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.

Anthropogenic effects on reproductive effort and allocation of energy reserves in the Mediterranean octocoral Paramuricea clavata

“…The proportion of colonies that are affected by epibionts can serve as an indicator for the intensity of disturbance and health state, as injuries promote epibiosis (Bavestrello et al 1997). For the sake of evaluating a larger area in the time available, we only distinguished between unaffected colonies and affected colonies with any visible degree of epibiosis, but did not distinguish between colonies with various de grees of epibiotic cover (but do suggest this focus (Table 1).…”

“…Although the impact of climate anomalies on this species has been the focus of several recent studies (e.g. Perez et al 2003, Linares et al 2005, Cupido et al 2008, other sources of mortality in P. clavata have received less attention, such as mortality due to tissue damage by fishing lines (Bavestrello et al 1997, Harmelin & Marinopoulos 1994 or suffocation by coverage of mucilage produced by filamentous algae (Mistri & Cecherelli 1993).…”

Coral assemblage off the Calabrian Coast (South Italy) with new observations on living colonies ofAntipathes dichotoma

“…Their presence and the professional fishing activity have to be considered as possible causes affecting the biodiversity of the area, both through the destruction of the habitat and through the direct action of fishing gear on the coral colonies affecting the integrity of their coenenchyme and therefore enhancing their level of epibiosis (Bavestrello et al 1997). …”

Integración de el índice ESCA por medio de los macro-invertebrados sésiles

“…Gorgonians, because of their long life and slow dynamics, are particularly vulnerable to largescale alterations such as climatic anomalies (Linares et al 2008, Garrabou et al 2009, Teixidó et al 2013, which are independent of the level of local protection (Cerrano et al 2000, Coma et al 2006, Huete-Stauffer et al 2011. However, local disturbances (such as sedimentation, anchoring and fishing activities) can also affect gorgonian populations, causing damage of varying extent (Bavestrello et al 1997) and explaining the patterns highlighted in the study.…”

“…Conversely, little is known about the response of sessile coralligenous macroinvertebrates to stress, even if some taxa are recognized to be sensitive to human-induced alterations (Bavestrello et al 1997, Garrabou et al 1998, Gatti et al 2015b). The concurrent use of both macroalgae and sessile macro-invertebrates allows a wider spectrum of human-induced alterations to be detected than when a single component is used, thus better evaluating the ecological quality of coralligenous assemblages (Kipson et al 2011, Sartoretto et al 2014, Gatti et al 2012.…”