Shaw Institute Co-Authors First-of-Its-Kind Research Published in Conservation Biology
BLUE HILL, MAINE — April 30, 2026 — The Shaw Institute today announced its role in a groundbreaking new study published in the journal Conservation Biology, providing the first global ranking of marine mammal vulnerability to plastic pollution.
Co-authored by Shaw Institute Executive Director Dr. Charles Rolsky, the research introduces a novel framework for assessing population-level risk across 117 marine mammal species—offering critical insights for conservation efforts worldwide.
“It’s a privilege for the Shaw Institute to collaborate with such a talented team of researchers on work like this,” said Dr. Rolsky. “Partnerships like these are how we continue to shed light on the many factors shaping the health of our natural world, and ultimately how we protect it.”
A New Approach to Measuring Risk
While plastic ingestion and entanglement have long been documented at the individual level, assessing impacts across entire species populations has remained a challenge. To address this, researchers from leading institutions—including University of Toronto, Arizona State University, and University of Georgia—developed a trait-based vulnerability framework.
The study evaluates species across three key dimensions:
- Likelihood of exposure to plastic pollution
- Biological sensitivity
- Population resilience
By analyzing 11 life-history traits—such as foraging depth and reproductive rates—the team identified which species are most susceptible to the impacts of larger plastic debris, known as macroplastics.
“Trait-based assessments allow us to evaluate risk across different levels of biological organization without requiring harmful experimentation on protected species,” said lead author Cassidy Fredette-Roman of Arizona State University.
Key Findings: Who Is Most at Risk?
Manatees and Dugongs Face the Highest Overall Risk
Marine mammals in the “sea cow” family ranked as the most vulnerable group on average. Their coastal habitats—where plastic concentrations are often highest—combined with grazing behaviors, increase their risk of ingestion.
Hawaiian Monk Seal Tops Global Rankings
The Hawaiian monk seal emerged as the single most vulnerable species. Its small population size and overlap with high-density plastic zones, particularly areas with abandoned fishing gear, place it at extreme risk.
Whales and Dolphins Show Wide Variation
Species such as the Vaquita, North Atlantic right whale, and Hector’s dolphin ranked among the most vulnerable due to behavioral traits and low population resilience.
Seals, Sea Lions, and Otters More Resilient Overall
These groups showed lower vulnerability on average, largely due to stronger reproductive rates and population resilience—though localized threats remain significant.
A Roadmap for Conservation Action
Beyond identifying at-risk species, the study provides a powerful tool for policymakers and conservationists. By pinpointing high-risk regions and species, resources can be directed toward targeted interventions such as:
- Cleanup efforts in critical habitats
- Mitigation of high-risk debris like fishing gear and plastic bags
- Protection of breeding and foraging grounds
“This research allows us to identify the most vulnerable marine mammal species and develop evidence-based protections,” said Dr. Rolsky. “When we can demonstrate population-wide impacts, it becomes much harder to dismiss these environmental concerns as insignificant.”
Access the Full Study
The full paper, “A global ranking of the relative vulnerability of marine mammals to macroplastic pollution,” is available in the April 2026 issue of Conservation Biology.
About the Shaw Institute
The Shaw Institute is a Maine-based nonprofit dedicated to advancing environmental and human health through innovative research, science education, and community engagement. Its work focuses on critical issues including plastic pollution, PFAS contamination, and marine ecosystems.
Help empower more research and education programs by donating today.
Frequently Asked Questions (FAQ)
What is the new study about marine mammals and plastic pollution?
The study provides the first global ranking of marine mammal species based on their vulnerability to plastic pollution, analyzing 117 species using a trait-based framework that measures exposure, sensitivity, and population resilience.
Which marine mammals are most vulnerable to plastic pollution?
Sea cows—such as manatees and dugongs—rank as the most vulnerable group overall. The Hawaiian monk seal is the most vulnerable individual species due to its small population and high exposure to plastic debris.
What are macroplastics and why are they dangerous?
Macroplastics are large plastic items like fishing nets, plastic bags, and packaging materials. They can cause serious harm through ingestion and entanglement, often leading to injury or death in marine mammals.
How did researchers determine vulnerability?
Scientists used a trait-based framework analyzing 11 life-history characteristics—such as feeding behavior, habitat range, and reproductive rates—to assess risk without harming protected species.
Why is this research important for conservation?
The study provides a roadmap for policymakers and conservation groups by identifying which species and habitats are most at risk, helping prioritize cleanup efforts and protective measures.
What types of plastic pose the greatest threat to marine mammals?
Abandoned fishing gear (“ghost gear”) and plastic bags are among the most dangerous, as they are frequently involved in entanglement and ingestion incidents.
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