Dispatches from SEA

By Jennifer Brett

A semester abroad is a life-changing experience during a student’s time at school. Now if that semester is aboard a tall ship doing research on ocean plastics in the North Pacific? Even more so!

Sea Education Association is based in Woods Hole, Massachusetts, and offers programs for high school and college students aboard their two ocean research vessels, the SSV Corwith Cramer and the SSV Robert C. Seamans. Kelly Anne Morgan, a recent graduate of UC Berkeley, studied aboard the Seamans this past summer on a voyage that took crew and students from San Diego, California, and through the “North Pacific Garbage Patch” to study marine plastics and ocean ecosystems. Here she shares with us what that trip was like and what they learned along the way.

Sailors for the Sea: How long was your trip and what was your route?

Kelly Anne Morgan: In total, the trip was forty-three days (June 24th - August 6th) at sea. We didn’t see land for at least 30 days and didn’t step foot on land for at least 33. The cruise track traced a large loop out into the North Pacific, from of the California Current System, through the North Pacific Subtropical Gyre, up to the North Pacific Transition Zone, and back down the coast of California.

SfS: How many students were on the boat? Were you split up into teams? If so, what were some of the general research topics?

KAM: There were 17 students on the boat and 13 professional crew members We were split into “watch groups” named A, B, and C. Each group was responsible for standing watch (accompanied by professional crew) in six-hour shifts: morning watch from 0700 to 1300, afternoon watch 1300 to 1900, evening watch from 1900 to 0100, and dawn watch from 0100 to 0700. We rotated through this watch schedule, six hours on, 12 hours off. In between watches was our opportunity to eat, sleep, and work on writing our research papers.

Research topics included studies on photosynthetic microorganisms and zooplankton diversity as well as plastic concentrations, characteristics, and the physical dynamics that affect this across varying ocean ecosystems.

SfS: Can you tell us about your research on plastics? How did you collect samples?

KAM: Many of our research projects aboard focused on plastics, largely because we cruised through the North Pacific Subtropical Gyre (NPSG), the site of the infamous “North Pacific Garbage Patch.” Most projects recorded how the concentration or characteristics of plastics changed across our cruise track. We sailed through several different ocean zones-- the California Current System, the North Pacific Subtropical Gyre, and the North Pacific Transition Zone. Each of these water masses are affected by variable ocean dynamics of upwelling, downwelling, and wind and wave transport that cause disparate distribution of plastics across them.

We collected samples for our plastics research using a device called a Neuston net: a long, fine-mesh net with an open, rigid mouth on one end and a collection cup on the other. During a deployment, we would suspend the net at the sea surface and tow it through the water at approximately 2 knots for 30 minutes. Water flows through the net, and is filtered and funneled into the collection cup, which catches anything larger than a couple hundred microns. Once pulled up on deck, the contents of the collection cup are processed: the fluid is poured through sieves and the remains sorted by hand. Using small scoops and tweezers, we extract all microplastics from the sieves visible to the naked eye. These plastics are counted, washed, and captured in vials to contribute to our student research projects and SEA’s extensive time series dataset on plastics. After a Neuston net deployment in the NPSG, I counted 2,220 microplastics in a single tow.

We performed other plastics research via visual sightings. Each hour during daylight, we conducted six-minute observation periods of our surroundings looking out for floating plastics. These ranged from plastic bottle caps to entire milk crates to massive ghost nets. Plastics were counted for the six-minute duration, then the total count extrapolated for the hour. While passing through the North Pacific Subtropical Gyre, we easily counted over 100 floating plastics passing by during our observations, equating the hundreds of plastics floating by every hour.

SfS: Did you notice a difference in samples depending on location or collection method?

KAM: The concentration of plastics varied dramatically depending on location. In transition from the California Current System to the North Pacific Subtropical Gyre, we observed a stark increase in the amount of microplastics and larger floating plastics upon entering the gyre formation. In a matter of days, microplastic concentrations jumped from a few tens of plastics to thousands. As mentioned, our direct-sight observations escalated to hundreds of floating plastics sightings every hour, whereas we had seen very few to none in the CA Current System. The number of floating plastics was so great that we had to have a lookout posted at all times with a walkie-talkie, calling back the position of large plastics we may be in danger of hitting.

Collection methods were constant and consistent at each deployment location across our cruise track to control for bias.

SfS: What was the strangest item of plastic pollution you came across?

KAM: “Ghost nets” were the strangest and most alarming item of plastic pollution we encountered. These nets are conglomerates of derelict fishing gear that drift through the ocean entangling other debris as well as marine organisms. Often these organisms are caught, die, and decay in the nets, causing the nets to sink to the ocean floor. Upon decomposition and disintegration of the organisms, the nets rise back up through the water column, continuing the vicious cycle of entanglement.

SfS: Were there any surprises during the trip, either with the research or the sailing?

KAM: Although high concentration of plastics in the NPSG is well researched and documented, and we predicted we would observe this pattern prior to departure, I was still stunned to see how much plastic is out there. Over a thousand nautical miles from the nearest landmass, seemingly out of human reach, the gyre circulates full of plastic. What could be considered as one of the wildest places on planet Earth, is the most polluted. Prior knowledge doesn’t prepare you to sail 20 days in the clear, blue, open ocean to come upon an expanse of plastics punctuating the swells as far as you can see.

SfS: In what area of plastic pollution do you think more research needed?

KAM: Plastic colonies need to be researched further because the utilization of plastics by marine organisms complicates the problem of plastic pollution. Most of the large floating plastics we observed up-close in the NPSG hosted colonies of algae, pelagic barnacles, and crabs. Container-like plastics also appeared to provide shelter for species such as frog fish and nudibranchs. Removing these plastics from the water disturbed these organisms and, in some instances, killed them. This issue convolutes the seemingly straight-forward initiative of cleaning up ocean plastics. Launching a grand, catch-all sweep of ocean plastics in the gyre system may not be the most far-sighted solution. We do not fully understand the contribution of plastic colonies to the pelagic ocean ecosystem and the impacts that would result from mass-removal from the environment.

SfS: What do you think is the biggest thing boaters can do to help keep our oceans healthy?

KAM: As boaters, we frequent the ocean and near-ocean environments often. Therefore, the waste we generate in these areas sequentially has a higher chance of ending up in the ocean. Be mindful of how you dispose of waste, consider reducing plastic waste, and secure waste properly to your vessel.

Furthermore, as major stakeholders in ocean health, it is important to advocate for proper waste management on our coastlines. Spread the word to your community members about the problems with plastic and vote for coastal management policies that prevent pollution.