Affect of oceanic pollution on marine biodiversity: in response to Laura Marriot

When considering the current state of the worlds ecosystems, it is proposed that 15 of the Earths 24 ecosystems area in decline, due to their reduction in biodiversity (Hooper et al, 2012). It is also estimated by Barnosky et al (2011) that in the next 2-300 years species will decline at a rate 100 times that of natural extinction rates. It is agreed in the literature that the loss of biodiversity is a global crisis requiring international solutions.

Why is this important?

The oceans ecosystems are no different. Anthropogenic impacts are affecting marine ecosystems and biodiversity in a big way.

With particular reference to the affects of oceanic plastic pollution it is estimated that at least 267 marine species are affected by entanglement or ingestion including seabirds, fish, turtles, seals and whales (Allsopp et al, 2006).

Within scientific literature it is agreed that plastics accumulate persistent, toxic contaminants such as PCBs, DDT and PBDEs (GESAMP, 2010). The large surface to volume ratios of plastic facilitate this chemical exchange. As such upon ingestion by marine organisms the material acts as a vector, passing toxins through the food chain.

This can have a potentially harmful impact on human health.

Other affects of oceanic plastic pollution are less obvious. Plastics when accumulated in near surface waters can act as a sanctuary for microbial communities, potentially introducing 'alien species' into the ecosystem. The accumulation of plastics can also lead to areas of oxygen becoming deoxygenated as gaseous exchange between the near surface ocean and atmosphere is reduced. This can lead to the asphyxiation of marine organisms and the creation of 'marine dead zones'.

Future predictions

With expected increases in the human population and concurrently plastic pollution the strain on the marine ecosystem will become increasingly worse.