Assessing the relative effects of fishing on the New Zealand marine environment through risk analysis

Risk analysis is a tool often used by management to aid decision-making. We present a risk-analysis framework that was developed to facilitate managing New Zealand fisheries. Using catch-effort and observer data, the likelihood that a certain fishery will impact upon five effects of fishing (EoF) issues (non-target species, biodiversity, habitat, trophic interactions, and legislated protected species) is determined. The consequences (impact and/or change) of such events are then determined to determine a relative risk ranking across fisheries. Consequence matrices were developed to assess each of the five EoF categories. To illustrate the model, a 13-y dataset of New Zealand fisheries catch-effort and observer data was analysed, using orange roughy (Hoplostethus atlanticus) as an example fishery. The New Zealand fisheries management framework follows a traditional model in which socio-political imperatives are determined (through risk assessment) after ecological impacts are assessed. By maintaining separation between ecological and socio-political imperatives, a transparent and objective framework is established.