4 Questions with David Battisti on El Niño and Climate Variability

This year’s spring Houghton Lecturer is David Battisti, a professor of atmospheric sciences and the Tamaki Endowed Chair at the University of Washington. As the scientist-in-residence within MIT’s Program of Atmospheres, Oceans, and Climate (PAOC), Battisti has spent the semester giving a series of talks on natural variability in the climate system. Some of his main research interests include illuminating the processes that underlay past and present climates, understanding how interactions between the ocean, atmosphere, land, and sea ice lead to climate variability on different timescales, and improving El Niño models and their forecast skill—something that is becoming increasingly relevant in a warming world.

Credit: National Oceanic and Atmospheric Administration

The Pacific Ocean is primed for a powerful double El Niño—a rare phenomenon in which there are two consecutive years of episodic warming of sea surface temperatures—according to some scientists. It’s been a few years since the Pacific Ocean experienced one strong warming event, let alone an event that spanned two consecutive years. A double El Niño could have large ripple effects in weather systems around the globe, from summer monsoons and hurricanes to winter storms in the Northern Hemisphere. Meanwhile, some scientists think it may signal the beginning of the end of the warming hiatus. Oceans at MIT asked Battisti about this phenomenon and what it does and doesn’t tell us about climate change.

How rare are double El Niños and what are the expected effects?

[Double El Niños] are not unheard of, but the last time it stayed warm for nearly two full years was back in the early 80s. In the tropics, climate anomalies associated with a typical El Niño event will persists as long as the event persists. For example, El Niño warm and cold events explain the lion’s share of the variance in monsoon onset date: conditions in late boreal summer causes a delay in the onset of the monsoon in Indonesia, which greatly reduces the annual production of the country’s staple food, rice. If El Niño conditions persist for two years spanning the onset time for the Indonesia monsoon, monsoon onset will very likely be delayed for two consecutive years.

In the mid-latitudes of the Northern Hemisphere, where we live, El Niño affects the climate by issuing persistent, large scale atmospheric waves from the tropical Pacific to the North Pacific and over most of North America. These waves are most efficient at reaching the mid-latitudes during our wintertime. If El Niño conditions span two consecutive northern hemisphere winters, we should expect the winter climate in these regions to be affected similarly over two consecutive winters.
During an El Niño event, there is a greater than normal chance for an unusually warm winter in the Pacific Northwest and in the north central US, and for a colder and wetter than normal winter in southern Florida. Alternately, El Niño has little impact on winter weather in New England. It also greatly affects precipitation in Southern California and the southwestern US — El Niño years are reliably wetter than normal, but just how much wetter than normal is very unpredictable.

Why haven’t we seen a strong El Niño in nearly two decades?

A large El Niño event is characterized by exceptionally warm conditions in the tropical Pacific, or by very warm conditions that persist for 18 months or so – about nine months longer than normal. It’s been over 20 years since we’ve seen a very large warm event, but it is not known how frequently very strong and exceptionally long events happen.

We categorize El Niño events (and their cold event siblings) by measuring sea surface temperature and zonal surface wind stress along the equator in the tropical Pacific. Good data to construct these indices extend back to the early 20th Century. Unfortunately, we can’t answer this question by examining the behavior of the high-end climate models because about only two high-end climate models in the world feature El Niño warm and cold events that are consistent with observations. However, the observational record shows three El Niño events with exceptionally large amplitude that were exceptionally long lived since 1950s, so a 20-year gap since the last large warm event is not surprising.

What does the hiatus refer to, and is it related to the El Niño phenomenon? The whole hiatus idea is based on the expectation that as carbon dioxide increases, so to should the global average temperature. And indeed, the global averaged temperature has increased over the course of the 20th Century by approximately 0.85 degrees Celsius. And climate models support that the primary reason the 20th Century increase is rising concentrations of greenhouse gases associated with human activity. However, over the past dozen years or so, the global average temperature has not increased – hence the moniker ‘the hiatus’.

