Wrecks on the Bottom: Useful, Ecological Sentinels?

Abstract

A B S T R A C TWrecks play an important role in enhancing marine biodiversity. SCUBA diving video-samplings were performed on eight wrecks, including seven shipwrecks and a sunken airplane, scattered over 180 km along the Ligurian coastline in the northwestern Mediterranean Sea, in water depths of 30-65 m. Differences in composition of macrobenthic communities were found to be related to the bottom sedimentology and the composition and geometry of the investigated structures. The iron, flat, and even substrata of shipwrecks were dominated by Bivalvia (Ostrea edulis) and Anthozoa (Corynactis viridis), whereas the aluminum, cage-like structure of the airplane was dominated by massive sponges and bryozoans. Furthermore, abundances of some macrobenthic invertebrates were greater on the wrecks than those observed on natural, rocky substrates. Because of the increasing popularity of use of video and photo digital apparatuses among recreational divers, combined with wreck resistance to corrosion, artificial geometries and available surfaces that facilitate species' settlement and growth, data from wrecks consisting of images and related metadata (depth, date, water temperature, etc.) could provide a new opportunity for monitoring Mediterranean marine biodiversity.

Basin-scale occurrence and distribution of mesophotic and upper bathyal red coral forests along the Italian coasts

“…The absence of colonies on wrecks in areas characterised by a high occurrence of red coral (e.g., SE Sardinia, Liguria, Calabria) suggests that this material could be unsuitable for the species' settling. The type of metal of a wreck, in fact, is known to influence the community composition of the fouling organisms (Peirano, 2013). The lack of literature records of red coral on iron could support this observation; however, the influences of water circulation, larval dispersal ability, as well as depth, status and biocoverage of the wreck needs to be verified with further targeted investigations.…”

Offshore Wind Farms as Potential Locations for Flat Oyster (Ostrea edulis) Restoration in the Dutch North Sea

“…In areas with large amounts of silt, the oysters could only be found on large rocks. In the northwestern part of the Mediterranean, oyster growth on shipwrecks is dominated by Ostrea edulis [102]. Based on this dispersal data, coarse sand (grain size >210 µm) was classified as unsuitable, fine sand (>63 µm) as moderately suitable, and firm silty sand, or silty gravel with shells and stones (not defined in terms of grain size), was considered suitable for oyster growth [78].…”

Distribution of Caulerpa taxifolia var. distichophylla (Sonder) Verlaque, Huisman & Procaccini in the Mediterranean Sea

“…Bulleri and Airoldi 2005;Ruiz et al 2009;McNeill et al 2010;Mineur et al 2012). In this respect, artificial structures could act as sentinel places for monitoring the appearance of new NIS (Ruiz et al 2009;Peirano 2013). The analysis of literature data highlighted how, in colonised areas, C. taxifolia var.…”