Biodiversity in extreme aquatic environments: Lakes, ponds and streams of the Ross Sea sector, Antarctica

Abstract

The Ross Sea Sector (RSS) of Antarctica lies between the lines of longitude 150°E and 150°W and contains diverse landscapes with a variety of lakes, ponds and streams. Neither insects nor crustacean species have been recorded in these ecosystems but most contain planktonic and/or benthic communities that are composed exclusively of microscopic organisms. Microbial biodiversity is low with a small number of species (e.g. filamentous cyanobacteria of the family Oscillatoriaceae) occurring under a broad range of environmental conditions throughout the region. There is no evidence to date of microbial endemism in the RSS; however, there is a need to apply molecular and cellular techniques to compare biodiversity and genetic characteristics with assemblages elsewhere in Antarctica and with comparable communities in the north polar zone. A series of hypotheses are advanced to help guide further work. These derive from the conclusion that environmental extremes plus biogeographical isolation control the biodiversity of RSS communities, and that biological interactions (competition, grazing, predation, parasitism) are weak and play a minor role by comparison with temperate latitude ecosystems.

Microbiology of Eutrophic (Ornithogenic and Hydrocarbon-Contaminated) Soil

“…Soils at the margins of lakes, glacial streams, and ponds are reliant on the short period of the austral summer when liquid water can be sustained (Stanish et al 2012). Ponds are the most common inland bodies of water and are scattered at all elevations around the Dry Valley system; they are usually small and typically undergo complete freeze/thaw cycles each year relying on snow and ice melt for replenishment (Vincent and James 1996). Lakes are larger inland bodies of water typically with permanent ice cover and a large reservoir of liquid water year round (Howard-Williams and Hawes 2007), and are usually replenished during summer by glacial and snow pack melt water streams (Vincent and James 1996).…”

“…Ponds are the most common inland bodies of water and are scattered at all elevations around the Dry Valley system; they are usually small and typically undergo complete freeze/thaw cycles each year relying on snow and ice melt for replenishment (Vincent and James 1996). Lakes are larger inland bodies of water typically with permanent ice cover and a large reservoir of liquid water year round (Howard-Williams and Hawes 2007), and are usually replenished during summer by glacial and snow pack melt water streams (Vincent and James 1996). These streams vary greatly in size and occur with intermittent flow for a few weeks during the summer months (Howard-Williams and Hawes 2007).…”

Transparency of Antarctic ice‐covered lakes to solar UV radiation

“…We thank Rob Edwards, Rob Smith, and Nick Russell for expert assistance in the field, and the VXE-6 squadron of the U.S. Navy for logistic support. community structure that is limited by extreme isolation and the harsh continental environment (Vincent and James 1996). These communities must now contend with the additional stress of increasing short-wave ultraviolet radiation.…”

Toxin production in cyanobacterial mats from ponds on the McMurdo Ice Shelf, Antarctica

“…Habitats range from dilute meltwater and hypersaline ponds, ice shelf and glacier pools to mesotrophic and ultraoligotrophic lakes (Vincent and James, 1996). An extensive meltwater system is produced in the ablation zone of the McMurdo Ice Shelf, in the northwest of the Ross Ice Shelf, where a 1500±2000 km 2 region of marine and moraine sedimentcoated ice is to a large extent covered by water at the end of the austral summer season.…”