Archive for June, 2017

Jun 30 2017

Mysterious ‘sea pickles’ invade the West Coast

Warming waters may be the cause


Pyrosomes are usually found in more tropical waters, but started to appear on the West Coast in 2014. They are made of many small multicellular organisms, “linked together in a tunic to form a tubelike colony that is closed on one end,” according to a release from the Northwest Fisheries Science Center.

A research trip by NOAA in May showed large populations of pyrosomes stretching from approximately 40 to 200 miles off the Oregon coast.

Aaron Baldwin, a fishery biologist for the Alaska Department of Fish and Game, said fishermen were seeing pyrosomes “every few inches.”

“They were reporting them everywhere,” he said.

Pyrosomes off the Oregon coast in May, 2017.

Fishing nightmare

Milstein said the beauty of the creatures can be startling. “When looking at underwater pics of these guys, it’s kinda like looking at the stars.”

Not only are pyrosomes large in numbers, they can also be more than two feet long, leading to complications for fishing boats. Milstein said he’s heard of fishermen towing a net for five minutes and picking up 60,000 pyrosomes. “We’ve heard stories of some nets breaking under the weight of these things.”

According to Baldwin, the pyrosomes first appeared this February, stopping some fishermen in their tracks. “People were not fishing,” Baldwin said, “just returning to port.”

While the number of pyrosomes is down in Alaska from where it was earlier in the year, Baldwin said people are still feeling the impact they had. “Some of these seasons are pretty short,” he said. “So delays like this can have a big impact.”

Originally posted:

Jun 30 2017

Seafood meets science at new marine conservation center

June 26, 2017 – Opah crudo, prepared by chef Davin Waite of Wrench and Rodent Seabasstropub, for a sustainable seafood event at Scripps Institution of Oceanography at UC San Diego. (Jessica Waite)


A new Scripps Oceanography center will include labs, classrooms — and a test kitchen, where chefs and scientists will develop tasty, marketable dishes from sustainable seafood.

Marine researchers discussed the project with top chefs at a forum Monday, where they considered how to take pressure off popular seafood such as tuna and swordfish by creating markets for new delicacies.

Guests at the event sampled some of those specialties, prepared by seafood experts such as San Francisco Michelin Star Chef Matthew Dolan, and Davin Waite, owner of the pioneering Oceanside sushi bar, Wrench & Rodent Seabasstropub. Offerings included fresh sea urchin, halibut crudo, veggies with fish sauce, and bacon sliders made from Opah, a round predator also known as moonfish.

“How do we get those to market?” asked Richard Norris, a professor of paleobiology at Scripps Institution of Oceanography at UC San Diego. “How do we get people to eat these kind of odd-looking things on their plates?”

That’s the question they’ll explore in the new marine conservation facility, to be located in the old National Oceanic and Atmospheric Administration building adjacent to the Scripps campus. The building will undergo renovation starting this December, and open in December 2018, said Steve Gallagher, assistant vice chancellor for Scripps Oceanography.

The facility will have research labs piped with local saltwater, and classrooms where university students, as well as local elementary and high school students, can learn about fisheries and marine ecosystems. It will also feature the test kitchen, where researchers from Scripps and NOAA will collaborate with chefs to determine the best kinds of fish to use and the best way to cook them.

They’ll develop novel recipes using locally caught seafood and parts of fish — such as heads and stomachs — that aren’t typically part of the American diet. The facility will also include a cafe where students, staff and visitors can try out the new creations, Gallagher said.

The plan is part of a push to produce sustainable seafood — including farmed fish, less sensitive species and underutilized parts of fish — that appeals to consumers’ appetites. It capitalizes on San Diego’s unique intersection of marine science and adventurous eating.

“We have the ingredients for a solution,” said Sarah Mesnick, an ecologist and science liason for the National Oceanic and Atmospheric Administration’s Southwest Fisheries Science Center. “We are poised to be the sustainable seafood capital of the world. The chefs in town are setting the bar for seafood at an entirely new level.”

They’re setting it even higher at the new center, where Mesnick compared their vision to that of famed Berkeley chef Alice Waters, whose restaurant “Chez Panisse” popularized the use of local, organic food in gourmet cuisine.

