Photo Credit: Dr. Paul Ponganis/Antarctic Photo Library
|Emperor penguins leap out of the water near their colony at Cape Washington. The colony and a nearby silverfish nursery received special protection under the Antarctic Treaty earlier this year.|
Posted July 19, 2013
A 286-square-kilometer swath in the Ross Sea , designated as Cape Washington and Silverfish Bay, became the 73rd Antarctic Specially Protected Area (ASPA) . The designation is given to sites with special environmental, scientific, historic, aesthetic and/or wilderness values. An ASPA requires a special permit to enter.
In the case of Cape Washington and Silverfish Bay, the ASPA encompasses an emperor colony that boasts as many as 20,000 breeding pairs, as well as a nursery and hatchery for silverfish, a herring-sized fish that is a key species in the Ross Sea food web. All but two percent of ASPA No. 173 is marine territory.
“I think it was important to create an ASPA for Cape Washington because it has the second, if not the largest, emperor penguin colony in the world,” said Dr. Paul Ponganis , “and also because an adjoining section of Terra Nova Bay is the only known nursery site of the Antarctic silverfish.
“Both are valuable biological sites worth preserving and protecting,” he added.
An anesthesiologist and marine biologist, Ponganis has studied Antarctica’s largest penguin species for more than 20 years, research first pioneered in the 1960s by his colleague at the University of California-San Diego’s Scripps Institution of Oceanography, Gerry Kooyman . [See previous article — A big breath; Study tackles emperor penguin diving physiology, population dynamics and even leopard seals.]
Both Ponganis and Kooyman provided advice and data for the proposed ASPA, which was officially adopted at the 36th Antarctic Treaty Consultative Meeting (ATCM) in Brussels, Belgium, in May of this year.
The Cape Washington colony competes with Coulman Island, also in the Ross Sea, as the largest emperor penguin colony in the world. The former represents about eight percent of the global emperor population and accounts for roughly a fifth of the Ross Sea population.
Emperor penguins, Aptenodytes forsteri, are the largest of 17 species. They are unique in their breeding habits, incubating a single egg throughout the Antarctic winter. The fat reserves of the male, in combination with a huddle strategy, help protect the males and their eggs through the winter when coastal temperatures can drop below minus 30 degrees Celsius.
No colony is more successful at breeding than the one at Cape Washington, which averages about 95 percent of chicks successfully fledged, according to one six-year study. Colonies in East Antarctica average around a 60 to 70 percent success rate.
About 20 kilometers west of Cape Washington is Silverfish Bay, where the first documented nursery and hatching area for Antarctic silverfish (Pleuragramma antarcticum) is located.
According to the ASPA description, recent research has shown that the concentration of spawning can extend all the way across the embayment to Cape Washington, with the first “ground-breaking” studies on the life history of this species taking place at the site.
One of the biggest challenges in designing the Cape Washington and Silverfish Bay ASPA involved protecting the site while still allowing access for tourists and personnel from nearby research stations, according to Colin Harris, director of Environmental Research & Assessment (ERA) . ERA helps prepare environmental documents and assessments on behalf of the National Science Foundation (NSF) , which manages the U.S. Antarctic Program (USAP) .
“Initially, we encountered considerable opposition to the proposal for this reason,” Harris explained by e-mail. “The boundaries needed to be designed in accordance with the environmental and scientific values, although this meant that visitors without a permit would be excluded from the breeding locality of the emperors.”
The compromise involved establishing a boundary that allows visitors to access sea ice in the vicinity of the main colony to view penguins but does not grant access to the core of the breeding area, which is usually centered about one kilometer northwest of the cape.
There are two research stations within the immediate vicinity. One is Mario Zucchelli , an Italian station that operates only during the summer months, from October to February. Nearby is also a summer-only German research station, Gondwana.
In addition, the emperor colony has drawn a modest number of tourists for the last 20 years. Over the last decades, the site has averaged about 200 people each year. Nearly 35,000 tourists visited Antarctica in 2012-13, most visiting the Antarctic Peninsula, on the others side of the continent.
The size of the Cape Washington and Silverfish Bay ASPA is relatively modest compared to other specially protected areas, according to Harris.
“It was recognized that the emperors forage far beyond this limit, extending right across the Ross Sea, so it was decided to focus on the breeding area of the emperors, as well as the ‘nursery’ area of the silverfish in the context of the concentration of human activities in the vicinity,” he explained.
The Cape Washington ASPA also affords protection to a number of species that nest or forage within the ASPA.
A south polar skua colony of about 50 pairs of birds is located on the ice-free slopes of Cape Washington, overlooking the emperor colony. Snow petrels have been recorded as breeding in niches in the Cape Washington cliffs.
Photo Credit: Dr. Paul Ponganis/Antarctic Photo Library
A leopard seal prowls for prey near Cape Washington.
Large pods of killer whales, with groups of up to 100 individuals, are regularly observed foraging around Cape Washington. Other whales spotted in the area include minke whales and Arnoux’s beaked whales.
Three species of seal — Weddell, leopard and crabeater — are also commonly seen in the area.
The United States has put forth 15 ASPAs over the years. Last year, the Antarctic Treaty nations adopted the first sub-aerial ASPA, Lower Taylor Glacier and Blood Falls ASPA 172 , also proposed by the United States. [See previous article — Environmental precedent: Blood Falls becomes first subglacial ASPA to protect scientific values.]
Blood Falls hosts a subglacial ecosystem that is home to a unique microbial community, which scientists believe has evolved over hundreds of thousands of years to subsist on a chemical soup of sulfur and iron compounds in the absence of oxygen and light. It’s the sort of conditions that might exist on another planet or moon, making it a valuable natural laboratory to study exobiology.
ASPA No. 173 will protect yet another natural laboratory where scientists can continue to study Antarctica’s unique ecosystem.
“I think the value of the Cape Washington ASPA is the recognition of the biological value of its larger emperor penguin colony and the silverfish nursery, and, consequently, the value of ensuring preservation and protection of the region in the future,” Ponganis said.