Archive for June, 2018

Jun 29 2018

Stuck on imports: U.S. seafood trade deficit increased in 2017

The U.S. imported more than 6 billion pounds of seafood valued at more than $21.5 billion in 2017. NOAA photo.

Samuel Hill  June 26, 2018

The United States imported more foreign seafood than ever in 2017, according to NOAA.

The U.S. imported more than 6 billion pounds of seafood valued at more than $21.5 billion in 2017. U.S. exports paled in comparison — more than 3.6 billion pounds of seafood were exported, valued at $5.4 billion.

According to NOAA, the United States imports more than 90 percent of the seafood the public consumes, despite its own active industry. The amount of seafood exported for processing and reimported is unknown, but considered “significant” by NOAA.

Commerce Secretary Wilbur Ross has identified reducing this deficit as a priority for the government. One prominent strategy would be increasing the amount of aquaculture-based farming Jennie Lyons, a NOAA spokeswoman, told the Associated Press.

The United States trades in seafood with countries all over the world, and the countries it buys the most from include Canada, China and Chile. Major buyers of U.S. seafood include China, Japan and South Korea.

While markets in China have been growing, those markets are at risk as an all-out trade war seems plausible between China and the United States. On June 15, U.S. and Chinese officials announced a bundle of tariffs, each targeting the other nation’s exports.

President Donald Trump announced a 35 percent tariff on all Chinese goods containing “industrially significant technologies,” an estimated $50 billion worth of Chinese goods. China responded with retaliatory 25 percent tariff on various U.S. exports, including many seafood products. Roughly 170 seafood products have been targeted, including salmon, lobster, shrimp, cod, tuna, pollock, oysters, scallops, Dungeness and snow crab, blackcod and geoduck.

Seafood and fishing industry leaders from all U.S. coasts spoke out against the latest tariffs soon afterward, saying the policy will cost American jobs.


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

Jun 28 2018

Saildrone launch begins test to improve West Coast fisheries surveys

June 2018

Contributed by Michael Milstein

Two autonomous Saildrones launched from Neah Bay, Wash., Tuesday on a summer-long partnership between Saildrone Inc., NOAA Fisheries and Fisheries and Oceans Canada (DFO) to find out whether the wind and solar-powered vehicles can improve the efficiency and accuracy of fisheries surveys off the West Coast.

The two Saildrones will first head to the northern end of Vancouver Island and will then turn south, following a series of transects along the Coast south to San Francisco. Two other Saildrones will join the project fleet next week from Alameda, Calif., following transects from San Francisco south to the Southern California Bight. (See map.)

They will gather acoustic data on Pacific hake (whiting) and pelagic species such as sardines, anchovy and mackerel that make up many of the West Coast’s most important commercial fisheries. Fishermen unloaded 558 million pounds of hake worth about $47 million in ports such as Astoria, Ore., and Westport, Wash., in 2016.

The NOAA ship Reuben Lasker will also follow the transects and gather similar acoustic data for comparison. The Lasker is specially equipped with advanced echosounders for accurately surveying fish populations.

Technicians prepare the first two Saildrones for launch from Neah Bay, Wash. NOAA Fisheries/NWFSC

A fifth Saildrone launching from Alameda in August will test its value for conducting focused fisheries surveys, such gathering data in near-shore areas that large NOAA research ships cannot safely reach. The fifth vehicle will focus particularly on historically important areas for fisheries, such as Monterey Bay and off the San Francisco Bay Area.

“This partnership is putting some of the most important new marine technology to work for the West Coast,” said Toby Garfield, Acting Deputy Director of NOAA Fisheries’ Southwest Fisheries Science Center in La Jolla, Calif., and part of the team directing the fifth Saildrone. “The more complete and accurate data we have, the better decisions our fisheries managers can make in real terms of catch levels and seasons.”

The first two Saildrones left Neah Bay about 1 p.m. Tuesday. The vehicles were operating normally, scientists said, but must travel to Canadian waters before they begin collecting data on their transects heading south. The Saildrone team extended its thanks to the Makah Tribe, which authorized the launch from its marina in Neah Bay.

