US Navy study raises estimate of marine mammal casualties due to sonar and explosives

By the Associated Press

The U.S. Navy may hurt more dolphins and whales by using sonar and explosives in Hawaii and California under a more thorough analysis that reflects new research and covers naval activities in a wider area than previous studies.

The Navy estimates its use of explosives and sonar may unintentionally cause more than 1,600 instances of hearing loss or other injury to marine mammals each year, according to a draft environmental impact statement that covers training and testing planned from 2014 to 2019. The Navy calculates the explosives could potentially kill more than 200 marine mammals a year.

A notice about the study is due to appear Friday in the Federal Register.

The old Navy analysis — covering 2009-2013 — estimated the service might unintentionally cause injury or death to about 100 marine mammals in Hawaii and California, although no deaths have been reported.

The larger numbers are partially the result of the Navy’s use of new research on marine mammal behavior and updated computer models that predict how sonar affects animals.

The Navy also expanded the scope of its study to include things like in-port sonar testing — something sailors have long done but wasn’t analyzed in the Navy’s last environmental impact statement. The analysis covers training and testing in waters between Hawaii and California for the first time as well.

“Each time around, each time we swing through this process, we get better, we take a harder look, we become more inclusive,” said John Van Name, senior environmental planner at the U.S. Pacific Fleet.

The Navy isn’t saying it will injure whales and dolphins as it trains sailors and tests equipment. It’s telling the public and environmental regulators that its actions have the potential to harm or otherwise prompt a reaction in the animals.

The Navy takes a variety of measures to prevent harm to the animals, including turning off sonar when marine mammals are spotted nearby. It says the actual numbers of injured animals would be lower as a result.

Read more from The Washington Post:

Pacific garbage patch 100x larger than in 1972; fish ingest up to 24,000 tons of plastic each year

By University of California, San Diego

A 100-fold upsurge in human-produced plastic garbage in the ocean is altering habitats in the marine environment, according to a new study led by a graduate student researcher at Scripps Institution of Oceanography at UC San Diego.

In 2009 an ambitious group of graduate students led the Scripps Environmental Accumulation of Plastic Expedition (SEAPLEX) to the North Pacific Ocean Subtropical Gyre aboard the Scripps research vessel New Horizon. During the voyage the researchers, who concentrated their studies a thousand miles west of California, documented an alarming amount of human-generated trash, mostly broken down bits of plastic the size of a fingernail floating across thousands of miles of open ocean.

At the time the researchers didn’t have a clear idea of how such trash might be impacting the ocean environment, but a new study published in the May 9 online issue of the journal Biology Letters reveals that plastic debris in the area popularly known as the “Great Pacific Garbage Patch” has increased by 100 times over in the past 40 years, leading to changes in the natural habitat of animals such as the marine insect Halobates sericeus. These “sea skaters” or “water striders”—relatives of pond water skaters—inhabit water surfaces and lay their eggs on flotsam (floating objects). Naturally existing surfaces for their eggs include, for example: seashells, seabird feathers, tar lumps and pumice. In the new study researchers found that sea skaters have exploited the influx of plastic garbage as new surfaces for their eggs. This has led to a rise in the insect’s egg densities in the North Pacific Subtropical Gyre.

Such an increase, documented for the first time in a marine invertebrate (animal without a backbone) in the open ocean, may have consequences for animals across the marine food web, such as crabs that prey on sea skaters and their eggs.

“This paper shows a dramatic increase in plastic over a relatively short time period and the effect it’s having on a common North Pacific Gyre invertebrate,” said Scripps graduate student Miriam Goldstein, lead author of the study and chief scientist of SEAPLEX, a UC Ship Funds-supported voyage. “We’re seeing changes in this marine insect that can be directly attributed to the plastic.”

The new study follows a report published last year by Scripps researchers in the journal Marine Ecology Progress Series showing that nine percent of the fish collected during SEAPLEX contained plastic waste in their stomachs. That study estimated that fish in the intermediate ocean depths of the North Pacific Ocean ingest plastic at a rate of roughly 12,000 to 24,000 tons per year.

The Goldstein et al. study compared changes in small plastic abundance between 1972-1987 and 1999-2010 by using historical samples from the Scripps Pelagic Invertebrate Collection and data from SEAPLEX, a NOAA Ship Okeanos Explorer cruise in 2010, information from the Algalita Marine Research Foundation as well as various published papers.

In April, researchers with the Instituto Oceanográfico in Brazil published a report that eggs of Halobates micans, another species of sea skater, were found on many plastic bits in the South Atlantic off Brazil.

“Plastic only became widespread in late ’40s and early ’50s, but now everyone uses it and over a 40-year range we’ve seen a dramatic increase in ocean plastic,” said Goldstein. “Historically we have not been very good at stopping plastic from getting into the ocean so hopefully in the future we can do better.”

From PhysOrg: http://phys.org/news/2012-05-plastic-trash-ocean-habitats.html

Ocean Acidification May Weaken or Kill Plankton

Ocean Acidification May Weaken or Kill Plankton

By Monash University

Changes in the ocean’s chemistry, as a result of increasing atmospheric carbon dioxide (CO2) levels, threaten marine plankton to a greater extent than previously thought, according to new research.

The research, published in Nature Climate Change, revealed around half the CO2 released through human activity dissolves in the ocean, where it forms carbonic acid leading to a decrease in seawater pH.