“Not unlike the revolution that Alice Waters did with ‘farm to table,’ they’re doing it with ‘ocean to table,’” Mesnick said.

To accomplish that, Waite said, they’ll need to push consumers past their comfort zone. He’s succeeded in that experiment at the “Wrench and Rodent,” where his zero waste approach to seafood preparation has resulted critically acclaimed dishes such as Kentucky fried tuna heads and sausage made from fish egg casing.

At the new center, chefs and scientists will put their heads together to bring those unconventional but sustainable tastes to a broader group of consumers.

“How do we market it to the American public and what they’re used to?” Waite asked. “How do you make it cool?”

Originally posted:

Jun 20 2017


PORTLAND, OREGON – Two important West Coast groundfish stocks that were formerly overfished have now been rebuilt.

Bocaccio and darkblotched rockfish, which are managed by the Pacific Fishery Management Council, were under strict rebuilding plans that have constrained West Coast fisheries for more than a decade. Bocaccio was declared overfished in 1999, and darkblotched rockfish in 2000; both were rebuilt well before their original target dates.

The Pacific Fishery Management Council is one of eight regional fishery management councils that manage ocean fisheries in the United States. Altogether, the Pacific Council manages more than 100 species of groundfish.

Managing groundfish fisheries under rebuilding plans has been an immense challenge for the Council and the National Marine Fisheries Service (NOAA Fisheries). These plans required sharp reductions in commercial and recreational fisheries targeting groundfish, which included widespread fishing closures through the establishment of Rockfish Conservation Areas off the West Coast and other measures. Since 2003, managing overfished species through area closures such as the Rockfish Conservation Areas has helped to reduce fishing impacts and rebuild overfished groundfish species.  In addition, the groundfish fleet has had to limit fishing for other more abundant species to avoid unintentional catch of the overfished stocks.

“The rebuilding strategies used to achieve this conservation success, coupled with favorable environmental conditions for groundfish productivity, have paid huge dividends in rebuilding our overfished groundfish stocks and resurrecting West Coast groundfish fisheries,” said Council Chair Herb Pollard.

The successful rebuilding of these species reflects the support and sacrifice of West Coast ports and fishermen who recognized the difficult actions and fishing cutbacks necessary to restore the stocks.  The rebuilding of bocaccio and darkblotched rockfish will lead to increased harvest opportunities beginning in 2019.

“By working together, we’ve brought bocaccio and darkblotched rockfish back to where they will again be part of a sustainable West Coast groundfish fishery that creates renewed opportunity for the fishing fleet, as well as more options for seafood consumers,” said Barry Thom, Regional Administrator of NOAA Fisheries West Coast Region.

Between 1999 and 2017, ten West Coast groundfish stocks were declared overfished, as surveys documented their declining numbers. Pacific whiting, for example, was declared overfished in 2002. The Council, working with NOAA Fisheries and the fishing industry, reduced commercial harvests. Combined with strong reproduction and recruitment, the fishing cutbacks led to the rapid rebuilding of Pacific whiting by 2004. The Council and NOAA Fisheries developed rebuilding plans for the other nine overfished stocks—bocaccio, darkblotched rockfish, lingcod, canary rockfish, cowcod, Pacific ocean perch, widow rockfish, petrale sole, and yelloweye rockfish.

Lingcod was declared rebuilt in 2005, and widow rockfish in 2012. Both petrale sole and canary rockfish were declared rebuilt in 2015. Rebuilding plans remain in place for three remaining overfished species: cowcod, Pacific ocean perch, and yelloweye rockfish.  New assessments for Pacific ocean perch and yelloweye rockfish will be reviewed this summer and may be adopted in September.  Cowcod is expected to be rebuilt by 2019.

“The Council is a transparent, science-based, inclusive approach to fisheries management,” said Council Executive Director Chuck Tracy. “Our progress in rebuilding overfished stocks shows the effectiveness of this approach. West Coast fisheries are a model of sustainable resource management, and they will continue to provide healthy seafood, jobs, and support for coastal communities, as well as access to this resource for all Americans.”


The bocaccio and darkblotched rockfish assessments were developed by scientists at NOAA Fisheries and were reviewed by the Council’s scientific advisory bodies.  NOAA Fisheries confirmed the stocks’ status as rebuilt on June 16.

