With the Oceans covering 71% of the Earth’s surface, it could be thought that due to its vast size we may be able to dump pollutants such as plastic without enduring any cost. This is what was originally thought, but due to vast quantities of plastic that’s produced globally, we as human race have been successful in polluting the oceans which is causing detrimental effects. The rainforests have been around for 400 million years and yet in the space of a century we’ve destroyed 80% of it. Humans are pretty good a destroying stuff and currently have an equally as bad attitude to repairing the mess that we’ve created, but what are the detrimental effects are actions have caused? Working in size order we start with the microplastics, in particular nurdles. Despite their minuscule size, these plastics have the potential to pose as one of the greatest health risk to face the human race in the near future.
Tiny copepods, which form part of the zooplankton in the ocean typically feed on phytoplankton in the ocean However; resent study’s suggested that zooplankton were consuming nurdles and microscopic plastic fragments which has now been proven on camera. With the use of florescent microscopic polystyrene particles, scientists were able to film zooplankton eating the plastic. Once consumed, many zooplanktons eventually die over time due to the plastics toxic nature. Not only dose plastic contains its own array of toxic chemicals but nurdles have been found to attract background pollutants such as PCBs and DDE. In Japan, these toxic contaminates were found to be up to one million times higher than the levels detected in surrounding sea water. Nurdles ability to absorb contaminates means that any organism that consumes the toxic nurdles thereby ingests the toxic chemicals. These chemicals remain trapped inside organism poisoning it’s self potentially leading to death or enter another organism if eaten. This gives toxic chemicals such as PCBs, DDE and DDT the ability to move up the food chain. Zooplankton are the staple diet of most marine animals at the bottom of the food chain which increases the rate of which toxic chemicals like PCBs are moved up the food chain. Often the severity of the problem is only realised when we think who’s at the top of the foods chain, us! In 2012 UK households purchased 380,000 tonnes of seafood. With the consumption of sea food being so high in the UK alone it’s now clearly visible what impact this could have on a world wide scale. In theory this makes sense however, is there any backing evidence? Chelsea Rochman from the University of California Davis School of veterinary medicine and her team visited two fish markets to investigate whether there was a presence of artificial debris in the fish. The two markets they visited were Half Moon Bay and Princeton in California and in Makassar, Indonesia. 76 fish from 12 species and one shellfish species were examined from the California market whilst 76 fish from 11 species were examined the market in Indonesia, the fish at both markets were caught locally. When examined the team found that 55% of the fish sampled in Indonesia contained human produced debris. Meanwhile, 67 % of fish sourced from Half Moon Bay were found to have debris inside their tissue and gut, the majority of tissue was found to be textile fibres. In both cases a form of plastic debris was found in fish tissue which does support this startling theory that toxic microplastics are able to move up a food chain. Whilst it’s possible to avoid the gut when consuming sea food as this is where the highest concentration of microplastics are, we can’t avoid the toxins such as PCBs absorbed by micro plastics. Despite once absorbing toxic chemicals, these toxic chemicals are slowly released into the gut of the fish which are then absorbed into tissue. If consumed by humans or other animals these toxic chemicals (which are in a high concentration) then pass into the human gut and tissue. PCBs have been found to cause adverse effects in animals and humans which highlight the severity of the problem of microplastics. Effects on fertility, reproductive organs, and female hormonal activity have been observed during in animal testing when PCBs were planted in their food. Furthermore, since 1976 fifty studies have been conducted predominantly on people which had been exposed to PCBs at work indicated increases in mortality from cancers of the gastrointestinal tract, the liver, the organs and tissues involved in the production of blood, including bone marrow. Whilst the study above does prove a trend that PCBs are causing adverse health effects, a study in 2012 has provided much more solid evidence to support the claim that PCBs are effecting fertility. The $10 million study which was described as "an amazing study" and "unprecedented in its cost, scope and details." Has been able to provide more comprehensive evidence to the claim. 