action/assessments Cons: is not an estimate of stock status species are a lower priority for management action relative to species with higher vulnerability estimates (>2.0 PSA score) priority for management action and frequent assessment Underwater Visual Surveys FISHED: UNFISHED DENSITY RATIO (FOR KEY TARGET SPECIES) Pros: a relative quick and cheap way to assess the status of target species. Cons: assumes that a fully-functioning and well-enforced NTZ has been sited appropriately with representative habitat, not useful for highly mobile targets. Fished:unfished density of target species > 0.6 Fished:unfished density of target species < 0.4 Density Ratio Fish and invertebrates that are habitat associated, not a good indicator for highly mobile targets FISHED: UNFISHED BIOMASS RATIO (CORAL REEF THRESHOLD AGGREGATED ACROSS SPECIES) Pros: provides an estimate of ecosystem status and capacity to support fishing, useful for setting precautionary management to meet EBFM goals. Cons: assumes that a fully-functioning and well-enforced NTZ has been sited appropriately with representative habitat, not useful for highly mobile targets. Assumes NTZ are representative of historical, unfished biomass. Fished:unfished biomass ratio > 0.5 Fished:unfished biomass ratio < 0.25 Coral Reef Thresholds Multi-species finfish fishery
AVERAGE LENGTH Pros: easy, cheap metric to assess changes in the status of a fishery Cons: does not capture selectivity of the fishery, or is fishing is prosecuted in nursery grounds Decrease in the size of unfished individuals outside of the NTZ, in comparison to previous years Rapid decrease in the size of individuals outside of the NTZ, in comparison to previous years Average Length Multi-species, habitat associated targets, not a good indicator for highly mobile targets Fishery Dependent Survey FISHING MORTALITY (F) Pros: mortality rates are critical for determining abundance of fish populations Cons: all of the models assume equilibrium conditions. Most of these methods only reflect fish that have recruited to a fishery and does not reflect the full age structure of a stock. F/M <1 (F is fishing mortality, M is natural mortality) F=2M Catch Curve Finfish (groupers, snapper, grunts, etc.), and invertebrates with determinant growth (lobsters, crabs). Use with care for targets that have deterministic growth and episodic recruitment. Mean Length (Lbar) Bounded Mean Length Mortality Estimator Mean Weight Mortality Estimator SPAWNING POTENTIAL RATIO (SPR) Pros: can be used with fishery independent and dependent data. Cons: Assumes equilibrium conditions and a index based on the early life history of a fish, it must be remembered that many things can happen to the fish before they are large enough to harvest. slow growing species, M/k< 1 (grouper) SPR > 40% (M is natural mortality, k is von Bertalanffy growth rate) fast growing species, M/k >1 (lobster) SPR =20% slow growing species, M/k< 1 (grouper) SPR <40% fast growing species, M/k >1 (lobster) SPR <20% Length-based SPR (LBSPR) Finfish (groupers, snapper, grunts, etc.), and invertebrates with determinant growth (lobsters, crabs). Use with care for targets that have deterministic growth and episodic recruitment. Composition
AVERAGE LENGTH Pros: easy, cheap metric to assess changes in the status of a fishery when stratified across sampling unit (gear, efforts, fishing zone) Cons: With little to no historical information on the length of the catch or with no information on gear selectivity, the average length could biases the expected potential size distribution. Increase in average length Decrease in average length or mature adults Average Length All targets, especially nearshore targets. In an ideal scenario an historic record of average length would be used to compare current to past estimates. FROESE INDICATORS Pros: proved estimate of the status of the stock, in comparison to sustainability reference points Cons: does not contribute to biomass sustainability reference points 100% of catch – optimal < 10% of the catch are megaspawners 90% of the catch are mature adults <80% of catch – optimal < 20% of the catch are megaspawners 50% of the catch are mature adults Froese Sustainability Indicators All fish and invertebrate target with known relationships Catch Reporting System & Boat Site Survey CPUE Pros: can be used to infer population trends of an exploited stock. Standardized time series of CPUE are often regarded as indices of abundance. Cons: seldom proportional to abundance history and an entire geographic range. Can be skewed, depending on sampling regime. May have species-specific biases. Stable CPUE Rapidly Decreasing CPUE, previous year or in comparison to running average Catch Trends All targets that do not have high selectivity of habitat stratification.