The decade long hiatus isn’t inconsistent from what we would expect from natural variability and human forced climate change. For example, a typical El Niño cycle features a very warm year, followed by a moderately cold year, and then nothing happens for a while. Somewhere between three and seven years later there’s another warm event followed by a cold event, but the duration between these events  is quite random. Selecting any single period—for example, the last 10 years—we would expect decades in which the global average temperature fluctuates by 0.15 degrees Celsius or so due to the randomness in natural climate variability. The regional patterns of temperature change and the hiatus in global average temperature over the past decade aren’t distinguishable from a superposition of the cold phase of natural variability with the expected warming due to human activity.

Is this a sign that the warming hiatus is coming to an end?

El Niño does increase the global average temperature so we will see the average global temperature spike a bit this year compared to the last few years, which will bring us back up toward what the models say is the forced warming response. But El Niño events are not predictable more than a year or so in advance, so it is not possible to say what will happen over the next few years, or even the next decade.

On the other hand, if you view the change in global average temperature over the past thirty years as being a superposition of a steady increase due to human-induced forcing and decade-long periods of warm (the 1980’s and 1990’s) and cold (the 2002-2013) anomalies due to natural variability including El Niño, then decade-long periods of very large warming and very weak warming or even weak cooling should be expected. Exactly when these periods end is only obvious in retrospect.

For 25 years, Henry Houghton served as Head of the Department of Meteorology—today known as PAOC. During his tenure, the department established an unsurpassed standard of excellence in these fields. The Houghton Fund was established to continue that legacy through support of students and the Houghton Lecture Series. Since its 1995 inception, more than two dozen scientists from around the world representing a wide range of disciplines within the fields of Atmosphere, Ocean and Climate have visited and shared their expertise with the MIT community.

Originally posted: http://oceans.mit.edu

‘Substantial’ El Nino event predicted

The El Nino effect, which can drive droughts and flooding, is under way in the tropical Pacific, say scientists.

Australia’s Bureau of Meteorology predicted that it could become a “substantial” event later in the year.

The phenomenon arises from variations in ocean temperatures.

The El Nino is still in its early stages, but has the potential to cause extreme weather around the world, according to forecasters.

US scientists announced in April that El Nino had arrived, but it was described then as “weak”.

Australian scientists said models suggested it could strengthen from September onwards, but it was too early to determine with confidence how strong it could be.

“This is a proper El Nino effect, it’s not a weak one,” David Jones, manager of climate monitoring and prediction at the Bureau of Meteorology, told reporters.

“You know, there’s always a little bit of doubt when it comes to intensity forecasts, but across the models as a whole we’d suggest that this will be quite a substantial El Nino event.”

Aftermath of flooding in California put down to El Nino

An El Nino comes along about every two to seven years as part of a natural cycle.

Every El Nino is different, and once one has started, models can predict how it might develop over the next six to nine months, with a reasonable level of accuracy.

How can we predict El Nino?

In the tropical Pacific Ocean, scientists operate a network of buoys that measure temperature, currents and winds. The data – and other information from satellites and meteorological observations – is fed into complex computer models designed to predict an El Nino. However, the models cannot predict the precise intensity or duration of an El Nino, or the areas likely to be affected, more than a few months ahead. Researchers are trying to improve their models and observational work to give more advance notice.

A strong El Nino five years ago was linked with poor monsoons in Southeast Asia, droughts in southern Australia, the Philippines and Ecuador, blizzards in the US, heatwaves in Brazil and extreme flooding in Mexico.

Another strong El Nino event was expected during last year’s record-breaking temperatures, but failed to materialise.

Prof Eric Guilyardi of the Department of Meteorology at the University of Reading said it would become clear in the summer whether this year might be different.

“The likelihood of El Nino is high but its eventual strength in the winter when it has its major impacts worldwide is still unknown,” he said.

“We will know in the summer how strong it is going to be.”

Weather patterns

The El Nino is a warming of the Pacific Ocean as part of a complex cycle linking atmosphere and ocean.

The phenomenon is known to disrupt weather patterns around the world, and can bring wetter winters to the southwest US and droughts to northern Australia.

The consequences of El Nino are much less clear for Europe and the UK.

Research suggests that extreme El Nino events will become more likely as global temperatures rise.