The northernmost surveys are particularly important for hake, a deep-water fish that supports an international fishery that the United States and Canada manage jointly under the Pacific Whiting Treaty. DFO scientists are assisting in management of the mission.

Please follow the progress of the West Coast Saildrone fisheries mission on the blog “Unmanned! Saildrone Expedition 2018.”

NOAA Fisheries’ Alaska Fisheries Science Center has been testing Saildrone technology, along with NOAA Research’s Pacific Marine Environmental Laboratory in Alaska for the past three years to gather oceanographic data, acoustic data on endangered North Pacific right whales, information on walleye pollock, and for prey surveys within the foraging range of a declining population of northern fur seals. This year, the focus in Alaska will be on studying abundance and distribution of Arctic cod in the Chukchi Sea.

The launch of Saildrones along the West Coast demonstrates NOAA Fisheries’ continued commitment to embrace new technologies to maximize efficiencies and advance its mission.

Teams ready a Saildrone for launch from Neah Bay, Wash. NOAA Fisheries/NWFSC


Originally posted: https://www.nwfsc.noaa.gov/

Jun 25 2018

El Nino, squid tariffs concern California’s ‘wetfish’ sector as prices dive

A California market squid. Photograph courtesy of the National Oceanic and Atmospheric Administration.

 

Facing difficulties in the other pelagic species it catches, squid was a much needed bright spot for the ‘wetfish’ sector in the US state of California. Until last week.

Landings of California market squid (Doryteuthis loligo opalescens) totaled over 68,211 metric tons for the 2017 to 2018 season, which ran from April 2017 until March. That compared to 38,510t for the 2016/17 season, a sign the fishery was climbing back from years of depressed catches due to El Nino.

Nearly 8,200t have been caught during the first three months of the current season, and with the news that the sector’s key export market, China, will impose 25% tariffs on the product on top of existing 27% tariffs, a bountiful season this year may not be a good thing.

“Fishing is slow right now which is probably better because it gives it a chance to adapt,” John DeLuca, president and CEO of the J DeLuca Fish Company, told Undercurrent News.

He said that like other ‘wetfish’ harvesters, his San Pedro, California-based firm has seen China-bound orders cancelled ahead of the July 6 deadline when the new rates are supposed to come into effect.

The solution, DeLuca said, will be to “wake up old customers and markets” such as Malaysia, Indonesia, and the Philippines, although none of those countries buy squid at the prices and volumes that China does currently.

The result, DeLuca predicted, will be lower prices for processors and fishermen. Ex-vessel prices for squid, currently around, $1,000 per metric ton, are poised to go lower to $700, perhaps even as low as $500, he said.

“How far its going to go down, what’s the bottom going to be, we still don’t know,” he said.

‘Wetfish’ worries

Days earlier, squid processors told Undercurrent that prior to the new tariffs China was paying roughly $3,500/t for squid, which included a 27% tariff already. However, once the new 25% tariff ($911.25) is added on, the cost of squid in China will go from a total of $3,645/t to $4,556.25/t, which Chinese buyers likely won’t bear.

For Diane Pleschner-Steele, the executive director of the California Wetfish Producers Association, that means the fishermen and processors could be forced to receive less for their efforts.

“That gets down the slippery slope of, if you’re going to reduce the price you have to pay the boats less and are the boats going to be able to go fishing at the lower price given the fact that fuel is now $4 per gallon?” she said.

New markets remain an option, she added, although it will depend on global supply and demand for squid.

The processors that her group represents are historically known as “wetfish” producers because their target pelagic species —  sardine, anchovy and mackerel — were canned while still wet.

But in addition to the trade woes, Pleschner-Steele said that the return of El Nino conditions could cause further issues. The National Oceanic Atmospheric Administration issued an “El Nino watch” earlier this month for the Pacific.

The agency predicted “neutral” El Nino conditions for the Northern Hemisphere for the rest of the summer with “the chance for El Nino increasing to 50% during fall, and ~65% during winter 2018-19”.

