Sessile biota fouling farmed mussels: diversity, spatio-temporal patterns, and implications for the basibiont

Abstract

The structure of sessile epibiotic assemblages fouling the shells of farmed populations of the common Mediterranean mussel Mytilus galloprovincialis, a species known to be involved in ecosystem engineering processes, was investigated in the north Aegean Sea. Mussel samples were collected from three aquaculture installations and all sessile organisms were examined. Fifteen species were recorded, one macroalga and 14 macro-invertebrates. Four colonial species covered up to 20% of the mussel shell. Among solitary organisms, polychaetes dominated followed by barnacles. The diversity of sessile epibionts associated with farmed mussel populations was comparable to that observed on natural mussel beds in contrast to their abundance/cover, which was higher in the former, possibly due to the higher trophic status in the farming areas. The structure of epibiotic assemblages exhibited limited variability at the spatial scale, in general. On the contrary, strong temporal variability with decreased diversity and abundance/cover values during the cold period of the year was assessed, in accordance with the life cycles of species involved and prevailing environmental conditions. Mussel epibionts appeared to have a negative impact on their basibiont since a reduced condition index was detected; however this impact was rather weak and further data are required to generalize the consequences of epibiosis on farmed mussels.

Fouling assemblages associated with off-coast aquaculture facilities: an overall assessment of the Mediterranean Sea

“…Colonising organisms result in added weight and drag to the structures, reducing water flow and affecting cage behaviour in the case of fish farms (Swift et al, 2006) or damaging the farmed organisms in the case of shellfish farms (Antoniadou et al, 2013). They involve additional economic cost to the aquaculture industry because of the need for cleaning to prevent negative effects on production (Ross et al, 2004;Willemsen, 2005).…”

“…Hodson et al, 1995;Cook et al 2006;Guenther et al, 2010 and references therein). Bivalves, especially mussels, algae, hydroids and ascidians are the main fouling organisms found on aquaculture fish cages (Sarà et al, 2007;Fitridge et al, 2012) and shellfish long-lines (Antoniadou et al, 2013). These benthic sessile organisms can act as ecosystem engineers, creating biogenic habitats through the provision of an additional biofouling surface, shelter or food for associated flora and motile fauna (Roberts et al, 2008 and references therein).…”

New Mediterranean Marine biodiversity records (June 2013)

“…It has been noted that this species commonly co-oc- (Kerckhof et al, 2010), which was also the case in this study. The species is widely distributed in the North Aegean Sea (Koukouras & Matsa, 1998) including the Gulf of Thessaloniki (Antoniadou et al, 2013). This is the first record of this species in the Saronikos Gulf.…”

Ascidiacea (Chordata: Tunicata) of Greece: an updated checklist

“…So far, this work was the only comprehensive systematic account on the Greek ascidians, combining primary data with an exhaustive literature review. After this publication, a number of studies have been conducted covering various aspects of ascidian biology, such as population dynamics (Panagiotou et al 2007, Panagiotou et al 2008, Vafidis et al 2008), reproduction (Panagiotou et al 2008, Vafidis et al 2008), fisheries (Antoniadou and Vafidis 2008), and ecology in general (Morri et al 1999, Antoniadou et al 2006, Antoniadou et al 2013, Sini et al 2014) or focusing on ascidian associations with other invertebrates (Voultsiadou et al 2007, Voultsiadou et al 2010). This research effort has led to some new records of ascidian species in the Aegean Sea (i.e.…”