Originally posted at: www.bbc.com

Why Poop-Eating Vampire Squid Make Patient Parents

The mysterious vampire squid is not actually a vampire or a squid–it’s an evolutionary relict that feeds on detritus. (MBARI)

Squid and octopuses are famous for their “live fast, die young” strategy. At one-year-old or younger, they spawn masses of eggs and die immediately. But scientists have just discovered a striking exception, reported April 20 in the journal Current Biology.

Females of the bizarre species known as “vampire squid” can reproduce dozens of times and live up to eight years. This strategy is probably related to the vampire squid’s slow metabolism and its habit of eating poop.

These shoebox-sized animals have fascinated biologists since their discovery in 1903, not because of any actual vampiric habits, but because of their puzzling place within the cephalopods—the group of animals that contains squids and octopuses.

Vampire squid are neither a squid nor an octopus, and they’re tricky to study because they live hundreds of meters below the surface, in frigid water with very little oxygen.

In addition to eight webbed arms, they have two strange thread-like filaments, whose purpose—collecting waste for the vampire squid to eat—wasn’t understood until 2012. A clear picture of the habits and evolution of these animals remains elusive.

Take a Rest Between Eggs

Henk-Jan Hoving, currently at the Helmholtz Centre for Ocean Research in Kiel, Germany, began his investigation of vampire squid while at the Monterey Bay Aquarium Research Institute. For the spawning study, he worked with specimens that had been collected by net off southern California and stored in jars at the Santa Barbara Museum of Natural History.

Out of 27 adult females, Hoving and his colleagues found that 20 had “resting ovaries” without any ripe or developing eggs inside. However, all had proof of previous spawning.

As in humans, developing eggs are surrounded by a group of cells called a follicle. After a mature egg is released, the follicle is slowly resorbed by the ovary. The resorption process in vampire squid is so slow, in fact, that the scientists could read each animal’s reproductive history in its ovaries.

Counting 38 to 100 separate spawning events in the most advanced female, and estimating that at least a month elapsed between each event, Hoving and his co-authors concluded that adult female vampire squid spend three to eight years alternately spawning and resting.

This length of time is reminiscent of the deep-sea octopus who brooded her eggs for over four years. In both cases, the animals’ actual lifespan must be longer than their reproductive period, which suggests truly venerable ages for members of a group whose most common representatives live for just a few months. These long life spans are related to a slow metabolism and the chill of the deep sea—around 2 to 7 degrees Celsius, or 35 to 44 Fahrenheit.

Limited Calories, But Limited Danger

A single spawning event is not actually a strict rule for octopuses and squid. A few species are known to spawn multiple batches of eggs, even as they continue to eat and grow. However, all species reach a continuous spawning phase at the end of their lives.

Once a female starts to lay, her body is in egg-production mode until she dies, her ovaries constantly producing. That’s why the discovery of a “resting phase” in the ovaries of vampire squid was so surprising.

But this unexpected strategy makes sense in the context of a vampire squid’s lifestyle. The mass spawnings of other cephalopods are fueled by a carnivorous diet of fish, crabs, shrimp and even fellow squids and octopuses.

By contrast, the fecal material and mucus that make up most vampire squid meals are not nearly as calorie-rich. The animals may be simply unable to muster enough energy to ripen all their eggs at once.

There’s an advantage, however, to living in the food-poor, oxygen-poor depths of the ocean. Few large predators can survive there for long, so vampire squid are relatively safe—compared to their cousins, who are constantly on the run from fish, dolphins, whales, seabirds and each other.

When you face a high risk of being eaten on any given day, it’s a good idea to get all your eggs out as quickly as possible. But vampire squid are free to engage in leisurely, repetitive spawning. It’s the ultimate work-life balance: alternately popping out babies, then returning to business as usual.

The vampire squid was named for its fearsome appearance, but those “spines” are just soft flaps of skin. (MBARI)

A fossil cephalopod from the Middle Jurassic, thought to be an early vampire squid.

Read the original post: http://blogs.kqed.org/

Ray Hilborn: Analysis Shows California Sardine Decline Not Caused by Too High Harvest Rate

Posted with permission from SEAFOODNEWS — Please do not repost without permission.

