- Houda Fellah, graduate from the Master in Sustainable Fisheries Management organised by CIHEAM Zaragoza and the University of Alicante, analyses the effect of fish escapes on fish market prices
The expansion of aquaculture in the Mediterranean, together with climate change, has increased the frequency of fish escape events in recent decades. Storms are more intense and structural failures cause accidental release of fish into the surrounding waters, with subsequent ecological, social and economic effects. Although many studies have analysed the impact of these escapes on biodiversity and fisheries, their effect on fish prices at market is less known.
Houda Fellah, graduate from the International Master in Sustainable Fisheries Management of CIHEAM Zaragoza and the University of Alicante, analysed this question in her Final Master Thesis (TFM). Her research focused on two of the most important species in the Mediterranean: gilthead seabream (Sparus aurata) and seabass (Dicentrarchus labrax).
Gilthead seabream, more sensitive to fish escapes
The results show considerable differences between the two species. In gilthead seabream, the probability of escape events was a determining factor in price formation, with a strong, statistically significant, negative effect. Even small-scale escapes generated clear market signals, causing falls in prices at the landing port due to oversupply.
On the contrary, in the case of seabass the probability of escape events did not show a statistically significant effect, which suggests that small-scale escapes do not directly affect price dynamics. This species reacts mainly to large-scale events and spatial factors associated to the location of fish farms.
According to data, differentiated approaches are required in economic and environmental management of escapes, and in the assessment of their impact on artisanal fisheries and local markets.
The GLORiA 2 project
This TFM was developed in the framework of the GLORiA 2 project (GLObal Change Resilience in Aquaculture-2), cofinanced by the European Maritime and Fisheries Fund and the Pleamar Programme of the Biodiversity Foundation. The project assesses the resilience of aquaculture to global change, integrating ecological, social and economic impacts.
The study used first-sales data from 14 landing ports for gilthead seabream and 7 for seabass in the Valencian Community and the Region of Murcia (Spain) during the period 2004-2021. Through panel data econometric analysis, Fellah evaluated how escape probability indicators affected price fluctuations, controlling for other market factors.
Tools for sustainable management of the sector
Quantifying the economic impact of escapes provides practical evidence applicable to various scenarios: improving aquaculture risk management (prevention, insurance, post-storm protocols); reducing the possible impact of escapes (oversupply) on local markets; and improving adaptation of the fishing and aquaculture sector to climate change.
Common escape factors, with particular attention to net flaws and sea-cage operations.
The research work established a direct connexion between the escape events and price formation at the landing ports and compared the effect between species. Integrating the escape probability function in econometric models is an innovative approach, as the existing bibliography focuses mainly on biodiversity and fisheries, without taking into account market dynamics.
This TFM of the Master in Sustainable Fisheries Management of CIHEAM Zaragoza and the University of Alicante provides quantitative tools for a more resilient management of the sector against the challenges of climate change.
ABOUT THE AUTHOR
Houda Fellah is a specialist in fisheries management and stock assessment, with particular interest in the impacts of climate change and the relationship between economics and natural resources.
With this TFM, she was awarded the official qualification of Master in Sustainable Fisheries Management (CIHEAM Zaragoza/University of Alicante, 2023–2025). The research work was conducted under the supervision of Kilian Toledo-Guedes (University of Alicante) and Ángel Perni Llorente (Pablo de Olavide University).
Between 2020 and 2023, Fellah was head of the Entrepreneurship and Innovation Service at ENSSMAL – the Higher National School of Marine Science and Coastal Development – of Algeria, leading projects in fisheries economics, protected marine areas, and technical and economic studies in aquaculture. She has also engaged in teaching and supervised final research projects in bioeconomics and fisheries management.
She is currently conducting a doctorate at the University of Alicante, where she continues her line of research in sustainable fisheries management.