Plastic Pollution Endangering Marine Life
Scientists are warning that much more research must be conducted on the impact of plastic pollution on sea life such as sharks, rays and whales. Studies suggest that these creatures may be swallowing hundreds of bits of micro-plastic every day. Scientists say that micro-plastic pollution could result in the reduction of the population of large filter feeders, however very little research is being conducted into the risk it poses. European and American researchers have examined data on the threats to large filter feeders from these plastic pieces measuring less than five millimetres long and found they can be extremely harmful to aquatic life.
We have no idea what the magnitude of risk is
Researchers say the full magnitude of the risk of ingesting micro-plastics has not yet been fully investigated. Risks could include damage to the digestive system, reduction in nutritional uptake and exposure to toxins. The final risk could have an impact on many biological processes including growth and reproduction which puts further strain on the filter feeding population. The research suggests that large filter feeders which tend to be economically important as well as charismatic species should be the priority when it comes to further research in to the risks of micro-plastics.
Plastic is extremely toxic
Filter feeding species process hundreds of cubic metres of water every day in order to obtain their nutritional requirement and obviously swallowing such huge amounts of water will inevitably include ingesting micro-plastics in the process. This type of plastic is very similar in size and mass to many forms of plankton. Studies have shown that the chemicals associated with micro-plastics have ended up in the bodies of fin whales and whale sharks. Scientists say that exposure to the toxins associated with micro-plastics are a significant threat to these species because it can change the hormones that regulate their growth, development, metabolism and reproductive functions.
Huge amounts of plastic are ingested
The study estimates that whale sharks that feed off the coast of Mexico where they also breed swallow as many as 200 pieces of plastic each day. Fin whales located in the Mediterranean Sea are believed to swallow almost 2,000 particles of micro-plastic per day. The researchers say that a whale carcass in France contained 800 kilograms of plastic. Another carcass in Australia contained six square metres of plastic sheeting and an addition 30 complete plastic carrier bags.
Flagship species
Whale sharks and other species that are considered to be flagship may serve as a point of focus for research particularly in countries that depend on tourism. Researchers add that using iconic species such as whale sharks, manta rays and whales will attract the attention of communities and policy makers who may implement rules that will benefit their marine ecosystems. Many filter feeding species are on the brink of extinction and whilst they do have a long life-span, they give birth to few offspring over the course of their lives. The IUCN has listed the whale shark as Endangered and put the species on its Red List.