SEAFOODNEWS.COM [SeafoodNews]  (Commentary) by  Ray Hilborn April 22, 2015

Two items in the last weeks fisheries news have again caused a lot of media and NGO interest forage fish. First was publication in the Proceedings of the National Academy of Sciences of a paper entitled “Fishing amplifies forage fish population collapses” and the second was the closure of the fishery for California sardine.  Oceana in particular argued that overfishing is part of the cause of the sardine decline and the take home message from the PNAS paper seems to support this because it showed that in the years preceding a “collapse” fishing pressure was unusually high.

However what the PNAS paper failed to highlight was the real cause of forage fish declines.  Forage fish abundance is driven primarily by the birth and survival of juvenile fish producing what is called “recruitment”.  Forage fish declines are almost always caused by declines in recruitment,  declines that often happen when stocks are large and fishing pressure low.  The typical scenario for a stock collapse is (1) recruitment declines at a time of high abundance, (2) abundance then begins to decline as fewer young fish enters the population, (3)  the catch declines more slowly than abundance so the harvest rate increases, and then (4) the population reaches a critical level that was called “collapsed” in the PNAS paper.

Looking back at the years preceding collapse it appears that the collapse was caused by high fishing pressure, when in reality it was caused by a natural decline in recruitment that occurred several years earlier and was not caused by fishing.

The decline of California sardines did not follow this pattern, because the harvest control rule has reduced harvest as the stock declined,  and as fisheries management practices have improved this is now standard practice.  The average harvest rate for California sardines has only been 10% per year for the last 10 years, compared to a natural mortality rate of over 30% per year.  Even if there had been no fishing the decline in California sardine would have been almost exactly the same.

In many historical forage fish declines fishing pressure was much higher, often well over 50% of the population was taken each year and as the PNAS paper highlighted, this kind of fishing pressure does amplify the decline.  However many fisheries agencies have learned from this experience and not only keep fishing pressure much lower than in the past, but reduce it more rapidly when recruitment declines.

So the lesson from the most recent decline of California sardine is we have to adapt to the natural fluctuations that nature provides.  Yes, sea lions and birds will suffer when their food declines, but this has been happening for thousands of years long before industrial fishing.  With good fisheries management as is now practiced in the U.S. and elsewhere forage fish declines will not be caused by fishing.

Ray Hilborn is a Professor in the School of Aquatic and Fishery Sciences, University of Washington specializing in natural resource management and conservation.  He is one of the most respected experts on marine fishery population dynamics in the world.

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Sardine Assessment Shows Cyclic Decline in Population

Pacific sardines are known for wide swings in their population: the small, highly productive species multiplies quickly in good conditions and can decline sharply at other times, even in the absence of fishing. Scientists have worked for decades to understand those swings, including a decline in the last few years that led to the Pacific Fishery Management Council‘s recommendation on April 13th to suspend commercial sardine fishing off the West Coast for the first time in decades..

An updated stock assessment by NOAA Fisheries’ Southwest Fisheries Science Center (SWFSC) was the basis for the Council’s action. Stock assessments are research tools that estimate the status and size of the sardine population. The Council uses the assessments to set fishing quotas.

Models that support the sardine assessment combine NOAA data on past and current abundance of sardine eggs, larvae and mature fish with other data on sardine biology and fishery catches. The data on sardine abundance come from two SWFSC research vessel surveys conducted off the West Coast each year.

These surveys employ two methods to estimate the current size of the sardine population. They use underwater acoustic equipment (like sonar) to estimate the size of fish schools, followed by the use of trawl nets to verify the species comprising the schools. Additionally, the surveys employ devices that measure the density of sardine eggs in the water as a gauge of sardine spawning. Scientists can then calculate how large the spawning population must be to produce the measured density of sardine eggs.

These data feed a computer model to estimate sardine population trends and provide the foundation for projections of the total population of sardines off the West Coast in the next fishing year.

“The assessment produced this year suggests that cool ocean water temperatures off the West Coast beginning around 2007 may have reduced the survival of juvenile sardine resulting in a population decline”, said Kevin Hill, a fisheries biologist who oversees the stock assessment for the SWFSC. The number of surviving young fish appears to have dropped to the lowest levels in recent history and has likely remained low in 2014. This has led to a steady decline in the fishable sardine stock biomass, which is defined as the total volume of sardines at least one year old. This is the measure the Council relies on when setting fishing quotas.

