Tiny pieces of plastic contaminate almost every sea in the world. Now scientists have found that marine creatures like fish and birds are eating this microscopic waste, which may be harming their health.
The main concern is that microplastics are plastic pieces too small to see with the naked eye. They may be small by design, or be fragments of larger pieces of plastic waste.
Their size means they can be mistaken for food by even the smallest sea creatures, as well as large animals like seabirds and fish.
Scientists are concerned about the damage this could be causing. Plastics could block animals’ digestive systems or lower the amount of food they can eat. Not only that, but microplastics can carry toxic chemicals on their surface. So, scientists are calling for further research into pollution from microscopic waste.
“Things have progressed in terms of understanding where you can find microplastics and how much is out there, but we still haven’t worked out what damage this is doing to animals,” says Matthew Cole from the Plymouth Marine Laboratory and the University of Exeter, who has co-authored a major review of all published microplastic studies.
“We’re still on the tip of the iceberg in terms of understanding how these particles affect the health of marine animals,” he adds.
Mass production of plastic began in the 1940s and has since exploded. In 2009, 230 million tonnes of plastic were produced, equivalent to the weight of a double-decker bus every two seconds. The increase in large plastic waste in the sea quickly concerned people, because of its visibility. Understandably, the spread of microscopic plastic fragments has gone largely unnoticed by the general public.
But the chemicals these fragments carry may be more dangerous than the plastics themselves. Plastic often contains additives to make it last longer. These additives can be harmful to health, changing hormonal patterns in fish and birds. And, because plastics are oil-based, they are particularly good at attracting waterborne pollutants from other sources.
These persistent organic pollutants can lead to hormone disruption, development problems and cancer. If marine animals swallow tiny plastic particles, the chemicals on their surface could be easily taken up.
“Almost like a Trojan horse, microplastics can help transfer potentially dangerous chemicals to animals,” Cole explains.
The scientists also looked at where these microplastics come from. Some are designed to be microscopic. These include the beads used in exfoliating facial washes, as well as those used in air-blasters to remove rust and paint from the hulls of boats. Other microplastics may be fragments of bigger objects, from plastic bags to fishing gear.
Half the world’s population lives within just 50 miles of the coast, so it’s easy to see how plastic waste gets into the marine environment. It finds its way into storm drains and sewage systems, where it slips through the filters in wastewater treatment works into rivers and out to sea. Around 80 percent of plastic debris in the sea comes from inland.
Now, Cole is trying to work out whether the tiniest sea creatures, called zooplankton, can take up microplastics. This is the first stage in trying to understand whether these particles can travel up the food chain. If they can get into zooplankton, then they could be passed on to bigger animals that eat them. This so-called trophic transfer could ultimately affect us too.
“If they’re trophically transferred they could end up in the human food supply,” says Cole. “But, without doing a lot more work we won’t know what the full effects of these compounds are.”
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.
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.”
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.
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.
