Introduction
It covers how to report on the performance of target species and the rest of the ecosystem. In the long term, this will include explicit recognition of the role of social and economic considerations in fisheries management decision-making (including resource allocation).
Overview
The recruitment of this species is highly variable and, as a result, the catch varies widely from year to year, independent of the level of spawning that triggered it. Of the seven issues identified for the SBS fishery, two (impacts on sand/shell and coral/sponge habitat) were assessed as moderate risk, two (impacts of catching and discarding fish) were assessed as minor risk and three (discarded shells, translocation and turbidity) were judged to be negligible.
Background on the SBS Fishery
DESCRIPTION OF THE FISHERY
Over the period since 1982, the annual catch and value of the fishery has varied greatly. Diagrammatic representation of the type of bycatch reduction device used in Shark Bay and its location in the shrimp trawl (same as for scallop).
BIOLOGY OF SAUCER SCALLOP
The planktonic, larval stage of the scallop lasts between 12 and 24 days (Rose et al., 1988), although recent work has produced deposited saliva in nine days (P. McGowan, pers. comm.). One week after settling, a byssal notch and associated threads develop on the dissoconch of the right valve, although attachment to the substrate remains very weak and is never permanent (Rose et al., 1988).
MAJOR ENVIRONMENTS
Physical Environment
Economic Environment
Social Environment
Outline of reporting process
SCOPE
OVERVIEW
ISSUE IDENTIFICATION (component trees)
SBS fishing trees were developed prior to the first workshop and reviewed at the first workshop in June 2001.
RISK ASSESSMENT/PRIORITISATION PROCESS
COMPONENT REPORTS
APPLICATION TO MEET EPBCA REqUIREMENT
In terms of impact on cuttlefish breeding stock levels, the consequence of SBS fishing is considered "negligible". The impact on provisioning as a result of discarding bycatch from the SBS fishery is considered. A monitoring review is maintained by the Department of Fisheries and SBSMAC on the functionality of the management arrangements.
Current: Report annually to Parliament and the community on the status of the fisheries. Ensure periodic evaluation of the performance of fisheries management arrangements and management strategies, objectives and criteria. A full description of the management arrangements for commercial fisheries can be found in the attached management plan.
In terms of impact on squid farming stocks, the impact of SBS fishing is taken into account. Of the seven issues identified for SBS fisheries, two (impacts on sand/shell and coral/sponge habitats) were assessed as moderate risk, two (impacts of trapping trapped and non-contained species and fish discards) were assessed as low risk and three (discarded shell, translocation and turbidity) were assessed as negligible.
OVERVIEW TABLE
Performance reports
RETAINED SPECIES
Primary species
- Scallops
Spawning early in the spawning season (April–June) accounts for the bulk of recruitment each year, especially in high recruitment years. Summary: The management scheme of recent years has ensured that the start date of the season is set in such a way that sufficient spawning can take place during the spawning period. With this research, the start date of the fishery can be determined and the spawning stock can be managed.
This level of recruitment was reflected in the catch (1,700 tons total weight) taken in 1999, which was in the middle of the expected range for the season.
By-product species
- Cuttlefish
- Bugs
- Blue swimmer crabs
Due to fishing closures, much of the potential trawl area is not actually fished, further protecting the species. The species composition of the catch in Shark Bay is not known, but one of the species present is Sepioteuthis lessoniana. In relation to the risk assessment, it was determined that it was "likely" that the fishery had only one.
Fishing accounts for 8% of the total crab catch for the state with traps taking the majority of crabs, (85%) (Fisheries WA, 2002).
NON-RETAINED SPECIES
Captured in nets
- Threatened/listed species loggerhead turtles
- Threatened/listed species green turtles
- Protected species syngnathids
- Protected species seasnakes
- Discarded fish
Loggerhead turtles (Caretta caretta) were incidentally caught in the SBS fishery over the period of its operation. The Department of Fisheries continued the observer program for the 2002 season in the SBS fishery. Syngnathids are sometimes caught by accident in the SBS fishery and are usually discarded, presumed dead.
Sea snakes are regularly caught in small numbers in the SBS fishery and are generally alive when discarded.
Interaction but no capture
- Threatened species green and loggerhead turtles
- Protected species dugongs and other cetaceans
This issue will be reviewed as more information on breeding aggregations becomes available from CALM. This section addresses the issue of the interaction between fisheries and dugongs and cetaceans, notably resulting in no capture, the issue of dugongs being hit by the hulls of the vessels in the fishery. Consequently, although trawling is physically separated from areas used by dugongs for most of the winter season, there is some overlap between trawlers and dugongs.
If the number of dugongs increases, it may increase the chances of this occurring.
