The Blog Aquatic » Carmen Yeung http://blog.oceanconservancy.org News, opinions, photos and facts from Ocean Conservancy Thu, 14 Aug 2014 17:21:33 +0000 en-US hourly 1 http://wordpress.org/?v=3.4.2 Sea Star Epidemic Plagues Oregon http://blog.oceanconservancy.org/2014/06/23/sea-star-epidemic-plagues-oregon/ http://blog.oceanconservancy.org/2014/06/23/sea-star-epidemic-plagues-oregon/#comments Mon, 23 Jun 2014 17:49:24 +0000 Carmen Yeung http://blog.oceanconservancy.org/?p=8617

Since June 2013, millions of sea stars along the West Coast have disintegrated and died. Scientists have relentlessly tried to identify the cause of the “sea star wasting syndrome.” (See map of locations with outbreak.)

Typically, the first signs of an afflicted sea star are white lesions appearing on its body. Shortly thereafter, sea stars lose their limbs and their internal organs disintegrate. Although sea stars have the ability to regenerate limbs, the disease often progresses too quickly for them to recover. The exact cause of this disease is unknown. Scientists believe that sea star wasting syndrome may be due to a viral or bacterial infection, and could be exacerbated by increased water temperature. Populations of the ochre and sunflower sea stars, two common West Coast species, have been hit especially hard. Similar die-offs have occurred in the past, but never at the magnitude we see today, and over such a wide geographic area.

Oregon’s sea stars seemed to have been spared the dreadful fate of their West Coast neighbors. However, in recent weeks, Oregon’s monitoring networks have estimated that 30-50% of ochre sea stars in the intertidal area show symptoms of the syndrome. Researchers project that they may see local extinction of ochre sea stars at some Oregon sites.

While pretty to look at, most people do not usually think about the importance of sea stars. They’re not economically beneficial like oysters or salmon. And when you think of the ocean’s top predators—sea stars don’t usually come to mind.

However, sea stars are ravenous hunters who serve an important role controlling sea urchin and other invertebrate populations. Without some sea star species, unchecked populations of sea urchins have the ability to devastate kelp beds, which act as important nesting and foraging grounds for many species of fish.

Though sea star wasting syndrome may only affect sea stars themselves, the impact of the disease can cause a ripple effect through the marine ecosystem. This devastating outbreak highlights the need for consistent science funding and continued marine research. Once the cause and transmission of the disease are known, scientists will have a better idea how the environment will be impacted and whether sea stars will be able to recover.

How can people help? West Coast residents and divers can help scientists by recording observations of where they have and haven’t seen the wasting syndrome in sea stars at seastarwasting.org. This information will help researchers assess and, hopefully reverse this devastating syndrome.

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One of the Biggest Arctic Migrations You’ve Never Heard of http://blog.oceanconservancy.org/2014/05/12/one-of-natures-wonders-spring-migration-in-the-arctic/ http://blog.oceanconservancy.org/2014/05/12/one-of-natures-wonders-spring-migration-in-the-arctic/#comments Mon, 12 May 2014 16:29:11 +0000 Carmen Yeung http://blog.oceanconservancy.org/?p=8265

Photo Credit: NOAA National Marine Mammal Laboratory

Ocean Conservancy will be publishing a blog series exploring the wonder of the Bering Strait and highlighting threats and solutions to this region.

The Bering Strait—located between Alaska’s Seward Peninsula and Russia’s Chukotka Peninsula—is the only marine gateway connecting the Arctic Ocean and Pacific Ocean. At its narrowest point, the strait is just 55 miles wide. Big Diomede Island (Russia) and Little Diomede Island (U.S.) are located near the middle of the Bering Strait, and are separated by a strip of water less than three miles wide. Despite its cold, remote location, the Bering Strait is a key biological hotspot, a region that contains a significant number of species – some of which are found nowhere else on Earth. This strait is both a bottleneck and a pathway for marine life.

In the middle of the Bering Strait, Big Diomede Island is located to the west and Little Diomede Island is to the east.

Each spring, millions of seabirds and hundreds of thousands of marine mammals traverse the narrow strait as they migrate to the Arctic Ocean. Sea ice—frozen seawater that floats on the ocean surface—plays a major role in this seasonal migration. In the spring, migratory birds and marine mammals gather in the Bering Sea and follow the retreating ice edge north through the Bering Strait and into the Chukchi Sea and the Arctic Ocean. The ice edge is highly productive, and the sea ice itself provides important habitat for microorganisms, birds and marine mammals. The Bering and Chukchi Seas are one of the most productive ocean ecosystems in the world.

