MBARI research is revealing our close connection to the ocean—how it sustains us and how human actions affect marine animals and environments. The deep sea is not immune to threats like overfishing, climate change, and pollution. Even miles beneath the ocean’s surface, we find trash, much of it plastic. Too often, MBARI’s remotely operated vehicles (ROVs) encounter plastic bottles, bags, balloons, and more.

As the team in MBARI’s Video Lab catalogs our extensive archive of deep-sea video, they have logged thousands of observations of deep-sea debris at dive sites in Monterey Bay and beyond. In all regions MBARI has explored, we have found garbage in the deep sea, and more than a third of that is plastic. 

Researchers in MBARI’s Bioinspiration Lab and Midwater Ecology Team have examined how plastic moves through the ocean food web. Tiny plastic particles accidentally ingested by animals in the midwater are repackaged and rapidly transported to the deep seafloor. 

Plastic trash

Large amounts of discarded trash end up in the ocean. Plastic bags, aluminum cans, and fishing debris not only clutter our beaches, but accumulate in the open ocean and even the deep sea.

In 2013, researchers in MBARI’s Video Lab conducted a comprehensive review of our meticulously-cataloged underwater video looking for observations of ocean trash. The largest proportion of the debris consisted of objects made of plastic. Of these objects, more than half were plastic bags. 

Plastic pollution puts deep-sea animals at risk. On the seafloor, bags and other plastic trash can smother marine life. In the midwater, drifting debris can entangle or choke animals or damage their delicate structures.


Plastic trash also breaks down into smaller and smaller bits and pieces called microplastic.

Microplastic has been found throughout the ocean, from the surface to the seafloor. High-tech research tools developed by MBARI engineers have revealed how tadpole-like animals called larvaceans collect and ingest microplastic in their snot palaces. Plastic particles are passed into the larvaceans’ fecal pellets and accumulate in their cast-off mucous filters, which sink rapidly through the ocean, carrying microplastics to the deep seafloor.

Many deep-sea animals eat tiny bits of food about the same size as microplastic. Feathery mouthparts and elaborate mucous structures cannot tell the difference between food and plastic. We still have a lot to learn about how microplastics affect deep-sea animals and communities.

Take Action

Abandoned fishing gear, including a red plastic float on the left and light-green rope on the right, decays on a sandy beach. The fishing gear is entangled in a mass of knotted, dried brown kelp. The background is breaking waves with several small seabirds running in the surf.

The deep sea is closer than you think. Our actions on land ripple across the ocean, from beaches and coasts to the open sea and the depths below.

We are creating and using plastic faster than we can sustainably manage plastic waste. More and more plastic is finding its way to the ocean, impacting marine animals and habitats from the sunlit surface waters to the inky depths below.

To protect the amazing animals of the deep, we need to turn off plastic pollution at the tap. 

MBARI’s education and conservation partner, the Monterey Bay Aquarium, is working in California, the U.S., and internationally to reduce the amount of plastic going into our ocean. The Aquarium’s Into the Deep / En lo Profundo exhibition also helps visitors understand the deep impact of plastic. 

As individuals, we can take action by reducing the amount of single-use plastic products and packaging we purchase. Single-use plastic—items like water bottles, takeout containers, coffee lids, straws, and shopping bags—make up a large percentage of plastic waste. We can make a significant dent in ocean plastic pollution by choosing reusable alternatives.


Choy, C. A., B.H. Robison, T.O. Gagne, B.E. Erwin, E. Firl, R.U. Halden, J.A. Hamilton, K. Katija, S.E. Lisin, C. Rolsky, and K.S. Van Houtan. 2019. The vertical distribution and biological transport of marine microplastics across the epipelagic and mesopelagic water column. Scientific Reports, 9(7843): 1–9.

Katija, K., C.A. Choy, R.E. Sherlock, A.D. Sherman, and B.H. Robison. 2017. From the surface to the seafloor: How giant larvaceans transport microplastics into the deep sea. Science Advances, 3(8): 1–5.

Schlining, K., S. Von Thun, L. Kuhnz, B. Schlining, L. Lundsten, N. Jacobsen Stout, L. Chaney, and J. Connor. 2013. Debris in the deep: Using a 22-year video annotation database to survey marine litter in Monterey Canyon, Central California, USA. Deep Sea Research I, 79: 96–105.