Council Role  

The Pacific Fishery Management Council is one of eight regional fishery management councils established by the Magnuson Fishery Conservation and Management Act of 1976 for the purpose of managing fisheries 3‐200 nautical miles offshore of the United States of America coastline.  The Pacific Council recommends management measures for fisheries off the coasts of California, Oregon, and Washington.



Ms. Jennifer Gilden, Communications Officer,, 503-820-2418

Mr. John DeVore, Groundfish Staff Officer,, 503-820-2280

Mr. Chuck Tracy, Executive Director, 503-820-2280

Mr. Jim Milbury, National Marine Fisheries Service, 310-245-7114

Michael Milstein, National Marine Fisheries Service, 503-231-6268

On the Web

Pacific Fishery Management Council:


Bocaccio stock assessment:

Darkblotched rockfish stock assessment:

NOAA Fisheries article on rockfish rebuilding:

Jun 16 2017

FAQs: West Coast drift gillnet (DGN) fishery & protected species

Current measures minimizing marine mammal and sea turtle entanglements, and NOAA Fisheries’ withdrawal of a proposed rule for hard caps on interactions with protected species


Jun 15 2017

Controversial drift-gill net fishery wins long-fought battle

Federal fishery managers denied a proposal this week to immediately shut down Southern California’s most controversial fishery in the event that wide-mesh gill nets accidentally kill a handful of certain marine mammals or sea turtle species.

The swordfish and thresher shark fishery will remain open, even if it kills several whales or sea turtles, the NOAA’s National Marine Fisheries decided.

The decision not to institute so-called hard caps on the fishery comes after a public review period initiated last year was extended to discuss the law proposed by the state’s Pacific Fishery Management Council in 2014.

For the few dozen fishers who still catch swordfish and thresher sharks off Southern California in deep-water drift gill nets, the decision brought a big sigh of relief.

“It’s a great feeling to know that NOAA is using science and not political pressure to decide this issue,” said longtime local fisherman David Haworth. “We have just a few people fighting against millions of environmentalists who think taking one of anything is too many: That would be great, but we have to feed the whole world.”

The decision was a blow to Oceana, The Pew Charitable Trusts and other conservation groups that have lobbied for years to close the fishery.

“We’re disappointed that NOAA Fisheries decided to abandon these plans. It’s a long time coming,” said Paul Shively, project director for The Pew Charitable Trusts. “We did a poll (in 2015) that showed overwhelming support with Californians to shut down the fishery.

“This still remains the most harmful fishery on the West Coast when it comes to marine mammals and sea turtles.”

Existing protections working

The proposed hard caps would have forced a seasonal closure if gill nets killed two sea turtles or fin, humpback or sperm whales, or four short-fin pilot whales or bottlenose dolphin over a two-year period.

In 2015, 18 drift gill net vessels landed 66 metric tons of swordfish worth $454,000, according to a report by NOAA — the National Oceanic and Atmospheric Administration. Meanwhile, the U.S. imported 8,386 metric tons of the fish from other countries.

Fishers and National Marine Fisheries Service regulators say protections they’ve instituted since the mid-1990s, when drift gill nets were indiscriminately killing tons of marine animals, have come a long way.

“We increased our net size and that helped (reduce bycatch) a lot,” Haworth said. “What’s very discouraging for us right now is that most marine mammal species are on the increase now. They wanted to shut us down over animals that are doing better. So, it was like, ‘What’s going on here?’ ”

NOAA fishery biologist Jim Carretta, who specializes in creating marine mammal protections, said regulations implemented since the 1990s have greatly reduced gill net damage.

Gill nets are now made with wider mesh to allow larger animals to escape, and are placed 36 feet below the ocean’s surface to avoid marine mammal interaction. They also have acoustic pingers that divert dolphins and other species.

“If you have a bycatch problem, you don’t immediately shut down the entire fishery. You start examining what factors are driving the problem,” Carretta said. “We’ve had great success in reducing bycatch in this fishery. But it’s not going to go to zero.”

Regulators and fishers are also testing new technologies to bring additional protections for bycatch, such as a new deep-set buoy gear and electronic observers on boats to monitor catches.

