Summary: | Progress Code: completed These data accompany the paper 'Long-distance Southern Ocean environmental DNA (eDNA) transect provides insights into spatial marine biota and invasion pathways for non-native species'. Samples (n=138) were collected aboard the RSV Aurora Australis on a resupply voyage between Hobart, Tasmania (42°52’54.84”S 147°20’29.76”E) and Davis Station, Antarctica (66°26’14.28”S 77°28’24.6”E) in November 2019 (Figure 1; Table A1). Two combinations of water volume and filter pore sizes were tested at each sampling location: 12 L with 20 μm, and 2 L with 0.45 μm, herein referred to as “LargeVF” and “SmallVF” respectively. Water samples were collected and filtered approximately every 4 hours (4.52 ± 0.23) via the ship’s uncontaminated seawater intake line (4 ± 2 m depth). The seawater intake line was run for 3 – 5 minutes prior to sample collection to ensure the sample collected represented the seawater surrounding the ship at the time. SmallVF water samples (2 L, n=69) were filtered using a Sentino microbiology peristaltic pump (Pall Life Sciences) through 47 mm diameter, 0.45 μm pore size polyethersulfone filter membranes (Pall Life Sciences). Simultaneously, LargeVF water samples (12 L, n=69) were filtered using a Masterflex L/S console pump system (Cole-Parmer) through 25 mm diameter, 20 μm pore size nylon filter membranes (Merck). SmallVF filter membranes (47 mm diameter) were cut in half and immediately preserved at -80°C, with one half to be analysed and one to be stored as a reserve and a form of eDNA biobanking (Jarman et al., 2018). LargeVF filter membranes were not cut in half due to their smaller diameter (25 mm) and were stored whole at -80°C. Filtration equipment was rinsed with a 10% bleach solution and freshwater from the laboratory in between every sample, and soaked for 15 minutes with 10% bleach every tenth sample. Field controls consisted of 500 mL samples (n=10) of laboratory freshwater and the 10% bleach solution used for sterilisation, taken approximately every 10 samples. DNA ...
|