Dr. Holly Fearnbach, SR3’s Marine Mammal Research Director, just finished an extremely productive month of collaborative research on whale health around the Antarctic Peninsula. She was joined by Dr. John Durban and Trevor Joyce (NOAA Southwest Fisheries Science Center), Leigh Hickmott and Jessica Farrer (SR3) onboard Lindblad Expedition’s National Geographic Explorer to conduct research assessing how top predators (killer whales) and top consumers (humpback and minke whales) are impacted by the rapid warming of this marine ecosystem.
To extend long-term population monitoring (since 2004), they collected photo-identification data from 12 groups of killer whales comprising Antarctic Types A, B1 and B2. Laser measurements of body size were collected from killer (Type A and B2), humpback and Antarctic minke whales to infer trophic requirements. Using a small unmanned hexacopter, they were able to collect aerial images from five killer whale groups, comprising more than 80 Type B2s, eight Type B1s and six Type A killer whales. Photogrammetry measurements from these images will be used to monitor body condition to assess nutritional status and will add to data collected from 2016-2018 on the body size of the different types to understand the energetics underpinning their predatory impacts.
Unlike previous years, no emaciated whales were documented, but a large number of new calves and several pregnant females were photographed. Aerial images were also collected from 11 humpback whales, matched with 2 blow samples- these paired image/blow samples will be used to link the respiratory health of individual whales to their body condition. A big surprise of the season was that the team documented almost two dozen Antarctic blue whales in nearshore waters of the Antarctic Peninsula. Historical whaling reduced the Antarctic blue whale population to < 1% of its original size, but increased sightings in recent years is a great sign for the recovery of the population.
This study is supported by the Lindblad Expeditions-National Geographic Conservation Fund (LEX-NG), NOAA Southwest Fisheries Science Center, SR3 and Pew Charitable Trusts.