Farmers in Vietnam's central region are struggling with the mass mortalities of their lobster crops. Meanwhile, farmers in the Mekong Delta in the south are constantly fighting against heavy tiger and white-legged shrimp deaths.

The provincial Departments of Agriculture and Rural Development in the Mekong Delta report that many provinces have begun the newest shrimp crop this year -- but large amounts have succumbed to disease.

So far, 848.3 million breeder shrimp have been released on 12,412 ha by 11,563 farming households in coastal areas in Tra Vinh Province, of which over 40 million on more than 1,017 ha farmed by 800 households have die.

As bee populations continue to decline, researchers are scurrying to try and find an answer as to why.

A new study from Harvard School of Public Health has linked one of the most widely used pesticides, imidacloprid, as the bee's nemesis.

The authors wrote in a paper being published in the Bulletin of Insectology that they have found "convincing evidence" of the link between imidacloprid and Colony Collapse Disorder (CCD), in which adult bees abandon their hives.

"The significance of bees to agriculture cannot be underestimated," Alex Lu, associate professor of environmental exposure biology in the Department of Environmental Health, said in a press release. "And it apparently doesn't take much of the pesticide to affect the bees. Our experiment included pesticide amounts below what is normally present in the environment."

The team conducted a study in Worcester County, Massachusetts to try and replicate how imidacloprid may have caused the CCD outbreak.

They monitored bees in four different bee yards, each of which had four hives treated with different levels of imidacloprid and one control hive.

Wildlife experts are studying whether fur loss and open sores detected in nine polar bears in recent weeks is widespread and related to similar incidents among seals and walruses.

The bears were among 33 spotted near Barrow, Alaska, during routine survey work along the Arctic coastline. Tests showed they had "alopecia, or loss of fur, and other skin lesions," the U.S. Geological Survey said in a statement. "The animals were otherwise healthy in appearance and behavior."

Blood and tissue samples were collected from the sedated polar bears to see if the symptoms are related to those seen in ringed seals and walruses.

Patchy hair loss has been seen before in polar bears, but the high prevalence in those spotted recently and the earlier seal and walrus incidents raise a concern, Reuters quoted Tony DeGange, the chief biologist for the USGS in Alaska, as saying.

"There's a lot we don't know yet," he said, "whether we're dealing with something that's different or something that's the same."

Thousands of dead or dying dolphins have washed ashore in Peru since January, a marine mystery potentially caused by a combination of stress, pollution and disease.

When a retired fisherman called to report that about 1,500 dolphins had washed up dead on Peru's northern coast, veterinarian Carlos Yaipén's first reaction was, "That's impossible."

But when Yaipén traveled up the coast last week, he counted 615 dead dolphins along a 135-kilometer stretch of coastline.

Now, the death toll could be as high as 2,800, based on volunteers' counts. Peru's massive dolphin die-off is among the largest ever reported worldwide.

The strandings, which began in January, are a marine mystery that may never be unraveled. Experts say the causes could be acoustic impact from testing for oil or perhaps an unknown virus or other pathogen. Little marine research takes place in Peru, and even in the United States, of 55 marine mammal strandings since 1991, the National Oceanographic and Atmospheric Administration (NOAA) has classified 29 as "undetermined."

Kelp off Southern California was contaminated with short-lived radioisotopes a month after Japan's Fukushima accident, a sign that the spilled radiation reached the state's coastline, according to a new scientific study. Scientists tested giant kelp from the ocean off Orange County and other locations after the March, 2011 accident and detected radioactive iodine at peak concentrations 250-fold higher than levels found in West Coast kelp before the nuclear accident. "Basically we saw it in all the California kelp blades we sampled," said biology professor Steven Manley of California State University, Long Beach. The radioactivity had no known effects on the giant kelp, or on fish and other marine life, and it was undetectable when the kelp was tested again a month later. Iodine 131 "has an eight-day half life so it's pretty much all gone," Manley said. "But this shows what happens half a world away does effect what happens here. I don't think these levels are harmful but it's better if we don't have it at all."

Kelp off Southern California was contaminated with short-lived radioisotopes a month after Japan's Fukushima accident, a sign that the spilled radiation reached the state's urban coastline, according to a new scientific study.

Scientists from California State University, Long Beach tested giant kelp collected in the ocean off Orange County and other locations after the March, 2011 accident, and detected radioactive iodine, which was released from the damaged nuclear reactor.

The largest concentration was about 250-fold higher than levels found in kelp before the accident.

"Basically we saw it in all the California kelp blades we sampled," said Steven Manley, a Cal State Long Beach biology professor who specializes in kelp.

The radioactivity had no known effects on the giant kelp, or on fish and other marine life, and it was undetectable a month later.

Iodine 131 "has an eight-day half life so it's pretty much all gone," Manley said. "But this shows what happens half a world away does effect what happens here. I don't think these levels are harmful but it's better if we don't have it at all."

A year ago, Manley watched coverage of the tsunami and Fukushima accident and wondered what impact it might have on California's marine life, particularly his favorite subject matter - kelp.

Spread in large, dense, brown forests across the ocean off California, Macrocystis pyrifera, known as giant kelp, is the largest of all algae and grows faster than virtually any other life on Earth. It accumulates iodine so Manley realized it would be a useful dosimeter to check how far radioactive material spreads.

