Archive for the Research Category

Aug 12 2013

Environmental cost of conservation victories

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In recent years, Marine Protected Areas (MPA), where fishing is severely restricted or not allowed, have become the Holy Grail of marine conservation for both nongovernmental organizations and governments. In the United States, the Papahānaumokuākea Marine National Monument in the NW Hawaiian Islands became the first large-scale reserve closed to fishing in 2006 (1). This reserve is 90% the size of California and was followed by the Pacific Remote Islands Marine National Monument, about half the size of California, in 2009 (2). In total, the United States has established MPAs 19-times the size of California or roughly the area of the Continental United States.

The United States is not alone. The South Georgia and South Sandwich Islands Marine Protected Area in British sub-Antarctic waters is roughly 2.5-times the area of California, and most recently Australia has declared its economic zone in the Coral Sea a no-take area of 3.1 million square kilometers, an area eight times the size of California. All of these areas are heralded as great conservation victories and the Convention on Biodiversity has set a target of 10% of the ocean protected by 2020.

Are these indeed victories? Not necessarily. I suggest it is likely that the world’s environment is actually worse off once such victories are evaluated globally.

Read the full article here.

Aug 7 2013

New Posters Highlight Local CA Seafood

Many of us may be pretty clueless about what fishermen catch off our coast, the gear they use, or the species that are farmed.

To help educate the public, California Sea Grant has created four regional posters that highlight local, commercially caught and farmed marine seafood.

The posters are available free for download and printing at Discover California Fisheries.

Read the full story here.

Central Coast Seafood

Aug 2 2013

A convenient truth: 90% of the tunas are gone!

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Last week, I had the privilege of presiding over the defense of the Ph.D. dissertation of Maria José Juan-Jordá in La Coruña, Spain. Maria José is a bright young researcher and has already published several chapters of her dissertation in the peer-reviewed literature.

The first chapter in her dissertation(1) is the last in a series of peer-reviewed scientific papers that demonstrate that the combined biomass of large oceanic predators (mostly tunas) has not declined by 90% as stated in another scientific paper ten years ago.

The 90% decline figure came from an analysis published in 2003 which concluded that “large predatory fish biomass today is only about 10% of pre-industrial levels” [Myers and Worm, 2003(2)].  Those analyses relied heavily upon catch rates from a single fishing gear type (longline) and aggregated catch across species to estimate trends in “community biomass”. The paper quickly became high-profile in the tuna world. Many environmental groups embraced it as proof that all tunas, not just the bluefins, were in serious trouble. On the other hand, tuna scientists who were actually conducting stock assessments, especially for tropical tunas knew immediately that the 90% number was totally wrong.

Over the next few years, a number of peer reviewed publications(3,4,5,6,7,8) showed that the conclusions in Myers and Worm (2003) were fundamentally flawed. Two of the most important reasons for this are: The aggregation of data, and the use of data from a single fishing method. The end result is that the 90% decline is an overestimate. This process of rebuttal is a natural part of the way science develops. Sometimes scientists reach conclusions that are wrong, for whatever reason, and other scientists discover flaws and point to them. A paper, once published, is not necessarily immortal.

Nevertheless, the notion of 90% global demise of tuna populations is still out there. It is repeated in many consumer guides published by various environmental groups that want to influence market preferences. It also pops up elsewhere: Earlier this year, I visited the web site of a newly-formed commission that aims to improve governance of ocean resources, and I was surprised to see the 90% number mentioned there. A colleague of mine who also noticed it said he was “disappointed that one of the most rebutted fisheries paper of all time continues to raise its head.”

Read the full story here.

