Hundreds of sharks and rays tangled in plastic

JULY 5, 2019

by University of Exeter

Hundreds of sharks and rays have become tangled in plastic waste in the world's oceans, new research shows.

University of Exeter scientists scoured existing published studies and Twitter for shark and ray entanglements, and found reports of more than 1,000 entangled individuals.

And they say the true number is likely to be far higher, as few studies have focussed on plastic entanglement among shark and rays.

The study says such entanglement—mostly involving lost or discarded fishing gear—is a "far lesser threat" to sharks and rays than commercial fishing, but the suffering it causes is a major animal welfare concern.

"One example in the study is a shortfin mako shark with fishing rope wrapped tightly around it," said Kristian Parton, of the Centre for Ecology and Conservation on Exeter's Penryn Campus in Cornwall.

"The shark had clearly continued growing after becoming entangled, so the rope—which was covered in barnacles—had dug into its skin and damaged its spine.

"Although we don't think entanglement is a major threat to the future of sharks and rays, it's important to understand the range of threats facing these species, which are among the most threatened in the oceans.

"Additionally, there's a real animal welfare issue because entanglements can cause pain, suffering and even death."

Read on

38 million pieces of plastic waste found on uninhabited South Pacific island

Henderson Island, part of the Pitcairn group, is covered by 18 tonnes of plastic – the highest density of anthropogenic debris recorded anywhere in the world

Elle Hunt

Monday 15 May 2017 20.00 BST Last modified on Tuesday 16 May 2017 09.04 BST 

One of the world’s most remote places, an uninhabited coral atoll, is also one of its most polluted.

Henderson Island, a tiny landmass in the eastern South Pacific, has been found by marine scientists to have the highest density of anthropogenic debris recorded anywhere in the world, with 99.8% of the pollution plastic.

The nearly 18 tonnes of plastic piling up on an island that is otherwise mostly untouched by humans have been pointed to as evidence of the catastrophic, “grotesque” extent of marine plastic pollution.

Nearly 38m pieces of plastic were estimated to be on Henderson by researchers from the University of Tasmania and the UK’s Royal Society for the Protection of Birds, weighing a combined 17.6 tonnes.

The majority of the debris – approximately 68% – was not even visible, with as many as 4,500 items per square metre buried to a depth of 10cm. About 13,000 new items were washing up daily.

Jennifer Lavers, of the University of Tasmania’s institute for marine and antarctic studies, told the Guardian the sheer volume of plastic pollution on Henderson had defied her expectations.

“I’ve travelled to some of the most far-flung islands in the world and regardless of where I’ve gone, in what year, and in what area of the ocean, the story is generally the same: the beaches are littered with evidence of human activity ...

“However, my thought was the remarkable remoteness of Henderson Island would have afforded it some protection. I was totally wrong.

“The quantity left me speechless and that’s why I went to such pains to document it in such detail.”

Lavers found hundreds of crabs living in rubbish such as bottle caps and cosmetics jars, and has been told of one living inside a doll’s head.

“From the looks on people’s faces, it was quite grotesque,” she said. “That was how I felt about all these crabs – we are not providing them a home, this is not a benefit to them.

Continued 

Whales are starving – their stomachs full of our plastic waste

Philip Hoare

Thirteen sperm whales stranded on the German coast had ingested huge amounts of plastic. They are symbolic of our shocking disregard for marine life

Wednesday 30 March 2016 13.52 BSTLast modified on Wednesday 30 March 201614.11 BST

In January, 29 sperm whales stranded on shores around the North Sea. The results of the necropsies (the animal equivalent of autopsies) of 13 of those whales, which beached in Germany, near the town of Tönning in Schleswig-Holstein, have just been released. The animals’ stomachs were filled with plastic debris. A 13-metre-long fishing net, a 70cm piece of plastic from a car and other pieces of plastic litter had been inadvertently ingested by the animals, who may have thought they were food, such as squid, their main diet, which they consume by sucking their prey into their mouths.

Robert Habeck, environment minister for the state of Schleswig-Holstein, said: “These findings show us the results of our plastic-oriented society. Animals inadvertently consume plastic and plastic waste, which causes them to suffer, and at worst, causes them to starve with full stomachs.” Nicola Hodgins, of Whale and Dolphin Conservation, added: “Although the large pieces will cause obvious problems and block the gut, we shouldn’t dismiss the smaller bits that could cause a more chronic problem for all species of cetacean – not just those who suction feed.”

The notion of these vast, sentient and placid creatures being stuffed with our trash is emblematic enough of the unequal relationship between man and sperm whale. The fact that the latter possess the largest brains of any animal that has ever lived only underlies this disconnection.