State Sen. Ben Allen, whose district includes much of the South Bay coast, proposed a bill last year that would hasten the use of deep-set buoy gear and ban gill nets. It remains in committee.

“We already have allowable take numbers for these marine mammals,” Carretta said. “The hard cap levels seemed arbitrary to me. They were not thoroughly steeped in the science behind calculating how much bycatch is sustainable.”

The Marine Mammal Protection Act and the Endangered Species Act also continue to set protections for vulnerable marine animals that were hunted to near-extinction.

‘Redheaded stepchild of fishing’

Mike Conroy, president of West Coast Fisheries Consultants that represents fishers, said he believes the rule would have been overturned in the courts if it had passed.

“Twenty years ago, the drift gill net fishery was the Wild West, but I can’t even remember the last time a turtle was caught,” Conroy said. “(The proposed rule) probably wasn’t enforceable anyway.”

Gary Burke, a veteran drift gill net fisher, also said he hasn’t seen a sea turtle in years.

But Shively questioned whether environmentalists can rely on the word of fishers whose livelihood depends on keeping the fishery opened. He advocates for having observers on board every fishing boat to ensure they’re accurately reporting bycatch. Regulators say that’s not feasible.

“We’re been the redheaded stepchild of fishing,” Burke said. “All fisheries have bycatch. But we’ve done great jobs to limit what we can. We are going to have some, but the question is whether we’re killing too many. That’s why NOAA takes estimates and decides how many can be removed to maintain healthy populations.”

Originally posted:

Jun 15 2017

Two Decades Later, Focused Efforts on Reducing Entanglements in Gillnet Fishery Still Paying Off

June 2017

In the early 1990s the drift gillnet fishery targeting swordfish off the U.S. West Coast took a high toll on whales, sea turtles and dolphins, with the drifting nets entangling and killing hundreds of these protected species each year. It was clear that management action was needed to reduce entanglements.


Swordfish. Photo: copyright William Boyce

In 1996, NOAA Fisheries convened a “take reduction team,” under the Marine Mammal Protection Act. The team brought together scientists, fishermen, representatives of environmental organizations, and others to develop strategies that would reduce the entanglements. Those strategies included net modifications and sound-emitting devices.

The recommendations of the Pacific Offshore Cetacean Take Reduction Team (POCTRT) quickly reduced entanglements, as documented by observers aboard fishing vessels in the late 90s. Today, some 25 years later, the drift gillnet fishery that catches swordfish, opah, and some sharks off the West Coast continues to have low impacts on protected species; it entangles very few whales, sea turtles, and dolphins.

Source: Carretta, J.V., J.E. Moore, and K.A. Forney. 2017. Regression tree and ratio estimates of marine mammal, sea turtle, and seabird bycatch in the California drift gillnet fishery: 1990-2015. NOAA Technical Memorandum, NOAA-TM-NMFS-SWFSC-568. 83p. Available online at


Source: Carretta, J.V., J.E. Moore, and K.A. Forney. 2017. Regression tree and ratio estimates of marine mammal, sea turtle, and seabird bycatch in the California drift gillnet fishery: 1990-2015. NOAA Technical Memorandum, NOAA-TM-NMFS-SWFSC-568. 83p. Available online at

“This fishery has made great improvements in the last two decades,” said Barry Thom, Regional Administrator of NOAA Fisheries’ West Coast Region. “If you look at the numbers of whales, turtles, and dolphins affected, they have all declined over the years and remain very low today.”

For instance, the drift gillnet fishery killed or seriously injured almost 20 endangered leatherback turtles per year in some years in the early 1990s. Now leatherback deaths and injuries are rare, with an estimate of just one since 2009. An estimated 50 beaked whales were injured or killed in drift gillnets in some years in the early 1990s, but estimates now show just one seriously injured or killed since 2002.

Humpback whales are among the most common whales off California but estimates show none have been killed or seriously injured in drift gillnets since 2008.

Improvements in the fishery include pingers, which are devices that emit sounds to warn marine mammals away from the gillnets; and net extenders that lower the nets at least 36 feet beneath the surface, leaving room for surface-swimming animals such as dolphins to pass above them. In addition, the agency designated two large conservation areas off the West Coast that are off-limits to drift gillnets when endangered sea turtles are known to frequent the areas.