Scientists found the changes in the pH levels, along with global warming, could lead to poor growth if not death of marine plankton.

“On examining individual cells, we found many of the species were highly sensitive to increased acidity, reducing their individual silicification rates by 35-80%. These results revealed not only are communities changing, but species that remain in the community are building less-dense cell walls.”

Professor John Beardall from the School of Biological Sciences at Monash University collaborated with international researchers from Swansea University’s Centre for Sustainable Aquatic Research, who led the study, the Marine Biological Association, Plymouth, the University of Dundee and the University of Technology in Sydney.

Professor Beardall said the impact that ocean acidification-induced changes have on plankton was a major concern.

“This research suggests the impact of oceanic acidification upon marine plankton could be more serious than previously thought,” Professor Beardall said.

“Acidity levels will more than double by the end of the century as a result of the increase in CO2 levels in the ocean, but it is unclear how the growth of plankton will respond to this increase.”

Using mathematical modelling and their understanding of cellular physiology, the team has found that many marine plankton will experience a substantially more acidic environment than currently suggested.

Professor Beardall plans to develop the research further to understand the effects of ocean acidification and other aspects of climate change on key Australian phytoplankton species.

From Monash University News: http://www.monash.edu.au/news/show/global-warming-puts-oceans-plankton-under-greater-threat

Photo by Marek Okon on Unsplash

BP preparing to launch three new oil rigs in Gulf of Mexico

By Rupert Neate / The Guardian

BP is planning to start three new oil drilling rigs in the Gulf of Mexico this year. The launch of the new rigs will bring the number of BP rigs in the Gulf to eight – more than the oil giant had before the devastating Deepwater Horizon disaster three years ago.

Bernard Looney, BP’s executive in charge of new wells, said BP is expecting to spend $4bn (£2.5bn) on new developments in the Gulf of Mexico this year and hopes to “invest at least that much every year over the next decade”.

“After much soul-searching in the fall of 2010, we concluded it would be wrong to walk away [from the Gulf of Mexico],” Looney said at an offshore oil conference in Houston, Texas, on Monday. “We would have been walking away not only from our past, but from a key component of our future.”

He said the Deepwater Horizon disaster, which killed 11 people, had “challenged us to the core”, but said the company has been working hard to help prevent “such an accident from ever happening again”.

While conceding that BP was in “absolutely no position to preach”, he called on the industry to adopt broader safety standards.

Last October US regulators granted BP its first permit to drill a new well since the Deepwater Horizon oil spill, that spewed 4.9m barrels of oil into the fragile Gulf of Mexico ecosystem. The permit, for drilling in BP’s Kaskida field 250 miles south-west of New Orleans, was approved after BP’s well design met more stringent post-spill standards.

Looney did not state where the new rigs will drill, but industry figures said they expect an appraisal well in BP’s “giant” Tiber field 250 miles south-west of New Orleans. BP has long wanted to explore the area it discovered in 2009, but had been banned by regulators.

The company’s next big project, Mad Dog phase 2, is expected to start production towards the end of the decade. Looney said the field, which was discovered in 1998 and first began producing oil in 2005, holds more than 4bn barrels of oil – enough to promote it to the “super-giant” oil field category.

From The Guardian: http://www.guardian.co.uk/business/2012/apr/30/bp-new-gulf-mexico-oil-rigs

Researchers double estimate of plastic trash in oceans after examining waste below the surface

By Jeanna Bryner / Live Science

An oceanographer who noticed a disappearing act in which the surface of the ocean went from confetti-covered to clear now suggests wind may driving large amounts of trash deeper into the sea.

Oceanographer Giora Proskurowski was sailing in the Pacific Ocean when he saw the small bits of plastic debris disappear beneath the water as soon as the wind picked up.

His research on the theory, with Tobias Kukulka of the University of Delaware, suggests that on average, plastic debris in the ocean may be 2.5 times higher than estimates using surface-water sampling. In high winds, the volume of plastic trash could be underestimated by a factor of 27, the researchers report this month in the journal Geophysical Research Letters.

Plastic waste can wreak havoc on an ecosystem, harming fish and other organisms that ingest it, possibly even degrading a fish’s liver; the trashy bits also make nice homes for bacteria and algae that get carried to other areas of the ocean where they could be invasive or cause other problems, the researchers noted.

In 2010, the team collected water samples at various depths in the North Atlantic Ocean. “Almost every subsurface tow we took had plastic in the net,” Proskurowski told LiveScience, adding that they used a specialized tow net that isolated certain layers of the water, so it would only open at a specific depth and close before being pulled up.

Next, they combined the trash tally with wind measurements to come up with a mathematical model, which allowed them to calculate the amount of debris at different depths on average as well as look at how that amount changed with different conditions, such as on a windy day.

They found 2.5 times more debris in the layers of water below the “surface water” (defined as the top 9.8 inches or 25 centimeters) as was found in that surface section. The debris was distributed down to a depth of about 65 to 82 feet (20 to 25 meters).

The findings mean the estimates of plastic litter in the ocean, conducted by skimming the surface water only, may in some cases vastly underestimate the true amount of plastic debris there.

“The scope of the [plastic debris] problem is not just at the very surface but goes down to 20 meters or so, and that plastic is distributed throughout this layer,” Proskurowski said during an interview.

He and his colleagues plan to publish a simplified version of the model so others investigating ocean plastics can use it.

From Live Science: http://www.livescience.com/19940-plastic-trash-oceans-underestimated.html