“We’re starting to see all the signs of it again. We’re seeing the red crabs coming again. We’re seeing fish pushing north. Usually when they start catching squid in Oregon it means that El Ninos aren’t far behind,” Pleschner-Steele said.

Unfortunately for wetfish fishermen, conditions for the pelagic species they catch haven’t been optimal either. Anchovy landings have been low, and a judge recently invalidated a rule allowing for a 25,000t quota, mackerel haven’t been plentiful, and the sardine fishery has been closed to directed commercial fishing although an incidental fishery is allowed.


Originally posted: https://www.undercurrentnews.com/ | Author: jason.smith@undercurrentnews.com

Jun 22 2018

China stops buying US squid in advance of tariffs

A California market squid. Photograph courtesy of the National Oceanic and Atmospheric Administration.

The 25% retaliatory tariffs that China has promised to slap on about a billion dollars worth of US seafood imports don’t go into effect for another three weeks, but US squid producers already are feeling the pain.

Chinese buyers have started cancelling their orders out of concern that shipments won’t arrive in time, Undercurrent News has learned.

“People are not buying anything right now,” said Jeff Reichle, president of Lund’s Fisheries, a squid harvester, processor and exporter based in Cape May, New Jersey. “China is completely dead.”

China issued its retaliatory tariffs late on Friday, including nearly 200 seafood items along with numerous agricultural goods in a list of some 545 total items worth a combined $50bn, as part of a tit-for-tat trade battle with US president Donald Trump. Trump earlier in the day had updated the list of Chinese products for which he had levied a 25% import tariff, increasing the number to 1,102 worth $50bn.

Calamari. Photo courtesy of Del Mar Seafoods.

Following China’s response, the White House on Monday night further upped the ante by ordering the US Trade Representative to draw up a new list of $200bn-worth of Chinese goods to hit with an additional 10% tariff.

Beijing’s tariffs threaten to hit a number of seafood sectors particularly hard when they go into effect in a few weeks, including the US lobster industry, which counted on China to buy 7,894 metric tons of lobster in 2017 worth $136.9 million.

Not too far behind the US lobster industry in its reliance on China is the US squid industry.

The US sent China 34,713t of squid worth $92.8m in 2017, nearly half of its overall 71,165t squid export volume and more than half of its $181.9m overall export value, based on National Oceanic and Atmospheric Administration data (NOAA).

By comparison, the second and third largest markets for US squid are Vietnam, which imported 8,855t worth $25.4m last year, and Japan, which imported 8,055t worth $21.5m.

‘We’re all dazed and confused here’

In particular, it’s the California market squid (Doryteuthis loligo opalescens) that the Chinese love. China imports roughly 70% of the 107,048 metric tons of the species caught off the California coast, estimates Joe Cappuccio, founder and president of Del Mar Seafoods, the US’ largest harvester and processor of the species.

Smaller and less expensive than most other squid, the California market squid can reach a total “tube length” of 28 cm, though a more typical size is 10 to 15 cm. They live just six to nine months, dying shortly after they reproduce, but are known for being able to handle a high amount of fishing pressure.

The California squid fishery was started in 1863 by Chinese immigrants, who used torches at night to attract them and skiffs to encircle a net around them. Today they’re caught by purse seiners and light boats who still use lights to draw them in.

When it comes to consuming the creature, “there is no substitute for California squid”, Reichle said. “The person that goes to a restaurant in China and orders a lobster is not the same person that orders squid. The squid, in China, is eaten by everyone, regardless of income level.”

Americans see squid and think calamari. But in China, squid is often served in a hotpot, dropping it into boiling water at a table. As a result, it’s popular during winter months.

China’s move was a punch to the gut for Del Mar, Cappuccio said. His company maintains eight of its own squid harvesting vessels and contracts with three other independent boats to harvest 20% to 25% of the California quota.

Lund’s, which also maintains a West Coast operation, catches and processes about 10% of California’s squid, said Reichle.

“We’re all dazed and confused here,” Cappuccio said on Tuesday.