“The environment is a very strong driver of stock productivity. If ocean conditions are not favorable, there may be successful spawning, but fewer young fish survive to actually join the population,” Hill said. “Small pelagic fish like sardine and anchovy undergo large natural fluctuations even in the absence of fishing. You can have the best harvest controls in the world but you’re not going to prevent the population from declining when ocean conditions change in an unfavorable way.”

The current decline adds to a series of ups and downs that illustrate the boom-and-bust nature of sardine populations. The sardine biomass rose from about 300,000 metric tons in 2004 to a high point of more than 1 million in 2008 and is predicted to decrease to an estimated 97,000 metric tons by this coming July.

Because of these swings in sardine populations, the Council’s management framework for sardines includes built-in mitigation measures and safeguards to exponentially reduce fishing pressure as the stock declines.  One of these Council measures is a cessation in directed fishing on sardines when the biomass falls below 150,000 metric tons. “The fishing cutoff point is included in the guidelines adopted by the Council and is designed to maintain a stable core population of sardines that can jump-start a new cycle of population growth when oceanic conditions turn around,” Hill said.

In the course of reviewing the 2015 updated assessment, it became evident that the final model used in the 2014 assessment did not correspond to the best fit to the data. The data were reanalyzed and a better fit to the 2014 model was achieved. This re-examination resulted in a lower 2014 biomass estimate of 275,705 metric tons, down from the previous estimate of 369,506 metric tons, which is still above the fishing cutoff value of 150,000 metric tons.

The revised model applied to the 2015 assessment resulted in a biomass estimate of 97,000 metric tons, which is below the fishing cutoff.  As a result, the Council decided to close the 2015-2016 sardine fishing season and requested that NOAA Fisheries close the remainder of the 2014-2015 sardine fishing season. The sardine population is presently not overfished and overfishing is not occurring; however, the continued lack of recruitment observed in the past few years could decrease the population, even without fishing pressure.

The NOAA Ship Bell M. Shimada is currently conducting a new sardine survey off the West Coast to collect updated information on the size and location of the sardine stock. In addition, a large-scale 80-day survey this summer will collect data on sardine and whiting (hake) populations from the Mexican border to Canada. This new information will support the next stock assessment SWFSC prepares for the Council and NOAA fisheries managers.

Learn more:

Pacific sardine stock assessment
Executive summary
Full report 

In the Field: Spring Sardine Survey 2015
Pacific Fishery Management Council Coastal Pelagic Species
California Cooperative Oceanic Fisheries Investigations (CalCOFI)
Video – Coastwide Sardine Survey

Green Seas Blue Seas – Interactive Guide to the California Current 

For more information, please contact: Michael.Milstein@noaa.gov or Jim.Milbury@Noaa.gov (West Coast Regional Office Public Affairs), Dale.Sweetnam@noaa.gov (Southwest Fisheries Science Center) and Joshua.Lindsay@noaa.gov (West Coast Regional Office)

Read the original post https://swfsc.noaa.gov

Scat may contain clues to marine mammals’ Southern California deaths

Biologist Mark Lowry collects sea lion and elephant seal scat.
(Brian van der Brug / Los Angeles Times)

By Louis Sahagun

Mark Lowry has collected sea lion and elephant seal scat from San Nicolas and San Clemente islands for more than three decades to track the long-term health of marine mammal life off the California coast.

But the federal biologist’s work has new meaning — and urgency — this year. Analyses of the specimens could solve the mystery of why so many young sea lions have been found dead and dying on Southern California beaches.

Keeping a wary eye on a herd of elephant seals lolling on rocks perched over the pounding surf here on a recent weekday, Lowry put on rubber gloves and used a dinner spoon to scoop up piles of seal scat and plop them into plastic specimen bags.

Lowry, a National Oceanic and Atmospheric Administration biologist, hoped the pungent material contained answers to why at least 2,250 dehydrated and underweight sea lions started showing up on local beaches in January — around the time he detected evidence of an unprecedented shift in the species’ eating habits.

Specifically, Lowry found what he described as “mystery stuff — gooey bits of substance you’d expect from a diet of jellyfish or tube worms.”

