Geography Reference
In-Depth Information
itself, the CAML noted 9,350 verified species, ranging in size from the microbe to the Blue
Whale.
Thus, the CAML investigated Antarctic marine biodiversity, and considered how climate
change has affected the abundance and distribution of marine life in the Southern Ocean.
This project, operating between 2005 and 2010, aimed to enhance public basis of claim to
territorial sovereignty in Antarctica Treaty Peninsula and scientific understanding, in the
light of fears that ongoing climate change is disrupting marine biota uniquely adapted to
extreme environments. Seventeen research vessels during IPY were traversing the Southern
Ocean, collecting samples, mapping species records, and cataloguing specimens. The idea
of the census is to provide a benchmark for future studies on the extraordinary range of
creatures inhabiting the Antarctic's cold waters. While documenting different species
matters, one major outcome has been to locate marine biodiversity 'hotspots'.
One such hotspot is the Ross Sea. Accounting for only 2% of the Southern Ocean, the Ross
Sea is an embayment between East and West Antarctica. Its claim to marine biodiversity
fame lies in the strong presence of top predators in the Southern Ocean food chain.
According to scientists, nearly 40% of the world's Adélie Penguins are to be found in the
Ross Sea, along with 25% of Emperor Penguins and thousands of whales, seals, and large
finfish including the commercially lucrative Patagonian Toothfish - a favoured target of the
Ross Sea Killer Whale. This high density of so-called top predators is very unusual in
marine environments in terms of dominating the system's biomass and driving the entire
ecosystem. The current norm, in terms of the ecological pyramid, is the predominance of
phytoplankton at the base, with small numbers of top predators at the apex of the pyramid.
One area of research, as a consequence of this unusual ecological profile, is to imagine the
Ross Sea region as not unusual in one sense but merely indicative of an environment where
commercial fishing has not (yet) decimated top predators such as fish, seals, and whales.
Typically, the predatory life in the Ross Sea consume zooplankton, usually krill and
copepods. By the end of the summer season, levels of zooplankton have declined and the
larger predators such as whales and penguins turn to eating smaller predators such as
silverfish, and the end result is that there remains a large amount of phytoplankton, which is
not consumed by the now depleted krill. Sinking to the ocean floor, the phytoplankton help
to nourish the benthic floor (the lowest level of water in an ocean or lake), and thus generate
a biodiversity hotspot for hundreds of species of invertebrates such as sponges and corals.
The CAML revealed that the Ross Sea was one of the world's least disrupted marine
ecosystems. The impact of human behaviour was low compared to many other
environments, even within the Antarctic itself. But this will change, not least because New
