11.1 Commercial Net and Trap Fisheries
There a high level of both quantitative and qualitative information available on the impacts of commercial fishing activities within the PHE. This information is considered to be sufficient to estimate and assess outcome status for each ecosystem component and support the management measures in place. Sufficient data continue to be collected to detect any increase in risk for each component and to assess ongoing mortalities of all retained and ETP species.
This information is considered to be sufficient to allow the main consequences for the ecosystem from commercial fishing activities to be inferred.
Commercial fishers are required to report all retained species catches (kg), effort and any ETP species interactions in statutory monthly catch and effort (CAES) returns to the Department’s research division. In order to improve reporting accuracy, fishers have been provided with a Protected Marine Species Identification Guide (National Heritage Trust 2005), which contains a picture and brief description of relevant protected species, specific details to include in interactions reports and current contact details for interaction reports.
This information is monitored by DoF and is considered to be sufficient to quantitatively estimate the outcome status of ETP species with a high degree of certainty. All CAES returns are checked by Departmental staff, and any possibly erroneous entries or gaps are verified directly with skippers or the fishing company.
The information provided in CAES returns is confirmed by processor unloads, which are also provided to the Department on a monthly basis. This data is also validated by commercial monitoring information collected by Departmental research staff on-board commercial vessels throughout the fishing season.
Further information is available for the dedicated blue swimmer crab trap fishery from monthly on-board observer monitoring conducted by the Department. The current monitoring program was established in 2007. As part of this program, Departmental research staff board one commercial fishing vessel operating in the Peel Inlet region and one operating in the Harvey Estuary region each month. During these surveys, research staff collect information on the catch, size, sex and condition of blue swimmer crabs caught in crab traps, as well as information on bycatch, fishing effort and location (using GPS).
Since the 1980s, there have been intermittent fishery-independent research surveys of the blue swimmer crab population in the PHE (Potter et al. 1983; de Lestang 2002; Johnston et al. 2014a). Collectively, the data highlight critical aspects of life-history traits, stock structure and changes in blue swimmer crab population dynamics over time. The sampling conducted since 2007 has also enabled the development of recruitment (sexually-immature males and females) and breeding (sexually-mature females) stock indices for blue swimmer crabs in the estuary.
Some information on bycatch composition in the net fishing sector (haul nets only) is available from a bycatch observer program that took place in March 2015 (see Section 9.3.1).
Options for ongoing bycatch monitoring in this fishing sector are currently being explored.
11.2 Recreational Drop and Scoop Net Fisheries
Qualitative and some quantitative information are available on the amount of retained and bycatch species caught in the blue swimmer crab recreational fishery from periodic fishing surveys undertaken by the Department. Some of the surveys have focused solely on the PHE, while others have been designed to provide broader-scale estimates of recreational fishing catch and effort in the whole bioregion or State.
To date, two dedicated recreational fishing surveys have been undertaken in the PHE in 1998/99 and 2007/08. These surveys included recreational boat- and shore-based fishers, with a focus on those fishers targeting blue swimmer crabs. Each survey spanned a 12-month period and was stratified by season, time of day, weekdays or weekends and area (each area was further stratified by ramp). Catch (number of each retained species), bycatch (number of each discarded species) effort, fishing location, and demographic data were collected from fishers. Field staff also measured a random sample of crabs and fish from each fisher during the interview (Malseed & Sumner 2001; Lai et al. 2014).
More recently, an integrated system involving several survey methods has been used to survey boat-based recreational fishers in WA (Ryan et al. 2013). This system uses three complementary components (off-site phone surveys, on-site boat ramp surveys and a remote camera survey) to collect information on fishing catch, effort, location and other demographic information. Two statewide recreational fishing surveys have been completed to date using this methodology, in 2011/12 (Ryan et al. 2013) and 2013/14 (Ryan et al. in prep.).
These surveys are restricted to boat-based fishers holding a RFBL and were designed to provide estimates of catch and effort for a number of species throughout the state. As such, they are used to provide an estimate of the boat-based blue swimmer crab catch in the PHE.
However, they are not considered to provide reliable estimates of the total recreational blue swimmer crab catch or effort, as shore-based fishers are not included in the sample frame.
These four surveys have provided information on both retained and bycatch species by recreational crab fishers within the PHE, as well as spatial distribution of fishing effort throughout the estuary (1998/99 and 2007/08 surveys only). Ongoing monitoring of the blue swimmer crab recreational fishery in the PHE is conducted as part of the integrated recreational fishing survey system, with boat-based fisher information collected every two years.
Should recreational fishers (or other estuary users) encounter an ETP species within recreational fishing gear, they are asked to contact the DPaW via the Wildcare Helpline11.
11 http://www.dpaw.wa.gov.au/about-us/contact-us/wildcare-helpline
The information provided by fishers is considered to be sufficient to estimate and assess outcome status for all components and support the management measures in place. Sufficient data continue to be collected to detect any increase in risk for each component and to assess ongoing mortalities of all retained species. As the primary impact from recreational blue swimmer crab fishing is the removal of blue swimmer crabs from the estuary, this information is considered to be sufficient to allow the main consequences for the ecosystem from recreational blue swimmer crab fishing activities to be inferred.
MSC Principle 3
MSC Principle 3 relates to the effective management of the fishery under assessment. Within this context, the fishery must demonstrate that it meets all local, national and international laws and must have a management system in place to respond to changing circumstances and maintain sustainability (MSC 2013).