Microplastics

What are microplastics?

Plastic comes in all shapes and sizes. Microplastic is a term used to describe plastic material less than 5 millimeters in size. That’s about the size of a coffee bean! There are two types of microplastic, primary and secondary. Primary microplastics are plastic products created to be 5 millimeters or less in size. Primary microplastics typically include the major microplastic category of microbeads. These may originate from products such as abrasive scrubbers, beaded fillings of weighted blankets, or plastic craft supplies. Secondary microplastics are created by the breakdown of larger plastic materials, such as bottles, bags, or fishing line, through a process called photodegradation

Where do Microplastics come from? How are they transported?

Marine plastic debris is a pervasive pollutant that has been found in all major ecosystems, continents, and even human blood!  Plastic material originates from terrestrial sources, and can enter the environment through many different pathways. Some of these major pathways include mismanaged waste, textile washing, wastewater treatment plants, and tire ware. High precipitation events and coastal flooding rinses the wasted material into our river systems where it is ultimately led to our oceans.

What does Microplastic Pollution look like in the Delaware Bay?

In the Delaware Bay, microplastics are present in almost all major outflows, with the bay itself having an estimated concentration of 1.24 microplastic particles per cubic meter.  The Delaware Bay estuarine turbidity maximum (ETM), is an area of growing interest for plastic research, as physical processes in this region cause the aggregation of plastic material 2x higher than that of the ambient bay.

We find most microplastic in the Delaware Bay to fall into the category of bead, fiber, or fragment. Through μ-FTIR spectroscopy we have determined polymer identities, with beads primarily identified as polystyrene, fibers to be polyester or a semi-synthetic material known as rayon, and fragments to most commonly be identified as polyethylene or polypropylene.

Ongoing Microplastic Investigations:

To properly understand the sources, fate, and impacts of microplastic in the Delaware Bay; we have a few projects currently underway;

  1. Terrestrial Hot-Spot mapping; using GIS to determine how and where microplastic is deposited into the Delaware Bay.  
  2. Aggregation of plastic material due to estuarine circulation and tidal patterns.
  3. Body Burden analysis of microplastic material in estuarine organisms. 
  4. Physiological impacts of microplastic debris on zooplankton, such as mysids and crab zoea