Species-specific artificial reef models for lobster (Homarus gammarus Linnaeus 1758)

Abstract

The objective of this study is to determine the possible artificial reef models preferred by lobster species (Homarus gammarus Linnaeus, 1758). For this purpose, eight artificial reef models at different shapes and sizes have been designed. These models include flat, grilled, U-type, cowl, fireplace chimney brick shapes made from the materials of wood, concrete and metal. Artificial reefs were deployed at 5, 10, 20 m water depths and 500 m from the shore on the coast of Erdek Ocaklar Bay in Marmara Sea. Then, monthly monitoring was conducted and SCUBA equipment were used during underwater monitoring. The time for deploying artificial reefs on the sea bottom (effort) was 233 minutes/diver and the time spent underwater by the divers was calculated as 540 minutes/diver. As a result of the study, 32 individuals of H. gammarus were observed in/around the artificial reefs. A significant increase was observed in the number of lobsters when the temperature dropped below 14°C. However, it was determined that lobster individuals preferred only concrete artificial reef models at the depth of 20 m. In addition, it was observed that small individuals preferred 40×80 cm flat concrete model (24 individuals) and large individuals preferred U-type concrete model (8 individuals). Therefore, it has been proposed to the usage of concrete artificial reef models in order to protect and ensure the sustainability of the reared lobster stocks and to release them into these artificial reefs while introducing them to the natural environments. In this context, this study will shed light on future studies.