Limpets constitute an important key species in the intertidal zone. The limpets’ assemblage is evaluated in Plane Island (Paloma Island, Algerian West coast) by detailed censuses which were performed in 8 zones in the main island and 9 islets. Results allowed the estimation of a total population of 3993 of the endangered Patella ferruginea (1.78ind/m), 1861 P. rustica (0.82ind/m), and 383 of the blue Mediterranean limpet P. caerulea (0.17 ind/m). The ferruginous limpet distribution around Plane Island was influenced by abiotic factors as hydrodynamics and the sea current direction. Conversely, anthropogenic factors had an important impact despite the island's distance from the mainland. This study finds that in the face of global warming, the island surface will be reduced, however limpets will have an important contribution to the island's areas and its conservation of biodiversity.

A frequently occurring species with high market value in Algeria, the Norway lobster Nephrops norvegicus (Linnaeus, 1758) (Decapoda Nephropidae) has attracted the interest of many professional fishermen. Fishery for this species has been growing rapidly in recent years. In this work, we collected data on the eco-biology, production, and monitoring of fishing effort and calculated yields. Our main objective is to provide an introduction to the fishing activity of this crustacean decapod in western Algeria, to provide a database for further studies of the lobster stock, and to contribute to the improvement and development of lobster fishery in Algeria.