Risk from Microplastics Exposure to Blue Crab Larvae in Delaware Bay and Coastal Waters

A microscopic crab larvae is being viewed through a microscope.

Researchers from the University of Delaware are evaluating the effects microplastics have on blue crab larvae at different developmental stages and will test whether exposure during these stages impacts blue crab survival and settlement to Mid-Atlantic Bight estuaries. 

Type of Project: Research

Region: Mid-Atlantic

Project Dates: August 2019 - July 2021

Who is involved?
Researchers from the University of Delaware, with support from a NOAA Marine Debris Program Research Grant, are investigating how microplastics may affect blue crab larvae at different developmental stages. Data collected from the field, modeling exercises, and lab experiments will allow researchers to quantify risk of blue crab survival and movement into the Delaware Bay as a result of microplastic ingestion.

What is the project and why is it important?
Blue crabs are an economically important species in Delaware Bay and other Mid-Atlantic estuaries. These crabs begin life as tiny plankton drifting in coastal surface waters. After going through numerous developmental stages, crab larvae settle onto the seafloor where they continue to develop and spend the rest of their lives as the crabs we are familiar with. While in the surface waters, crab larvae are exposed to microplastics along with natural food sources (plankton). This study will quantify the risk to blue crab larvae from exposure to microplastics, especially with respect to survival and recruitment in Delaware Bay.

Researchers will use a combination of field measurements, hydrodynamic modeling, and laboratory experiments to calculate risk to blue crab larvae from exposure to microplastic. Field data on both microplastics and crab larval distributions will be collected from coastal waters outside of Delaware Bay to be incorporated as modules within an existing Regional Ocean Modeling System (ROMS) framework. In this study, ROMS will model the spatial (distance) and temporal (time) distribution of both microplastics and crab larvae. In addition, lab experiments will be conducted exposing blue crab larvae (across several developmental stages) to a series of concentrations of microplastics to determine effects from microplastic ingestion. Researchers are specifically interested in effects causing larvae death and growth or developmental delays due to microplastic ingestion. Exposure data from the field, modeling exercises, and results from the lab will be applied in a quantitative risk framework to assess the hazardous effects of microplastics exposure in blue crab larvae to individual crab larvae and blue crab populations. The risk assessment will result in a decision making tool for blue crab managers in the mid-Atlantic region.