Artificial spawning substrates and participatory research to foster cuttlefish stock recovery: A pilot study in the Adriatic Sea

This two-year study evaluates the effects of new management strategies directed at helping the recovery of Adriatic cuttlefish populations. The ability of three specially developed artificial spawning devices–seagrass collectors (SC; deployed on artificial reefs), longline collectors (LC; deployed at mussel farms), and trap collectors (TC; delivered to 19 professional and 54 recreational trap fishermen together with a dedicated logbook)–to attract egg deposition was tested. All devices were provided with a polyethylene floating rope 8 mm in diameter that served as a collector for egg deposition. Total rope length was 1,440 m in SC (2,880 segments of 0.5 m), 250 m in LC (500 segments of 0.5 m), and 250 m in TC (10 m per trap). Although the sites where SC and LC were deployed were sheltered from the action of destructive fishing gears, heavy winter storms destroyed the SC after a year. Most recreational fishermen and none of the professional fishermen provided detailed information on percent egg coverage on their collectors. The collectors attached to the three devices proved highly suitable for cuttlefish spawning, collecting more than 500,000 eggs on 2,440 m of rope. The analysis of egg diameter distribution suggested three laying events during the spawning season. The logbook data showed that egg number peaked in June. The present approach, combining habitat reconstruction and participatory research, has the potential to contribute to the recovery of cuttlefish stocks in the framework of a broader management plan.