3.1.3 Stock assessment of lobster and octopus

Description

Managing the sustainability of marine invertebrate populations that have been and continue to be extracted from the Ningaloo Marine Park (NMP) requires some baseline assessment of abundance and spatial distribution of the targeted organisms. This project reports the findings of research into the status of targeted invertebrate populations, with specific focus on lobster and octopus, along the length of the Ningaloo Marine Park during 2008-9.

Aims

• A report on stock status for targeted invertebrate species along the length of Ningaloo Marine Park including octopus and lobster.
• A characterization of habitats associated with high numbers of targeted species.
• A comparison of stock abundance in relation to differing levels of visitor access.

Methods

• Underwater visual surveys (UVC)
• SCUBA transects 5 x 100m
• Habitat visual records; Landscape photos and descriptions
• GPS location data recorded
• Passive and attractant traps
• Night lights used as attractants

Outcomes

Both lobsters and octopus are extremely vulnerable to human impacts by virtue of their predictable habitat requirements, clumped patterns of distribution, and relative ease of capture. There is little doubt that past human activities have played an important part in the devastating decline of lobsters, and there is strong evidence to suggest that octopus populations are also under threat from the same source. There is also little doubt that lobster and octopus will come under increasing pressure in line with projected increases in visitation rates if no additional management action is taken.