Antarctic Biodiversity Studies 2006 (Ross Sea, Scott Island, and Balleny Islands) (TAN0602)

Study Extent

Eastern and Central Ross Sea, Scott Island & Balleny Islands, Antarctica, 2006.

Sampling

During daylight hours hourly counts of seabird abundances and continuous recording of marine mammal sightings with occasional directed in situ sampling using epibenthic sleds, still and video cameras and krill nets

Method steps

1. Instantaneous counts of birds at 3 distances and bird transect counts
2. Marine mammal transect counts
3. Camera stations (still and video) were used to test the feasibility of obtaining relative abundance estimates and local density estimates of demersal fishes by comparing fish abundances, size frequencies and species compositions in still camera images during periods of continuous lighting vs. occasional strobe lighting during benthic camera transects when the camera system was actively “flown” 5-10 m above the bottom while the Tangaroa was slowly drifting or underway (~0.5 knot). A colour video camera recorded fish behaviour during the flood-lit phase and verified the period that the flood light was on. The work was planned to take place at randomly positioned stations in one depth stratum < 1000m of one area of higher demersal fish abundance identified from existing catch rate data.
4. Meso-zooplankton (2x2m fine-mesh (2mm)) net was used to opportunistically sample midwater andcsurface swarms of krill and other mesopelagic species.
5. Epibenthic sled (mouth opening 1.4 x 0.5 m, 2 m long, 25 mm mesh diameter) was used to sample the uppermost infaunal and the epifaunal components of the benthic communities. The epibenthic sled was towed at a speed of 1.5 knots for a distance of ~0.5 nm parallel to the depth contour yielding paired sled and photographic estimates of benthic macro-invertebrate abundance and composition suitable for tests of association with demersal fish abundance and community composition.

Ross Sea, Scott Island, and Balleny Islands