Repaired shell damage in the commercial scallop Zygochlamys patagonica (King & Broderip, 1832), Argentine Sea Laura Schejter ⁎ , Claudia Bremec CONICET, Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina INIDEP, Instituto Nacional de Investigación y Desarrollo Pesquero, Laboratorio de Bentos, Paseo Victoria Ocampo 1, B7602HSA, Mar del Plata, Argentina Received 8 May 2006; accepted 27 February 2007 Available online 19 March 2007 Abstract We present an overview of repaired shell damage in the scallop Zygochlamys patagonica in the commercial beds of the Argentine Sea. Presence of scars was registered in 11 962 scallops, ranging from 20 to 90 mm total height, from the fishing grounds in 2003 and also in 1995 (pre-fishery condition). Values of percentage of scarring (presence) were variable in all areas. Samples collected in 1995 showed the highest percentage of scars. As the highest records of scarring were registered in pre-fishery conditions, it is not possible to regard these marks as absolute indicators of anthropogenic disturbance caused by trawling activities. Moderate and severe damage was mostly recorded in individuals of commercial size (≥ 55 mm). This indicates not only the fragility of smaller scallops, but also the accumulation of damage in older specimens, probably more resistant to damage because of their thicker shells. The selective removal of commercial individuals could explain in part our results that indicate a higher percentage of repaired shell damage in 1995, when the average size of the population was also higher. Future investigations are needed to assess effects of scarring at different shell sizes (ages) and relate these to levels of survival in Patagonian scallops thrown back into the sea during processing on board. © 2007 Elsevier B.V. All rights reserved. Keywords: Repaired shell damage; Scars; Zygochlamys patagonica; Fishing disturbance; Argentine Sea 1. Introduction Conspicuous scars in shells are detected in many molluscs. They are the result of a sub-lethal damage that has subsequently been repaired. Several studies have attempted to establish the factors that could produce repair of shell damage in different species (Checa, 1993; Gaspar et al., 1994; Ramsay et al., 2000; Green- field et al., 2002; Cadée, 1999; Alexander and Dietl, 2001; Lomovasky et al., 2005 and references therein). Trawling and dredging activities are mentioned as important causes of shell scarring in the gastropod Buccinum undatum (Mensink et al., 2000), and in the bivalves Arctica islandica (Witbaard and Klein, 1994), Glycymeris glycymeris (Kaiser et al., 2000; Ramsay et al., 2000, 2001; Ramsay and Richardson, 2000), Ensis siliqua (Gaspar et al., 1994) and Ensis arcuatus (Robinson and Richardson, 1998). Ramsay et al. (2000) suggested that scarring in Glycymeris glycimeris could be used to differentiate between severely fished and lightly fished areas. It has also been suggested that marks on scallop shells provide information on the Journal of Sea Research 58 (2007) 156 – 162 www.elsevier.com/locate/seares ⁎ Corresponding author. CONICET, Consejo Nacional de Investi- gaciones Científicas y Técnicas, Buenos Aires, Argentina. E-mail address: schejter@inidep.edu.ar (L. Schejter). 1385-1101/$ - see front matter © 2007 Elsevier B.V. All rights reserved. doi:10.1016/j.seares.2007.02.005