Fish Landings
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Increase the weight and variety of species landed
No change observed
Gökova Bay to Cape Gelidonya
Türkiye
Problem: Unregulated and unsustainable fishing in the Mediterranean Basin has led to a sharp decrease in the last 20 years in the catch size and number of target species in local fisheries.
Action: No-Fishing Zones (NFZs) have been established by the government in collaboration with AKD and local fishers to promote sustainable fishing practices and allow refuges for fish to spawn and grow. AKD are increasing areas within NFZs that are patrolled, and are engaging with fishers to deter illegal fishing activities within NFZs.
Indicator: An increase in the weight and variety of fish species landed indicates spillover effects from the NFZs into fishing zones, demonstrating that the establishment of NFZs (i.e. restricting fishing) actually benefits fishers. As abundance, size and diversity of fish are allowed to rebound in the NFZs, some of those fish inevitably leave the NFZ and are caught by small-scale fishers, increasing the number, size and diversity of fish in their daily landings. This indicator demonstrates that effectively enforced NFZs can provide sustainable fish populations, a provisioning service that is important to fishers’ livelihoods.
Methods
Fish landings data, for fishing outside NFZs using trammel nets and longlines, was recorded daily at four fishing cooperatives: Akyaka and Akcapinar in Gökova, and Göcek and Çalış in Fethiye. For each fisher’s daily catch, the total fish weight per species (kg) was recorded when it was purchased by the cooperative. Catch per unit effort (CPUE) was then calculated as kilograms of fish per 1000 metres of trammel net or kilograms per 1000 longline hooks deployed, depending on the fishing method used.
Results
There were no statistically significant trends in fish landing data at any of the cooperatives between 2019-2023.
Table 1: Mean daily catch per unit effort using trammel nets and longlines for fisheries cooperatives in Gökova and Fethiye. Error bars show standard deviation.
Interpretation
The results show variable catch per unit effort (CPUE) across locations and years, reflecting changes in fish abundance, fishing practices, and environmental conditions. The decrease in Akyaka net CPUE in 2020 could suggest changes in fishing effort during the Covid-19 pandemic for example, and the increase in Göcek could show impacts from NFZ establishment in 2020 although it is likely to be early to see these effects.
While some positive effects from NFZs are evident, the differing start times of data collection across cooperatives (3 – 5 years of data) complicate trend analysis. CPUE changes may reflect management efforts, but environmental factors also play a role. Additionally, changes in CPUE may also be influenced by conservation activities or management strategies, like seasonal restrictions on species and size-weight limits. Overall, more time is likely to be needed to see significant results, and longer-term monitoring will help to track this.
Publications
Kızılkaya, Z., Saydam, E., Walker, K. et al. Progress and challenges of multi-habitat marine restoration in the eastern Aegean Sea, Türkiye. npj Ocean Sustain 4, 12 (2025). https://doi.org/10.1038/s44183-025-00114-9
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