Ever wondered what marine mammals are present, where and when in the waters of the U.S. East Coast and Gulf of Mexico? Scientists at the Marine Geospatial Ecology Lab at Duke University did, and they have now produced amazingly detailed maps of the densities and movements of 35 marine mammal species in the area!

The maps combine data from a whopping 1.1 million linear km of surveys and more than 26,000 sightings collected by researchers from 5 institutions over 23 years. The 35 species of marine mammals included in this dataset include dolphins, porpoise, beaked whales and baleen whales. The sightings data were modelled against environmental data that relate to cetacean habitat (such as sea surface temperature and chlorophyll levels) to produce cetacean density maps. The information is all freely available online and can be viewed by species and by area and in different formats including maps, data sheets and reports. The website also hosts some pretty cool animations including a flight simulator for aerial marine mammal transect surveys, tracklines of all aerial and vessel surveys included in the analysis, oceanographic data and animated density maps over time.

Why is this dataset important?

Many of the marine mammal species around the U.S. East Coast and Gulf of Mexico are threatened or endangered. These new maps identify areas where each species is most likely to be located, at different times of the year. This information is crucial in helping the management and monitoring of these species and can help to reduce the risk of harmful impacts. Data such as these can help inform the timing of potentially disruptive activities. For example, knowing when and where a key marine mammal species will be can help to inform area and seasonal restrictions.

Jason J. Roberts, lead researcher at the Marine Geospatial Ecology Lab, said:

“Though protected under U.S. law, many cetacean species still face persistent threats from accidental ship strikes, fishery bycatch, offshore energy development, pollution, climate change and underwater noise from human activities. Our maps give government agencies and other interested parties better tools to help protect these highly mobile animals and guide future ocean planning, including decisions about the siting of wind energy and oil and gas exploration along our coasts.”

Check out the maps and data at the Habitat-Based Cetacean Density Models for the U.S. Atlantic & Gulf of Mexico website here.

The publication in Natures Scientific Reports can be accessed here.