Sea lions are opportunistic predators that typically feed on mackerel, sardines, rockfish and market squid. But amid El Niño-like conditions and a dearth of fish and squid to prey on, they may be trying to sustain themselves on novel food sources, he said.

“These findings are preliminary,” Lowry said. “But it could mean sea lions are starving and eating what little they can find to fill their stomachs up.”

There were 350 ailing sea lion pups stranded on local beaches in January, 850 in February and 1,050 in March, according to the latest numbers released by the National Marine Fisheries Service.

The overall health of the California sea lion population, however, remains robust.

“The sea lion population is increasing at a rate of about 5.1% per year,” said Lowry, who also conducts annual aerial surveys of California’s pinniped populations. “In 1964, the sea lion population was about 30,000. Today, it is a tad over 300,000.”

Most of those sea lions breed on the wind-raked beaches of 3-mile-by-9-mile San Nicolas Island, the outermost of the eight Channel Islands and pinniped capital of the United States.

San Nicolas is populated by about 200 military and civilian residents. But for several months beginning in December and continuing into spring, it is breeding grounds for tens of thousands of California sea lions, elephant seals and harbor seals.

Lugging his collecting gear and buckets down a sandstone bluff toward raucous herds of sea lions and elephant seals weighing as much as 3,000 pounds, Lowry, 64, said with a laugh, “This is field biology at its finest.”

Moments later, he was in his element, on his knees and harvesting seal scat on this desert isle used by the Navy to test the latest missile defense systems.

“If flies are interested in it, I’m interested,” he said. “No joke.”

He aimed to collect 15 pounds of the stuff for analysis later in his La Jolla laboratory. That process involves soaking the samples in buckets of fragrant soapy water, then pouring them through wire-mesh seines to separate out bony particles that can determine the species, size and age of the fish and squid eaten.

“The value of Mark’s data is enormous,” said Doug Demaster, science and research director of NOAA’s Alaska region fisheries. “Shifts in the diets of sea lions are among the earliest signals we get of impending El Niño events, which mean wholesale shifts of wind and storm patterns, and changes in the marine ecology.

“Beyond that, we all want to know why the number of dying sea lion pups on California’s beaches has jumped from a few dozen a year to thousands in the past three months alone.”

Seals have altered their feeding habits several times over the last three decades, Lowry said. In the 1980s, for example, they were eating mostly anchovies and sardines. In the 1990s, they started going after squid. During El Niño events, they chase rockfish.

“The mystery stuff I’m finding now is altogether new,” he said. “I intend to figure out exactly what it is.”

Lugging a 5-gallon bucket full of scat samples back to his pickup after a productive day of prospecting, Lowry smiled and said, “I have no plans to retire, and my bosses are very happy about that.”

Seal scat
Brian van der Brug / Los Angeles Times

Biologist Mark Lowry uses a large tablespoon to scoop up sea lion and elephant seal scat to track the long-term health of marine mammal life on San Nicolas Island.

Read the original post: L.A.Times.com

Broccoli, sardines, blueberries good for your eyes, says study

Found in blueberries, the pigment anthocyanin can help maintain cornea health. – AFP Relaxnews pic, April 2, 2015.

Anyone concerned with maintaining healthy eye function may want to add more broccoli, sardines and blueberries to their diet, according to the recommendations from an expert at Loyola University Chicago.

Several nutrients are essential to eye health, and some may even help to improve eyesight and prevent problems such as cataracts and macular degeneration.

Dr James McDonnell, a paediatric ophthalmologist at the Loyola University Health System, has compiled a list of these nutrients and the foods that contain them.

Omega-3: Protection from macular generation is yet another benefit of this remarkable fatty acid, which by now is well known to nutrition-savvy consumers. Good sources include oily fish (sardines, mackerel, etc.), flaxseed and canola oil.

Astaxanthin: This pigment is a powerful antioxidant with the power to stave off cataracts and even blindness. Seaweed and wild salmon (not farmed) are among the top sources.

Anthocyanins: These pigments, which range in colour from bright red to blue, can help maintain the health of the cornea and of the blood vessels throughout the eye. Blueberries and blackcurrants are rich in these colourful nutrients.

Zeaxanthin: Found in dark leafy green vegetables such as broccoli, kale, collard greens and spinach, this nutrient may help reduce the risk of age-related macular degeneration.

