright © 2018 Seafoodnews.com

SEAFOODNEWS.COM [University of Southern California] August 23, 2018

A new, comprehensive survey led by USC scientists shows the Southern California coast harbors some of the world’s highest concentrations of an algal toxin dangerous to wildlife and people who eat local seafood.

Episodic outbreaks of algae-produced toxins make headlines every few years when stricken marine animals wash ashore between Santa Barbara and San Diego. The USC research is the most thoroughgoing assessment yet and reveals the growing scale of the problem over the last 15 years. The researchers say their findings can help protect human health and environment by improving methods to monitor and manage harmful algal blooms.

The findings are a “smoking gun” linking domoic acid produced by some types of algae to deaths of marine birds and mammals, according to David Caron, a biologist at the USC Dornsife College of Letters, Arts and Sciences, and postdoctoral researcher Jayme Smith, the study’s main authors.

“We are seeing an increase in harmful algal blooms and an increase in severity,” Caron said. “The Southern California coast really is a hot spot and our study also shows that the concentrations of particulate domoic acid measured in the region are some of the highest – if not the highest – ever reported.”

The findings appear in Harmful Algae.

Domoic acid is produced by microscopic Pseudo-nitzschia, needle-like diatoms in the water; half of the species in its genus can produce the neurotoxin. It can stain the ocean, a condition generically called “red tide,” although this particular toxin is brown. The substance accumulates in shellfish and moves up the food chain, where it attacks the nervous system of fish, birds, seals and sea lions. It can cause amnesic shellfish poisoning (ASP) in people. ASP symptoms include rapid onset of headaches, abdominal pain, cramping, nausea or vomiting; severe symptoms include permanent short-term memory loss, seizures, coma or shock in 48 hours. Although human fatalities are rare, the California Department of Public Health monitors coastal waters and shellfish for the toxin.

The research encompasses the years 2003 to 2017 between Santa Barbara and the Mexico border, and includes new samples and tests collected over the past three years to supplement historical data. The study suggests that while natural processes lead to the formation of blooms, they could be exacerbated by nutrients discharged from man-made sources, including runoff and sewage outfalls.

Among the key findings:

Pseudo-nitzschia is the culprit behind domoic acid. It’s been present along the Southern California coast for decades, but its role in wildlife mortality is recent and increasing.
The world’s highest domoic acid measurement in water occurred near San Pedro in March 2011. It was 52.3 micrograms per liter – about five times higher than a level of concern.
Through the years, researchers found a strong correlation between domoic acid in the water and impaired marine wildlife on shore.
Domoic acid is ever-present offshore, either in shellfish or the water. Some years it’s abundant, while other years it’s scarce.
Conditions are worse in the spring, due to seasonal upwelling of nutrients that spur plankton growth. The toxin is less abundant in the summer and winter.
Domoic acid in shellfish can occur at high concentrations off the coast of San Diego, Orange and Los Angeles counties, but it tends to be more prevalent in Ventura and Santa Barbara counties due to local environmental conditions.
Man-made sources of nutrients contribute to algal blooms, but that doesn’t explain disparities in time and location of some of the domoic acid outbreaks. Other environmental factors are likely in play.
The algae and its toxin diminish on the West Coast when water temperatures exceed 68 degrees Fahrenheit, apparently due to temperature sensitivity of the microorganisms.
Also, a warming Pacific Ocean appears to be helping spread Pseudo-nitzschia species farther north. For example, harmful algal blooms have been widespread along the west coast of North America from Central California to Alaska in the past two years, according to the study. Separately, harmful algae blooms have been reported along the Gulf Coast this summer and the governor of Florida declared a state of emergency for affected counties last week.

The USC study brings together diverse data and observations that shed light on the environmental conditions that promote harmful algal blooms. Of note, an extreme drought across the U.S. Southwest between 2014 and 2016 resulted in very low concentrations of domoic acid off the Southern California coast. The findings imply a link between surface waters flowing to the ocean, or other drought-related conditions, and coastal algal blooms.

Those nuances and uncertainties need further exploration to explain the regional and year-to-year variations favoring toxic algae – key steps before more reliable health forecasts can occur, the USC scientists say.

