Analyzing gaps in policy: Evaluation of the effectiveness of minimum landing size (MLS) regulations in Turkey

Abstract

The Mediterranean and Black Sea host the most intense overfishing and Turkey has the largest commercial fisheries in them (when both seas considered). However, the state of the Turkish fisheries is in critical condition as both the quality (i.e, in number of caught species, value and sizes of fish) and quantity of fisheries catches have been rapidly declining in recent decades. One pioneer fisheries management initiative thoroughly evaluated here pertains to minimum landing size (MLS) regulations for commercial taxa, with the aim of promoting stock sustainability by ensuring fish reproduce before they are caught. This study examines 29 taxa in relation to MLS by analyzing changes in catch per unit effort trends pre-and post MLS to gauge regulation effectiveness, changes to MLS regulations since implementation, and finally evaluates the Turkish MLS sizes in relation to Turkish maturity sizes, to provide advice for taxa requiring changes. It seems intensive fishing may have reduced the size at maturity for many species in Turkey, as they mature smaller here than the Mediterranean and global averages. Eleven taxa listed in MLS regulations are under the lengths of first maturity (L-mat) sizes in Turkish waters and need to be increased, especially that of bonito, hake, swordfish and bluefish (by 18 cm, 10 cm, 10 cm and 8 cm, respectively), while 16 taxa still require national studies to determine their L-mat sizes in Turkish waters. In conclusion, in Turkey, MLS regulations are completely ineffective due to a lack of monitoring and control for juvenile fish at landing sites, markets and processing plants, along with insufficient penalties for such infractions, yet, there remains plenty of room for improvement. To improve the state of the fisheries, MLS measures could be improved by increasing fines, monitoring and control, making some gear types more selective and use of real-time closures and no fishing zones to protect spawning and nursery habitats.