Above: A large area of ocean off the coast of California and Oregon is off limits to drift gillnet fishing each year to protect endangered leatherback sea turtles.  Another area off southern California is closed during El Nino years (as determined by NOAA Fisheries) when water temperatures are warmer than average and loggerhead sea turtles are likely to be present.

The improvements have helped the drift gillnet fishery off the West Coast provide a local and sustainable domestic source of seafood with less environmental impact than many alternatives, including swordfish from some foreign fisheries that take a greater toll on marine mammals and sea turtles. After years of adaptive management to reduce the fishery’s impacts, the drift gillnet fishery now has impacts on protected species comparable to other U.S. fisheries, including the U.S. Atlantic swordfish longline fishery, which is certified by the Marine Stewardship Council.

Improvements in the fishery have been recognized by others, including the Monterey Bay Aquarium’s Seafood Watch Program that considers swordfish and most other species caught with drift gillnets on the West Coast a “good alternative” for consumers.

“Although sea turtle interactions used to be an issue in this fishery, management measures put into place in 2001 have greatly reduced these incidental encounters,” Seafood Watch said in a recent update of its ratings for swordfish from the West Coast drift gillnet fishery.

While the improvements have been substantial, fishery managers continue to look for additional ways to harvest swordfish with even less impact. The Pacific Fishery Management Council and NOAA Fisheries have encouraged research into new fishing methods such as deep-set buoy gear, which in early trials has proven to catch swordfish with almost no bycatch of non-marketable fish or impacts on protected species.

NOAA Fisheries is also collaborating with industry and co-managers on the West Coast to reduce impacts of other fisheries on large whales off the West Coast.

“We’re always looking for opportunities to reduce impacts on whales, sea turtles, and other protected species,” said Chris Yates, Assistant Administrator for Protected Species in NOAA Fisheries’ West Coast Region. “Fortunately we have built good partnerships, and we’ve made substantial progress.”

LEARN MORE about the fishery and recent management actions

LEARN MORE about North Pacific swordfish harvest and sustainability at FishWatch

WATCH a short movie about efforts in West Coast fisheries to protect sea turtles and marine mammals

Read the original post:

Jun 13 2017

Trump administration overturns rule limiting by-catch of whales, sea turtles and dolphins

The Trump administration decided Monday to withdraw an Obama-era rule limiting the number of whales, sea turtles and dolphins inadvertently caught in nets used by sword fishermen.

At first glance, the decision by the National Oceanic and Atmospheric Administration appears to be part of a pattern by administration officials of overturning or delaying rules that are deemed too burdensome on industry. Federal officials say they moved to scrap the rule based in part on how costly the new rule would have been to fishermen. But they also say it was redundant and not backed by science.

The rule, which was still in the process of being developed, would have set firm limits on the number of sea turtles, whales and dolphins that could be accidentally snared in drift nets. If more than two to four animals became entangled, the entire West Coast sword fishery would be shut down for up to two years.

Part of the problem is the method fishermen use to catch swordfish: long, mesh nets that hang in the water from floats. In the early 1990s, up to 500 dolphins a year were getting tangled in the nets, according to NOAA. Thirty-three beaked whales, so-called because of their long, narrow snouts, got stuck between 1990 and 1996.

In response, California banned drift gillnets in state waters in 1990. Six years later, NOAA convened the Take Reduction Team, a group of scientists, academics, environmentalists and fishermen to try to solve the problem in federal waters.

The team decided fishermen should use “pingers,” baton-like devices that hang from the nets and emit a high-frequency noise only detectable by marine mammals, not fish.

The results were dramatic: after 1996, no beaked whales got stuck. In 2015, less than 50 dolphins were entangled. The numbers declined for other species, too.

But the Pacific Fishery Management Council, which is a similar stakeholder group to the Take Reduction Team and makes fishery management recommendations to NOAA, wanted to go further. The group, which is also made up of a mix of fisherman, scientists, government officials and academics, voted to put into place strict limits on bycatch and recommended NOAA create a new regulation, which the agency began working on in the final months of the Obama administration.

