First characterisation of aLeiopathes glaberrima(Cnidaria: Anthozoa: Antipatharia) forest in Maltese exploited fishing grounds

Abstract

A remotely operated vehicle (ROV) survey conducted in the deep (250-400 m) Maltese waters in 2013 revealed, for the first time, the characteristics of an extended coral forest, constituted almost exclusively by the arborescent, longevous black coral Leiopathes glaberrima. This species is a major component of the deep coral forests of the Mediterranean Sea and its occurrence in dense populations greatly enhances the benthic biodiversity of the sites in question. The existence of such a complex benthic ecosystem is particularly interesting for Malta, since this area represented, in the 1980s, the only sanctioned site within the Mediterranean basin for the commercial exploitation of black corals. The occurrence of the large black coral population hints that, at least within the investigated area, the coral resource has not greatly suffered from past coral harvesting activities. The major current concern, however, is represented by the massive anthropogenic impact due to benthic fishing activities carried out on the rocky bank, as evidenced by the high amount of discarded fishing gear directly impacting the specimens. The data here presented, despite being preliminary in nature, suggests that the investigated benthic area should be considered a vulnerable marine ecosystem valuable for future scientific monitoring exercises. Appropriate benthic fishing restrictions for the area in question, which might be considered for inclusion within an marine protected area (MPA), should be contemplated.

First report of live deep-water cnidarian assemblages from the Malta Escarpment

“…Bo et al 2009;Deidun et al 2010;Angeletti et al 2014;Deidun et al 2014). In some cases, L. glaberrima provides a habitat for commercially important crustaceans, as reported in the Atlantic and Pacific Oceans (e.g.…”

“…By and large, the most relevant actors of such aphotic communities are cnidarians and sponges associated with poorly sampled hard bottoms at depths exceeding 200 m. This is primarily the case for the so-called white coral communities documented at bathyal depths in the Strait of Sicily, southern Adriatic, Ionian, Ligurian, Marmara, northwestern Mediterranean and Alboran seas (Tursi et al 2004;Taviani et al 2005aTaviani et al , 2005bTaviani et al , 2011aFreiwald et al 2009;Mastrototaro et al 2010;Vertino et al 2010;Gori et al 2013;Angeletti et al 2014;Fabri et al 2014), the sponge-dominated habitats in the Tyrrhenian, Ionian and Adriatic seas (Bo et al 2012;Calcinai et al 2013), and antipatharian-gorgonacean communities in the Tyrrhenian, Ionian and Adriatic seas and in the Strait of Sicily (Costantini et al 2010;Taviani et al 2010;Bo et al 2011;Angeletti et al 2014;Deidun et al 2014). From this ecological perspective, the Malta Escarpment in the central Mediterranean happens to be one of the least explored in European waters.…”

Fish Distribution and Habitat Complexity on Banks of the Strait of Sicily (Central Mediterranean Sea) from Remotely-Operated Vehicle (ROV) Explorations

“…This complex topography influences the circulation scheme of the Strait characterized by filaments, meanders and eddies, that along the shelf edge of the banks can produce upwelling, locally increasing the biological productivity [4,5] and making this area an important hotspot of biodiversity within the Mediterranean [6,7]. Furthermore, several authors highlighted the presence of important nursery and spawning areas for many fishery resources [7,8,9,10,11,12], in the Strait, mainly where banks are present.…”

“…In addition, in 2015 during the second RAC/SPA (Regional Activity Centre for Specially Protected Areas), experts started the review of the existing literature on the Strait of Sicily [6,9,10,11,12,16,17,18,19,20,21] to assess the possibility of creating one or more Specifically Protected Areas of Mediterranean Importance (SPAMIs) including these banks. Overall, these environments are poorly investigated owing to difficulties in carrying out scientific surveys and investigations in areas characterized by a rough topography, offshore location, and a strong hydrodynamic regime [22].…”

Overview of the conservation status of Mediterranean anthozoa

“…Giusti et al 2015;Maldonado et al 2013;Deidun et al 2015). However, there is no information on the extent of these practices at country level, and more efforts are needed to assess and enforce, if necessary, measures to prevent, deter and eliminate the fishing of these protected species.…”