Vitamin D: Moderate sun exposure is one way to ensure an adequate supply of Vitamin D, and consuming fish oils, liver and egg yolks can provide an additional boost. Supplementing with Vitamin D3 has been shown to reduce retinal inflammation and even improve vision.

Bioflavonoids: These antioxidants belong to the polyphenols family and may reduce the risk of cataracts and macular degeneration. They are found in citrus fruits, cherries, tea and even red wine.

Beta-carotene: Found in carrots, sweet potatoes and butternut squash, this provitamin helps to improve night vision and to prevent dry eyes.

Lutein: Supplementing with this carotenoid, which is found in organic eggs from pastured hens, may help prevent macular degeneration. – AFP Relaxnews, April 2, 2015.

Read original post: themalaysianinsider.com

NW scientists discover Pacific fish surviving dead zones

Some species of Pacific Ocean rockfish have been found to survive in low-oxygen dead zones off the West Coast, while other species struggle significantly, researchers in Oregon and Washington reported in a recent study. (Cindy, Oregon Coast Aquarium)

GRANTS PASS — Scientists say they have found that some fish can survive in low-oxygen dead zones that are expanding in deep waters off the West Coast as the climate changes.

While the overall number and kinds of fish in those zones are declining, some species appear able to ride it out, according to a study published this month in the journal Fisheries Oceanography.

The study focused on catches from 2008 through 2010 of four species of deepwater groundfish — Dover sole, petrale sole, spotted ratfish and greenstriped rockfish.

Catches of ratfish and petrale sole both declined in low-oxygen areas, while catches of greenstriped rockfish and Dover sole showed no changes. Dover sole are well-known for being adapted to low oxygen, but greenstriped rockfish are not.

Oregon State University oceanographer Jack Barth, a co-author, says commercial fishermen will likely start taking oxygen levels into account as they decide where to tow their nets.

“It’s rearranging that ocean geography,” Barth said of the low-oxygen conditions. “If you go out to a spot where you’ve always gone before commercial fishing, and you don’t catch what you expect, is it because the oxygen has gone low and things moved someplace else?”

Dead zones were first noticed off Oregon in 2002, where they peaked in 2006, and have since spread to Washington and California waters.

Some, such as where the Mississippi River flows into the Gulf of Mexico, are caused by agricultural runoff. On the West Coast, scientists have demonstrated they are triggered by climate change.

North winds cause the ocean to turn over, drawing cold low-oxygen water up from the depths. Conditions get worse as tiny plants, known as phytoplankton, are drawn to the surface, where sunshine triggers a population explosion. As they die, they sink and use up more oxygen as they decompose.

Underwater videos have shown crabs and other slow-moving bottom-dwellers in shallow waters die, but scientists from NOAA Fisheries Service and Oregon State wanted to know what happened to fish.

NOAA Fisheries was already chartering fishing trawlers to do annual surveys of groundfish populations off the West Coast. They equipped the nets with oxygen sensors.

Lead study author Aimee Keller, a fisheries biologist for the NOAA Fisheries Service’s Northwest Fisheries Science Center in Seattle, said scientists ultimately want to see whether fish forced out of preferred habitats grow more slowly, are less successful reproducing, and whether other species adapted to low-oxygen conditions move in.

The next step, she said, is to expand the surveys to include more commercially important species.

Tim Essington, professor of fisheries at the University of Washington, was not part of the study but said it was significant for covering a large geographic area, and was consistent with what has been seen in estuaries. He added he expects fish to congregate along the edges of low-oxygen zones, where predators will be able to feed on less active fish inside the zone.

NOAA oceanographer Bill Peterson, who was not part of the study, said there was no doubt that low-oxygen waters were expanding, but it was a slow process that would take decades to be felt.

Read the original post: http://www.oregonlive.com

Trawling has “negligible” effect on soft-bottom

Petrale sole, a flatfish caught by trawling on soft-bottom seafloor. Credit: The Nature Conservancy

A groundbreaking new study recently conducted by California fishermen, The Nature Conservancy and CSU Monterey Bay indicates that bottom trawling only has a “negligible effect” on the seafloor and fish habitat in certain types of soft sea bottom.