Jul 29 2013

Study reveals mechanism behind squids’ and octopuses’ ability to change color

This shows the diffusion of the neurotransmitter applied to squid skin at upper right, which induces a wave of iridescence traveling to the lower left and progressing from red to blue. Each object in the image is a living cell, 10 microns long; the dark object in the center of each cell is the cell nucleus. Credit: UCSB

This shows the diffusion of the neurotransmitter applied to squid skin at upper right, which induces a wave of iridescence traveling to the lower left and progressing from red to blue. Each object in the image is a living cell, 10 microns long; the dark object in the center of each cell is the cell nucleus. Credit: UCSB

Color in living organisms can be formed two ways: pigmentation or anatomical structure. Structural colors arise from the physical interaction of light with biological nanostructures. A wide range of organisms possess this ability, but the biological mechanisms underlying the process have been poorly understood.

Two years ago, an interdisciplinary team from UC Santa Barbara discovered the mechanism by which a neurotransmitter dramatically changes color in the common market squid, Doryteuthis opalescens. That neurotransmitter, acetylcholine, sets in motion a cascade of events that culminate in the addition of phosphate groups to a family of unique proteins called reflectins. This process allows the proteins to condense, driving the animal’s color-changing process.

Now the researchers have delved deeper to uncover the mechanism responsible for the dramatic changes in color used by such creatures as squids and octopuses. The findings –– published in the Proceedings of the National Academy of Science, in a paper by molecular biology graduate student and lead author Daniel DeMartini and co-authors Daniel V. Krogstad and Daniel E. Morse –– are featured in the current issue of The Scientist.

Read the full article here.

Jul 26 2013

People who eat more fish live 2.2 years longer, say latest results from Harvard health study

Seafood News
The July Tufts Health Newsletter highlights the latest results from the long running Harvard public health study. According to Dr. Dariush Mozaffarian, the new results were among the first to look at the relationship of Omega-3 levels in the blood stream and overall mortality of older adults.

“The advantages of eating fish are many,” says Alice H. Lichtenstein, DSc, director of Tufts’ HNRCA Cardiovascular Nutrition Laboratory. “Fish offers omega3 fatty acids and, depending on how it is prepared, is low in calories and saturated fat.” Besides the inherent nutritional positives of fish, she adds, substituting fish (not fried or heavily breaded) for entrées such as steak and quiche pays off doubly.

The American Heart Association recommends eating fish at least twice a week, particularly fatty varieties high in omega-3s such as salmon, mackerel, herring, lake trout, sardines and albacore tuna. A “serving” is 3.5 ounces cooked, or about three-quarter cup of flaked fish.

Now there’s fresh evidence that following that advice can not only reduce your risk of cardiovascular disease, but actually help you live longer—especially if you’re already age 65 or older. “Although eating fish has long been considered part of a healthy diet, few studies have assessed blood omega-3 levels and total deaths in older adults,” says Dariush Mozaffarian, MD, PhD, of the Harvard School of Public Health. New findings by Dr. Mozaffarian and colleagues published in Annals of Internal Medicine, he says, “support the importance of adequate blood omega-3 levels for cardiovascular health, and suggest that later in life these benefits could actually extend the years of remaining life.”

The researchers examined 16 years of data from about 2,700 US adults age 65 or older who participated in the long-term Cardiovascular Health Study. Participants, average age 74, were generally healthy and did not take fishoil pills. Rather than relying on dietary questionnaires to measure fish consumption, the study took blood samples at baseline to analyze total omega-3s as well as levels of three specific omega-3s found in fish: DHA (docosahexaenoic acid), EPA (eicosapentaenoic acid) and DPA (docosapentaenoic acid).

Overall, study participants with the highest total omega-3 levels had a 27% lower risk of total mortality due to all causes, and in particular were less likely to die of coronary heart disease and arrhythmia. Those with the most blood omega-3s lived, on average, 2.2 years longer than those with the lowest levels.

Read the full story here.

Jul 26 2013

Voyage to study effects of ocean acidification off U.S. West Coast

Scientists aboard the survey ship Fairweather will travel along the U.S. West Coast to study ocean acidification. (National Oceanic and Atmospheric Administration / July 25, 2013)

Scientists aboard the survey ship Fairweather will travel along the U.S. West Coast to study ocean acidification. (National Oceanic and Atmospheric Administration / July 25, 2013)

A team of scientists is setting out on a research expedition along the U.S. West Coast to study ocean acidification, the greenhouse gas-driven change in the chemistry of seawater that has been called climate change’s “evil twin.”

