User:Cosettepatterson/sandbox

Deep-Sea Debris[edit]
Edits to Marine debris article on Wikipedia, adding to 'Deep Sea' section:

- My edits are in bold

Deep-sea debris[edit]
'''Although an increasing number of studies have been focused on plastic debris accumulation on the coasts, in off-shore surface waters, and that ingested by marine organisms that live in the upper levels of the water column, there is limited information on debris in the mesopelagic and deeper layers. Studies that have been done have conducted research through bottom sampling, video observation via remotely operated vehicles (ROVs), and submersibles. They are also mostly limited to one-off projects that do not extend long enough to show significant effects of deep-sea debris over time. Research thus far has shown that debris in the deep-ocean is in fact impacted by anthropogenic activities, and plastic has been frequently observed in the deep-sea, especially in areas off-shore of heavily populated regions, such as the Mediterranean. '''

Litter, made from diverse materials that are denser than surface water (such as glasses, metals and some plastics), have been found to spread over the floor of seas and open oceans, where it can become entangled in corals and interfere with other sea-floor life, or even become buried under sediment, making clean-up extremely difficult, especially due to the wide area of its dispersal compared to shipwrecks. '''Plastics that are usually negatively buoyant can sink with the adherence of phytoplankton and the aggregation of other organic particles. Other oceanic processes that affect circulation, such as coastal storms and offshore convection, play a part in transferring large volumes of particles and debris. Submarine topographic features can also augment downwelling currents, leading to the retention of microplastics at certain locations.  A Deep-sea Debris database by the Global Oceanographic Data Center of the Japan Agency for Marine-Earth Science and Technology (JAMSTEC), showing thirty years of photos and samples of marine debris since 1983, was made public in 2017. From the 5,010 dives in the database, using both ROVs and deep-sea submersibles, 3,425 man-made debris items were counted. The two most significant types of debris were macro-plastic, making up 33% of the debris found – 89% of which was single-use – and metal, making up 26%. Plastic debris was even found at the bottom of the Mariana Trench, at a depth of 10,898m, and plastic bags were found entangled in hydrothermal vent and cold seep communities. '''

Microplastic pollution[edit]
The extent of microplastic pollution in the deep sea has yet to be fully determined, and as a result scientists are currently examining organisms and studying sediments to better understand this issue. A 2013 study surveyed four separate locations to represent a wider range of marine habitats at depths varying from 1100-5000m. Three of the four locations had identifiable amounts of microplastics present in the top 1cm layer of sediment. Core samples were taken from each spot and had their microplastics filtered out of the normal sediment. The plastic components were identified using micro-Raman spectroscopy; the results showed man-made pigments commonly used in the plastic industry. In 2016, researchers used an ROV to collect nine deep-sea organisms and core-top sediments. The nine deep-sea organisms were dissected and various organs were examined by the researchers on shore to identify microplastics with a microscope. The scientists found that six out of the nine organisms examined contain microplastics which where all microfibers, specifically located in the GI tract. Research performed by MBARI in 2013 off the west coast of North America and around Hawaii found that out of all the debris observed from 22 years of VARS database video footage, one-third of the items was plastic bags. This debris was most common below 2000 m depth. A recent study that collected organisms and sediments in the Abyssopelagic Zone of the Western Pacific Ocean extracted materials from samples and discovered that poly(propylene-ethylene) copolymer (40.0%) and polyethylene terephthalate (27.5%) were the most commonly detected polymers.

'''Another study was conducted by collecting deep-sea sediment and coral specimens between 2011 and 2012 in the Mediterranean Sea, Southwest Indian Ocean, and Northeast Atlantic Ocean. Of the 12 coral and sediment samples taken, all were found with an abundance of microplastics. Rayon is not a plastic but was included in the study due to being a common synthetic material. It was found in all samples and comprised 56.9% of materials found, followed by polyester (53.4%), plastics (34.1%) and acrylic (12.4%). This study found that the amount of microplastics, in the form of microfibres, was comparable to that found in intertidal or subtidal sediments. A 2017 study had a similar finding – by surveying the Rockall Trough in the Northeast Atlantic Ocean at a depth of more than 2200 meters, microplastic fibers were identified at a concentration of 70.8 particles per cubic meter. This is comparable to amounts reported in surface waters. This study also looked at micropollution ingested by benthic invertebrates Ophiomusium lymani, Hymenaster pellucidus and Colus jeffreysianus and found that of the 66 organisms studied, 48% had ingested microplastics in quantities also comparable to coastal species. '''