Trawling is continually criticised by environmental advocates for the damage it causes to rocky marine habitats and the long-lived animals that occur in them. However, important questions remain about the extent of any damage to sandy and muddy environments.

During the three-year study, fishermen trawled patches of the ocean floor off Morro Bay. Those areas were analysed by underwater photos and video and compared with nearby areas that were untouched.

Their peer-reviewed work, published in the Fishery Bulletin, found that California’s largely soft-bottom seafloor saw little lasting impacts from trawling with a small-footrope trawl.

The researchers say that their study adds to a growing body of literature from around the world showing trawling impacts are context-dependent – the impacts depend on the type of gear used, the types of habitats trawled and how often trawling occurs.

The scientists point out that their study does not imply that all soft-bottom habitats should be open to trawling; but, with new research and technology, “we can fine-tune our fishery regulations to protect truly vulnerable habitats.”

One of the researchers, Dr. James Lindholm has been studying marine ecosystems for 20 years and this autumn he will conduct a similar experiment off Half Moon Bay using trawling nets of different sizes. Commercial fishermen will also be involved.

Read the original post: www.worldfishing.net

NBCNews.com Replaces Reality, Regulation and History with Hyperbole

Original post: AboutSeafood.com | © 2015 National Fisheries Institute | Published with permission.

A story this week on NBCnews.com about the state of the seafood industry is packed with sensationalism and hyperbole, yet absent much of the real science, facts and figures that drive actual sustainability.

To begin, U.S. fisheries are among the world’s best managed and most sustainable. Though not referenced by name a single time in this article, the National Oceanic and Atmospheric Administration, NOAA, regulates U.S. seafood with headquarters in Washington D.C., five regional offices, six science centers and more than 20 laboratories around the country and U.S. territories.

Author John Roach, however, perpetuates doom and gloom throughout this piece, asserting “voids” left by cod, halibut and salmon that need to be filled by other fish. We’re guessing Mr. Roach isn’t aware that salmon shattered modern-day records in 2014, returning to the Columbia River Basin in the highest numbers since fish counting began at Bonneville Dam more than 75 years ago. Could you tell us again about that void?

Mr. Roach also intones a narrative of sustainability disaster for popular predators like tuna but forgot to mention groups like the International Seafood Sustainability Foundation (ISSF), a coalition created through a partnership between WWF, the world’s leading conservation organization, and canned tuna companies from across the globe to insure the long-term conservation and sustainable use of tuna stocks. In an article that claims the sky is falling for species like tuna it’s odd that ISSF gets nary a nod or even a mention.

Switching gears, Mr. Roach goes on to blame giant trawlers “armed” with technology and massive nets as part of the reason we’re “running low” on fish. As in any industry, technology gets better by the day, creating more efficient ways to do business. However, new technology is by no means exempt from standing national and global fishery regulations, such as catch-limits, by-catch laws, compliance, and so forth. To suggest that enhanced technology or “bigger or faster” boats are causing our fish supplies to dwindle ignores the impact of technology on sustainability and even regulatory oversight. There are pros and cons to every catch-method and there is no one-size-fits all solution to sustainability challenges but to blame technology without recognizing its contribution to solutions is folly.

Hyperbolic rhetoric about sustainability continues to be discounted by legitimate fisheries experts in the scientific community. In fact, one “report” forecasting empty oceans by 2048 was challenged by a number of independent researchers who described the study that promoted the statistics as, “flawed and full of errors.” Including Ray Hilborn, a professor of aquatic and fishery sciences at the University of Washington in Seattle whose research into the study lead him to say, “this particular prediction has zero credibility within the scientific community.” After Hilborn’ s analysis the author of the original study himself explained that his research was not in fact predicting worldwide fish stock collapse at all but merely examining trends. Articles like this track along precisely with the discounted, overblown storyline that gave birth to the empty oceans by 2048 nonsense.

Whether you’re a “natural optimist” or not, there is no question that seafood harvested from U.S. fisheries is inherently sustainable as a result of NOAA’s fishery management process and global fisheries management is far from the wild west scenario bandied about.  Things aren’t perfect and there’s work to be done but the “game” is not “almost over” and those who suggest it is, willfully propagate that narrative not because it’s accurate but because bad news sells.