Toxicity of copper to three Macquarie Island marine gastropods
The three gastropod species in this study were collected from the subantarctic Macquarie Island (54.6167 degrees S, 158.8500 degrees E), which is located in the Southern Ocean, just north of the Antarctic Convergence. Sea temperatures surrounding Macquarie Island are relatively stable throughout the...
| Other Authors: | , , , , , , , , , |
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| Format: | Dataset |
| Language: | unknown |
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Australian Antarctic Data Centre
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| Online Access: | https://researchdata.ands.org.au/toxicity-copper-macquarie-marine-gastropods/699073 https://doi.org/10.4225/15/57464E2C8CA61 https://data.aad.gov.au/metadata/records/AAS_4100_Toxicity_Gastropods http://nla.gov.au/nla.party-617536 |
| Summary: | The three gastropod species in this study were collected from the subantarctic Macquarie Island (54.6167 degrees S, 158.8500 degrees E), which is located in the Southern Ocean, just north of the Antarctic Convergence. Sea temperatures surrounding Macquarie Island are relatively stable throughout the year, with average temperatures ranging from ~4-7 degrees C (Reynolds and Banzon, 2008). Seawater samples were taken from collection sites of this study and verified as free from metal contamination by analysis by inductively coupled plasma optical emission spectrometry (Varian 720-ES) (ICP-OES). The three gastropod species were collected from a range of habitats within the intertidal and subtidal zone (Figure 1). Individuals of Laevilittorina caliginosa were often located in pools high on the intertidal zone, but can occur throughout the intertidal zone. Collections of this species were not specific to any one habitat. Macquariella hamiltoni, endemic to Macquarie Island, was collected from macroalgae in the high energy areas of the subtidal zone. Finally, Cantharidus capillaceus coruscan, was collected from the undersides of boulders in deep tide pools as well as from crevices in the shallow subtidal. This species was also abundant on the floating fronds of Macrocystis pyrifera in deep water which is up to several hundred meters from shore. Toxicity tests Toxicity tests were conducted at Macquarie Island, over the 2013/14 austral summer, and at the Australian Antarctic Division (AAD) in Tasmania, Australia, in 2015. The first round of tests with Laevilittorina caliginosa and Macquariella hamiltoni as well as both tests for Cantharidus capillaceus coruscan were done on Macquarie Island, while the second test for L. caliginosa and M. hamiltoni were done in Australia. Gastropods for use in tests in Australia were transported by ship to the Marine Research Facilities at the AAD where they were housed in purpose-built recirculating aquariums at 6 degrees C for 2 months prior to being used in tests. For tests done at the Macquarie Island laboratory, gastropods were acclimated to laboratory conditions for 2 days prior to their use in tests. Test solutions were prepared 24 hours prior to the addition of animals. All experimental vials and glassware were acid washed with 10% nitric acid and rinsed with MilliQ water three times before use. Five copper concentrations in seawater plus a control were prepared using 500 micrograms/L CuSO4, MilliQ water stock solutions. Seawater was filtered to 0.45 microns and water quality parameters were measured using a TPS 90-FL multimeter at the start and end of tests. Dissolved oxygen (DO) was greater than 80% saturation, salinity was 33-35 ppt, and pH was 8.1-8.3 at the start of tests. Tests were conducted under a light-dark regime (at 2360 lux) of 16:8h light:dark in summer, 12:12 for tests in the rest of the year and were kept in controlled temperature cabinets set at 6 degrees C. Temperatures within cabinets were monitored throughout the test using ibutton data loggers. Water samples of each test concentration were taken at the start (day 0) and end of tests (day 14). Samples were filtered through a 0.45microns Minisart syringe filter and acidified with 1% ultra-pure nitric acid before being analysed by ICP-OES to determine dissolved metal concentrations. Measured concentrations at the start of tests were within 96% of nominal target concentrations. These were averaged with measured concentrations at the end of tests, to estimate exposure concentrations which were then used in the statistical analyses (Table 1). Two different water renewal regimes were used and tests ran for 7 to 14 d. A static non-renewal test regime was used for L. caliginosa and M. hamiltoni, while water was renewed every second day for tests with C. capillaceus coruscan. Tests were terminated when surviving individuals occurred in less than two concentrations, which occurred sooner (7-10 d) for C. capillaceus coruscan, in both tests. Tests were done in lidded plastic vials of varying sizes, depending on the size and number of individuals in the test. For L. caliginosa and M. hamiltoni, tests were done in 120 mL vials containing 100 mL of seawater with 10 individuals per vial and 5 replicates per concentration. For the larger species, C. capillaceus coruscan, tests were done in 500 mL vials containing 450 mL seawater with 5-6 individuals per vial and 5-6 replicates per concentration. Two tests were run for each species. Concentrations used in replicate tests were not the same, as information on the sensitivity of different species acquired from the first test was used to guide appropriate concentrations in the second test. Two endpoints were used to determine sensitivity to copper; mortality and sublethal effects. Vials were checked daily and survival and sublethal/behaviour was observed and recorded on days 1, 2, 4, 7, 10 and 14. For all species, mortality was scored when opercula were open and there was no response to the stimulus the touch of a probe on the operculum. All dead individuals were removed from test vials when observed. At the termination of each test, individuals that had retracted into their shell were placed in clean seawater for 24 hours to determine their ability to recover following exposure to copper. |
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