Photo Credit: NASA, May 2000

Photo Credit: NASA, August 2000

Four species of ice-dependent seals—bearded, ribbon, ringed and spotted—use the sea ice for resting and as a platform from which to feed on prey like fish, shrimp and crabs. Polar bears and Pacific walruses hunt and feed on or from the sea ice. Open areas of the ice—called leads or polynyas—attract dozens of bird species, including the short-tailed albatross, spectacled eider and Steller’s eider. These and other bird species use the Bering Strait’s rich waters for foraging and as a pathway to the summer habitat in the Arctic.

Photo Credit: NOAA Fisheries

Under the chilly spring water, nearly 10,500 bowhead whales follow leads in the sea ice as they move north through the narrow passage of the Bering. These rotund black whales use their enormous heads to break through thick sea ice. Their common name originates from their bow-shaped skulls, which are over 16.5 feet long and about 35 percent of their total adult body length. In addition to bowhead whales, beluga and gray whales travel through the Being Strait on their way north to raise their young or feed.

With huge pulses of birds and marine mammals passing through this gateway from the Pacific to the Arctic each year, spring migration in the Bering Strait is truly one of nature’s wonders. There is no question that this narrow and biologically rich stretch of water is critically important, not only to Arctic species like walruses, bowheads and spectacled eiders, but also to wider-ranging species like gray whales and migratory seabirds.

The yearly migrations of marine mammals are essential to people living in Bering Strait communities and beyond. People living in the region’s communities rely on the continued productivity of the region’s marine ecosystem to support their subsistence way of life and cultural traditions as well as to meet other economic and community needs.

Of course, fish, birds, marine mammals, and subsistence hunters do not have a monopoly on the Bering Strait. As the retreat of summer sea ice in the Arctic Ocean has accelerated, the region is attracting more attention from industry. There is growing interest in shipping, oil and gas exploration, tourism and other commercial activities that contribute to increasing levels of vessel traffic through the Bering Strait. Increased traffic in this fragile ocean space could result in more pollution, ship strikes on marine mammals, as well as chronic and catastrophic oil spills among other potential impacts to the marine environment. The Bering Strait region is particularly vulnerable because it is home to such high concentrations of wildlife. We’ll explore these issues—and potential solutions—in future blog posts.

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Hilton Worldwide Bans Shark Fin Dishes http://blog.oceanconservancy.org/2014/03/06/hilton-worldwide-bans-shark-fin-dishes/ http://blog.oceanconservancy.org/2014/03/06/hilton-worldwide-bans-shark-fin-dishes/#comments Thu, 06 Mar 2014 21:41:35 +0000 Carmen Yeung http://blog.oceanconservancy.org/?p=7661

Recently, Hilton Worldwide announced that they will stop serving shark fin and cease taking new orders for shark fin dishes by April 1, 2014. This ban will take place at restaurants and food and beverage facilities operated by Hilton Worldwide’s 96 owned and managed properties in the Asia Pacific region. This commitment supports the ‘Living Sustainably’ pillar of the company’s global corporate responsibility strategy.

An estimated 100 million or more sharks are killed every year – the demand of shark fin has been a major cause for the decline of global shark populations.  A quarter of the world’s sharks and rays are at risk of extinction. Shark fins are harvested by cutting off all the fins of sharks and often discarding the body back into the water. This process is fatal to sharks.

Hilton Worldwide’s shark fin ban will help preserve the longevity and future of sharks, who are critical for keeping the marine ecosystems healthy. We hope that other hotel and restaurant industry leaders will follow in showing their commitment to protect sharks. By evaluating and taking responsibility for their impact on the environment, companies with strong leadership can play a major role in protecting our ocean.

Please join us in thanking Hilton Worldwide for no longer being a part of the shark fin trade.

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Scientists Discover How BP Oil Affects Tuna Hearts http://blog.oceanconservancy.org/2014/02/24/new-study-bp-oil-is-damaging-tuna-hearts/ http://blog.oceanconservancy.org/2014/02/24/new-study-bp-oil-is-damaging-tuna-hearts/#comments Mon, 24 Feb 2014 16:25:07 +0000 Carmen Yeung http://blog.oceanconservancy.org/?p=7544

Photo: NOAA

During the spring and summer of 2010, the BP Deepwater Horizon disaster released over 4 million barrels of crude oil into the Gulf of Mexico. This was an unprecedented amount of toxic material discharged into the Gulf, and scientists have been researching its impacts on marine and coastal wildlife ever since. One of the species of concern is the imperiled Atlantic bluefin tuna, which was spawning at the time and location of the BP disaster.

