Research demonstrates need for increased oversight of waterways
A new study led by the University of Washington using Global Fishing Watch data has found that fewer than 7 percent of global hotspots for whale and ship collisions have protection measures in place, underlining the urgent need for greater oversight of waterways that overlap with whale migration or feeding areas.
According to the study, published today in Science, thousands of whales are injured or killed each year after being struck by ships, particularly large container vessels that carry 80 percent of the world’s traded goods across the oceans. Although collisions are the leading cause of death worldwide for large whale species, global data on ship strikes are hard to come by — impeding efforts to protect vulnerable whale species.
“Whale-ship collisions have typically only been studied at a local or regional level — like off the east and west coasts of the continental U.S., and patterns of risk remain unknown for large areas,” said Anna Nisi, a University of Washington postdoctoral researcher at the Center for Ecosystem Sentinels and the study’s lead author. “Our study is an attempt to fill those knowledge gaps and understand the risk of ship strikes on a global level. It’s important to understand where these collisions are likely to occur because there are some really simple interventions that can substantially reduce collision risk.”
Of the limited measures now in place, most are along the Pacific coast of North America and in the Mediterranean Sea. In addition to speed reduction, other options to reduce whale-ship strikes include changing vessel routings away from where whales are located, or creating alert systems to notify authorities and mariners when whales are nearby.
The international team behind the study, which includes Global Fishing Watch as well as researchers from across five continents, looked at the waters where blue, fin, humpback and sperm whales live, feed and migrate by pooling data from disparate sources — including government surveys, sightings by members of the public, tagging studies and even whaling records.
The team collected some 435,000 unique whale sightings from regions already known to be high-risk areas for ship strikes as well as understudied regions at high risk for whale and ship collisions, including: southern Africa; South America along the coasts of Brazil, Chile, Peru and Ecuador; the Azores; and East Asia off the coasts of China, Japan and South Korea. They then combined this novel database with information on the courses of 176,000 cargo vessels from 2017 to 2022 — tracked by each ship’s automatic identification system and processed using an algorithm from Global Fishing Watch and supported by Google’s computing resources — to identify where whales and ships are most likely to meet.
“The increase in human activity at sea poses acute threats to ocean biodiversity and the future of ocean sustainability. That’s where Global Fishing Watch comes in, ” said Tyler Clavelle, Global Fishing Watch senior data scientist and co-author of the study. “Our data can shed light on human activity, reveal patterns and help prioritize actions to address a wide range of critical threats, from illegal fishing to ship collisions with whales.”
The authors hope the study will spur local or regional research to map out the hotspot zones in finer detail, inform advocacy efforts and consider the impact of climate change, which will change both whale and ship distributions as sea ice melts and ecosystems shift.
Read the full study in Science.