Our use and abuse of animals seems in inverse proportion to the almost ritual reverence in which we purport to hold them

Sadly, to anyone who follows the ongoing story of our impact on cetaceans, the terrible predicament of German whales is not new – although the scale of last January’s strandings is. In 2011, a young sperm whale was found floating dead off the Greek island of Mykonos. Its stomach was so distended that scientists believed that the animal might have swallowed a giant squid. But when they dissected its four stomachs (sperm whales, although predators, have digestive processes similar to ruminants), they found almost 100 plastic bags and other pieces of debris. One bag had the telephone number of a souvlaki restaurant in Thessaloniki. The scientists joked, grimly, that the whale could not call up to complain about the damage caused by their product.

Continued ...

Urban bees using plastic to build hives

Date:

February 11, 2014

Source:

University of Guelph

Summary:

Once the snow melts, bees will be back in business -- pollinating, making honey and keeping busy doing bee things. For at least two urban bee species, that means making nests out of plastic waste. A new study reveals that some bees use bits of plastic bags and plastic building materials to construct their nests.

Read on

Plastic waste in the Thames will devastate marine life, report warns

An unseen stream of plastic rubbish flowing along the bed of the river Thames and out into the North Sea will have far-reaching effects onmarine life, a new report indicates.

Scientists from the Natural History Museum and Royal Holloway, University of London, collected rubbish over a three-month period at the end of 2012 from seven locations along the river bed of the upper Thames estuary, between Crossness and Broadness Point.

The team netted 8,490 items including plastic cigarette packaging, food wrapping and cups that may have been blown or washed into the river down storm drains. More than 20% of waste was made up of sanitary products such as pads and plastic backing strips, which had most likely been flushed straight down the toilet. The full extent of the unseen waste could be far worse, the study warned, as plastic bags and other large items may have escaped the small nets used in the study.

Continued

New life discovered growing on ocean plastic waste dubbed the 'plastisphere' - via Herp Digest

Penny Orbell ABC Environment 13 Nov 2013

The dents in which the bacteria were found give scientists hope that they may be breaking down the plastic waste. Credit: Environmental Science and Technology

A whole new group of microscopic creatures has been found growing of the vast amount of discarded plastic floating in the world's oceans.

VAST AMOUNTS OF of plastic debris floating in the ocean are supporting new forms of microscopic life and whole new ecosystems. Scientists writing in the journal Environmental Science & Technology are collectively calling this new life the 'plastisphere'.

Previous studies have thoroughly outlined the harmful effects of plastic on animals such as fish, birds and other forms of marine life. However, none had fully assessed the effects of plastic on microscopic ocean dwellers.

The team, which included Tracy Mincer at the Woods Hole Oceanographic Institution in Massachusetts and Linda Amaral-Zettler of the Marine Biological Laboratory in Woods Hole, used fine mesh nets to collect pieces of plastic — around 1 to 5mm in diameter — from sites in the North Atlantic Ocean.

Using a combination of high-resolution imaging and genetic sequencing, they discovered unique ecosystems living on two kinds of plastic, with communities composed of microbes that are genetically distinct from those on other natural surfaces in the surrounding waters, such as driftwood or feathers. The plastic communities were also more diverse than those in seawater samples, which are typically dominated by only a few species.

"The organisms inhabiting the plastisphere were different from those in surrounding seawater, indicating that plastic debris acts as artificial 'microbial reefs'," said Mincer. "They supply a place that selects for and supports distinct microbes to settle and succeed."

More than 1,000 species of microbes were found in the study, including plants, algae and bacteria, some of which remain unidentified. These communities typically had a natural order: with plant-like organisms at the bottom of the food chain and higher order creatures that feed on them. Other organisms that live in harmonious relationships with each other were also identified.

"We're not just interested in who's there. We're interested in their function, how they're functioning in this ecosystem, how they're altering this ecosystem, and what's the ultimate fate of these particles in the ocean," said Amaral-Zettler. "Are they sinking to the bottom of the ocean? Are they being ingested? If they're being ingested, what impact does that have?"

Electron microscope images also reveal that some bacterial members of the plastisphere were nestled in 'pits' on the plastic surface, supporting the idea that these organisms may actually be contributing to the degradation of the plastic.

Studies conducted over the last 22 years found that despite an increase in the production of plastics, the amount of plastic oceanic debris has remained relatively stable. The scientists hope that 'pit formers' are breaking down the plastic, though they caution that more experiments need to be conducted.

"When we first saw the 'pit formers' we were very excited, especially when they showed up on multiple pieces of plastic of different types of resins," said Zettler. "Now we have to figure out what they are by sequencing them and hopefully getting them into culture so we can do experiments."

As the research is in its infancy, it is difficult to speculate yet about the potential effects of the emerging plastisphere on marine ecological environments.

Researchers are concerned that as the plastics, along with the unique micro-organisms they harbour, drift widely they have the potential to act as vectors for dispersal of harmful pest species or pollutants.

