Quantifying the decline in Corallium rubrum populations: Reply to Santangelo & Bramanti (2010)

Abstract

In the comment on Bruckner (2009; Mar Ecol Prog Ser 397:319-332), Santangelo & Bramanti (2010; Mar Ecol Prog Ser 418:295-297) suggest that the available data for Corallium rubrum populations cannot be used to make conclusions about population trends for the species throughout the Mediterranean. Their main concerns relate to (1) different methodologies used to sample populations; (2) insufficient population information from deep water; and (3) limited data on sampling area and density of colonies. While I recognize many of the limitations of the data, the conclusions in Bruckner (2009) were based on multiple datasets, including population demography and reproductive patterns, as well as landings data, trade statistics and biological information. The primary comparison involves differences between depths, levels of fishing pressure, and historic populations using information from representative habitats off Costa Brava, Spain; recent data were collected using similar methods and included size structure, reproductive information, and density and abundance of colonies. At the time of Bruckner (2009), most fisheries were in shallow water (<70 m depth), but they were already progressively expanding into deeper areas. Since publication of the manuscript, the fishery for C. rubrum has entered a new phase, SCUBA fishing using mixed gases and new technology (e.g. ROVs) to reach greater depths (70 to 150 m) and increase landings, mostly because shallow populations have been overharvested. This new trend is problematic, because the science does not exist to determine sustainable harvest levels at these depths. © Inter-Research 2010.