Unfished area has a low density and does not represent a healthy virgin area (NTZ is small with large amounts of species movement between fished and unfished areas)  Consider expansion or relocation of NTZ and Consider precautionary management by making fisheries management controls more restrictive (i.e., decrease TAC, decrease allowable effort, add or modify certain controls, etc.) Limit >= Indicator High fishing pressure has caused an ecosystem state change; fishery in danger of collapse  Close fishery and Implement fishery recovery plan Extreme environmental stochasticity has caused an ecosystem state change; fishery in danger of collapse  Close fishery and Implement fishery recovery plan Coral Reef Thresholds (aggregated across species) Unfished biomass Indicator >= Target And fished:unfished biomass ratio >= Target Fishing pressure appropriate for maintaining or improving the health of the ecosystem  Make no changes to fisheries management controls or If trends have persisted for more than one year and there is no reason to believe precautionary management is necessary, make fisheries management controls less restrictive (i.e., increase TAC, increase effort cap, etc.) Unfished area has a low biomass and does not represent a healthy virgin area (significant illegal fishing is occurring within the NTZ)  Consider improved enforcement of NTZ and Consider targeted social marketing to improve compliance with NTZ and Consider precautionary management
by making fisheries management controls more restrictive (i.e., decrease TAC, decrease allowable effort, add or modify certain controls, etc.) Unfished area has a low biomass and does not represent a healthy virgin area (NTZ is new and has not yet led to substantial improvements in ecosystem health)  Consider precautionary management by making fisheries management controls more restrictive (i.e., decrease TAC, decrease allowable effort, add or modify certain controls, etc.) Unfished area has a low biomass and does not represent a healthy virgin area (NTZ is small with large amounts of species movement between fished and unfished areas)  Consider expansion or relocation of NTZ and Consider precautionary management by making fisheries management controls more restrictive (i.e., decrease TAC, decrease allowable effort, add or modify certain controls, etc.) Unfished area does not have comparable habitat to fished area (unfished area habitat not as healthy as fished area)  Consider expansion or relocation of NTZ and Consider precautionary management by making fisheries management controls more restrictive (i.e., decrease TAC, decrease allowable effort, add or modify certain controls, etc.)
Limit <= Unfished biomass Indicator <= Target And Limit <= fished:unfished biomass ratio <= Target High fishing pressure putting ecosystem at risk for impending state change  Make fisheries management controls more restrictive (i.e., decrease TAC, decrease effort cap, add or modify certain controls, expand NTZ, etc.) Environmental stochasticity putting ecosystem at risk for impending state change  Consider precautionary management by making fisheries management controls more restrictive (i.e., decrease TAC, decrease allowable effort, add or modify certain controls, etc.) Unfished area has a low density and does not represent a healthy virgin area (significant illegal fishing is occurring within the NTZ)  Consider improved enforcement of NTZ and Consider targeted social marketing to improve compliance with NTZ and Consider precautionary management by making fisheries management controls more restrictive (i.e., decrease TAC, decrease allowable effort, add or modify certain controls, etc.) Unfished area has a low density and does not represent a healthy virgin area (NTZ is new and has not yet led to substantial improvements in ecosystem health)  Consider precautionary management by making fisheries management controls more restrictive (i.e., decrease TAC, decrease allowable effort, add or modify certain controls, etc.)
