Algalita Marine Research Lab - Sample Analysis

Located at the S.E.A. Lab in Redondo Beach, CA, the Algalita Marine Research Lab is a multi-use research facility designed to process and evaluate plastic pollution samples from around the world. Our groundbreaking research provides a wealth of scientific data for scientists, educators, and policy makers.

How does the Algalita research team collect, analyze and estimate marine plastic pollution?

Our research begins by collecting water samples from the surface of the ocean using a Manta trawl, a device that captures surface debris in a fine mesh net. The manta trawl skims the ocean surface and can trap particles as small as 1/3 of a millimeter. The trawl has two angled wings that keep it floating on the ocean surface, as well as a hood that directs surface splash back into the trawl. The trawl has an opening which is 90cm wide and 30cm tall, called an aperture. At the end of the aperture a 333 micron (or .333mm) mesh net is attached which terminates in a small collection sock called the cod end.

After several miles of trawling (trawl length depends on volume of debris and zooplankton filling the trawl) the Manta trawl is lifted out of the ocean. The inside of the mesh net is washed into the cod end, which is then removed, strained, and preserved in a collection jar for land-based analysis. Each sample is labeled and stored with a corresponding data sheet which includes the start and stop time and location of the trawl, start and stop numbers on the flow meter (the flow meter measures the distance trawled), time of day, and any other miscellaneous notable information about the trawl.

 

Back on land...

Algalita biologists begin the first steps of analysis. The samples are sorted by hand with a dissecting microscope. At this stage, the goal is to separate the plastic from the plankton.
While some plastic is large and easy to pick out, other plastic is small, similar to the size of zooplankton and requires a lot of time to sort. Oftentimes the plastic is clear, which makes it harder yet to separate it from the plankton.

Some of these plastic fragments are even smaller than the zooplankton!


Debris is sorted in to the following categories: plastics, plankton, and other organic and non-organic matter. The plastics are further categorized as: fragments, styrofoam, pellets, polypropylene/monofilament line, thin plastic films, and resin. Each category was sorted into size classes using Tyler sieves of 4.75, 2.80, 1.00, 0.71, 0.50, 0.35mm and then counted.

In order to figure out how plastic and zooplankton compare, the dry weight of each sample group is taken. Plastics are oven dried at 60°C for 1 hour and the plankton and other plant material are oven fried at 60°C for 24 hours, then weighed. All of the data is recorded on datasheets by hand, and then entered into a computer database.

 

How does Algalita share data with scientists, educators and policy makers?

.................. GIS Data Mapping ....................................................................... Research Papers
Mapping Plastic PollutionResearch Papers