A large spawning aggregation of giant Australian cuttlefish (Sepia apama) usually occurs on a discrete area of rocky reef adjacent to Pt Lowly in northern Spencer Gulf. This is the only known dense aggregation of spawning cuttlefish in the world and it is highly valued by local residents, the tourism industry, and recreational divers. A cephalopod fishing closure was established in the spawning area in 1998 due to a rapid increase in catches in the area and concerns about the sustainability of the resource.

A series of anecdotal reports, filtered through various media sources, has indicated that this year’s (2011) spawning aggregation appears significantly reduced. There is considerable speculation as to why breeding cuttlefish have “failed to turn up” on the Point Lowly Peninsula spawning grounds, ranging from natural variation in their population dynamics, localised pollution by coastal industrial development, and environmental irregularities. In order to effectively respond to this decline, it is important to determine whether it is an ongoing trend, and if so, what its cause is. Structured cuttlefish surveys, where the data have been made publically available, have not occurred since 2005 (see Steer and Hall, 2005), therefore, it is has not possible to ascertain the magnitude of the annual variation in cuttlefish abundance and biomass. Furthermore, there has not been any structured environmental monitoring within the broader northern Spencer Gulf area to investigate any potential casual links between local environmental conditions and cuttlefish aggregative behaviour. Clearly there is a need to develop an on-going monitoring program that quantifies the abundance and biomass of cuttlefish on the spawning grounds, coupled with a structured environmental monitoring program. This is of particular importance as the spawning grounds are located in close proximity to coastal industry and proposed further infrastructure development.