China recently has paid top dollar for the California squid – roughly $2,700 per metric ton – plus a roughly 27% tariff based on a “minimum price” set by the Chinese government of $3,500 ($945). However, once the new 25% tariff ($911.25) is added on, the cost of squid in China will go from a total of $3,645 per metric ton to $4,556.25, an amount he and Reichle are both convinced the Chinese importers will not being willing to bare.

There are few remaining options for the US companies, except for reducing costs in order to keep the pain as low as possible for the Chinese buyers, the two men said.

“We’re all going to have to cut our margins back, the harvesters and the processors,” Cappuccio said.

On the bright side, as the price of squid is reduced, doors might open in other countries that were outbid by China. Cappuccio mentioned the Philippines, which he suggested could buy eager to buy more than the 1,732t of squid it spent $4.2m on in 2017.

Chinese importers similarly will struggle to replace California squid, Reichle said. There aren’t other kinds of squid that can easily take its place. In recent years when El Ninos, bands of warm ocean water that develop in the central and east-central equatorial Pacific, have hurt production, China simply went without importing as much squid, he said.

Solution needed before October

Undercurrent confirmed at least one report of squid containers on the water that may not get into China. Cappuccio said his company is keeping its fingers crossed for a few that were en route to China on Friday when the news broke about the tariffs.

But it could be worse, he said.

The Monterey Bay area of the California coast where squid are being harvested now accounts for only 20% to 30% of the total annual quota. The much larger portion, roughly 80%, will get harvested in the more southernly California coast between early October and late December.

However, should the Trump administration not be able to work out its differences with China before early October, the US squid industry could be in trouble.

“Come October, our company alone will be packing and shipping 30 containers a day, and we’ve done as many as 40,” Cappuccio said, noting that a single container typically contains 50,000 lbs.

Multiple trade experts have been quoted in the press as expressing skepticism that a deal can be reached between China and the US before July 6, and one trade expert said it could take the rest of the year. But Cappuccio is trying to remain optimistic.

“I think it’s too early right now to know what to think,” he said Tuesday. “We’re all guessing at this point.”


Originally posted: https://www.undercurrentnews.com/2018/06/20/china-stops-buying-us-squid-in-advance-of-tariffs/

Contact the author jason.huffman@undercurrentnews.com

Jun 20 2018

Judge rules for Oceana in California anchovy dispute

Just how many anchovies are there off the northern coast of California and are there enough to fish commercially?

Environmental activist group Oceana and the National Marine Fisheries Service (NMFS) have different answers to those questions, and a federal judge’s ruling recently favored Oceana’s view, reducing opportunities for California fishermen.

At issue is the science that NMFS relied on in reaching a 2016 decision to set the total allowable catch (TAC) for northern California anchovy at 25,000 metric tons. The agency set that limit — even though landings typically only total less than a third of that, 7,300t — judging the stock’s maximum sustainable yield to be 123,000t, and calculating an acceptable biological catch of 100,000t. The TAC was set, conservatively, the agency said, at a fourth of that level.

However, after the 2016 rule was adopted, Oceana sued NMFS in federal court arguing that the rule violated principles established in the the Magnuson-Stevens Act because the agency failed “to articulate the scientific basis for this catch limit”.

In January, judge Lucy Koh approved Oceana’s motion for summary judgment vacating the 25,000t TAC rule. NMFS had asked judge Koh to amend that judgement but last week, she declined to do so. When contacted by Undercurrent News, representatives of NMFS’ parent agency, the National Oceanic and Atmospheric Administration (NOAA), said that its lawyers were reviewing the judgment. It has not decided if it will appeal.

NMFS is currently working on new assessments of the stock to inform future TAC decisions.

Precipitous decline?

In its lawsuit, Oceana, claiming that the anchovy stock had “declined precipitously”, argued that NMFS hadn’t conducted a stock assessment for the species since 1995 and that the true size of the northern anchovy biomass averaged between 10,000t to 15,000t from the 2009 to 2011 period.

It made this claim in part due to a piece of independent research authored by Alec MacCall, which looked at densities of anchovy eggs and larvae.

NMFS argued that that the MacCall study had shortcomings.

