Damage by fishing activities to the Gorgonian coralParamuricea clavata in the Ligurian Sea

Abstract

1. The analysis, by means of line transects, of a Paramuricea clavata (Anthozoa: Gorgonacea) population forming a facies of the Mediterranean coralligenous community along the Portofino Promontory (Ligurian Sea, Italy) evidenced a high per cent of lesions inflicted to the gorgonian coenenchyme by anchoring and fishing activities. 2. This damage favours the development of aggregates of epibionts (mainly hydroids and bryozoans) which leads to greater mechanical stress through increased resistance of the colonies to water movement; where polychaetes and nematodes colonize the denuded skeleton, their burrowing activity weakens the colony. 3. In situ tissue regeneration experiments suggested that aggregation of epibionts can develop only if the injuries result, from continuing abrasion. 4. Injuries caused by anchoring and fishing can therefore be considered the major cause of mortality of Paramuricea clavata in the Portofino Promontory. 5. Paramuricea clavata re‐colonizes experimentally denuded areas slowly and colonies take many years to reach the size of existing individuals and can be damaged easily by fishing and anchoring. 6. Special protection is needed for this key species of Mediterranean coral at Portofino Promontory, which is proposed as a Natural Marine Park. © 1997 John Wiley & Sons, Ltd.

Effects of aquaculture effluents on the slender sea pen Virgularia mirabilis

“…Interestingly, poor health condition of sea pen close to the farm didn’t trigger colonisation of the sea pen skeleton by epibionts. This contrasts with the results of previous studies, showing that the presence of sessile associated taxa on corals can be an efficient proxy of poor health condition, as these taxa can colonise damaged tissue and bare skeleton 55 – 57 . However, the majority of the sessile taxa considered in the previously cited studies are algae and the results are therefore not applicable to our study site that is fully in aphotic conditions.…”

The Diversity, Structure, and Development of the Epibiont Community of Paramuricea clavata (Risso, 1826) (Cnidaria, Anthozoa)

“…Perez et al [9] recorded microorganism colonization after a few days, while Hydrozoa, followed by Bryozoa and Serpulidea, were observed some weeks later. This evolution was confirmed by other authors [4,13,16,68]. Our data, obtained on single colonies photographed in different years, indicate that the epibiont assemblage persists for several years.…”

“…Although we identified numerous species, some groups, virtually unidentifiable through photos, were considered as higher taxa (e.g., Hydrozoa) or as OTUs (e.g., encrusting sponges); this fact clearly indicates that the described diversity is underestimated. The recorded assemblage is similar to that previously observed in the Ligurian Sea [4].…”

Effects of deep-sea bottom longlining on the Hatton Bank fish communities and benthic ecosystem, north-east Atlantic

“…Chuenpagdee et al (2003) indicate that the level of by-catch and the habitat impact associated with demersal longlines is moderate. However, the present longline survey agrees with previous studies (Bavestrello et al , 1997; Butler & Gass, 2001; Krieger, 2001; Witherell & Coon, 2001; Fosså, et al , 2002; Krieger & Wing, 2002; Reed, 2002; Gass & Willison, 2005; Mortensen et al , 2005, 2008; Orejas et al , 2009) suggesting that bottom longlining has negative impact on VMEs when their distributions overlap with the fishing grounds. In the presence of strong currents, large weights were required for bottom longlining, and such weights can also damage corals as Reed (2002) suggests.…”