The presence of microplastics in juvenile Chinook salmon and their nearshore environments

Microplastics are an emerging problem in the world’s oceans. These small plastic particles (size) can be produced from primary or secondary sources and are becoming globally ubiquitous in the marine environment through inputs such as wastewater discharge, coastal litter and industrial materials. Microplastic ingestion has been documented in a variety of marine species ranging from zooplankton to fish to marine mammals. Potential risks from microplastic consumption occur through internal physical damage (e.g., abrasion or blockage) and/or chemical damage. Microplastics can host concentrations of persistent organic pollutants several orders of magnitude higher than ambient marine waters. Ingestion of microplastics by lower trophic level organisms can provide an entry point for these chemicals and plastics to amplify through the food chain. This project focuses on ingestion of microplastics by juvenile Chinook salmon in nearshore areas where they reside upon leaving their natal stream. Specific project objectives are to determine the incidence and quantity of microplastics in juvenile Chinook salmon and their associated nearshore environments (water and sediment) in order to determine microplastics “hotspots” and potential sources. We completed a series of beach seines, plankton tows and sediment cores along the east coast of Vancouver Island in nearshore areas of particular importance to juvenile salmon. Because microplastic work is still in its infancy, method testing is currently ongoing to develop an accurate, cost effective and efficient protocol to isolate microplastics from biological tissue, water and sediment. Once completed, this study will allow us to assess the distribution of microplastics in important nursery habitats and aid further research into microplastics as a potential threat to juvenile Pacific salmon.