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Ecological Risk Assessment – a process for prioritising research and management in diverse and data-limited ecosystems Shane Griffiths, Shijie Zhou, Alistair Hobday and Tony Smith CSIRO Marine and Atmospheric Research SPC workshop 14 June 2010 www.csiro.au Outline What is an Ecological Risk Assessment? Existing risk assessment methods CSIRO ERA Methodology Sustainability Assessment for Fishing Effects (SAFE) Application in Australia’s Northern Prawn Fishery Ecological Risk Assessment What is an Ecological Risk Assessment? “An assessment that can determine the risk of a species’ population, assemblage or habitat becoming unsustainable in the long-term due to the effect of a specific perturbation”. Allows scientists to provide advice to managers about “high risk” species in order to both protect the species & ensure the longevity and profitability of the fishery. Ecological Risk Assessment Australia’s Northern Prawn Fishery 1 million km2 115 boats 9 prawn species 8000-10 000 t yr-1 AU$80 million yr-1 Ecological Risk Assessment Australia’s Northern Prawn Fishery 100’s of non-target species caught Byproduct (e.g. squid, scallops, reef fish) Bycatch (discarded) 30,000 t yr-1 of bycatch discarded, mostly dead. Introduction of TEDs and BRDs in 2000 to reduce bycatch Ecological Risk Assessment Ecological Risk Assessment Ecological Risk Assessment Environment Protection and Conservation Act 1999 in Australia requires export fisheries to demonstrate ecological sustainability Possible for target species – but 100’s of bycatch species? All species equal – monitoring is expensive & impractical Ecosystem models – data intensive & often not species-specific Ecological Risk Assessment – cost-effective & data-limited Ecological Risk Assessment Ecological Risk Assessment Methods Several ecological risk assessment methods developed worldwide Qualitative – Likelihood-Consequence Analysis, Scale Intensity Consequence Analysis (SICA), Fuzzy Logic Expert System Semi-quantitative attribute-based methods (e.g. PSA) Quantitative models – Sustainability Assessment for Fishing Effects (SAFE), and stock assessment models (not often used) Ecological Risk Assessment CSIRO ERA Methodology Scoping Identify objectives Hazard Identification Level 1 Risk Assessment Qualitative assessment Medium or High Risk Low Risk Level 2 Risk Assessment Semi-quantitative assessment Medium or High Risk Level 3 Risk Assessment Quantitative assessment Medium or High Risk Ecological Risk Assessment Low Risk Low Risk Management response to risk Scoping 0 or 1 score given for a range of risk activities If any activity score is 1, the fishery enters Level 1 analysis Direct impact of Fishing Fishing Activity Score (0/1) Documentation of Rationale Capture Bait collection 0 No bait collection occurs Fishing 1 Capture of organisms due to gear deployment, retrieval and actual fishing. Incidental behaviour 0 No specific activity identified Bait collection 0 No bait collection occurs Fishing 1 Organisms may come into contact with TED or net; benthic species may be damaged by net moving over them. Incidental behaviour 1 Possibly hooking of sharks and hooks remaining in the animal Gear loss 1 Uncommon but may occur Anchoring/ mooring 1 Occurs during day light throughout the fishery except the JBG, where fishing usually occurs 24 hrs Navigation/steaming 1 Continuous searching and trawling during the night, often steaming between locations during the day. Direct impact without capture Ecological Risk Assessment Level 1 – Scale Intensity Consequence Analysis (SICA) Target, bycatch, byproduct, TEP, habitat, community analyses If a consequence score >3 move to Level 2 - PSA Incidental behaviour Ecological Risk Assessment 0 1 0 6 2 Population size Arius bilineatus 1.2 3 4 Confidence Score (1-2) Consequence Score (1-6) Intensity Score (16) Operational objective (S2.1) Unit of analysis Fishing Activity Bait collection Fishing Sub-component Direct impact of fishing Capture Updated Presence (1) Absence (0) Spatial scale of Hazard (1-6) Temporal scale of Hazard (1-6) Component - Bycatch/Byproduct spp. Rationale 2 Fishing occurs in 24% of the 770,000 km2 NPF managed area for about 3 months each year => Population size likely to be affected before major changes in other sub-components => this species of catfish is likely to be most affected by fishing as it's been identified as the bycatch species most at risk of depletion as it's slow-moving, easily entangled in net mesh and has low reproductive capacity => intensity moderate as fishing often restricted to areas with suitable habitat => consequence major as large impacts have been documented and fishing