Penny Orbell wrote this article as part of her science communication studies at the University of Melbourne.

Researchers find plastic in more than 9% of fish in northern Pacific Ocean

The first scientific results from an ambitious voyage led by a group of graduate students from Scripps Institution of Oceanography at UC San Diego offer a stark view of human pollution and its infiltration of an area of the ocean that has been labeled as the “Great Pacific Garbage Patch.”

These are two lanternfish and several bits of plastic collected during the SEAPLEX voyage [Credit: J. Leicther]

Two graduate students with the Scripps Environmental Accumulation of Plastic Expedition, or SEAPLEX, found evidence of plastic waste in more than nine percent of the stomachs of fish collected during their voyage to the North Pacific Subtropical Gyre. Based on their evidence, authors Peter Davison and Rebecca Asch estimate that fish in the intermediate ocean depths of the North Pacific ingest plastic at a rate of roughly 12,000- to 24,000 tons per year.


Their results were published June 27 in the journal Marine Ecology Progress Series.

During the SEAPLEX voyage in August 2009, a team of Scripps graduate students traveled more than 1,000 miles west of California to the eastern sector of the North Pacific Subtropical Gyre aboard the Scripps research vessel New Horizon. Over 20 days the students, New Horizon crew and expedition volunteers conducted comprehensive and rigorous scientific sampling at numerous locations. They collected fish specimens, water samples and marine debris at depths ranging from the sea surface to thousands of feet depth

Of the 141 fishes spanning 27 species dissected in the study, Davison and Asch found that 9.2 percent of the stomach contents of mid-water fishes contained plastic debris, primarily broken-down bits smaller than a human fingernail. The researchers say the majority of the stomach plastic pieces were so small their origin could not be determined.

“About nine percent of examined fishes contained plastic in their stomach. That is an underestimate of the true ingestion rate because a fish may regurgitate or pass a plastic item, or even die from eating it. We didn’t measure those rates, so our nine percent figure is too low by an unknown amount,” said Davison.

The authors say previous studies on fish and plastic ingestion may have included so-called “net-feeding” biases. Net feeding can lead to artificially high cases of plastic ingestion by fishes while they are confined in a net with a high concentration of plastic debris. The Scripps study’s results were designed to avoid such bias. The highest concentrations of plastic were retrieved by a surface collecting device called a “manta net,” which sampled for only 15 minutes at a time. The short sampling time minimizes the risk of net feeding by preventing large concentrations of plastic from building up, and also by reducing the amount of time that a captured fish spends in the net. In addition to the manta net, the fishes were also collected with other nets that sample deeper in the water column where there is less plastic to be ingested through net feeding.

The new study focused on the prevalence of plastic ingestion, but effects such as toxicological impacts on fish and composition of the plastic were outside of the study’s goals.

The majority of fish examined in the study were myctophids, commonly called lanternfish because of their luminescent tissue. Lanternfishes are hypothesized to use luminescence for several purposes, including counter-illumination (thwarts predators attempting to silhouette the lanternfish against sunlight), mate attraction and identification and illumination of prey. Such fish generally inhabit the 200- to 1,000-meter (650- to 3,280-foot) depth during the day and swim to the surface at night.

“These fish have an important role in the food chain because they connect plankton at the base of the food chain with higher levels. We have estimated the incidence at which plastic is entering the food chain and I think there are potential impacts, but what those impacts are will take more research,” said Asch.

Rather than a visible “patch” or “island” of trash, marine debris is highly dispersed across thousands of miles of the North Pacific Subtropical Gyre. The debris area cannot be mapped from air or space, so SEAPLEX researchers collected samples in 132 net tows (130 of which contained plastic) across a distance of more than 2,375 kilometers (1,700 miles) in an attempt to find the boundaries of the patch. The region, a “convergence zone” where floating debris in water congregates, is generally avoided by mariners due to its calm winds and mild currents. The North Pacific Subtropical Gyre has been understudied by scientists, leaving many open questions about marine debris in the area and its long-term effects on the marine environment.

“This study clearly emphasizes the importance of directly sampling in the environment where the impacts may be occurring,” said James Leichter, a Scripps associate professor of biological oceanography who participated in the SEAPLEX expedition but was not an author of the new paper. “We are seeing that most of our prior predictions and expectations about potential impacts have been based on speculation rather than evidence and in many cases we have in fact underestimated the magnitude of effects. SEAPLEX also clearly illustrates how relatively small amounts of funding directed for novel field sampling and work in remote places can vastly increase our knowledge and understanding of environmental problems.”

Author: Mario Aguilera
Source: University of California - San Diego
http://archaeologynewsnetwork.blogspot.com/2011/07/researchers-find-plastic-in-more-than-9.html