Our first season of right whale work at South Georgia has come to an end, and we are cleaning up our gear, packing boxes, doing inventories and taking stock. It was a difficult season, with many bad weather days. Our opportunities to do work were brief and we had to seize those moments when they came- often at 6am before the wind picked up, and often in very marginal conditions where wind and swell were building up and could interfere with our work at any moment. The team worked very hard to make the most of each weather gap, and we began to joke that right whales only come out when the wind is 20 knots or more. It often felt like that. Whale expeditions can be like this: you can put an enormous amount of energy to bring the right people and equipment into place to do this research, only to have the weather and the whales not comply with your tiny human plans. In this case, we are happy to report that the right whales are certainly present in South Georgia waters these days – we found them on nearly every sonobuoy deployment, and on nearly every day when the weather permitted survey.
Here are our vital statistics: 31 days in the field, of which 19 days were spent in South Georgia waters. Within this, there were seven days in which weather conditions permitted any survey work, and within each day sometimes as little as 2 hours had good weather conditions before the day deteriorated. However! We encountered cetaceans 36 times, and encountered right whales 15 times. From these encounters, we saw 31 right whales and obtained photo-identification images of 21 of these. We consider this aspect a great success considering the conditions. Comparing these photographs with those collected on the calving grounds in Argentina and Brazil is the next step to link these whales in with longer-term studies and measure their connections to the South American calving grounds.
Sadly we were not able to deploy a single satellite tag or fly a single drone over a whale, as weather conditions were never good enough when these whales were present to safely carry out these activities. Geneticists Emma and Matt waited valiantly at the bow for many hours for opportunities to collect skin samples.. some days were more successful than others…
We have four skin samples from these efforts- a small number, but one which reflects a lot of field effort in marginal conditions and a valuable resource for our work.
From reviewing the photographs of the right whales we can also inspect the body condition of the animals, so even though we could not run drone flights to measure whale health this year, we can still make some assessments. Our initial sense is that a lot of the whales we encountered in South Georgia were ‘skinny’, with loose skin behind the head. Comparing these images with those from the calving grounds associated with South Georgia (Brazil and Argentina) and from other right whale feeding grounds will be important to understand whether these observations are a cause for concern.
Other highlights of the cruise included an encounter with an Antarctic blue whale mother, calf and escort, and acoustic detections of Antarctic blue whales calling to the north of us throughout the time we were in South Georgia waters (we think they are at the South Georgia continental shelf). This is a really nice sign that Antarctic blue whales are using South Georgia waters in the summer once more. Over 42,000 were killed in these waters during the commercial whaling period, so this is exciting news. We also recorded southern right whale vocalisations for the first time on their feeding grounds, and were able to use these sounds to locate whales. As the evidence of industrial whaling and sealing slowly fades into the wild landscape of South Georgia, the oceans are beginning to hum with whales once more.
Our work continues as we assess body condition and population connections, and investigate the sightings and acoustic data we collected in order to better understand whale distribution. All tourist contributed photographs will also be really helpful to add individuals to the South Georgia right whale catalogue and assess connections. Next year we will return to South Georgia to further assess population recovery of right whales, learning from these experiences and surely building new ones.