Chemists and biologists from the National Oceanic and Atmospheric Administration will board the survey ship Fairweather next week, sailing from Canada to Mexico to collect samples of water, algae and plankton, officials said Thursday. The goal of the monthlong voyage is to better understand how marine ecosystems are responding to water that is becoming more acidic as a result of the buildup of carbon dioxide in the atmosphere.

“We will for the first time not only study the chemistry of acidification but also study at the same time the biological impacts,” Richard Feely, an oceanographer with NOAA’s Pacific Marine Environmental Research Laboratory, told reporters in a telephone briefing.

Oceans have absorbed about 25% of the greenhouse gases that have accumulated in the atmosphere from the burning of fossil fuels, buffering some of the effects of climate change, Feely said. But that comes at a great cost to marine life because when carbon dioxide dissolves in seawater, it lowers itsthe water’s. The gradual change in chemistry poses a particular threat to shellfish such as oysters and clams that require alkaline water to build their protective shells.

The research expedition could shed light on whether acidification is harming pteropods, marine snails that are especially sensitive to changing acidity and are a key food source for fish, birds and whales. Scientists also want to know whether acidification is making harmful algae blooms more toxic to marine life. Increased toxicity has been shown in laboratory experiments but not observed the field.

Read the full story here.

Jul 2 2013

Agency says Pacific great white shark not in danger of extinction

 A great white shark plies waters at Guadalupe Island in 2007. (Al Seib / Los Angeles Times / November 15, 2007)

A great white shark plies waters at Guadalupe Island in 2007. (Al Seib / Los Angeles Times / November 15, 2007)

The National Oceanic and Atmospheric Administration announced Friday that the northeastern Pacific Ocean population of great white sharks is not in danger of extinction and does not warrant listing under the Endangered Species Act.

NOAA had been researching the health of the great white population since last year, when the environmental groups Oceana, Shark Stewards and the Center for Biological Diversity filed a petition calling for endangered species protection.

The petitioners were reacting to the first census of great whites ever attempted. Conducted by UC Davis and Stanford University researchers, and published in the journal Biology Letters in 2011, the census estimated that only

219 adult and sub-adult great whites lived off the Central California coast, and perhaps double that many were in the entire northeastern Pacific Ocean, including Southern California.

Read the full story here.

Jul 2 2013

Oxford University reveal that a fishy diet can improve reading and concentration in kids

Sunday Express

Omega-3 fatty acids called EPA and DHA, found in fish and seafood, are essential for the brain’s structure and function as well as for maintaining a healthy heart.

Research carried out at Oxford University and published in the journal PLOS One, found children’s blood levels of DHA “significantly predicted” how well they were able to concentrate and learn.

Blood omega-3 levels were studied in 493 UK schoolchildren aged from seven to nine.

Read the full story here.

Jun 28 2013

Fishery Stock Assessments—It’s All About the Science

NOAA Fisheries

NOAA Fisheries’ scientific stock assessments are critical to modern fisheries management. Using data gathered from commercial and recreational fishermen and our own on-the-water scientific observations, a stock assessment describes the past and current status of a fish population or stock, answers questions about the size of the stock, and makes predictions about how a fishery will respond to current and future management measures.

Read more here.

Jun 12 2013

Harvard study finds eating tuna, mackerel, swordfish boosts memory

Seafood News

Eating tuna could boost memory and slow age-related mental decline, say researchers from Harvard Medical School.

They looked at the diet of 6,000 women with an average age of 72 and monitored them for nearly ten years, measuring their memory and mental ability at different points.

The women who ate tuna, mackerel or swordfish once a week had significantly better verbal memory compared to women who did not regularly eat the fish. There were no links between memory and consumption of light-meat fish or shellfish. It’s thought the benefits are down to the high omega-3 content in tuna and mackerel — other studies suggest this may help boost memory.

Read the full story here.