Unassessed Fisheries


Until very recently, researchers and managers have only known the condition of a small fraction of the world’s fisheries--the large valuable fisheries for which we have ample data. These well-studied fisheries represent only a few hundred of the world’s 10,000+ fisheries, meaning our view of the overall health of global fisheries is skewed. Though we lack sufficient information on their condition, more than 70% of the world’s total catch comes from unassessed fisheries. In order to make more informed decisions on how to sustainably manage them, SFG researchers have developed an innovative method for assessing the health of the world's data-limited stocks.

The findings of our research indicate that biomass levels in the majority of unassessed fisheries are low, and this confirms our hypothesis that unassessed fisheries are in poor condition. When we began our analysis in 2012, about 18% of unassessed stocks were collapsed, and it was clear that the proportion of collapsed stocks would only increase if fishing levels were to stay the same. This forecast would have serious implications for the developing world’s coastal communities, where small-scale fisheries play a significant role in providing economic and food security benefits. But ailing unassessed fisheries are not only a developing world problem; many small-scale fisheries in developed nations, including the United States, are in a similar condition.

Another interesting finding of our research is that assessed stocks show signs of ongoing recovery and stabilization at sustainable levels, a trend that is consistent regardless of the country that manages them. And while management institutions play a key role in determining the condition of fisheries, the biological characteristics of the target species can also render a fishery vulnerable to overfishing. For example, we found that many struggling fisheries target species with a specific set of life history traits, such as slow growth, late maturation, and large body sizes.

While our research findings raise concerns about the status of global fish stocks, we have identified excellent opportunities for improving fishery yields and conservation outcomes for many of the world’s most depleted fisheries. These improvements could be achieved in part by implementing innovative fishery reforms, such as data-limited stock assessments and rights-based fishery management. Our results suggest that significant food security and conservation benefits could be achieved if overfished stocks were rebuilt to sustainable levels: more than 60% of unassessed stocks would provide increased sustainable catches, and the average in-water biomass levels would increase by more than 50%. Most importantly, our results demonstrate that fisheries in regions or countries dominated by small-scale operations stand to achieve the greatest benefits, a promising finding for sustaining food security and vibrant coastal economies worldwide.