“We should not be killing any” marine mammals, said Geoff Shester, a senior scientist at the advocacy group Oceana, which is not part of the council but supported the proposed rule. He said he was “furious” when he found out NOAA had decided to abandon the rule, especially because it had been crafted with industry support.

“We don’t usually see politics from a high level affect fisheries,” he said. “The fact that this rule was something that came out of the Pacific Fishery Management Council, and was denied, that’s highly unusual.”

But NOAA officials say their decision had nothing to do with politics. Jim Carretta, a research fishery biologist for NOAA in La Jolla, said he was happy to see the rule pulled because he thought the limits that the council set on by-catch were arbitrary.

“They didn’t seem to be informed by the theoretical underpinnings of how marine mammal populations increase and recover,” he said.

He also said the rule was unnecessary, given the progress the Take Reduction Team has had at reducing by-catch.

Finally, he thought the consequence for inadvertently catching just two to four whales, dolphins or sea turtles – the closure of the fishery – was too severe.

“Nobody likes by-catch. No one ever wants to see a dead dolphin. But one always has to put it in the context of the population as a whole,” Carretta said.

In other words, he said if the number of dolphins inadvertently snared isn’t enough to threaten the population as a whole, and allowing fishing will keep fishermen employed, it’s OK.

David Haworth, a sword fisherman from San Diego, agrees. “It upset me they were going to shut down fisheries over one or two marine mammals,” he said. “If we were harming an endangered species, we should not fish, we should shut down.” But the rule, he said, went way beyond that.

Currently, there are just 16 boats that go out each year to catch sword fish – down from over 200 in the 1980s. Haworth says the fish just aren’t there any more — they’ve moved up the coast into areas where sword fishing is even more restricted than it is off the coast of Southern California.

Originally posted:

Jun 13 2017



June 12, 2017 — Speaking at the SeaWeb Seafood Summit on Wednesday, 7 June in Seattle, Washington, U.S.A., University of Washington fisheries researcher Ray Hilborn said the perception that the world’s fish stocks are declining is incorrect, and that fishing could sustainably be stepped up in areas with good management.

Hilborn pointed to figures from the RAM Legacy Stock Assessment Database that indicate that fish stocks dipped through the last part of the 20th century, but have since recovered in many fisheries.

“There is a very broad perception that fish stocks around the world are declining. Many news coverages in the media will always begin with ‘fish stocks in the world are declining.’ And this simply isn’t true. They are increasing in many places and in fact, globally, the best assessments are that fish stocks are actually stable and probably increasing on average now,” Hilborn said.

The RAM Legacy Database collects information on all the stocks in the world that have been scientifically assessed, which is a little more than half of the world’s catch.

“What we don’t really know about is the big fisheries in Asia, in the sense that we don’t have scientific assessments of the trends in abundance,” Hilborn said.

He added that the general consensus is that the status of those stocks is poor, a result of, among other things, poor fisheries management, reinforcing surveys that have shown a direct correlation between high stock abundance and high intensity of management.

“For most of the developed world fisheries’ management is quite intense, and South and Southeast Asia stand out as really not having much in the way of fisheries’ management systems, particularly any form a enforcement of regulations, if regulations exists,” he said.

But in much of the developed world, Hilborn said fish stocks are robust, even when they sometimes get labeled as overfished.

“Overfished is a definition with respect to potential yield, and a stock that is overfished is not necessarily a stock that is going extinct or a stock that has in any sense collapsed. It simply means you’re getting less yield from that stock than you could get if was well-managed,” Hilborn added.

Hilborn generally recommends lower fishing pressure that does not try to maximize sustainable yield, with a potential of up to 20 percent loss on yield. But he added that even this level of fishing will lead to overfished stocks.

“If you really want to have no overfished stocks, you’re going to have to reduce fishing pressure so far that we would probably lose half of the global food production,” Hilborn said.

Originally posted at Seafood Source

Jun 7 2017

Cause of 2015 Toxic Algal Bloom in Monterey Bay Identified

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

Copyright © 2017

Seafood News


SEAFOODNEWS.COM [Monterey Herald] by Tommy Wright – June 7, 2017

Monterey – Upwelling caused the toxic algal bloom that poisoned large numbers of marine animals and led to the closure of commercial fisheries in Monterey Bay in 2015, but a research paper published Monday shows an imbalance between two nutrients may have caused high toxicity levels.

