An independent review (FishListic Pty Ltd. 2019) identified knowledge gaps that need to be addressed for the SGPF to have a successful re-assessment of their MSC certification. The review found that detailed information was needed on the percentage of key seafloor habitat types within and outside the trawl footprint.
The review highlighted the need to visually monitor the SGPF’s associated habitats to address knowledge gaps of habitat extent, regeneration, detailed mapping, sensitivity and understanding of gear impacts. Specific knowledge gaps are: a) the presence/extent of sponge and rhodolith habitats currently in medium to high-intensity trawl areas; b) regeneration of sponge and rhodolith habitats previously subjected to high-intensity trawling; c) post-capture survivability of rhodolith pavement; and d) impact of gear on specific habitats.
The MSC Fisheries Standard for Habitats (PI 2.4) requires explicit assessment of the fishery’s impact on commonly encountered habitats, vulnerable marine ecosystems (VMEs) and minor habitats. While VMEs are not currently designated in Spencer Gulf, the common, sensitive and minor habitats associated with the SGPF need to be evaluated. Data are needed on the amount of exposure of these habitats to prawn trawling in Spencer Gulf, as well as on their protection and recovery, to determine their status.
In order for the SGPF to maintain its status as one of the world’s best managed prawn trawl fisheries and retain its social licence to operate, the requirements of MSC Principle 2: Habitat (2.4) need to be addressed. Seafloor habitat types found within the trawl grounds need to be visually monitored, described, quantified, and impacts from prawn trawling assessed.
New understanding of the spatial and temporal distribution of key habitats and impacts from fishing in the context of the entire Spencer Gulf is needed to protect fisheries resources and the environment that supports them, and for integrated ecosystem-based management to be implemented in the future.
Final report
This study characterised and quantified seafloor habitats and species abundances in Spencer Gulf, assessing the impact of the Spencer Gulf Prawn Fishery (SGPF) on by-catch species and key seafloor biological habitats. The Spencer Gulf Prawn Fishery (SGPF), a wild-capture, demersal trawl fishery, is the third most valuable prawn fishery in Australia and targets the Western King Prawn (Penaeus latisulcatus, formally Melicertus latisulcatus). The fishery employs best practices and has held Marine Stewardship Council (MSC) certification since 2011, undergoing reassessment every five years. The SGPF was the first prawn fishery in the Asia Pacific and the first king prawn fishery in the world to receive MSC certification.
Public attention on the effects of trawl fisheries on seafloor ecosystems has increased, and demonstrating the environmental sustainability of trawling presents significant challenges. Information required to quantify the wider ecological effect of trawl fisheries includes: i) the distribution, extent and recovery times of different seafloor habitat types; ii) the intensity and spatial and temporal distribution of all bottom trawling activities; and iii) the direct impact of a single pass of the trawl gear on different habitats and species. The MSC Fishery Standard is the leading international benchmark for sustainable fishing and is used to assess if a fishery has used best practices. Certification of a fishery by the MSC recognises that a fishery is sustainable and gives assurance to consumers that their seafood choice is ecologically responsible. New data collected during this study, combined with previous by-catch surveys, environmental data, and trawl effort information, was used to predict biological habitats and species distribution and their percentage of overlap with the cumulative trawl footprint of the SGPF and protected areas in Spencer Gulf that included marine parks and voluntary industry closures.