likely to cause long-term decline in population size => confidence high as impacts on bycatch well documented Level 2 Productivity - Susceptibility Analysis (PSA) Limited data required, can use “guesstimates” Criteria describe biological, ecological and fishery aspects for every species Each species is given a rank (1-3) for each criteria Low 3 Water column position Diel behaviour Locomotion etc Susceptibility 2.5 2 1.5 High 1 1 Low 1.5 2 Recovery 2.5 3 High Mortality Fecundity Ecological Risk Assessment Breeding strategy etc Productivity - Susceptibility Analysis Advantages Conceptually and mathematically simple Can analyse hundreds of species with limited data Rapid and cheap assessment using existing information Disadvantages Relative ranking – are “highest risk” species really at risk? Thus, cannot demonstrate ecological sustainability of a fishery Ecological Risk Assessment Level 3 – Sustainability Assessment for Fishing Effects (SAFE) New model quantifies risk on each species by estimating: 1) the proportion of the population impacted by the fishery 2) Species sustainability using a simple population model A simple quantitative “filtering” approach to identify any high risk species to monitor Ecological Risk Assessment SAFE Data Requirements 1. Presence/absence data for each impacted species across entire fishery managed area – fished and unfished areas 2. Susceptibility – the relative susceptibility to capture 3. Escapement - proportion of catch escaping (e.g TEDs, BRDs) 4. Post-capture survival – proportion of catch surviving discard 5. Natural mortality Ecological Risk Assessment Fishery Impact Component NF I N F NU Where I = proportion of the species population potentially impacted NF = Number of animals in the “fished area” NU = Number of animals in the “unfished area” But how is abundance estimated for low-value bycatch species? Ecological Risk Assessment A “simple” model Abundance calculated from presence-absence data in a model incorporating gear-specific detection probabilities and species site occupancy probability. m n L( R , F , d R | m, n) d R (1 d R ) mn R ,1 (1 d R ) m R ,1 (1 R ,1) n 0 n n 0 F 1 F 1 m n m n m d (1 d ) (1 d ) (1 ) R R ,0 R R,0 R ,0 R n 0 n n 0 F 0 F 0 N N N A /a a a a mi ni 0 mi ni mi L( N , D | mi , ni , A, a) D (1 D) 1 1 (1 D) 1 1 1 A A A i 1 ni ini 10 ni 0 A1 / a Huh…??? Ecological Risk Assessment Fishery Impact Component F Iq( 1 )S Where F = adjusted proportion of the species population impacted I = proportion of the species population potentially impacted q = the relative susceptibility of a species by a particular gear type Experimental data (Great Barrier Reef) E = proportion escaping after entering the net (e.g. TED & BRD) S = proportion of the landed catch surviving discarding Species-specific data not available for some parameters. Used data from closely related species or “ecomorphotypes” Ecological Risk Assessment Hypothetical Example NPF “Fishery” >5 boat days White tip shark distribution The fishery potentially impacts 115700 of 479800 fish = 24% A “catchability” of 0.3 for a trawl reduces impact to 7.2% TED “escapement” of 50% reduces impact to 3.6% Post-capture survival of 65% results in final impact of 2.3% Ecological Risk Assessment Population model Once fishing mortality calculated, the sustainability of the population is estimated using a modified Graham-Schaefer’s production model Natural mortality used to calculate the maximum sustainable fishing mortality (FMSM) before the population begins to decline If fishing mortality exceeds the (FMSM) reference point, the population is at “high risk” of becoming unsustainable Management action would then be to remove the risk or monitor the species and apply more rigorous populations models to assess status Ecological Risk Assessment NPF Teleost Bycatch Results 1.00 Fishing mortality + 95%CI 0.80 Dendrochirus brachypterus 0.60 Scorpaenopsis venosa 0.40 0.20 0.00 0.00 0.20 0.40 0.60 Maximum sustainable fishing mortality rate Ecological Risk Assessment 0.80 1.00 Conclusions Ecological Risk Assessment can be a rapid and cost-effective way of assessing the risk of anthropogenic activities on marine organisms CSIRO ERA methodology is a simple method that engages all stakeholders to assess risks The process is transparent and may increase acceptance of risks and uptake of management measures by stakeholders New quantitative risk assessment methods (SAFE) can allow fishery managers to more confidently introduce risk mitigation measures Reduces cost to the fishery to only monitor/manage true “at risk” species Ecological Risk Assessment Thank You Contact: Shane Griffiths Phone: 07 3826 7364 Email: Web: [email protected] www.csiro.au www.csiro.au