“These egg/larval data were collected by the California Cooperative Oceanic Fisheries in a fairly small portion of the range of the stock between San Diego and Point Conception, California,” NMFS lawyers argued, adding that the model used in the study did not take into account anchovies that didn’t spawn during the period studied or laid their eggs elsewhere.

But the judge wrote that “defendants’ arguments fail to discredit the MacCall Study”, and said that because the 25,000t TAC wasn’t based on “best available science”, it would be vacated.

Wetfish worries

Speaking to Undercurrent about the ruling, Diane Pleschner-Steele, the executive director of the California Wetfish Producers Association, also characterized the MacCall study as flawed. Her group’s members have seen a “huge abundance” of anchovy despite concerns that the stock has collapsed.

Pleschner-Steele said that her group worked last year with the California Department of Fish and Wildlife to perform an aerial survey of anchovy stocks.

“The department’s plane flew along the coast inside the area that the NOAA acoustic trawl survey was transecting at the same time, and our spotter pilot estimated tonnage of the schools he observed,” she wrote.   “We documented tens of thousands of tons of coastal pelagic species — both sardine and anchovy —  that the NOAA cruise did not see or factor into its assessment because they survey largely offshore and don’t come into nearshore waters.   This is now recognized as a problem, and we’re hopeful that we can improve stock assessments over time.”

The California ‘wetfish’ industry that traditionally relied on squid harvesting but supplements that fishery with anchovy, sardines and mackerel. Unfortunately for the fishermen, the sardine fishery has been closed to directed commercial fishing — although an incidental fishery is allowed — and mackerel landings have been low in recent years.

“Things are still pretty tenuous. Right now the only fishery we have is squid,” she said.

Original article:  https://www.undercurrentnews.com/ | Contact the author jason.smith@undercurrentnews.com

Jun 11 2018

Choice matters: The environmental costs of producing meat, seafood

Three beef heifers looking into the sun with blue sky background

Which food type is more environmentally costly to produce — livestock, farmed seafood, or wild-caught fish?

The answer is, it depends. But in general, industrial beef production and farmed catfish are the most taxing on the environment, while small, wild-caught fish and farmed mollusks like oysters, mussels and scallops have the lowest environmental impact, according to a new analysis.

Growing oysters at a farm in Thailand. jomkwan/Istock/Thinkstock

The study appears online June 11 in the journal Frontiers in Ecology and the Environment, and its authors believe it is the most comprehensive look at the environmental impacts of different types of animal protein production.

“From the consumer’s standpoint, choice matters,” said lead author Ray Hilborn, a University of Washington professor in the School of Aquatic and Fishery Sciences. “If you’re an environmentalist, what you eat makes a difference. We found there are obvious good choices, and really obvious bad choices.”

The study is based on nearly a decade of analysis, in which the co-authors reviewed hundreds of published life-cycle assessments for various types of animal protein production. Also called a “cradle-to-grave” analysis, these assessments look at environmental impacts associated with all stages of a product’s life.

Of the more than 300 such assessments that exist for animal food production, the authors selected 148 that were comprehensive and not considered too “boutique,” or specialized, to inform their new study.

As decisions are made about how food production expands through agricultural policies, trade agreements and environmental regulations, the authors note a “pressing need” for systematic comparisons of environmental costs across animal food types.

“I think this is one of the most important things I’ve ever done,” Hilborn said. “Policymakers need to be able to say, ‘There are certain food production types we need to encourage, and others we should discourage.’”

Broadly, the study uses four metrics as a way to compare environmental impacts across the many different types of animal food production, including farm-raised seafood (called aquaculture), livestock farming and seafood caught in the wild. The four measures are: energy use, greenhouse gas emissions, potential to contribute excess nutrients — such as fertilizer — to the environment, and the potential to emit substances that contribute to acid rain.

A fishing boat off the coast of Ireland.FrankMirgach/Istock/Thinkstock

The researchers compared environmental impacts across food types by using a standard amount of 40 grams of protein — roughly the size of an average hamburger patty, and the daily recommended protein serving. For example, they calculated how much greenhouse gas was produced per 40 grams of protein across all food types, where data were available.

