Retained Bycatch Species Sri Lankan Blue Swimming Crab Fishery Assessment

49 Principle 2: Ecological Impacts of the Fishery

2.1 Retained Bycatch Species

203 2.1.1 Status: The number of species and the quantity of the retained bycatch from the SLBSC fishery appears to be moderate to low, compared to other methods of harvesting BSC i.e., bottom trawling and trammel nets. Common benthic finfish and several ollus s species are retained by fishermen. Most of the retained finfish species are juveniles. Performance Indicators SG 60 SG 80 SG 100 Main retained species are likely to be within biologically based limits or if outside the limits there are measures in place that are expected to ensure that the fishery does not hinder recovery and rebuilding of the depleted species. Main retained species are highly likely to be within biologically based limits, or if outside the limits there is a partial strategy of demonstrably effective management measures in place such that the fishery does not hinder recovery and rebuilding. There is a high degree of certainty that retained species are within biologically based limits. If the status is poorly known there are measures or practices in place that are expected to result in the fishery not causing the retained species to be outside biologically based limits or hindering recovery. Target Reference Points are defined and retained species are at or fluctuating around their Target Reference Points. SLBSC Fishery Score = SG 60 FAIL Rationale: There is insufficient information available to assess whether there are any main retained species in the SLBSC fishery. To qualify as a main retained species, the species must comprise 5 of more of the commercial catch. The fishery assessment conducted by SEASL in 2013 is the only report that identifies species retained by SLBSC fishermen. This report identified around 15 finfish species and four species of molluscs that are retained by fishermen from the SLBSC fishery. The assessment does not contain sufficient information to estimate the percentage contribution of retained species to the overall landings of SLBSC in the fishery. Target  Identification and quantification of all species retained by fishermen from the SLBSC fishery  Identification of main any retained species i.e., 5 of the total catch Data Sources  Ecological Impact Assessment UNI Other 204 2.1.2 Management Strategy: The status of the retained bycatch from the SLBSC is unknown. No strategy is currently in place to manage either the variety or quantity of the retained bycatch from the SLBSC bottom-set gill net fishery. Performance Indicators SG 60 SG 80 SG 100 There are measures in place, if necessary, that are expected to maintain the main retained species at levels which are highly likely to be within biologically based limits, or to ensure the fishery does not hinder their recovery and rebuilding. There is a partial strategy in place, if necessary that is expected to maintain the main retained species at levels which are highly likely to be within biologically based limits or to ensure the fishery does not hinder their recovery and rebuilding. There is a strategy in place for managing retained species. There is some objective basis for confidence that the partial strategy will work, based on some information directly about the fishery andor species involved. The strategy is mainly based on information directly about the fishery andor species involved, and testing supports high confidence that the strategy will work. The measures are considered likely to work, based on plausible argument e.g., general experience, theory or comparison with similar fisheriesspecies. There is some evidence that the partial strategy is being implemented successfully. There is clear evidence that the strategy is being implemented successfully, and intended changes are occurring. There is some evidence that the strategy is achieving its overall objective. SLBSC Fishery Score = SG 60 FAIL Rationale: Insufficient information is available to assess whether this criterion needs to be applied to the SLBSC fishery i.e., whether there are any main retained species associated with the fishery see above and below. There are currently no measures in place regarding bycatch of any kind i.e., retained, discarded or ETP. 50 Target  Appropriate measures introduced and operational, for each main retained species if any identified Data Sources  SLBSC Fishery Management Plan DFAR 205 2.1.3 Information Monitoring: The status of the retained bycatch from the SLBSC fishery is unknown. An indication of the bycatch likely to be retained from the SLBSC bottom-set gill net fishery was gathered during the field assessment. No monitoring systems are currently in place. Performance Indicators SG 60 SG 80 SG 100 Qualitative information is available on the amount of main retained species taken by the fishery. Qualitative information and some quantitative information are available on the amount of main retained species taken by the fishery. Accurate and verifiable information is available on the catch of all retained species and the consequences for the status of affected populations. Information is adequate to qualitatively assess outcome status with respect to biologically based limits. Information is sufficient to estimate outcome status with respect to biologically based limits. Information is sufficient to quantitatively estimate outcome status with a high degree of certainty. Information is adequate to support a partial strategy to manage main retained species. Information is adequate to support a comprehensive strategy to manage retained species, and evaluate with a high degree of certainty whether the strategy is achieving its objective. Information is adequate to support measures to manage main retained species. Sufficient data continue to be collected to detect any increase in risk level e.g. due to changes in the outcome indicator scores or the operation of the fishery or the effectiveness of the strategy. Monitoring of retained species is conducted in sufficient detail to assess ongoing mortalities to all retained species SLBSC Fishery Score = SG 60 FAIL Rationale: Insufficient qualitative information is available on the amount of main retained species taken by the fishery. Information is inadequate to qualitatively assess the outcome status with respect to biologically based limit or support measures to manage main retained species. No bycatch monitoring system is in place Target  Identification and quantification of all species retained by fishermen from the SLBSC fishery, including any main retained species i.e., 5 of the total catch Data Sources  Ecological Impact Assessment UNI Other  Ecological Impact Monitoring

2.2 Discarded Bycatch Species