Spatial variation of plastic debris on important turtle nesting beaches of the remote Chagos Archipelago, Indian Ocean

Microplastics in the insular marine environment of the Southwest Indian Ocean carry a microbiome including antimicrobial resistant (AMR) bacteria: A case study from Reunion Island

The increasing threats to ecosystems and humans from marine plastic pollution require a comprehensive assessment. We present a plastisphere case study from Reunion Island, a remote oceanic island located in the Southwest Indian Ocean, polluted by plastics. We characterized the plastic pollution on the island's coastal waters, described the associated microbiome, explored viable bacterial flora and the presence of antimicrobial resistant (AMR) bacteria. Reunion Island faces plastic pollution with up to 10,000 items/km2 in coastal water. These plastics host microbiomes dominated by Proteobacteria (80 %), including dominant genera such as Psychrobacter, Photobacterium, Pseudoalteromonas and Vibrio. Culturable microbiomes reach 107 CFU/g of microplastics, with dominance of Exiguobacterium and Pseudomonas. Plastics also carry AMR bacteria including β-lactam resistance. Thus, Southwest Indian Ocean islands are facing serious plastic pollution. This pollution requires vigilant monitoring as it harbors a plastisphere including AMR, that threatens pristine ecosystems and potentially human health through the marine food chain.

Plastic pollution on remote islands: A baseline study of Príncipe, Gulf of Guinea

Plastic is the most abundant marine anthropogenic debris in the ocean and is of serious global environmental concern. Projects aimed at monitoring plastic pollution quantities are key in evaluating the success of reduction. This study provides baseline information on the quantities of marine debris found on the island of Príncipe in the Gulf of Guinea in the Atlantic coast of Central Africa. A total of 13,196 items were collected with 64.5% of these items being plastic. Plastic pieces the size of 2.5-50 cm made up 20.8% of all plastic items, followed by plastic bags (13.3%) and fishing material (11.39%). The density of mesoplastic items (<25 and >5mm) ranged between 0 and 6.78 items m-2. Beach location, community presence, and beach level (for turtle-nesting beaches) were important factors in explaining differences in plastic abundance and density around the island. Our results highlight the significance of high plastic pollution accumulation on remote islands.

The ecological impact of plastic pollution in a changing climate

Assessing three interlinked issues, plastic pollution, climate change and biodiversity loss separately can overlook potential interactions that may lead to positive or negative impacts on global ecosystem processes. Recent studies suggest that threatened species and ecosystems are vulnerable to both plastic pollution and climate change stressors. Here we consider the connectivity and state of knowledge between these three environmental issues with a focus on the Global South. Nine out of top ten Long-Term Climate Risk Index (CRI) (2000-2019) ranked countries are located within the Global South, yet research is focused in the Global North. A literature search for the top ten Long-Term Climate Risk Index (CRI) (2000-2019) ranked countries matched a total of 2416 (3.3% of global publications) search results on climate change, with 56 (4% of the global publications) on plastic pollution, and seven (7.7% of the global publications) on both climate change and plastic pollution. There is a strong correlation between the Global South and high biodiversity hotspots, high food insecurity and low environmental performance. Using Bangladesh as a case study, we show the erosion rates and sea level rise scenarios that will increase ocean-bound plastic pollution and impact high biodiversity areas. Poverty alleviation and promoting renewable energy and green practices can significantly reduce the stress on the environment. We recommend that these connected planetary threats can be best addressed through a holistic and collaborative approach to research, a focus on the Global South, and an ambitious policy agenda.