Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Setting target reference points for secondary species in the SESSF Simon Vieira, Mary Hormis, Andrew Penney & James Woodhams January 2013 Research by the Australian Bureau of Agricultural and Resource Economics and Sciences Background • There is general acceptance that applying individual MEY targets to all stocks in the SESSF is not consistent with fisherywide MEY . • In 2012 RAGs identified secondary species and provided catch recommendations for these species under both MSY and MEY. • This was done without any formal criteria or research based justification. • AFMA requested ABARES to fill this gap in December 2012. Department of Agriculture, Fisheries and Forestry Setting target reference points for secondary species in the SESSF Simon Vieira 31 January 2013 2 Objectives • Define the key issues related to targeting MEY across a multispecies fishery . • Outline the key questions for management. • Provide formal principles and criteria for identifying non-target species. • Outline the key factors that will influence target reference points for secondary species. • Discuss the implications of pursuing lower target reference points such as BMSY for secondary species. Department of Agriculture, Fisheries and Forestry Setting target reference points for secondary species in the SESSF Simon Vieira 31 January 2013 3 What does the Harvest Strategy Policy say? Fishery wide MEY MEY applies to the fishery as a whole and is optimised across all species in the fishery. Trade offs Given the different biology and economic characteristics of different species, there are likely to be trade-offs between the profits of different species. To maximise the overall profits of a fishery, it may be necessary to forego some profits of one species in order to generate higher profits from another. Limits Some secondary species (e.g. lower value species) may be fished at levels that will result in their biomass remaining below their target biomass reference point (BMEY). The biomass of these secondary species must be maintained above BLIM. By optimising MEY across the fishery, some individual stocks may be below B MSY. The estimated biomass of all species must be maintained above their limit reference point, BLIM. Considerations - Demonstrating that economic modelling and other advice clearly supports such action - No cost-effective, alternative management options are available. - The associated ecosystem risks have been considered in full. Department of Agriculture, Fisheries and Forestry Setting target reference points for secondary species in the SESSF Simon Vieira 31 January 2013 4 Theoretical justification: MEY BMEY MEY revenue Fishing Effort Revenue Yield (Catch) / $ $ BMSY MSY MSY Theoretical justification: two stock MEY Yield / $ Stock 1 Revenue Stock 2 Revenue Fishing Effort S1 BMEY S2 BMEY Theoretical justification: key points • The individual MEY effort level for the more profitable Stock 1 is higher than that for Stock 2. • Operating at Stock 1’s individual MEY biomass (BMEY) will require that Stock 2’s biomass be below its individual BMEY (and BMSY here). • Stock 2’s TAC will constrain the catch of Stock 1’s TAC: - some significant level of profit will be foregone. Department of Agriculture, Fisheries and Forestry Setting target reference points for secondary species in the SESSF Simon Vieira 31 January 2013 7 Theoretical justification: key points • Discarding of Stock 2 means that can operate at Stock 1’s BMEY but this will result in a fish down of Stock 2. • Fishery-wide MEY will be a compromise between the two (refer to paper). Department of Agriculture, Fisheries and Forestry Setting target reference points for secondary species in the SESSF Simon Vieira 31 January 2013 8 Key questions for management Given the complexity of actually doing multi-species bioeconomic modelling, a second best solution is preferred. To improve the situation, we need to address two questions: • What species can be defined as a secondary species? • What is an appropriate MEY-based target reference point for a secondary species? Department of Agriculture, Fisheries and Forestry Setting target reference points for secondary species in the SESSF Simon Vieira 31 January 2013 9 Identifying secondary stocks Secondary stock defined as: • A non-targeted stock whose catch exhibits a relatively low economic return relative to the return of targeted species it is caught with; • Will typically make up a relatively low proportion of GVP and will not be a driver of fishery profit. Classification should be based on relative contribution to GVP and the degree to which it is targeted: • Consistent with CSIRO and RAG classification approach; • However, no threshold based criteria were used. Department of Agriculture, Fisheries and Forestry Setting target reference points for secondary species in the SESSF Simon Vieira 31 January 2013 10 Commonwealth Trawl Sector secondary stocks Quota species Smooth Oreo Ribaldo Ocean perch John dory Jackass morwong Redfish Oreo, Basket Silver trevally Mirror dory Pink ling Department of Agriculture, Fisheries and Forestry Price ($/kg) $4.25 $2.16 $3.21 $6.70 $2.58 $3.47 $3.28 $3.89 $2.22 $5.49 Sum of Value ($'000) Percentage of CTS scalefish value Percentage of catch targeted 0% 0% 1% 1% 2% 1% 1% 1% 2% 8% 1% 14% 16% 26% 27% 36% 41% 45% 46% 48% $7 $112 $657 $597 $1,041 $298 $350 $701 $1,217 $4,126 Setting target reference points for secondary species in the SESSF Simon Vieira 31 January 2013 11 Commonwealth Trawl Sector secondary stocks Department of Agriculture, Fisheries and Forestry Setting target reference points for secondary species in the SESSF Simon Vieira 31 January 2013 12 Gillnet, Hook & Trap Sector secondary stocks Quota species Price ($/kg) Sum of Value ($'000) Percentage Percentage of GHTS of catch shark