Spreading the economic risk: Harvesting strategies of multi-method inshore fisheries during drought in eastern Australia

Droughts are likely to increase in frequency and severity with climate change, modifying the economic viability of inshore fisheries in regions of hydrological extreme. Variation in the revenue and profit associated with different mixtures of fishing methods between non-drought and drought conditions was examined for commercial fishing businesses in three estuarine and coastal systems in eastern Australia from 1997 to 2007. Mean monthly revenue decreased from 8 to 36% between non-drought and drought. Decreased mean monthly revenue was primarily attributed to reduced revenue generation from ocean prawn trawling (≥20%) and estuarine prawn trawling (≥34%) during drought. Fishing method diversity (measured by a modified form of the Shannon index) and mean monthly revenue were positively related; however, mean monthly profit decreased between non-drought and drought under a range of alternative cost scenarios. Reduced mean monthly profit was primarily attributed to losses from ocean prawn trawling (≥15%) and estuarine prawn trawling (≥30%) during drought. Although diversified harvesting behaviour increased revenue generation, initial results indicated that this marginal economic benefit could have been compromised by the greater costs associated with the increased diversification which reduced overall profitability. Results of this analysis indicated that the commercial fishing sector is a drought-affected industry in New South Wales.