The bloom, considered the most toxic ever observed in the bay, happened in late spring 2015, when scientists from Monterey Bay Aquarium Research Institute, UC Santa Cruz, Moss Landing Marine Laboratories and the National Oceanic and Atmospheric Administration were conducting a large-scale biology experiment in the bay called Ecology and Oceanography of Harmful Algal Blooms.

“It was a great coincidence and what it allowed us to do was to use the technologies that we love to use and to apply to see what’s going on,” said John Ryan, an MBARI oceanographer and lead author of the research paper. “That included these autonomous underwater vehicles that can not only map the environment and the distributions of the toxic algae at very high resolution, they can use their onboard sensors to take samples from the most dense bloom patches so we really know the what the extent of the most toxic populations is.”

The scientists also used environmental sample processors, which Ryan called “basically a laboratory in a can,” anchored at the northern and southern end of the bay. The processors take water samples, break open the algae cells and look at the DNA.

“That identified that one species (Pseudo-nitzschia australis) almost completely dominated this bloom,” Ryan said. “There are some 40 species of Pseudo-nitzschia, but it was this one that’s particularly toxic that dominated the bloom completely.”

While researchers considered unusually warm surface water in the Pacific Ocean a factor in the bloom, which stretched from Central California to the Alaska Peninsula, water in the Monterey Bay wasn’t unusually warm. Upwelling takes place when strong northwest winds move surface water away from the shore, allowing cold water, rich in nitrate, silicate and other nutrients, from deep in the ocean to rise to the surface.

“What was surprising is the warm anomaly had persisted already over a year, this ‘warm blob,’ was completely eliminated locally because of that upwelling of cold, nutrient-rich water,” Ryan said.

The warm water allowed the algae to bloom farther north than normal, which helped cause what Ryan called “the largest spacial scale over which marine mammals had ever been observed to be poisoned by this type of bloom” in the Northeast Pacific. Strong upwelling in Monterey Bay initiated the bloom locally and several milder events allowed the algae to persist and accumulate.
Pseudo-nitzschia australis is a regular inhabitant of Monterey Bay, but the bloom in 2015 contained especially high levels of domoic acid, which led to closures of anchovy, sardine, shellfish and crab fisheries. Algae diatoms need nitrate for biochemical processes, including the production of domoic acid. The diatoms need silicate to grow and reproduce. The researchers concluded the extremely high levels of domoic acid were caused by a low ratio of silicate to nitrate in Monterey Bay.

“This wasn’t a sudden occurrence in 2015, it accompanied the warm blob,” Ryan said. “So even though the temperature itself might not have had a direct effect, it may have had an indirect effect through its influence on ocean chemistry.”

According to Ryan, one of the key questions in understanding, predicting and preventing algal blooms is figuring out if humans have a role in the frequency or the severity of these events.

“We know that when we affect the nutrient chemistry of the coastal ocean, we can influence what types of microscopic algae bloom,” he said. “This very same species can be made more toxic when it’s exposed to urea, which can enter the coastal ocean from wastewater outflow. So we know that’s one example where we have to be careful about how we affect coastal ocean chemistry because it can come back and bite us. But in these case, it appears to be of much more natural, large-scale change in ocean chemistry that lasted at least as long as the warm blob. And we need a little more time of observation to determine if it’s fully returned to normal, or if this is part of a longer-term change in ocean chemistry that could promote more frequent or more severe toxic events.”


Jun 5 2017

Authors of New Research on Forage Fish Respond to Critiques from Lenfest Task Force

June 5, 2017The following was written by authors of a new paper on forage fish that found that previous research likely overestimated the impact of forage fishing. The piece addresses criticisms made by the Lenfest Forage Fish Task Force:

First we note that the press releases and video related to our paper (Hilborn et al. 2017) were not products of the authors or their Universities or agencies. Some of the authors were interviewed for the video, and each of us must be prepared to defend what was said on the video. The LENFEST Task Force authors criticize our statement in the video that:

“What we found is there was essentially no relationship between how many forage fish there are in the ocean and how well predators do in terms of whether the populations increase or decrease.”

