New records of cold‐water coral sites and fish fauna characterization of a potential network existing in the Mediterranean Sea

Abstract

New cold‐water coral (CWC) sites were recorded along the Apulian margin (Central Mediterranean). The species composition and depth distribution of CWCs were updated. A distribution of the CWC sites coincident with the course of the dense‐water masses that flow between the Southern Adriatic and Northern Ionian was confirmed. The faunal assemblages of five of these CWC sites were investigated and compared using experimental longlines during the spring–summer and autumn–winter seasons, between 2010 and 2014. Differences in ecological variables amongst the sites in each season were evaluated by means of a set of univariate and multivariate methods (analysis of variance, permutational multivariate analysis of variance, non‐metric multidimensional scaling). Although some differences were detected in relation to the different depths examined during spring–summer, the CWC sites showed similar features in terms of species richness and diversity as well as in the abundance of the same fish species (Galeus melastomus, Conger conger, Helicolenus dactylopterus, Merluccius merluccius, Phycis blennoides and Pagellus bogaraveo) most probably because of the distribution of adult specimens in structurally complex and heterogeneous habitats, which act as a potential ‘refuge network’ with respect to commercial fishing. The presence of maturing and mature individuals as well as post‐reproductive females indicates that these CWC sites also act as spawning areas, representing a potential ‘renewal network’ for the fish populations. The term ‘network’ used here refers to several similar subsystems (CWC sites) that play the same ecological role in a wider system (Apulian margin). These CWC communities need coherent conservation measures and management strategies according to the Ecosystem Approach to Fisheries.

New sites expanding the “Sardinian cold‐water coral province” extension: A new potential cold‐water coral network?

“…Similar to what has been documented in the Apulian margin (e.g. Angeletti et al, ; D'Onghia et al, ; Mastrototaro et al, ), the Sardinian CWC sites documented here may constitute a “network”, defined as a group of sites performing a similar ecological role, altogether being tiles of a wider and more complex system (D'Onghia et al, ; Ingrosso et al, ).…”

Ecosystem functioning of two marine food webs in the North‐Western Ionian Sea (Central Mediterranean Sea)

“…The continental shelf (considered from 10 to 200 m depth) and slope (down to 800 m in depth) cover approximately 3,130 and 3,530 km 2 , respectively. The Salento area is characterized by the presence of many sensitive habitats, such as the Santa Maria di Leuca (SML) coral province, characterized by living Madrepora‐Lophelia ‐bearing coral mounds, located between 350 and 1,100 m in depth (Calculli, Capezzuto, Carlucci, Carluccio, Maiorano et al, ; D'Onghia et al, ; Calculli, Capezzuto, Carlucci, Carluccio, Grehan et al, ), and sea‐lily facies Leptometra phalangium on the shelf edge located in the eastern area. Furthermore, Posidonia oceanica and Cymodocea nodosa meadows and coralligenous biocenosis are widespread in this geographic sector (Figure ).…”

Revealing the coral habitat effect on benthopelagic fauna diversity in the Santa Maria di Leuca cold‐water coral province using different devices and Bayesian hierarchical modelling

“…An effect for season was only detected for C. conger , probably because of an increase in food availability during spring in the C habitat or the reproductive requirements of adult specimens during this season linked to corals as spawning habitats (D'Onghia et al, ). In fact, the European conger is an opportunistic predator and a scavenger living and foraging close to rocky areas, where it finds refuge during the day (Morato, Sola, Gros, & Menezes, ; Xavier, Cherel, Assis, Sendão, & Borges, ).…”

“…Dead and living colonies are widespread in an area of over 1200 km 2 , between about 350 and 1100 m water depth, in the Northern Ionian Sea (southern Italy) (Bargain, Marchese, Savini, Taviani, & Fabri, ; Savini, Vertino, Marchese, Beuck, & Freiwald, ; Taviani et al, ; Tursi, Mastrototaro, Matarrese, Maiorano, & D'Onghia, ), playing an important role as nursery and spawning areas for several commercial benthopelagic species. In recent years many studies have been conducted in SML CWC province and the mobile fauna associated has been investigated using different sampling techniques, from different fishing gear to video systems, both in coral and non‐coral habitats (Capezzuto et al, ; Carlier et al, ; D'Onghia et al, , , , , , ; Freiwald et al, ; Linley et al, ; Maiorano et al, ; Mastrototaro et al, ; Tursi et al, ). Corals play a fundamental role in providing a complex habitat that hosts a high variety of species and acts as a refuge area from fishing, enhancing the diversity in the deep sea (e.g.…”

“…Corals play a fundamental role in providing a complex habitat that hosts a high variety of species and acts as a refuge area from fishing, enhancing the diversity in the deep sea (e.g. D'Onghia et al, , , , ). In particular, D'Onghia et al () and Capezzuto, Ancona, et al () observed a coral habitat effect on benthopelagic abundance.…”