value targeted Gummy shark $6.37 $12,233 89% 98% School shark $4.65 $988 7% 41% Sawshark $2.20 $254 2% 1% Elephantfish $0.97 $75 1% 1% Department of Agriculture, Fisheries and Forestry Setting target reference points for secondary species in the SESSF Simon Vieira 31 January 2013 13 Identifying secondary stocks: additional considerations Sustainability • Unconstrained fishery-wide MEY may put the sustainability of a secondary stock at risk, depending on its biological characteristics. • It remains a requirement under the HSP to maintain all stocks within acceptable and sustainable biomass ranges, and particularly above BLIM reference points. • None of the identified secondary species are classified as overfished or subject to overfishing, but some are uncertain. Department of Agriculture, Fisheries and Forestry Setting target reference points for secondary species in the SESSF Simon Vieira 31 January 2013 14 Identifying secondary stocks: additional considerations Quota latency In the example, the secondary species TAC would likely be filled before all the TAC of the primary stock is taken. A high amount of latent quota for a stock suggests that the benefits of managing that stock as secondary are likely to be low. Can result in there being low economic returns to fully catching the secondary species TACs, influenced by: • Transaction costs of acquiring quota; • The profitability of the secondary and primary stock; • The additional primary stock catch expected with catching a unit of secondary stock. Department of Agriculture, Fisheries and Forestry Setting target reference points for secondary species in the SESSF Simon Vieira 31 January 2013 15 MSY targets for secondary species: risks and benefits Applying BMSY targets instead of BMEY will result in: • Higher TACs for secondary stocks. • Lower biomass of secondary stocks; There are three main sources of potential benefit: • Increased secondary species revenue; • Increased target species revenue; • Decreased costs for a given total multi-species catch. Department of Agriculture, Fisheries and Forestry Setting target reference points for secondary species in the SESSF Simon Vieira 31 January 2013 16 Increased secondary species revenue Secondary Species MSY rec. MEY rec. Difference 2011-12 catch catch in catch financial (tonnes) (tonnes) (tonnes) year ($/kg, prelim.) Redfish * (T3) Difference in GVP terms ($,000) TAC (2011-12 season, tonnes) Quota latency (2011-12 season) 3,843 2,932 911 $3.47 $3,161 276 66% John Dory ** (T3) 762 614 148 $6.70 $992 221 60% Ribaldo (T4) 321 232 89 $2.16 $192 168 32% Ocean Perch (T4) 457 330 (Inshore, Offshore) (174, 283) (126, 204) 127 $3.21 $408 300 24% Saw shark*** (T4) 324 234 90 $2.20 $198 226 18% Elephantfish **** (T4) 258 186 72 $0.97 $70 89 15% Department of Agriculture, Fisheries and Forestry Setting target reference points for secondary species in the SESSF Simon Vieira 31 January 2013 17 Increased target species revenue Secondary species Secondary species quota latency (2011-12 season) Major companion species as identified in Klaer (2011) Companion target species quota latency (2011-12 season) Percentage of secondary species catch taken with major companion (Klaer 2011) Redfish (trawl) John dory (trawl) Ribaldo (trawl) 66% 60% 32% Ocean perch (trawl) 24% Silver trevally (trawl) 69% 0% 0% 66% 13% 0% 98% 0% 28% 13% 0% 39% 31% 46% 21% 20% 12% 12% 29% 20% 15% 23% 10% Sawshark (Gillnet) Elephantfish (Gillnet) 18% 15% Flathead Flathead Deepwater shark Blue grenadier Pink ling Other oreos Pink ling Mirror dory Blue Grenadier Flathead Deepwater flathead Gummy shark Gummy shark 18% 18% 96% 98% Department of Agriculture, Fisheries and Forestry Setting target reference points for secondary species in the SESSF Simon Vieira 31 January 2013 18 Decreased costs for a given catch • Unconstrained, fishers are most likely to direct their effort towards areas where they expect to achieve the most profitable catch. • In a multi-species fishery, the decision on where to operate will be different if a fisher is constrained by their limited holding and access to quota for a given secondary species. • The fisher’s objective will then be to operate in an area where it is expected that the target species can be caught most profitably with the least likelihood of catching the constraining secondary species. Department of Agriculture, Fisheries and Forestry Setting target reference points for secondary species in the SESSF Simon Vieira 31 January 2013 19 Minimum Safe Levels for secondary species Must maintain stocks above BLIM but how close can we go? ‘Precautionary approach’ limit reference points: • Proposed by ICES (1997) and taken up in the FAO Stock Assessment Manual (Cadima 2003); • Deals with stock assessment uncertainty and the requirement for a precautionary approach to ensure biological productivity not jeopardised. Recommended Bpa would be 29% - 33% B0, about half way between the current default proxies for BMSY and BLIM. Department of Agriculture, Fisheries and Forestry Setting target reference points for secondary species in the SESSF Simon Vieira 31 January 2013 20 Conclusions • The potential increase in returns are low from secondary species revenue increases. • Difficult to quantify returns from increased catches of target species, but likely to be the major source of benefit. • Difficult to quantify returns from a reduction in unit costs of fishing due to changed behaviour. Option to discard dampens the relevant incentives. • How low can you go? – an important question that will need to be addressed eventually. • The proposed suite of alternative targets should be MSE tested to ensure risk of B < BLIM is <10% for all species. Department of Agriculture, Fisheries and Forestry Setting target reference points for secondary species in the SESSF Simon Vieira 31 January 2013 21