A Habitat Model of the Short-finned Pilot Whale in Correlation with the Gulf Stream

Habitat models are crucial to understanding how a species interacts with its surrounding environments. Despite being a protected species under the Marine Mammal Protection Act, little is known about the spatial extent of the short-finned pilot whales that live along the eastern coast of the United States. The short-finned pilot whale (Globicephala macrorhynchus) is one of two pilot whale species found in the northwestern Atlantic with both habitats overlapping around the Mid-Atlantic Bight. Previous literature has shown that the whales forage along the continental shelf break just off the coast of North Carolina, with some evidence to excursions in the Gulf Stream. The aim of this project was to create a habitat model for the short-finned pilot whales and examine possible correlation with Gulf Stream front.

A General Additive Model (GAM) was created to better understand which environmental factors have the largest correlation with short-finned pilot whale sightings. Three environmental factors were analyzed based on their importance to pilot whales: sea surface temperature (SST), bathymetry, and proximity to continental shelf break. SST data was collected from the Moderate Resolution Imaging Spectrometer (MODIS) and the Hybrid Coordinate Ocean Model (HYCOM) to compare real-time high-resolution data to predictive low-resolution data.

I found that sea surface temperature and bathymetry had the largest correlation with short-finned pilot whale sightings across both datasets. This suggests that the whales have a strong preference to areas of certain temperature gradients and depth. I deduce that the short-finned pilot whales are likely to follow the Gulf Stream front as long as waters remain in their preferred temperature range. With this knowledge, we can better determine how the short-finned pilot whales may react to rising ocean temperatures and how their habitats will adapt along the way.