Alba Solsona-Berga – asolsonaberga@ucsd.edu
Scripps Institution of Oceanography
University of California San Diego
La Jolla, CA 92037
United States
Instagram: @sripps_mbarc
Popular version of 2pAO5 – Shaping the acoustic field in the Gulf of Mexico: marine mammals linked to topography and oceanographic features
Presented at the 188th ASA Meeting
Read the abstract at https://eppro01.ativ.me/appinfo.php?page=Session&project=ASAICA25&id=3859319&server=eppro01.ativ.me
–The research described in this Acoustics Lay Language Paper may not have yet been peer reviewed–
Exploring the Lives of the Ocean’s Deepest Divers
After the Deepwater Horizon oil spill, restoring marine mammal populations in the Gulf of Mexico became a priority. Protecting these animals starts with understanding how they use their habitat and where they go. Sperm whales and beaked whales are some of the ocean’s most extreme divers, spending much of their lives navigating the dark depths. They rely on bursts of sound called echolocation clicks to find their prey and navigate. These clicks act like acoustic fingerprints, helping us figure out where whales go and what environments they prefer.
To track their movements, we set up 18 underwater listening stations throughout the Gulf. These instruments recorded sounds continuously for three years. By analyzing this data, we discovered patterns in where the whales appeared and how those locations were linked to oceanographic features like currents and slopes.
Video: Deploying the instruments.
Where Whales Go
Different whale species tend to favor different parts of the deep Gulf. Goose-beaked whales often stay near deep eddies and steep slopes. Gervais’ beaked whales are more likely to follow surface and midwater eddies, while sperm whales mostly stick to areas where freshwater from rivers mixes with the open ocean. They tend to avoid the tropical Loop Current, a warm flow from the Caribbean into the Gulf, that seems to create conditions less favorable for these whales.
An example of how marine mammals use different parts of the Gulf of Mexico. The maps show ocean features at three depth ranges: surface (0-250 m), mid-depth (700-1250 m), and deep (1500-3000 m). Dolphins are shown in the surface plot, sperm whales in the mid-depth plot, and goose-beaked whales in the deep plot. Colors indicate water movement, with red showing strong currents and blue showing calmer areas. Circles mark recording stations, with bigger circles showing more animals detected.
Whales Shape Their Environment
Whales don’t just adapt to their surroundings, they also shape them. Their powerful clicks, produced by the millions, bounce off the seafloor and underwater features, making their presence a key part of the local acoustic environment. Where whales occur, the acoustic environment changes, influenced both by their vocalizations and by the prey that may be present. Prey layers can influence how sound propagates through the water, adding complexity to the acoustic field. Detecting whales in specific areas helps us understand how the acoustic environment might vary under different conditions. Mapping where whales are present also reveals potential biological hotspots and helps us understand how sound behaves in these deep-sea habitats.
Why This Matters
This research is a collaboration between scientists from the United States and Mexico, supported by NOAA’s RESTORE Science Program, the Deepwater Horizon Restoration Open Ocean Marine Mammal Trustee Implementation Group, and the Office of Naval Research Task Force Ocean. These detailed maps of whale distribution are vital for identifying critical habitats and guiding conservation strategies. They help us understand how threats like oil spills, industrial activity, and environmental changes impact whale populations, allowing us to plan effective mitigation and restoration efforts to maintain healthy ecosystems.