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- Environmental Variability
- Consequences of DWHOS
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- DEEPEND Publications
Master's Monday Blog - Microplastic ingestion in deep-sea fauna
Howdy! My name is Ryan Bos and I am here to aid in the fight against plastic! I am a Masters Candidate in Marine Science at Nova Southeastern University working with Dr. Tamara Frank and Dr. Tracey Sutton. Currently, I am doing an appraisal of microplastic ingestion in deep-sea fishes and crustaceans in the Gulf of Mexico (GoM).
Each day, nearly every person on Earth uses plastic items. It is all around us. It is in our clothes, cosmetics, vehicles, and if you carry a smartphone around with you, odds are that it has a plastic component. As humans, we manufacture and use plastic at alarming rates, and take it for granted. Plastic production is projected to increase with increases in the human population, yet plastic pollution is already infesting our oceans and will continue to persist for hundreds to thousands of years because of plastic’s inherent resiliency. I want to put the plastic crisis we are facing into perspective. There are ~34,000 extant species of fishes with the most abundant genus of fish, Cyclothone, consisting of 13 species. These 13 species are comprised of an estimated 1,000,000,000,000,000 individuals. By the year 2050, the number of fishes in our oceans will be equal to the number of plastics. What’s alarming about this statistic other than the number of fishes and plastic particles being equal? There are 33,987 more species that contribute to the total number of individual fish in our oceans, and most of these plastic particles can’t be seen with the naked eye!
Microplastics, as the name implies are small pieces of plastic that range in size from 1 - 5 mm that are categorized as being a fragment, film, spherule, foam, or fiber. These five categories can be further broken down into subcategories known as mini-microplastics that range in size from 1 µm - 1 mm and are named microfragments, microfilms, microbeads, microfoams, and microfibers. Once ingested, an animal may experience pseudosatiation (the feeling that they are full but have not received any nutrition), obstruction of feeding appendages, decreased reproductive fitness, and death. Pictures of these categories are portrayed below *excluding foams*. To determine if a particle is a piece of plastic, we are using what’s called the ‘hot-needle, or burn-test’. It is a rapid and cost-effective technique for plastic determination. If plastic is probed with a hot-needle it either leaves a burn mark, melts, or in the case of fibers, curls up or is repelled from the needle.
Pictured from left to right: Fragment, film, spherule, fibers
Pictured from left to right: Microfragment, microfilm, microbead, microfibers
Deep-sea animals are integral parts of pelagic ecosystems, as they serve as the base of the food web, contribute significantly to the overall abundance and biomass, make substantial contributions to carbon flux, and serve as a link between shallow and deep-pelagic waters. Regrettably, there are no previous estimates of microplastic ingestion by deep-sea fishes and crustaceans in the GoM. We discovered that approximately 28% of fishes (69/245) and 28% of crustaceans (83/292) have been shown to ingest at least one piece of plastic with 7% ingesting two or more pieces! One individual Sternoptyx diaphana (diaphanous hatchetfish) and Stylopandalus richardi ingested five spherules and six fibers, respectively!
Pictured from left to right: (Left): Two beautiful deep-sea hatchetfish (Argyropelecus aculeatus) that use photophores (light-producing cells) to counterilluminate rendering themselves less visible to predators lurking below. (Middle): A stunning shrimp (Oplophorus sp.) that can produce a bioluminescent spew (vomit) as a defense to distract potential predators. The spew can adhere to predators, which makes them visible to any other predators in the area. (Right): A formidable deep-sea dragonfish (Idiacanthus fasciola) with a smile not just used for good looks! This dragonfish and many other deep-sea piscivores (fish eaters) possess recurved teeth for capturing prey and not letting them go!
Our data reveal that more scrutiny should be given to deep-sea ecosystems with regards to plastic ingestion. Deep-sea food webs are largely understudied and have a stunning complexity to them. These food webs are understudied because of the enormous expense and difficulty of obtaining deep-sea samples. This makes the DEEPEND Consortium incredibly important for gathering these data and beginning to develop a story of community dynamics in the GoM.
A resource for learning more about plastic: https://marinedebris.noaa.gov/info/plastic.html
A brilliant new way to aid in the fight against plastic by doing laundry: https://coraball.com/