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Marine benthic habitat data for Tasmanian coastal waters from the LWM (Low water mark) to 40 metres in depth or 1.5 kms from shore. A full breakdown of habitat classifications is available on the SeaMap Tasmania website: http://seamap.imas.utas.edu.au/habitats/
Data is PCR amplification results of southern rock lobster (Jasus edwardsii) faecal material tested for sea urchin DNA (using unique primers for Centrostephanus rodgersii and Heliocidaris erythrogramma) in an attempt to determine in situ rates of consumption of sea urchins by lobsters. An efficient and non-lethal method was used to source and screen lobster faecal samples for the presence of DNA from ecologically important sea urchins. Lobster faecal samples were collected from trap caught specimens sourced in winter & summer seasons over 2 years (2009-2011) within two no-take research reserves; declared specifically for the purpose of rebuilding large predatory-capable lobsters to assess the potential for predator-driven remediation of kelp beds on rocky reefs extensively overgrazed by sea urchins (North Eastern Tasmania) and reefs showing initial signs of overgrazing (South Eastern Tasmania). Data for molecular assays showed high variability in the proportion of lobsters testing positive to sea urchins, with significant variability detected across different years and seasons but this was found to vary depending on different lobster size-classes. Sea urchin DNA was also amplifiable from sediments and urchin faeces collected from the reef surface where urchins occurred in high abundance. Furthermore, positive sea urchin DNA assays were obtainable from lobster faeces after lobsteres were fed sediment and urchin faecal material. Rates of predation obtained with genetics tests can also be compared to independent rates of urchin losses given known lobster abundances within research reserves (and at control sites). Data of changes in urchin abundances and lobster abundances are therefore also lodged as part of this record.
Belt transect surveys (50m) were used to monitor the benthic community structure through time at experimental (lobster additions/ research reserve sites or abalone diver urchin culls) and control sites in eastern Tasmania. Measures of percentage cover of key algal guilds, percentage of reef grazed by sea urchins, number of sea urchins (Centrostephanus rodgersii, Heliocidaris erythrogramma), Abalone (Haliotis Rubra), Rock lobsters (Jasus edwardsii) and type of substratum were recorded.