A new study from the University of Exeter has shown that plastic pollution has invaded nearly every marine habitat examined in the Galapagos Islands. Microplastics were found in all of the invertebrate species tested, and in all of the seabed and seawater samples.
Study lead author Dr. Jen Jones said the research highlights how far plastic pollution travels, and how it contaminates every part of marine ecosystems.
“Given the level of pollution we have found in this remote location, it’s clear that plastic pollution needs to stop at source. You can’t fix the problem just by cleaning beaches,” said Dr. Jones.
In collaboration with the Galapagos Conservation Trust (GCT), the researchers focused their investigation on San Cristobal, where Charles Darwin first landed in Galapagos.
Across the most polluted areas, including a beach used by the rare “Godzilla” marine iguana, more than 400 plastic particles were found per square meter of beach.
The findings suggest that most of the plastic pollution in Galapagos arrives from elsewhere on ocean currents.
“The pristine image of Galapagos might give the impression that the islands are somehow protected from plastic pollution, but our study clearly shows that’s not the case,” said study co-author Dr. Ceri Lewis of Exeter’s Global Systems Institute.
“The highest levels of plastic we found were on east-facing beaches, which are exposed to pollution carried across the eastern Pacific on the Humboldt Current.”
“These east-facing beaches include Punta Pitt, a highly polluted site that is home to Godzilla marine iguanas which – like so much Galapagos wildlife – are found nowhere else in the world.”
“There are less than 500 Godzilla marine iguanas in existence, and it’s concerning that they are living alongside this high level of plastic pollution.”
Dr. Jones noted that the potential health effects of plastic ingestion on marine animals are largely unknown, and more research is needed. “These animals are a crucial part of food webs that support the larger species that famously live on and around the Galapagos Islands,” she said.
All seven marine invertebrate species examined for the study were found to contain microplastics. Overall, 52 percent of the 123 individuals tested had ingested plastic.
Of the larger plastic pieces, only two percent were identified as coming from the Galapagos Islands. These “macroplastics,” which are items and fragments larger than five millimeters, were found at 13 of 14 sandy beaches studied, with 4,610 items collected in total.
Furthermore, the study revealed that significant amounts of plastic have accumulated in key habitats including rocky lava shores and mangroves.
Based on the IUCN conservation status of each particular Galapagos species, and also based on where each species can be found across the islands, the experts identified 27 species in need of urgent monitoring and mitigation.
“This situation is only going to get worse if we don’t dramatically change our use of plastics,” said study co-author Dr. David Santillo.
The experts have also identified marine vertebrates in the Galapagos that have the highest risk of swallowing plastic or getting entangled, including scalloped hammerheads, whale sharks, sea lions, and sea turtles.
The study is published in the journal Science of the Total Environment.
By Chrissy Sexton, Earth.com Staff Writer