In a new study, scientists from Stanford University and the National Oceanic Atmospheric Administration (NOAA) discovered that crude oil, specifically polycyclic aromatic hydrocarbons (PAHs), disrupts the cellular pathway that allows juvenile bluefin and yellowfin tuna heart cells to beat effectively. This causes a slowed heart rate, reduced ability of muscular heart tissue to contract, and irregular heartbeats that can lead to cardiac arrest and death.

Crude oil is known to be toxic to the developing hearts of fish embryos and larvae, reducing the likelihood that those fish will survive. But until now, the details of how crude oil harmed fish hearts were unclear.

How Crude Oil Slows the Heartbeat

The heart in vertebrates is made up of a collection of individual cells that interact to give the heart its ability to beat and pump blood. To beat effectively, the heart cell must move essential ions like potassium and calcium through channels into and out of the cell quickly. Very low concentrations of crude oil block these channels in heart cell membranes, which ultimately slow the fish’s heartbeat.

The ion channels observed in tuna heart cells are similar to the ion channels found in heart cells of many animals, including humans. This study provides evidence as to how petroleum products may be negatively affecting cardiac function in a wide variety of animals.

Implications for Other Species

After the BP Deepwater Horizon disaster, other fish, such as red snapper, spawned in offshore waters, these spawning habitats were potentially oiled as a result of the disaster. This raises the possibility that eggs and larvae of many species, which float near surface waters, were exposed to oil. The potential harmful impacts of the BP disaster on young fish are still being investigated.

Looking at the big picture, these new findings demonstrate how petroleum-derived chemical pollution from the BP oil disaster and other sources — such as urban stormwater runoff — could affect coastal and marine species in the Gulf or elsewhere. This study raises the concern that exposure to PAHs in many animals – including humans – could lead to cardiac arrhythmias and bradycardia, or slowing of the heart.

Restoring the Gulf of Mexico

This study is groundbreaking for many reasons. For one, it offers insight into how crude oil from the BP disaster could impact wildlife in offshore waters. Second, the study points to the types of data that scientists need to collect in order to monitor the environment’s health and recovery before and after an oil spill – like a doctor taking vital signs to monitor a patient’s health prior to and after a heart attack.

And lastly, it underscores the importance of funding long-term ecosystem monitoring to understand how daily pollution such as stormwater runoff and air pollution as well as large scale human-caused disasters affect the health of wildlife, habitats and humans.

In light of this significant discovery, it is essential that we continue to research and monitor the impacts of the BP Deepwater Horizon oil disaster so that we may understand the full scope of injury and implement strategies to restore the Gulf of Mexico to its former resilience and beauty.

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Will radiation from Fukushima harm distant seafood consumers? http://blog.oceanconservancy.org/2014/01/15/will-radiation-from-fukushima-harm-distant-seafood-consumers/ http://blog.oceanconservancy.org/2014/01/15/will-radiation-from-fukushima-harm-distant-seafood-consumers/#comments Wed, 15 Jan 2014 17:05:24 +0000 Carmen Yeung http://blog.oceanconservancy.org/?p=7346

Pacific bluefin tuna. Photo courtesy of NOAA Fisheries.

I’ve been receiving questions from concerned friends and family about how radiation from the Fukushima Dai-ichi nuclear power plant is affecting the marine environment and human seafood consumption. As ocean lovers, I’m sure you’re equally concerned. After reading different scientific articles and speaking with experts, I found that there are local impacts from radiation to humans and marine life around Fukushima – but impacts from radiation on the rest of the Pacific Ocean are not expected to be harmful to human consumers and marine animals.

Human tragedy and nuclear power plant meltdown

The Tōhoku earthquake and tsunami in Japan in March 2011 was a human tragedy, killing at least 15,550 people and displacing more than 130,000 people. Economic losses caused by the magnitude-9.0 earthquake and the resulting tsunami in Japan came to $210 billion, making it the costliest natural catastrophe of all time. This event also triggered the Fukushima Dai-ichi nuclear power plant meltdown, creating a radiation scare around the world. The plant released radiation from:

  • atmospheric deposition due to the meltdown during mid-March 2011;
  • direct discharge from the plant;
  • river runoff; and
  • contaminated underground water flow.

