호주
Casey marine sediment meiofauna 2005
Marine sediment meiofauna community composition and sediment environmental data collected in 2005 and published in Stark, J. S., M. Mohammad, A. McMinn, and J. Ingels. 2020. Diversity, abundance, spatial variation and human impacts in marine meiobenthic nematode and copepod communities at Casey station, East Antarctica. Frontiers in Marine Science 7:480. From the abstract: The composition, spatial structure, diversity and abundance of Antarctic nematode and copepod meiobenthic communities was examined in shallow (5 – 25 m) marine coastal sediments at Casey Station, East Antarctica. The sampling design incorporated spatial scales ranging from 10 meters to kilometres and included testing for human impacts by comparing disturbed (metal and hydrocarbon contaminated sediments adjacent to old waste disposal sites) and control areas. A total of 38 nematode genera and 20 copepod families were recorded with nematodes being dominant, comprising up to 95% of the total abundance. Variation was greatest at the largest scale (km’s) but each location had distinct assemblages. At smaller scales there were different patterns of variation for nematodes and copepods. There were significant differences between communities at control and disturbed locations. Community patterns had strong correlations with concentrations of anthropogenic metals in sediments as well as sediment grain size and total organic content. Given the strong association with environmental patterns, particularly anthropogenic disturbance, meiofauna may be seen as very useful indicators of natural and anthropogenic environmental changes in Antarctica. Methods derived from: Stark, J. S., M. Mohammad, A. McMinn, and J. Ingels. 2020. Diversity, abundance, spatial variation and human impacts in marine meiobenthic nematode and copepod communities at Casey station, East Antarctica. Frontiers in Marine Science 7:480. Sampling design Sampling was undertaken using a hierarchical, nested design with three spatial scales, Locations (separated by kms); within each location there were two sites (~ 100 m apart) and at each site there were two plots (~10m apart). Within each plot (1m diameter), two replicate cores were taken for meiofauna and two for environmental analysis, making a total of 8 meiofauna and 8 environmental cores per location, except at O’Brien Bay-5 where one meiofauna core was lost during sampling. Six locations were sampled around Casey Station. There were three control locations, two of which were within O’Brien Bay to the south of Casey (O’Brien Bay-1 (OB-1) and O’Brien Bay-5 (OB-5)); and one within Newcomb Bay, in McGrady Cove (Fig. 1). There were three locations adjacent to waste disposal sites: two locations were situated along a gradient of pollution within Brown Bay (Inner and Middle)(Stark et al. 2004, Stark 2008); and a third location was at Wilkes, adjacent to the abandoned waste disposal site at the derelict Wilkes station (Stark et al. 2003a), all within Newcomb Bay (Fig. 1). These waste disposal sites were used historically to dispose of all waste and rubbish generated on station and included used oil, building materials, electronics and batteries, food, clothing and chemicals (Snape et al. 2001, Stark et al. 2006). Both waste disposal sites are contaminated with metals and hydrocarbons above background levels (Stark et al. 2008, Stark et al. 2014b, Fryirs et al. 2015). Sample collection, meiofauna preparation and identification Sediment samples were collected by divers using modified 60 ml syringes with their intake end cut off to form a small core tube (28mm internal diameter). Cores were pushed into the sediment to a depth of 10 cm, extracted, and the bottom end was capped. In a few cases samples were only taken down to 5-7 cm, where sediments were less than 10 cm deep due to underlying rock. No sediments less than 5 cm deep were sampled. Cores were transported to Casey Station laboratories where they were emptied into sample jars and 4% formalin was added