500 couples who were going to try to conceive a baby within the next two months were analysed with urine and blood samples tested for 63 environmental pollutants. Having analysed the data collected, it was found that likelihood of a pregnancy fell by about 20% among men and women with high exposure to certain types of PCBs. Twelve other toxic chemicals found to be carried by microplastics were found to affect men. The mutable findings above conclude the danger microplastics pose to humans. This only highlights the potential consequences we could be faced with if we don’t act. However, the health problems these toxic chemicals are causing don’t stop at effecting humans, there effecting organisms right the way down the food chain. Researchers at Uppsala University have conducted studies which clearly display the effect chemicals such as PCB’s which are absorbed into microplastics are having on organisms further down the food chain. The Swedish researchers have said that “Young fish become hooked on eating plastic in the seas the same way that teenagers prefer unhealthy fast food” To observe the impact of micro-plastics on the early life stages of fish, researchers exposed perch larvae to varying concentrations of polystyrene in water tanks. From the experimentation they found the following, in the absence of micro-plastics, approximately 96% of the eggs successfully hatched. This dropped to 81% for those eggs exposed to large quantities of micro plastics. The fish that did hatching having been exposed to micro plastics were "smaller, slower, and more stupid" than their counterparts that had hatched in clean waters said Dr Oona Lonnstedt, from Uppsala University. As part of the experimentation both sets of fish were exposed to a predator. Approximately half the young perch from clean waters survived for 24 hours. Meanwhile, those that had been raised with the strongest plastic concentrations were all consumed by a predator over the same time period. Whilst only perch were experimented with, we can assume that almost all other fish can many sea life will have a similar behaviour to the perch. If so, it’s possible we could expect to observe a collapse of eco systems and fish stocks as a result of abiotic factor. Whilst the supply of fish would be effected, there’s a far larger problem. It’s highly possible as I said earlier other fish species may act in the same way to the perch tested. If so, we could see such a decline in fish and other marine life we may observe a rapid collapse in the food chain. Causing a rapid decrease in both species diversity and specie richness resulting in species diversity decline. Losing fish stocks worldwide causes further implications, which I believe are currently being over seen. In 2014 the fishing industry was valued at US$ 148 billion and estimated to employ 200million, that’s a lot of people and a lot if job’s. Perhaps now the severity of consequence is now apparent. Diminishing fish stocks globally may result in unemployment as fishing fleets shrink, food shortages as fish dependant countries such as Peru which supply 10% of the globes fish struggle for food. Furthermore we could expect to see the price of fish sore as we observe a contraction in the supply of fish globaly as well as some more fish depend economics such as Prue could potentially enter economic slowdowns simply due to the fact that the fishing industry accounts for such a large percentage of is economic activity. The tourism industry in some locations can expect to be hit along with the fishing industry as my countries, particular smaller LEDC rely upon visitors exploring the exotic fish and reefs they have to offer. This sort of impact to a small LEDC’s economy is likely to cause a chain effect amount other industry located there which cater for the tourism industry. LEDC’s which may be impact include locations such as the Maldives and Seychelles
Having covered the threat of toxins such as PCBs to humans and other organisms, it’s microplastics and macroplastics physical properties which create problems in the marine environment as well. Scientists have tracked plastic ingestion by seabirds for decades. In 1960, 5% of sea birds were found to have plastics in their stomach, but by 1980, this had leapt to 90% with experts saying they expect vertically every sea bird to have plastic in there stomach by 2050. This prediction was based on a spatial risk analysis using predicted debris distributions and ranges for 186 seabird species to model debris exposure. Whilst the problem is worldwide the worst effect areas are location with a close proximity to gyres, these locations include southern Australia, South Africa, and South America where coastlines are closest to loosely-concentrated collections as seen in. These findings are as a result of Chris Wilcox, a research scientist with Australia’s Commonwealth Scientific and Industrial Research Organization. Chris Wilcox went on to explain particularly how particular species are affected. From his findings he explained that sea birds like the albatross are more susceptible to consuming plastic. An albatross’s behaviour plays a large role in explain there susceptibility to plastic pollutants. When fishing an albatross skims the water with its beak and inadvertently swallow plastics from the surface of the water. Petrels and shearwaters are also susceptible to inadvertently ingesting plastics due to foraging behaviour. The plastic pollutants they consume range from bottle caps, bags, synthetic fibres from cloths and microplastics. Death is most commonly caused by starvation as the bird constantly feels full hence they don’t eat any food. One bird examined by scientist Denise Hardesty has consumed 200 pieces of plastic. However birds have also died as a result of chemical poisoning from plastics as well as punctured stomach due to sharp plastic pollutants. You would think it’s only the adult sea birds that are affected as young chicks are unable to fly, however parents end up feeding plastic to chicks thinking it’s food which results in a chick death. As a result of an increase in plastic pollutants over the past century there has been an 67% decline in seabird populations between 1950 and 2010. “Essentially seabirds are going extinct,” says Wilcox. “Maybe not tomorrow. But they’re headed down sharply. Plastic is one of the threats they face.”