A risk-management framework for avoiding significant adverse impacts of bottom fishing gear on Vulnerable Marine Ecosystems

摘要

CCAMLR adopted a new conservation measure in 2007 to ensure that significant adverse impacts of bottom fishing gear on Vulnerable Marine Ecosystems (VMEs) are avoided. Due to the high levels of uncertainty surrounding both the evidence of VME presence and the consequences of interaction with different types of gear, a risk-management framework is proposed, similar to that which has been used successfully to minimise the effects of longline fishing mortality on seabirds. Risk is broadly defined as the conditional probability of adverse impacts given particular bottom fishing activities multiplied by the consequences of those impacts. The aim of the risk-management framework is to avoid significant adverse impacts on VMEs from bottom fishing activities. The framework consists of four steps: (i) Risk analysis of current and proposed fishing activities; evidence of potential VMEs; scale of interactions between fishing activities and VMEs; impact of interactions on VMEs; and recovery potential of VMEs. (ii) Risk evaluation. Information on likelihood and consequences of interactions of bottom fishing gear with VMEs and associated uncertainties from risk analysis is combined to produce risk metrics. (iii) Risk elimination or mitigation. The spatial scale at which this framework operates should be related to the scale of VMEs, presently unknown. However, management at the level of fine-scale rectangles (0.5° latitude by 1.0° longitude) or smaller can be used in the first instance. Temporal scales must be matched to the recovery scale of VMEs, which are probably in the order of many decades or even centuries. Unacceptable levels of risk from bottom fishing activities to VMEs must be eliminated or reduced to acceptable levels through the use of management measures including, inter alia, closed areas around identified VMEs, open and closed management areas, by-catch limits for VME-forming organisms, gear modification or spatial distribution of fishing effort. (iv) Review. All of the above steps should be reviewed annually to ensure that all relevant or new information has been included, appropriate scientific research and data collection plans are in place and that risk mitigation measures are successful in their implementation.