Microplastics Sampling with Sail & Explore

Program Overview

Every year approximately 400 million tons of plastic waste are being produced which can then end up in the environment, where they become brittle and break down into micro- and nanoplastic particles. Exact numbers on the prevalence of smaller-sized microplastics (below 0.3 mm) and their potential impact on the environment and human health are missing. When plastics are taken up by marine and aquatic organisms, this can lead to their malnutrition, inflammation, reduced fertility, and mortality. Microplastics are well-known to travel up the food chain, where submicron-sized plastic particles (< 0.3mm) can accumulate in a greater number of species; moreover, lab research has shown that submicron-sized plastics can be taken up passively by cells in human tissue and transported throughout the human body. Up to now, there is only very sparse knowledge on the occurrence and cumulative effects of submicron-sized plastics in the environment, on marine life, and specifically how they may affect human health.

Microplastics in the Florida Keys:
The approximately 1,700 mangrove-fringed islands of the Keys provide important nursery habitat for commercial and recreational fish species, as well as above-water nesting grounds for vibrant bird populations. Furthermore, the Keys are a major producer and supplier of all the seafood consumed in Florida. Up to now, research around Florida showed that a high amount of fish specimen (1) and sea cucumbers (2) are contaminated with microplastics. However, there is no data available that focuses on submicron-sized plastics found in the waters and seafood such as mussels around the Keys.

1. https://nsuworks.nova.edu/hcas_etd_all/96
2. Marine Pollution Bulletin 158 (2020) 111437

Expedition Summary

From March 15–22, 2025, researchers from Sail & Explore Association conducted a microplastics survey in the Florida Keys National Marine Sanctuary in collaboration with the National Marine Sanctuary Foundation aboard DISCOVERY Vessel Seeker. The team deployed a modified Manta Trawl system 14 times to collect surface water samples, specifically targeting ocean plastic particles between 50–300 micrometers and those larger than 300 micrometers. Sampling efforts spanned from Sugarloaf Key to the Dry Tortugas, covering both inshore and offshore waters.

The team also deployed Citizen Science equipment from PlanktoScope three times, capturing images to contribute to a global plankton database.