“This method gives us a really consistent measurement people can relate to,” Hilborn said.

The analysis showed clear winners that had low environmental impacts across all measures, including farmed shellfish and mollusks, and capture fisheries such as sardines, mackerel and herring. Other capture fish choices with relatively low impact are whitefish like pollock, hake and the cod family. Farmed salmon also performed well. But the study also illuminated striking differences across animal proteins, and the researchers advise that consumers must decide what environmental impacts are most important to them when selecting their food choices.

Some of the additional findings include:

  • Overall, livestock production used less energy than most forms of seafood aquaculture. Farmed catfish, shrimp and tilapia used the most energy, mainly because constant water circulation must be powered by electricity.
  • Catfish aquaculture and beef produce about 20 times more greenhouse gases than farmed mollusks, small capture fisheries, farmed salmon and chicken.
  • Mollusk aquaculture — such as oysters, mussels and scallops — actually absorb excess nutrients that are harmful to ecosystems. In contrast, livestock beef production rated poorly in this measure, and capture fisheries consistently scored better than aquaculture and livestock because no fertilizer is used.
  • Because livestock emit methane in their manure, they performed poorly in the acid rain category. Farmed mollusks again performed the best, with small capture fisheries and salmon aquaculture close behind.
  • For capture fisheries, fuel to power fishing boats is the biggest factor, and differences in fuel use created a large range of performance in the greenhouse gas category. Using a purse sein net to catch small schooling fish like herring and anchovy uses the least fuel and, perhaps surprisingly, pot fisheries for lobster use a great deal of fuel and thus have a high impact per unit of protein produced. Dragging nets through water, known as trawling, is quite variable and the impact appears to be related to the abundance of the fish. Healthy stocks take less fuel to capture.
  • When compared to other studies of vegetarian and vegan diets, a selective diet of aquaculture and wild capture fisheries has a lower environmental impact than either of the plant-based diets.

In the future, the researchers plan to look at biodiversity impacts as another way to measure environmental costs. The analysis also mentions a range of other environmental impacts such as water demand, pesticide use, antibiotic use and soil erosion that were addressed in some of the studies they reviewed, but not consistently enough to summarize in the study.

Co-authors are Jeannette Banobi, a former UW research assistant in aquatic and fishery sciences; Teresa Pucylowski and Tim Walsworth, former UW graduate students; and Stephen Hall of Avalerion Capital.

The study was partially funded by the Seafood Industry Research Fund.

###

For more information, contact Hilborn at rayh@uw.edu.

Jun 6 2018

The Cost of Food

Everything we eat has environmental costs. We trade human health and nutrition for some necessary amount of environmental disturbance, though we should always strive to reduce our dietary impact. Seafood causes less environmental damage than any other animal proteins and should be considered in any low-impact diet.

Read it here:

http://sustainablefisheries-uw.org/seafood-101/cost-of-food/

Jun 6 2018

Fish will migrate as temperatures warm, putting fisheries at risk

A new paper projects how warming ocean temperatures will affect the geographic distribution of 686 commercially important species around North America. Species migration and shifting home ranges have serious implications for natural resource management, particularly fisheries.

Read about it here:
http://sustainablefisheries-uw.org/fish-will-migrate-as-temperatures-warm/

Research Article:

Projecting shifts in thermal habitat for 686 species on the North American continental shelf

Jun 3 2018

Marine heatwaves are getting hotter, lasting longer and doing more damage

Marine heatwaves occur everywhere in the ocean. Credit: Eric Oliver/Dalhousie University

On land, heatwaves can be deadly for humans and wildlife and can devastate crops and forests.

Unusually warm periods can also occur in the ocean. These can last for weeks or months, killing off kelp forests and corals, and producing other significant impacts on marine ecosystems, fishing and aquaculture industries.

Yet until recently, the formation, distribution and frequency of marine heatwaves had received little research attention.

Long-term change

Climate change is warming ocean waters and causing shifts in the distribution and abundance of seaweeds, corals, fish and other marine species. For example, tropical fish species are now commonly found in Sydney Harbour.