The latter three sources are now small and continuous sources of input. These pathways introduced mostly iodine-131, cesium-137 and cesium-134 but also low levels of tellurium, uranium and strontium to the area surrounding the power plant.

Local radiation impacts: fishery closures, leaking storage tanks, elevated cancer rates

Radiation from the plant is impacting the area near the disaster. In local coastal waters and bottom sediments near Fukushima, cesium levels for certain marine life, such as bottom-dwelling fish, have been above the Japanese government’s limits for seafood and have prompted local fishery closures and nearby countries to ban importing fish caught near Fukushima. Direct exposure to leaking nuclear waste storage tanks is causing health problems among plant workers. The power plant meltdown also likely caused higher rates of certain cancers – which will unfold in the years to come – in local residents.

Distant radiation impacts: no harm likely to marine animals and human consumers of seafood

The implications for the larger Pacific Ocean, however, will be much less deleterious. In the Pacific Ocean, currents, eddies and other physical ocean dynamics dilute radiation from Fukushima, making these concentrations much lower in the ocean with distance and time. While the overall concentration of radionuclides will increase in the Pacific Ocean from pre-Fukushima levels, the increased levels will not likely be enough to be harmful to marine animals and human consumers outside the local area.

For example, migratory Pacific bluefin tuna, traveling from Japan to California, had elevated radiation levels of cesium-134 in 2012, a year after the Fukushima accident, but these levels were below safety guidelines for public health and less than half those from 2011.

To understand health risks, scientists also calculated that the additional dose from Fukushima radionuclides to humans consuming tainted Pacific bluefin tuna in the United States was 0.9 and 4.7 μSv for average consumers and subsistence fishermen, respectively. Such radiation doses are comparable to, or less than, the dose all humans routinely obtain from naturally occurring radionuclides in many food items, medical treatments or air travel. (From a sustainable seafood perspective, Monterey Bay Aquarium Seafood Watch recommends avoiding bluefin tuna since they are being caught faster than they can reproduce.) With more scientific research, we can better understand how radioactivity from Fukushima will affect marine life and the food chain.

Dr. Ken Buesseler, senior scientist at Woods Hole Oceanographic Institution, has been studying the spread and impacts of radiation from Fukushima into the Pacific Ocean. He has an analogy to help understand the movement of Fukushima-derived radiation as it enters the ocean:

“The spread of cesium once it enters the ocean can be understood by the analogy of mixing cream into coffee. At first, they are separate and distinguishable, but just as we start to stir the cream forms long, narrow filaments or streaks in the water. The streaks became longer and narrower as they moved off shore, where diffusive processes began to homogenize and dilute the radionuclides. In the ocean, diffusion is helped along by ocean eddies, squirts, and jets that broaden, mix, and continue to dilute the cesium as it travels across the ocean. With distance and time, radionuclide concentrations become much lower in the ocean, something that our measurements confirm.”

For more information regarding the Fukushima nuclear power plant and radiation, check out Woods Hole Oceanographic Institution’s special series on Fukushima. For more information on sustainable seafood choices, visit Monterey Bay Aquarium Seafood Watch.

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Warming Arctic Means Frigid Weather Fronts for Us http://blog.oceanconservancy.org/2014/01/10/warming-arctic-means-frigid-weather-fronts-for-us/ http://blog.oceanconservancy.org/2014/01/10/warming-arctic-means-frigid-weather-fronts-for-us/#comments Fri, 10 Jan 2014 17:51:43 +0000 Carmen Yeung http://blog.oceanconservancy.org/?p=7336

Photo courtesy morningnettle / morningnettle/Flickr

Strong polar vortex winds normally trap cold air in the Arctic and circle the North Pole from west to east. This pattern broke down this month, allowing cold Arctic air to spill over the central United States and create record cold temperatures for the eastern half of the United States.

This isn’t the first time that the polar vortex has been weak. During late autumn and early winter in 2005, 2008, 2009 and 2010, weak polar vortex winds were associated with an increase of cold air moving south from the Arctic. During this event in 2009, North America was 3 to 18 °F cooler than normal monthly averages, and the Arctic region was more than 7 °F warmer than average.