Consider implementing a minimum size limit (if one does not already exist) Strong recruitment pulse (more small individuals entering the catch)  Make no changes to fisheries management controls or If trends have persisted for more than one year and there is no reason to believe precautionary management is necessary, make fisheries management controls less restrictive (i.e., increase TAC, increase allowable effort, remove or modify certain controls, etc.) Market selectivity for smaller individuals  Consider implementing a minimum size limit (if one does not already exist) Emigration of large individuals from fishing area  Make no changes to fisheries management controls Environmental stochasticity affecting size structure and spawning stock biomass  Consider precautionary management by making fisheries management controls more restrictive (i.e., decrease TAC, decrease allowable effort, add or modify certain controls, etc.) Target >= Indicator Fishing pressure appropriate for maintaining or improving size structure of population  Make no changes to fisheries management controls or If trends have persisted for more than one year and there is no reason to
Immigration of large individuals to fishing area  Make no changes to fisheries management controls Spawning Potential Ratio Indicator <= Limit High fishing pressure affecting size structure and spawning stock biomass; fishery in danger of collapse  Close fishery and Implement fishery recovery plan Extreme environmental stochasticity affecting size structure and spawning stock biomass; fishery in danger of collapse  Close fishery and Implement fishery recovery plan Limit > Indicator < Target High fishing pressure affecting size structure and spawning stock biomass  Make fisheries management controls more restrictive (i.e., decrease TAC, decrease effort cap, add or modify certain controls, expand NTZ, etc.) Fishers targeting nursery grounds  Make fisheries management controls more restrictive (i.e., decrease TAC, decrease effort cap, add or modify certain controls, expand NTZ, etc.) Gear shift towards less selective gear (more small individuals in catch)  Consider implementing a gear restriction on less selective gear and/or Consider implementing a minimum size limit (if one does not already exist) Strong recruitment pulse (more small individuals entering the catch)  Make no changes to fisheries management controls or If trends have persisted for more than one year and there is no reason to believe precautionary management is
Target > Lopt > Limit And/or Target > Lmat > Limit Market selectivity for smaller individuals  Consider implementing a minimum size limit (if one does not already exist) or Consider precautionary management by making fisheries management controls more restrictive (i.e., decrease TAC, decrease allowable effort, add or modify certain controls, etc.) High fishing pressure affecting size structure and spawning stock biomass  Make fisheries management controls more restrictive (i.e., decrease TAC, decrease effort cap, add or modify certain controls, expand NTZ, etc.) Fishers targeting nursery grounds  Make fisheries management controls more restrictive (i.e., decrease TAC, decrease effort cap, add or modify certain controls, expand NTZ, etc.) Strong recruitment pulse (more small individuals entering the catch)  Make no changes to fisheries management controls or If trends have persisted for more than one year and there is no reason to believe precautionary management is necessary, make fisheries management controls less restrictive (i.e., increase TAC, increase allowable effort, remove or modify certain controls, etc.)
Emigration of large individuals from fishing area  Make no changes to fisheries management controls Environmental stochasticity affecting size structure and spawning stock biomass  Consider precautionary management by making fisheries management controls more restrictive (i.e., increase TAC, increase allowable effort, add or modify certain controls, etc.) Limit > Lmega > Target Market selectivity for larger individuals  Consider implementing a maximum size limit (if one does not already exist) or Consider precautionary management by making fisheries management controls more restrictive (i.e., decrease TAC, decrease allowable effort, add or modify certain controls, etc.) High fishing pressure affecting size structure and spawning stock biomass  Make fisheries management controls more restrictive (i.e., decrease TAC, decrease effort cap, add or modify certain controls, expand NTZ, etc.) Weak recruitment pulse (fewer small individuals entering the catch)  Consider precautionary management by making fisheries management controls more restrictive (i.e., decrease TAC, decrease allowable effort, add or modify certain controls, etc.)
2 ✓ X ✓ Increased pressure or new gear Sampling bias that increases F Large recruitment pulse Response required; recommended action sequence: Confirm/monitor F values with multiple models/approaches No change (if F trends are stable/near limit) Reduce fishing mortality to reduce risk of overfishing 3 X ✓ ✓ Fishing rate sustainable and stock productivity healthy, but stock density at unhealthy levels/ approaching threshold Stock density could be low due to non-fishing factors or historical fishing impacts Error in calculations? Response required; recommended action sequence: Monitor MPA DR, F and SPR trends and recruitment, gear and behavior patterns Make no change if MPA DR stable or increasing and F and SPR trends stable/just above limits, Reduce fishing mortality if MPA DR decreasing, F trend increasing, SPR trend decreasing 4 X X ✓ Potential early warning of growth and recruitment overfishing Stock potentially nearing threshold Large recruitment pulse Response required; recommended action sequence: Confirm/monitor SPR values with multiple models/approaches No change (if SPR trends are stable/near limit) Reduce fishing mortality
5 ✓ ✓ X Abundance levels are healthy, overfishing is not occurring, yet SPR is low F or SPR estimate(s) in error? Response required; recommended action sequence: Confirm/monitor SPR with multiple models/approaches If SPR continues to be low, consider additional regulatory options to reduce fishing pressure 6 X ✓ X Overfishing resulting in reduced abundance and egg production, or Error in calculations Response required; recommended action sequence: Confirm/monitor SPR with multiple models/approaches Reduce fishing mortality If trend persists consider additional regulatory options to reduce fishing pressure 7 ✓ X X Overfishing Increased targeting, resulting in high fishing mortality that has not yet manifested as a detectable change in abundance, or Error in calculations Response required; recommended action sequence: Confirm/monitor SPR with multiple models/approaches Reduce fishing mortality If trend persists consider additional regulatory options to reduce fishing pressure