Deep within the Ross Sea, banks serve as a consistent food supply for Emperor Penguins, reaching a staggering depth of 400 meters.
In a groundbreaking study published in June's edition of Polar Biology, a team of researchers led by Gerald Kooyman of Scripps Oceanography at the University of California San Diego (UCSD) has uncovered remarkable details about the deep-diving activities of emperor penguins in the Ross Sea region Marine Protected Area (RSRMPA).
The RSRMPA, covering an expansive 1.55 million square kilometers (450,000 square nautical miles), is the largest marine protected area in the world. Created by a 25-nation commission in 2016, the RSRMPA includes the Crary Bank, a raised area of the seafloor where emperor penguins prefer to find their primary prey, the Antarctic silverfish.
The study, which analysed over 80,000 foraging dives by emperor penguins over a 22-year period, revealed that the penguins travelled up to 100 kilometers (60 miles) to Crary Bank. During these deep dives, the penguins often exceeded their oxygen storage limits for aerobic metabolism and developed an oxygen debt, requiring a prolonged recovery of 15 to 20 minutes after each dive, compared to the usual two to three minutes for shorter dives.
On more than 1,400 of those dives, the penguins dived deeper than 400 meters (1,300 feet). This extraordinary behaviour, according to Kooyman, provides some of the most comprehensive evidence ever of the lengths to which penguins will go for a meal.
The research was supported by the National Science Foundation and involved collaborations with researchers from NOAA, the National Marine Mammal Foundation, the University of Tokyo, and Principia College.
Scripps Oceanography, a part of UCSD, is renowned for its culture of exploration and experimentation. It operates a fleet of four oceanographic research vessels and offers undergraduate, master's, and doctoral programs. The institution is also one of the top 15 research universities in the world.
The study shows that the RSRMPA, particularly its inclusion of Crary Bank, makes the MPA considerably more effective in achieving its conservation goal. This finding underscores the importance of preserving such vital ecosystems for the survival of these remarkable creatures.
Birch Aquarium at Scripps, the public exploration center operated by Scripps Oceanography, welcomes 500,000 visitors each year, offering an opportunity for the public to learn more about the fascinating world beneath the waves and the creatures that inhabit it.