Scientists think there may be a connection between the intense, short-term cold weather patterns that hit many parts of the country and the warming Arctic. Understanding the link between more severe weather in the mid-latitudes and less sea ice and snow cover in the Arctic is an active area of research.

More work needs to be done to understand these global, atmospheric connections. But we already know that the Arctic is changing dramatically. The most visible indication of this change is the long-term decline of Arctic summer sea ice from climate change. The seven lowest levels of Arctic summer sea ice on satellite record have occurred in the last seven years, from 2007 to 2013. These changes in Arctic climate—together with the threats posed by increasing industrial activity in the region—could have dire consequences not only for the Arctic and its wildlife, but for our entire planet.

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When It Comes to Arctic Drilling, Cumulative Effects Add Up http://blog.oceanconservancy.org/2013/11/22/when-it-comes-to-arctic-drilling-cumulative-effects-add-up/ http://blog.oceanconservancy.org/2013/11/22/when-it-comes-to-arctic-drilling-cumulative-effects-add-up/#comments Fri, 22 Nov 2013 17:02:42 +0000 Carmen Yeung http://blog.oceanconservancy.org/?p=6997 Workers in the ArcticPicture five oil rigs in your nearby ocean. These oil rigs are different sizes and operate in different locations and at different times. Each of these rigs has an impact on marine life and water quality, but each to a different degree.

When the individual impacts of each of these rigs accumulate over time and space, it is known as “cumulative effects.” Think of this like a snowball fight. It’s easy to dodge snowballs when you’re up against one other person.  But when five people are throwing snowballs at you, it’s much harder to avoid getting hit. And the more hits you take, the more bruises you’re bound to get.

Cumulative effects recognizes that the impact of an individual action may be relatively minor on its own, but could be much more significant when considered in combination with the effects of other past, present and future actions. Effective assessment of cumulative effects is one of the most challenging issues in resource management.

Arctic food web and oil impactsAs the pace and scope of industrial activity in Arctic Alaska grows, the need to predict and account for the cumulative effects of oil exploration and development and increasing vessel traffic—including infrastructure and operations—becomes more critical. To avoid or minimize environmental degradation caused by industrial activities or accidents such as oil spills, federal agencies need a reliable way to assess the cumulative effects of proposed actions on the surrounding environment.

This is not an easy task, especially when dealing with multiple decisions that affect large areas over long time periods. The rewards, however, are significant: by understanding and considering the long-range impact of multiple activities over a large spatial area, industry, government regulators, communities and stakeholders may be able to better manage oil exploration and development in Alaska’s Arctic Ocean to avoid or minimize environmental harm.

Unfortunately, the Bureau of Ocean Energy Management (BOEM), the agency that manages offshore conventional and renewable energy resources (think offshore oil rigs and wind turbines), has not done a good job of analyzing potential cumulative effects in the Arctic in past environmental reviews.

For example, when assessing the cumulative impacts from an Arctic lease sale, BOEM reasoned that because there were 11 existing offshore projects, the proposed project would contribute approximately one-tenth the cumulative effects of waste water, construction, transportation and oil spills influencing water quality. Here, BOEM divided the number of proposed offshore projects (one) by the total number of offshore projects (11) to assess cumulative impact of oil development activities to water quality (=1/11).

This is a deeply flawed approach. Under this logic, each successive project would be responsible for incrementally less impact. With 100 projects, the new proposed project would only be responsible for 1/100 of the impact—but the cumulative effect of 100 projects would likely be far greater than the impacts of 10 projects. Also, this approach doesn’t account for the scale and location of each offshore facility, which are important factors to assessing harm. Combining all of the offshore projects together into a percentage masks the damages to the surrounding environment from a single offshore facility.

One major stumbling block for BOEM is the lack of a standardized approach and methodology for conducting cumulative effects analysis. BOEM can significantly improve its analysis of cumulative effects by developing and adhering to a standardized approach and methodology to cumulative effects analysis. Development of a transparent, broadly accepted approach and methodology for cumulative effects analysis, with common language and accounting for regional factors, will allow the agency to compare results across different planning areas.

A standardized approach and methodology that considers both positive and negative tradeoffs will provide BOEM with structure and guidance in analyzing cumulative effects. Recognizing the importance of cumulative effects, a governmental working group recommended improved understanding and consideration of the cumulative impacts of human activities in the Arctic.

The future health of sensitive Arctic ecosystem depends upon the use of sound analysis to determine the true impact of industrial activities. And good policies should be grounded in good science and analysis.

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