Examining the potential impacts of seismic surveys on Octopus and larval stages of Southern Rock Lobster
University of Tasmania
Jayson M. Semmens
CGG has NOPSEMA approval for a 3D seismic survey in the Gippsland Basin to commence in early 2020. This survey overlaps the Victorian shelter-pot octopus fishery off Lakes Entrance. This overlap has raised concerns from the fishing industry about the potential impacts to octopus and the fishers. Tank-based experiments simulating seismic exposure have resulted in high levels of damage in several species of octopus, however, it is unclear how experiments conducted in tanks translate into the field. Field-based seismic experiments have rarely been conducted on invertebrates, with no such studies conducted on octopus. However, the benthic and relatively sessile habit of octopus leaves them potentially vulnerable to impacts, as they have limited capacity to avoid the waterborne and ground-borne energy of seismic signals. CCG has agreed to provide funds to fill the knowledge gap surrounding the potential impact of seismic surveying on octopus and to do this in conjunction with a commercial scale seismic survey, with the lack of a full array often a perceived limitation of seismic research. CGG has also agreed to value add to the work around octopus. This opportunity allows for the potential impact of seismic surveying on larval forms to be examined, with some concerns around localised depletion of larvae of commercially and ecologically important species, such as southern rock lobster and commercial scallops. This project will use a field and laboratory experimental approach to provide a thorough assessment of the potential impacts of seismic surveys on octopus pallidus and its catches, along with rock lobster larvae and other important larvae. These approaches may assist fisheries and petroleum regulators to make informed decisions on the timing and manner in which future surveys are performed. Importantly, along with that of CGG, it has the support of the Victorian Fisheries Authority, who have also offered in-kind support, the two octopus fishers in the region, the Lakes Entrance Fishermen’s co-op, the sustainable shark fishing association and Southern Rock Lobster Inc.
1. Determine the impact of intense low frequency acoustic signals on adult pale octopus (Octopus pallidus)
2. Determine the impact of intense low frequency acoustic signals on the development of eggs, hatching rates and competency of the resultant hatchlings.
3. Outline threshold distances for potential impacts of seismic surveying
4. Determine the impact of intense low frequency acoustic signals on pale octopus (Octopus pallidus) catch.
5. Determine the impact of intense low frequency seismic signals on the pueruli of southern rock lobsters.
6. Determine the impact of intense low frequency seismic signals on important planktonic larvae, particularly crustaceans and molluscs.