Vanessa Adams, Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University

Much of the recent debate in designing and implementing marine protected areas (MPAs) has shifted recently to understanding the ‘costs’ associated with them. 

In marine systems, opportunity costs to fishers, the costs associated with foregone catch due to placement of a protected area, are highly relevant when designing MPAs. However, the bulk of the research done to date has been for developed countries and there is still little work designated to costs to subsistence fishers as much of their catch does not go to market for sale. 

For subsistence fishers in Fiji, current catch per unit effort (CPUE) surveys don’t necessarily capture the true costs to the fishers.  Two major issues keep CPUE methods from accurately reflecting opportunity costs in this context.  First, in Fiji and many other countries, protected areas are often community selected and supported and may be opened or re-configured frequently.  Thus, if costs to fishers are only considered based on typical catch per unit effort (CPUE) surveys, the MPA design will not consider areas that are currently closed.  Second, transport to fishing areas is often restricted to self-locomotion such as walking, swimming or paddling.  Therefore, CPUE maps will not capture future usage as access to motor boats increases and fishing effort shifts to offshore areas. 

In order to develop a more comprehensive model of opportunity costs to subsistence fishers, we developed a method of calculating opportunity costs based on modelled fish abundance of key food species and stratified fishers by gear type.  The model was developed for the Kubulau district on Vanua Levu, Fiji, based on ecological surveys and social surveys of all the villages.  Market value of expected catch was modelled based on biomass, abundance and gear type.  This allows us to investigate not only current fishing effort, which is correlated with the high abundance areas in our model, but to also look at projected use.  As shown for Kubulau, current usage is predominantly inshore due to the high percentage (nearly 80%) of fishers who use self-locomotion such as walking, swimming or paddling.  This means that only the select few with motor boats can fish further off shore, as shown in the CPUE map.  However, as more fisherman gain access to motor boats, fishing density will likely shift further offshore.  Although the market value of all fish species modelled is shown here, costs to different stakeholder groups can be calculated based on key species for each gear type, in this case: gillnet, trolling, spear gun, Hawaiian sling, and hand spear. 

In addition to market value, replacement costs of catch may play an important role in ensuring that additional MPAs won’t negatively affect the fishers’ access to adequate food supplies.  In Kubulau, fishers reported that they eat between 60% - 70%.  The next phase of the research will look at replacement costs of catch by estimating how much it would cost for the fishers to buy similar protein sources such as tinned fish and meat.  A comparison of the spatial distributions of replacement cost and market value will reveal whether replacement cost differs spatially from market value.  While the models developed here have been for direct consultation with the villages in Kubulau, the methods can be applied to any region or group of stakeholders.  Our method of calculating market value of catch gives an unbiased estimate of opportunity costs to multiple stakeholders in a marine environment that can be applied to any region using existing species data and some community consultation.  This is in comparison to the CPUE survey methods that only reports current usage and relies on fishers’ full disclosure of catch and fishing areas. 

Contact:  vanessa.adams@jcu.edu.au. 

Work undertaken in conjunction with the Wildlife Conservation Society (WCS) South Pacific Program, Suva, Fiji Islands.

Total catch per unit effort (fish person-1 hour-1 km2 -1) for the 125 ‘fishing vessels’ surveyed in Kubulau.

Estimated market value (FJD/2,500 m2) of catch for all gear types used in Kubulau including: gill-net, trolling, spear gun, Hawaiian sling and hand spear.