Summer Survey to Study the Trophic Ecology of Gulf of Mexico Bryde’s Whales - Post 1

On May 29th, 2019, NOAA scientists and partners embarked on the NOAA ship Gordon Gunter for the third in a series of ship-based research cruises. They will collect data on the foraging relationships between Gulf of Mexico Bryde’s whales (GoMex Bryde's whales) and the other organisms using the same habitat.

NOAA Ship Gordon Gunter.*

The primary goal of this project is to develop a more thorough understanding of GoMex Bryde's whales. This data will include the physical, oceanographic and biological features defining their habitat. Our goal is to develop meaningful conservation plans. To do that, we need a better understanding of where these whales occur, what constitutes suitable habitat, what they eat and the status of their food resources.

Researcher, Laura Dias, photo documenting a sighting.*

We use \visual and passive acoustic survey data to locate whales in their primary habitat and determine how they are distributed with respect to environmental conditions and potential prey. We will collect remote-biopsy samples of GoMex Bryde's whales for genetic and stable isotope analyses. When suitable animals are identified, we will deploy short-term suction cup tags, both acoustic and/or video. These will provide additional insights into their swimming, diving, and feeding behaviors. Scientific echosounder data, collected around the clock, and targeted mid-water trawls will help describe both the species composition and distribution of prey.

Other research techniques include testing small, unmanned aircraft systems (commonly referred to as “drones” or sUAS). We use these to collect images from directly overhead GoMex Bryde's whales while they are at or near the surface. We will also be collecting water samples to test for “environmental DNA” (eDNA). This eDNA approach analyzes water samples collected both near whales and in schools of potential prey near the bottom. We will use it to determine if we can identify genetic material left behind by these animals in their environment. This technique may provide another method for us to determine where these whales are located elsewhere and which prey species are important to them.

Three decades of visual and acoustic data indicate that GoMex Bryde's whales reside year round in Gulf, with the majority of sightings occurring within a restricted range along the 200 m depth contour, southeast of the De Soto Canyon in the northeastern Gulf of Mexico.*

It was a busy first week or so as we loaded and set up all the required equipment, calibrated instruments and made all the preparations for the various aspects of this cruise. For the next several weeks, we will be posting field notes from the expedition, so follow our activities if you want to hear more about some our research activities, like the use of sUAS to take overhead images to help develop the tools for assessing the health of individuals in this population.

Meet the Team

GoMex Bryde's Whale Survey Team, Summer 2019. Left to right: Nick Tucker, Beth Josephson, Grace Conger, Debra Abercrombie, Kat Ternus, Melissa Soldevilla, Tony Martinez, Vincent Quiquempois, Melody Baran; Kneeling L to R: Annie Gorgone, Heidi Malizia, Laura Dias, Joel Ortega-Ortiz

*All photos were taken under NOAA research permit #14450-05 and 21038, issued by the NMFS Office of Protected Resources to the SEFSC Marine Mammal Program.

Image

Debra Abercrombie was one of the bloggers on this post. She contributed to this blog in a big way but has since taken a position with the U.S. Fish and Wildlife Service.