"Kelp forests are some of the most productive ecosystems on Earth," he said. "I thought this would be an opportunity because one thing about macrocystis is it has a large surface canopy," which means it is continually exposed to the air - and whatever contaminants are in it.

In addition, giant kelp concentrates radioactive iodine 10,000-fold - for every one molecule in the water there would be 10,000 in its tissues.

Kelp was collected at three sites off Orange County, as well as Palos Verdes Peninsula in Los Angeles County, Santa Barbara, Pacific Grove and Santa Cruz. The highest concentration of iodine 131 was found in the kelp off Corona del Mar, which receives runoff from a large portion of Orange County. Its kelp was collected on April 15 of last year and tested five days later.

Mystery surrounds the appearance of more than a hundred dead catfish washed up at the Boyne River Mouth.

Residents have been finding the fish since Monday. Along the high tide line on Boyne Island, dead catfish were strewn every few metres along the high tide line from the morning before.

A spokesperson from the Department of Environment and Heritage Protection (DEHP) confirmed staff had inspected a section of the Boyne River on Monday and yesterday following reports of dead fish.

"Departmental staff have found over 100 dead catfish between the mouth of the Boyne River and the Bruce Highway bridge, approximately 20 kilometres south of Gladstone.

"The cause of death is currently unknown. Departmental staff are investigating and have conducted water quality monitoring and sampling.

"The water quality monitoring undertaken on 4 April 2012 identified reduced salinity levels due to freshwater inflow. All other monitoring results have found water quality is consistent with those of a healthy waterway."

Nearly two years after the Deepwater Horizon disaster gushed millions of barrels of oil into the Gulf of Mexico, tar balls from the spill still turn up on Alabama's shores after storms. Now, one researcher is recommending that people steer clear of these tar balls after studies find them chock-full of potentially deadly bacteria.

In research published online November 2011 in the journal EcoHealth, Auburn University microbiologist Cova Arias and colleagues discovered that Deepwater Horizon tar balls found months after the spill contained high levels of bacteria, including 10 times the level of Vibrio vulnificus as found in the surrounding sand, a finding first reported by the Associated Press. V. vulnificus is the leading cause of seafood-borne disease fatalities nationwide, and it has a fatality rate of 20 to 30 percent when it infects skin wounds.

"We don't know what the real risk is at this point," Arias told LiveScience. But to be safe, beachgoers should avoid handling the tar balls, she said.

About 4.9 million barrels of oil, or 205 million gallons, spilled from a riser pipe in the seafloor after the Deepwater Horizon rig exploded and sank in late April 2010. Some of that oil persists in the Gulf in the form of tar balls.

The dolphins in the Gulf of Mexico are in the midst of a massive die-off. The reasons why remain a complicated and mysterious mix of oil, bacteria, and the unknown.

Normally an average of 74 dolphins are stranded on the northern shore of the Gulf of Mexico each year, especially during the spring birthing season. But between February 2010 and April 1, 2012, 714 dolphins and other cetaceans have been reported as washed up on the coast from the Louisiana/Texas border through Franklin County, Florida, reported the National Oceanic and Atmospheric Administration (NOAA). 95 percent of the mammals were dead.

Since many of the dead dolphins sink, decompose or are eaten by scavengers before washing up, NOAA biologists believe that 714 represents only a fraction of the actual death count. NOAA declared the die-off an "Unusual Mortality Event" as per the Marine Mammal Protection Act of 1972.

Although the timing of die-off largely coincides with BP's Deepwater Horizon oil spill and its aftermath, the deaths actually started increasing about two months before the April 20, 2010 explosion which started the months long oil spill.

Before the spill, 112 dolphins had already been reported stranded on the shore.

Lima, Peru - So far in 2011, some 3,000 dead dolphins have washed up on the beaches in the northern Peruvian region of Lambayaque, supposedly having died from the effects of petroleum exploitation in the area, the daily Peru21 reported Sunday.

According to the science director for the Scientific Organization for Conservation of Aquatic Animals, or ORCA, Carlos Yaipen, the deaths of the oceanic mammals was due to a "marine bubble," an acoustic pocket that forms as a result of using equipment to explore for petroleum below the seabed.

"The oil companies use different frequencies of acoustic waves and the effects produced by these bubbles are not plainly visible, but they generate effects later in the animals. That can cause death by acoustic impact, not only in dolphins, but also in marine seals and whales," Yaipen told the daily.

A new study of dolphins living close to the site of North America's worst ever oil spill - the BP Deepwater Horizon catastrophe two years ago - has established serious health problems afflicting the marine mammals.

The report, commissioned by the National Oceanic and Atmospheric Administration [NOAA], found that many of the 32 dolphins studied were underweight, anaemic and suffering from lung and liver disease, while nearly half had low levels of a hormone that helps the mammals deal with stress as well as regulating their metabolism and immune systems.

More than 200m gallons of crude oil flowed from the well after a series of explosions on 20 April 2010, which killed 11 workers. The spill contaminated the Gulf of Mexico and its coastline in what President Barack Obama called America's worst environmental disaster.

The research follows the publication of several scientific studies into insect populations on the nearby Gulf coastline and into the health of deepwater coral populations, which all suggest that the environmental impact of the five-month long spill may have been far worse than previously appreciated.

Another study confirmed that zooplankton - the microscopic organisms at the bottom of the ocean food chain - had also been contaminated with oil. Indeed, photographs issued last month of wetland coastal areas show continued contamination, with some areas still devoid of vegetation.