Growth variations within a farm of mussel (Mytilus galloprovincialis) held near fish cages: importance for the implementation of integrated aquaculture

Abstract

Fish farming releases extensive amounts of particulate organic waste that can be exploited by bivalves in integrated culture. We tested if mussels Mytilus galloprovincialis cultured at two depths (1 and 6 m) in a raft, moored 170 m from a fish farm had greater growth than bivalves held 550 m from the fish cages. Mussel growth was monitored monthly, covering the second phase of the culture, from thinning-out to harvest (March to November 2011). We also studied if fish solid and dissolved nutrients increased the organic content of the seston and chlorophyll-a levels near the fish cages through weekly samples. Results showed no differences in seston, chlorophyll and physiochemical characteristics of the water among rafts. Maximum growth and Condition Index (CI) occurred during springsummer (April-August), when mussels had access to greater food quality and quantity. Mussels cultivated close to the cages showed similar shell length, weight and CI compared with mussels distant from the fish farm. Average shell length, meat dry weight and CI at harvest were 76.31 mm, 2.51 g and 23%. Bivalves cultured distant from the fish cages displayed 26% higher biomass than the other raft at the end of the experiment. Differences in biomass were explained by the significantly higher recruitment of mussel seed observed at the raft distant from the fish cages from June to November. The lack of a significant enhancement in growth of the bivalves cultured next to finfish is discussed.

Comparison between IMTA and monoculture farming of mussels (Mytilus galloprovincialis L.) in the Boka Kotorska Bay

“…These results agree with PEHARDA et al (2007), who found the highest growth rates of mussels in period from March to May, which could indicate that the highest growth during the spring period can be the result of increased food aviability. On the other hand, results of this study partly agree with results reported by IRISARRI et al (2014a), who found maximum growth in mussels during both spring and summer period. According to VAN ERKOM SCHURINK & GRIFFITHS (1992) as well as ŽUPAN & ŠARIĆ (2014), highest avaliability of food is at temperatures between 10°C and 20°C, when the recorded mussel growth is most intense, while the growth slows at temperatures above 20°C.…”

“…Integrated multi-trophic farming systems of various marine organisms are known worldwide (FAO, 2009;ABREU et al, 2009;NAVARRETE-MIER et al, 2010;REID et al, 2010;HUGHES & KELLY, 2011;HANDÅ et al, 2012;LANDER et al, 2012;IRISARRI et al, 2014a). The possibility of implementation of the integrated multi-trophic farming in the Mediterranean was well studied in the last ten years (PEHARDA et al, 2007;NAVARRETE-MIER et al, 2010;SARÀ et al, 2011;ŽUPAN, 2012;ŽUPAN et al, 2012;ŽUPAN et al, 2013;ŽUPAN et al, 2014;ISARRI et al, 2014a).…”

Performance measures and models for open‐water integrated multi‐trophic aquaculture

“…As in shellfish ecology studies, SFG is also common in shellfish aquaculture studies (Navarro et al 1991;Okumus ß & Stirling 1994;Newell et al 1998;Gibbs 2007;Sar a & Pusceddu 2008). Likewise, in IMTA systems SFG has been primarily used to assess the shellfish component (Gao et al 2008;Irisarri et al 2013aIrisarri et al ,b, 2014.…”

Untitled

“…M. galloprovincialis was considered as a suitable prey species for this kind of study with H. trunculus. Using this species as prey provides ease of comparison with the previous studies and more importantly, beside its key role in benthic communities, M. galloprovincialis is a valuable bivalve species and widely cultivated in Mediterranean area (Neofitou et al, 2014;Irisarri, Cubillo, Fernández-Reiriz, & Labarta, 2015) and H. trunculus is considered its pest in some culture areas (Peharda & Morton, 2006). …”