Pillar 3

Program evaluation to inform fishery management

This pillar involves various forms of meta-analyses of the datasets to measure performance and assess how performance is related to the local ecosystem, the social circumstances of the fishery, and the tools used in management. The pillar also involves the development of new methods for assessment of biological and social performance of fisheries that would feed back to the activities of the global network in collecting data. Perhaps most importantly, the specific questions addressed in this pillar will inform the data required from Pillars I and II.

Global fishery prospects under contrasting management regimes

What would extensive fishery reform look like? In addition, what would be the benefits and trade-offs of implementing alternative approaches to fisheries management on a worldwide scale? To find out, we assembled the largest-of-its-kind database and coupled it to state-of-the-art bioeconomic models for more than 4,500 fisheries around the world. We find that, in nearly every country of the world, fishery recovery would simultaneously drive increases in food provision, fishery profits, and fish biomass in the sea. Our results suggest that a suite of approaches providing individual or communal access rights to fishery resources can align incentives across profit, food, and conservation so that few trade-offs will have to be made across these objectives in selecting effective policy interventions.

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The Cost of Management Delay: The Importance of Reforming Mexican Fisheries Sooner Rather than Later

Management reform has the potential to rebuild fisheries and increase long-term harvest and profitability, but these benefits can be dissipated by delays in reform implementation. In a case study, we model the costs of delayed reform in terms of annual biomass, harvest, and profit for 28 Mexican fisheries. Our bioeconomic model is parameterized using fishery-specific data. Three types of reforms are examined:

  1. Harvest policy
  2. Elimination of illegal fishing
  3. Implementation of rights-based fisheries management

The harvest policies examined in this analysis are status quo (no reform), FMSY, and economically optimal fishing mortality. We find that prompt management reform leads to improved annual aggregate biomass, harvest, and profit over time. However, delayed reform results in substantial costs. Without reforms stock status can continue to decline, and the recovery of harvests and profits are further delayed. Over a given time-horizon, delayed reforms can dramatically reduce the number of healthy stocks. Our results show that delayed reform can significantly diminish expected benefits from improved management and highlights the importance of timing considerations during policy reform.

Effects of biological, economic and management factors on tuna and billfish stock status

Commercial tunas and billfishes (swordfish, marlins and sailfish) provide considerable catches and income in both developed and developing countries. These stocks vary in status from lightly exploited to rebuilding to severely depleted. Previous studies suggested that this variability could result from differences in life-history characteristics and economic incentives, but differences in exploitation histories and management measures also have a strong effect on current stock status. Although the status (biomass and fishing mortality rate) of major tuna and billfish stocks is well documented, the effect of these diverse factors on current stock status and the effect of management measures in rebuilding stocks have not been analysed at the global level. Here, we show that, particularly for tunas, stocks were more depleted if they had high commercial value, were long-lived species, had small pre-fishing biomass and were subject to intense fishing pressure for a long time. In addition, implementing and enforcing total allowable catches (TACs) had the strongest positive influence on rebuilding overfished tuna and billfish stocks. Other control rules such as minimum size regulations or seasonal closures were also important in reducing fishing pressure, but stocks under TAC implementations showed the fastest increase of biomass. Lessons learned from this study can be applied in managing large industrial fisheries around the world. In particular, tuna regional fisheries management organizations should consider the relative effectiveness of management measures observed in this study for rebuilding depleted large pelagic stocks.

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Science for Nature and People Partnership (SNAPP)

SNAPP delivers evidence-based, scalable solutions to global challenges at the intersection of nature conservation, sustainable development, and human well-being.

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Reconstruction of global ex-vessel prices of fished species

Economic dimensions of global fishery analyses are often limited by unavailable or inconsistent ex-vessel price data from the world’s fishing nations. We describe a novel method for estimating ex-vessel price time series for individual species by converting export prices of fishery commodities into ex-vessel prices and pairing these with species. The method relies exclusively on global, publicly-available data from the Food and Agricultural Organization of the United Nations (FAO). National datasets of ex-vessel prices are not used as inputs for the method, but comparisons of reconstructed ex-vessel prices with actual prices from national datasets showed strong correspondence. Correlation coefficients for paired reconstructed prices and actual prices of the same species were typically between 0.60–0.75 annually in the past two decades. There was a tendency for reconstructed prices to be less variable than actual prices, over-estimating actual prices at low values of actual prices and under-estimating actual prices at high values, likely the result of incomplete price transmission or assigning a given price time series to multiple species. However, there was no evidence of overall bias between reconstructed prices and actual prices, and correlations were strongest for comparisons involving multiple taxonomic groups. The method described carries advantages of global comprehensiveness and consistency across countries in reconstructed ex-vessel prices, reflecting the comprehensiveness and consistency of export price information. The method described links to species from the global FAO landings database, but can be modified to pair with other species lists or to focus on specific regions or countries. Data tables and source code are publicly available and ex-vessel price estimates can be updated annually following annual releases of the FAO fishery commodities database.

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