Our paper was specifically about U.S. forage fish, where we found very few relationships that were stronger than one might expect by chance. It is certainly likely that there are places where there is a significant relationship, but we noted that the LENFEST report did not include any analysis of the empirical data and relied only on models. Our point is that the models used by the LENFEST Task Force assume there will always be such a relationship, whereas in many, and perhaps most cases there may be little if any impact of fishing forage fish on the abundance of their predators. The scientific literature suggests that central place foragers, such as seabirds and pinnipeds at their breeding colonies, may be exceptions, and we acknowledge as much in our paper (p. 2 of corrected proofs, paragraph starting at the bottom of first column).

Specific response to the “shortcomings” of our study listed in the LENFEST Task Force response

  1. We included species not considered by the LENFEST Task Force to be “forage fish.” We simply looked for harvested fish and invertebrate populations that were an important part (> 20%) of the diet of the predators, and thus we would argue that our analysis is appropriate and relevant to the key question: “Does fishing the major prey species of marine predators affect their abundance?”
  2. The LENFEST Task Force authors criticize our use of estimates of abundance of forage fish provided by stock assessment models, and then suggest that because these models were not designed to identify correlations between predators and prey we were committing the same error that the LENFEST Task Force did, using models for a purpose they were not designed for. This is wrong: the stock assessment models are designed to estimate the abundance of fish stocks and the estimates of forage species we used to examine correlations with predators were considered the best available estimates at the time of the analysis. Similarly, the stock assessment models used for the predatory fish species represent the best available estimate of the abundance, and rate of change in abundance, of these predators. We did not claim the stock assessment models told us anything directly about the relationship between forage abundance and predator rates of change. We simply asked “Is there any empirical relationship between forage species abundance and either the abundance or rate of change in abundance of their predators?” The answer, with very few exceptions, was “no.”
  3. The LENFEST Task Force authors criticize our use of U.S. fisheries because they are better managed than the global average. Most of the key criticisms we made of the LENFEST study were unrelated to how fisheries are managed, but to the basic biological issues: recruitment variation, weak relationship between spawning biomass and recruitment, relative size of fish taken by predators and the fishery and the importance of local density of forage fish to predators rather than total abundance of the stock. U.S. fisheries are not only better managed, but also often better researched, so U.S. fisheries are a good place to start examining the biological assumptions of the models used by the LENFEST Task Force.
  4. We did not argue that fisheries management does not need to change – instead we argued that general rules such as the LENFEST Task Force’s recommendation to cut fishing mortality rates to half of the levels associated with maximum sustainable yield for “most forage fisheries now considered well managed” (LENFEST Summary of New Scientific Analysis) are not supported by sound science. Our analysis suggests that there’s little empirical evidence that such a policy will increase predatory fish abundance. Instead, every case needs to be examined individually and management decisions should weigh the costs (economic, social, and ecological) of restricting forage fisheries to levels below MSY against the predicted benefits, while accounting for uncertainty in both. Our abstract concludes “We suggest that any evaluation of harvest policies for forage fish needs to include these issues, and that models tailored for individual species and ecosystems are needed to guide fisheries management policy.”
  5. Essington and Plagányi feel we incorrectly characterized their paper. We simply rely on the words from the abstract of their paper. “We find that the depth and breadth with which predator species are represented are commonly insufficient for evaluating sensitivities of predator populations to forage fish depletion. We demonstrate that aggregating predator species into functional groups creates bias in foodweb metrics such as connectance.” Carl Walters, one of our co-authors and the person who conceived and built the EcoSim model certainly agrees that the models the LENFEST Task Force used were insufficient for the task they attempted.

Moving forward

We agree that the next steps are to move beyond U.S. fisheries and we are doing so. We have current projects doing a global analysis of relationships between forage fish abundance and the population dynamics of their predators. We have an almost complete review of recruitment patterns in forage fish stocks. We are doing specific case studies of other regions with models explicitly designed to evaluate the impact on predators of fishing forage fish. Finally, we are exploring alternative management strategies for forage fish, considering alternative recruitment patterns, across a range of case studies. We hope that many of the authors of the LENFEST report will collaborate with us in these efforts.

Originally posted by: Saving Seafood