“Our findings summarize our present level of understanding with respect to this important animal and human health risk in Southern California waters and identify several avenues of research that might improve understanding, prediction and eventually prevention of these harmful events,” Smith said.

Study authors include Smith as lead and corresponding author, Caron as senior author, as well as Paige Connell, Erica L. Seubert, Avery O. Tatters and Alyssa G. Gellene of USC; Richard H. Evans of the Pacific Marine Mammal Center; Meredith D.A. Howard of the Southern California Coastal Water Research Project; Burton H. Jones of the Red Sea Research Center, King Abdullah University of Science and Technology, in Saudi Arabia; Susan Kaveggia of the International Bird Rescue in Los Angeles; Lauren Palmer of the Marine Mammal Care Center in Los Angeles; Astrid Schnetzer of North Carolina State University; and Bridget N. Seegers of the NASA Goddard Space Flight Center and the GESTAR/Universities Space Research Association.

Photo credit: Restless Mind Media/Fotolia

Linda Lindner
Urner Barry 1-732-240-5330 ext 223
Editorial Email: Editor@seafood.com
Reporter’s Email: llindner@urnerbarry.com

Copyright © 2018 Seafoodnews.com

NOAA launches drones to sail the West Coast, survey anchovies, sardines and other fish

(Photo: Courtesy of John Gussman)

A bright orange and yellow drone boat will set sail in August, skimming down the West Coast as it collects data on fish and possibly changes the way experts study the ocean.

It’s one of five on a summer-long expedition to test the drones’ accuracy in assessing West Coast fish stocks. Those surveys help set limits on just how much fish can be caught each year.

“You want to use the best available science to come up with the best estimate of what the stock is, so that you can give a fair shake to the fishermen,” said Toby Garfield, director of environmental research division at Southwest Fisheries Science Center.

Typically, the surveys are done by ship. But the National Oceanic and Atmospheric Administration teamed up with Oceans Canada and Saildrone Inc. to test out the drones.

This is one alternative to collecting the data – one that may be able to go places ships can’t or to better estimate how many fish are out there, Garfield said.

Satellite imagery changed the way researchers looked at the ocean, he said, and “tools like Saildrone will give us another way to actually sample” it.

Two drones were launched last week from Neah Bay, Washington, and a second pair will be launched shortly. All four of those will follow the route of the NOAA ship Reuben Lasker.

Operators control the unmanned watercraft remotely from Saildrone’s headquarters in Alameda, California. Plans call for the drones to collect acoustic data on hake and pelagic fish, like sardines and anchovy, for up to 100 days.

Five Saildrones will be launched on the West Coast this summer. (Photo: Courtesy of John Gussman)

“Our ship is out there now. It’s out doing an 80-day survey from Vancouver Island down to the Mexican border,” Garfield said. “The two pairs are going to replicate that tract.”

Researchers will then compare the ship’s information to what’s collected by the drones to see if the new technology could be used to replicate some of the ship’s surveys.

They already know there will be differences, including that the drones will move slowly, about 1 or 2 knots.

There’s also a chance the drones could come closer to shore than the ships, which could help expand the surveys. Whether that’s possible depends on a lot of variables from the abundance of kelp to the number of recreational boats on the water.

That’s where the fifth drone comes in.

“That’s the one we’re going to try to use to explore whether we can come farther into shore,” Garfield said.

They’ll also want to use that drone to test whether it could sail in front of the ship to pinpoint the best spots to sample and, if instead of chasing the fish, they could use the drone in one area to track them as they swim by.

The fifth drone is scheduled to launch off Alameda on Aug. 13 and will be sailing for about six months. But it may not reach Ventura County.

“Originally, we were going to have the Saildrone operate all the way down to San Diego,” Garfield said Tuesday.

But the company had concerns about the traffic in the Santa Barbara Channel, as well as light winds in the summertime.

They’re going to make a decision closer to the date of the launch, he said. “It’s really going to depend on conditions.”

To follow the drones’ progress, go to NOAA’s blog at https://www.nwfsc.noaa.gov/news/blogs.

Original post and video: https://www.vcstar.com/