Scientists call for reference points to replace the current gridlock.The viability of the Western Central Pacific tuna fishery is at risk from a failure to reach decisions on management, driven by competing political and economic goals, according to scientists who attended the annual meeting of the Western and Central Pacific Fisheries Commission (WCPFC) held this month in Manila.
Recent analyses by the Secretariat of Pacific Community (SPC) fisheries scientists show that overfishing of bigeye tuna is already a problem, while the albacore tuna catch has risen rapidly to levels that threaten the profitability of Pacific Island fisheries.
Mike Batty, head of SPC Fisheries, says while not all tuna are at risk, stocks of all four main species have fallen to historically low levels. "Many Pacific Island countries rely on tuna fisheries for employment, food security and income. Continuing the increase in fishing effort will have a negative impact on these countries" he says.
The Western and Central Pacific tuna fishery is the world's biggest tuna fishery, with total catches worth $5.5 billion in 2011.
"Management decisions are reached through a consensus-based system which is fraught with competing interests and values," says Batty. "Such a system leads to gridlock and watered-down decisions that favour short-term economic interests at the expense of long-term productivity and sustainability."
To address this problem the WCPFC organised a special two-day management workshop which aimed to identify desirable levels of tuna stocks and drive sustainable management decisions. SPC scientists provided advice on and support to this process.
Batty explains that long-term objectives for the Pacific tuna fisheries needed to be based on economic outcomes such as revenue, employment and stable sources of fish for processing as well as environmental outcomes such as sustainability of fish stocks and reducing the by-catch and interaction with species such as sharks and turtles.
"These objectives will help us to identify desirable levels of tuna stocks and to drive sustainable management decisions," he says.
SPC's Dr Graham Pilling, believes management action needs to be based on a system of reference points. "The implementation of reference points and harvest control rules would allow fisheries managers to act swiftly and efficiently to ensure tuna stocks provide a sustainable and consistent supply of tuna to markets" he says.
SPC OFP wish to thank AUSAID, EU SCICOFISH, the WCPFC, PEW Charitable Trusts and the World Bank for the funding support which allowed this work to be undertaken.
A limit reference point is the minimum stock size that can be allowed, or level of fishing effort that cannot be exceeded without putting the resource in danger. It is the danger signal that should be avoided.
A target reference point is the specific fishery stock size or level of fishing effort that ensures a fishery provides optimum benefits - 'where we want to be'. The points are worked out by investigating biological, ecological, social and economic factors that affect a fishery.
A harvest control rule is the pre-agreed action to be taken by fisheries managers to achieve a target reference point. For example, "if the albacore fishery reaches 40% of its unfished state, then the level of fishing must be reduced by 20%".