Evaluating candidate monitoring strategies, assessment procedures and harvest control rules in the spatially complex Queensland Coral Reef Fin-fish Fishery

Abstract

Executive Summary
Fisheries management strategies are composed of three important stages:
1. the measurement or collection of data,
2. analysis or assessment using the collected to data to understand the state of the stock and fishery, and
3. a subsequent decision to affect control on the fishery (often through the manipulation of total allowable catch or effort).
It is important to realise that uncertainty or errors are possible in each of these stages. Observation or sampling error for example, can occur in measuring and collecting data in the first stage. Model estimation or statistical analysis can mis-specify or represent the stock in the second stage, and implementation error, representing the ability to implement a prescribed management action like a TAC, applies to the third. One of the purposes of management strategy evaluation (MSE) is to determine the effect of these uncertainties on the management of a fishery, and to identify a strategy, i.e. a combination of measurement, analysis and decision, that minimises the effects of these errors and ultimately achieves the purpose or objective of management.
Appropriate monitoring and data collection, assessment and decision procedures are needed to ensure sustainability and maximum economic benefit from the coral trout stocks in the Queensland Coral Reef Fin Fish Fishery (CRFFF). This is not an easy accomplishment in a fishery that is as spatially complex as the CRFFF, and so in order to determine whether procedures are worth implementing, it is better to try techniques on a virtual fishery before doing so in reality. This project addressed these issues in the CRFFF by evaluating the effectiveness of:
1. several potential monitoring and sampling regimes of the coral trout stock, including the existing Long Term Monitoring Program (LTMP) surveys,
2. different ways of analysing the data collected from a monitoring program, including evaluating the recently developed stock assessment model used to estimate the coral trout status, and
3. evaluating candidate harvest control rules that translate the perceived state of the fishery into a TAC.
Lastly, since quota trading was introduced to the fishery, industry has stressed the fact that the economic conditions of the fishery have changed substantially, and so an update of economic data was urgently needed to ensure the evaluation of the management strategies was relevant and useful.