Debris in the Seas

All over the world, bodies of water have been affected by human-produced debris, especially from plastics. In addition to being a “cause for concern” as a source of pollution of the environment in general, marine debris is also a serious concern for marine wildlife in the form of direct ingestion. Despite the fact that it presents a variety of problems for the environment and wildlife, contemporary research notes that “the scale of the marine debris problem and its potential to negatively impact biodiversity has not been widely evaluated.” Plastic debris is a particular concern due to how much of it is out there, and how persistent it is in the environment.

This study from the Marine Pollution Bulletin is an attempt to understand the scale and impact of marine debris on wildlife. Through a comprehensive and wide-reaching literature review (focusing on peer reviewed publications), the authors found that, “it is apparent that a wide range of species are affected by ingestion and entanglement in marine debris and that the frequency of encounters has increased over time.” However, they also note that the exact effects of marine ingestion vary widely, based on what type of debris is ingested, the amount, the species that ingested it, and so on. One thing that is clear is that a large percentage of marine animals have ingested marine debris in one form or another. One study found that 37% of the animals sampled had ingested microplastic, and the authors note that encounters with marine debris are of particular concern for species which are recognised as threatened; they note that “17% of all species reported here are listed as near threatened, vulnerable, endangered, or critically endangered on the IUCN Red List.”

This study can serve as a comprehensive source of information on the current state of marine debris, and can be useful for animal advocates in addressing the problem. While the results are already alarming, the authors note that their findings should be considered an “underestimate,” which highlights the need for more work to get better numbers and better evaluation of the problem. Of course, it also underscores the need to reduce the amount of marine debris and its impact on wildlife.