GENERAL ENVIRONMENT
Impacts from removal or damage to environment
- Fishing impacts, through all retained and non-retained species removals
- Impact to sand/shell habitat and ecology
- Impact to coral/sponge habitat
Seventy-three percent (73%) of all waters in Shark Bay are permanently closed to shark fishing. The impact of scallop fishing activities on coral and sponge habitats in Shark Bay is considered LOW. Analyzes of fished areas for 1999 show that only 11.5% of the Shark Bay region is actually fished by the scallop fleet (Refer to Appendix 6).
Reports from these exploration exercises document the sand and mud bottom nature of Shark Bay indicating that trawling has not significantly altered the habitat from pre-fishing conditions.
Addition of materials to the environment
- Discarding fish
- Discarding scallop shells
For 1999, the estimated release amount is 500 tonnes (based on 2 times the target catch of 250 tonnes and does not include discarded clam shells and mantle tissue). It is estimated that about 20 to 25% of the total weight of the scallop is the weight of the adductor tissue (which is stored), the rest of the scallop (i.e. mantle tissue) is discarded. Although this fishery generates a relatively small amount of bycatch (compared to shrimp trawling), this should be further reduced through the introduction of BRDs, including nets in 2003 and possibly fish exclusion devices.
Shell discarding has previously been a problem in the Abrolhos Island scallop fishery, where smaller boats were sometimes used.
General impacts on environment
- Creation of turbidity from trawling
- Translocation
Studies of the sediment composition over all trawl areas (Hall and Penn, 1979) also showed that the majority of the soil was dominated by coarse sand. This means that less than 10% of the sediment samples taken contained a noticeable mud component (>10% mud). In practice, most of the vessel exchange between Shark Bay and Abrolhos and Nickol Bay/Onlsow is the fishery.
Much of the west coast is connected via the Leeuwin Current and as such there is already a connection between Fremantle and the trawling area.
GOVERNANCE
- Department of Fisheries – Management
- Management effectiveness (outcomes)
- Management arrangements
- Compliance
- Allocation among users
- Department of Fisheries – legal arrangements
- OCS arrangements
- Department of Fisheries – consultation
- Consultation
- Department of Fisheries – reporting
- Assessments and reviews
As an all-encompassing sub-component, the performance of the management arrangement is assessed at two levels – the micro-level, i.e. explicit description of the management unit - The management unit is explicitly described in the 'Fisheries Declaration' section of the SBS Plan. The management of the scallop fishery is based on an extensive process of consultation and communication.
The performance of the fishery is reported annually against the agreed targets in the State of the Fisheries Report.
Bibliography
Geographic variation in the reproductive cycle of the scallop, Amusium balloti (Bernadi, 1861) (Mollusca: Pectinidae), along the Western Australian coast. An analysis of demersal fish resource yield in Australian waters of northern and northwestern Australia. Environmental effects of shrimp trawling in the northernmost part of the Great Barrier Reef Marine Park: 1991-1996.
A study of the effects of shrimp fishing on benthic communities in two South Carolina sounds.
Appendices
Terminology
Attendees lists
David Adams, Exmouth RFAC Errol Sporer, Department of Fisheries Felix Correia, Correia Holdings Pty. of Fisheries Keith Shadbolt, Denham RFAC Les Moss, Earl of Shark Bay Lindsay Joll, Department of Fisheries Mark Hook, Grade of Shark Bay Martin Holtz, Recfishwest. Mervi Kangas, Department of Fisheries Nic Dunlop, Conservation Council of WA Paul Bowers, Aboriginal Lands Trust.
National ESD consequence levels and likelihood definitions for risk
By-product/other non-conservation: Area of fishing is negligible compared to where the relevant stock of these species lives (< 1%) Protected species: Relatively few are affected. Small target/non-detained: May be detectable, but little impact on population size and none on their dynamics. By-product/other not retained: catches in this fishery are small (< 10% of total) compared to total catches by all fisheries and these species are explicitly included elsewhere.
By-product: Other not conserved: No information on relative area or susceptibility to capture or vulnerability of life history traits of this species.
Acronyms
Research
Figures
A6.2 General trawling areas by the scallop fleet (class A license vessels) at Shark Bay in 2000. A6.3 General trawling area by the scallop fleet (class A license vessels) at Shark Bay in 2001.
Materials supplied to Environment Australia against their specific guidelines . 82
The reports on the ESD component (see section 5) contain the available targets, indicators and benchmarks for measuring the effectiveness of the management arrangements for SBS fisheries.2. The WA Department of Fisheries employs a large number of operational staff to ensure compliance with critical aspects of the management arrangements for SBS fisheries. The ESD component reports provide a comprehensive assessment of the effectiveness of the SBS fishery based on the framework described in the ESD Policy (Fletcher, 2002).
Full descriptions of available information and levels of risk of impact on these by-product species from SBS fisheries are found in sections and 5.1.2.3. A relatively small number of loggerhead turtles are bycatch in the SBS fishery and almost all are released alive due to the short duration of the hauls. A formal risk assessment (see section 5.3 for details) has been completed for each of the identified issues relating to the SBS fishery (see the issue tree).