But these changes in ocean temperatures are not steady or even, and scientists have lacked the tools to define, synthesize and understand the global patterns of marine heatwaves and their biological impacts.

At a meeting in early 2015, we convened a group of scientists with expertise in atmospheric climatology, oceanography and ecology to form a marine heatwaves working group to develop a definition for the phenomenon: A prolonged period of unusually warm water at a particular location for that time of the year. Importantly, marine heatwaves can occur at any time of the year, summer or winter.

With the definition in hand, we were finally able to analyze historical data to determine patterns in their occurrence.

Analysis of marine heatwave trends

Over the past century, marine heatwaves have become longer and more frequent around the world. The number of marine heatwave days increased by 54 per cent from 1925 to 2016, with an accelerating trend since 1982.

We collated more than 100 years of sea surface temperature data around the world from ship-based measurements, shore station records and satellite observations, and looked for changes in how often marine heatwaves occurred and how long they lasted.

We found that from 1925 to 1954 and 1987 to 2016, the frequency of heatwaves increased 34 per cent and their duration grew by 17 per cent.

These long-term trends can be explained by ongoing increases in ocean temperatures. Given the likelihood of continued ocean surface warming throughout the 21st century, we can expect to see more marine heatwaves globally in the future, with implications for marine biodiversity.

‘The Blob’ effect

Numbers and statistics are informative, but here’s what that means underwater.

 

Yearly count of marine heatwave days from 1900 to 2016, as a global average. Credit: Eric Oliver/Dalhousie University

A marine ecosystem that had 30 days of extreme heat in the early 20th century might now experience 45 days of extreme heat. That extra exposure can have detrimental effects on the health of the ecosystem and the economic benefits, such as fisheries and aquaculture, derived from it.

A number of recent marine heatwaves have done just that.

In 2011, a marine heatwave off western Australia killed off a kelp forest and replaced it with turf seaweed. The ecosystem shift remained even after water temperatures returned to normal, signalling a long-lasting or maybe even permanent change.

That same event led to widespread loss of seagrass meadows from the iconic Shark Bay area, with consequences for biodiversity including increased bacterial blooms, declines in blue crabs, scallops and the health of green turtles, and reductions in the long-term carbon storage of these important habitats.

Similarly, a marine heatwave in the Gulf of Maine disrupted the lucrative lobster fishery in 2012. The warm water in late spring allowed lobsters to move inshore earlier in the year than usual, which led to early landings, and an unexpected and significant price drop.

More recently, a persistent area of warm water in the North Pacific, nicknamed “The Blob”, stayed put for years (2014-2016), and caused fishery closures, mass strandings of marine mammals and harmful algal bloom outbreaks along the coast. It even changed large-scale weather patterns in the Pacific Northwest.

As global ocean temperatures continue to rise and marine heatwaves become more widespread, the marine ecosystems many rely upon for food, livelihoods and recreation will become increasingly less stable and predictable.

The climate change link

Anthropogenic, that is human-caused, climate change is linked to some of these recent marine heatwaves.

For example, human emissions of greenhouse gases made the 2016 marine heatwave in tropical Australia, which led to massive bleaching of the Great Barrier Reef, 53 times more likely to occur.

Even more dramatically, the 2015-16 marine heatwave in the Tasman Sea that persisted for more than eight months and disrupted Tasmanian fisheries and aquaculture industries was over 300 times more likely, thanks to anthropogenic climate change.

For scientists, the next step is to quantify future changes under different warming scenarios. How much more often will they occur? How much warmer will they be? And how much longer will they last?

Ultimately, scientists should develop forecasts for policy makers, managers and industry that could predict the future impacts of marine heatwaves for weeks or months ahead. Having that information would help fishery managers know when to open or close a fishery, aquaculture businesses to plan harvest dates and conservation managers to implement additional monitoring efforts.

Forecasts can help manage the risks, but in the end, we still need urgent action to curb greenhouse gas emissions and limit global warming. If not, marine ecosystems are set for an ever-increasing hammering from extreme ocean heat.

More information on this and related studies can be found on www.marineheatwaves.org.