At open ocean in the Drakes Passage we began our southern ocean seabird survey. The Southern Ocean Seabird survey studies the distribution of birds at sea. These recordings help researchers understand how birds use oceanic habitat and how their behaviour and populations might be changing as a result of climate change. Every day we gathered at the ships poop deck (the deck aft of the ship) together with the voyage crew onboard, and we watched the sky all the way to the horizon for any sea birds in sight.
During the 30 min survey all birds in sight should be counted and identified with the use of binoculars and bird identification books and apps, all data is logged and saved in the eBird app or data spread sheets (date, time, location, GPS coordinates, number of observers, identified birds and how many).
Seabirds are very useful “sentinels” of ocean change. Studying them lets us learn about other aspects of the environment that are often difficult to study, such as the populations of fish and krill. The ocean is full of things like small currents, fronts, and eddies, and it is important for scientists to understand how these impact wildlife. Scientists know quite a lot about what the sea birds do when they come to land to breed, but much less about how they use oceanic habitats (and that’s where they spend most of their time!).
The main ocean current runs through the Drakes Passage flowing clockwise all around Antarctica, permitting just a restricted water interchange north and south following the coasts of southern Patagonia. The cold and dense waters from the southern continent meet along this current with the warmer and lighter ones from the subantarctic region, creating the so called Antarctic Convergence Area. As we sailed into Antarctic waters we recorded surface water temperature read 3.4ºC a decrease from our previous reading 5.7ºC, indicating that we just crossed the northern boundary of the Antarctic system. This also indicated a change in the sea bird species in our daily survey, as it starts revealing a decreasing number of albatrosses and firsts sights on our voyage of the Cape petrels and Southern fulmars. Giant petrels, ever-present every day since departure, keep flying around the ship.
