The organization Adventurers and Scientists for Conservation (ASC) is working the Marine and Environmental Research Institute (MERI) to study the prevalence of microplastics in waters throughout the world. As part of this effort, SALMoN collected samples in the marine waters near Sitka.
From our 5 samples, collected in January 2015, there was an average of 4 pieces per liter (variance from 0 to 15 pieces per sample). MERI, as of April 2015, stated that 95% of the samples collected globally had microplastics and that the global average was 21 pieces per liter. Pieces measured were a minimum of 5 millimeters. ASC has an online map showing all sample locations and results, as well as links to additional resources.
Recent research published by the National Academy of Sciences has shown that microplastics ingested by Pacific oysters negatively impacts their fertility.
Microplastics impact terrestrial organisms as well, shown by this study highlighted in Science in March 2016.