Fouling organisms on Perna perna mussels: is it worth removing them?

Abstract

A B S T R A C TPerna perna mussel spat were suspended from ropes on a long-line cultivation, at Coqueiro´s Beach, Anchieta, South-eastern Brazil, in order to quantify the fouling community structure and its effects on growth and biomass of mussels. Half of the ropes had the fouling removed monthly, half had the fouling left until the end of the experiment. Monthly samples of thirty mussels from each group were measured and their biomass determined. The fouling organisms were identified, quantified and their biomass evaluated on a monthly basis. After ten months, mussels on the cleaned treatment were significantly larger and heavier (ANOVA; P < 0.05; Bonferroni: unfouled > fouled), showing that fouling reduced mussel development. The most abundant epibiont organisms in terms of biomass were the algae Polysiphonia subtilissima (29%) and Ulva rigida (10.3%), followed by the bryozoans Bugula neritina (13.6%) and Perna perna spat (10.6%). Over 97 taxa and 42,646 individuals were identified, crustaceans being the most abundant group, predominantly one amphipod Cheiriphotis megacheles (12,980 ind.). Species abundance was positively correlated with algal biomass, revealing the influence of algae on vagile fauna, which provide both food and shelter. The benefits of fouling removal are discussed because the majority of species are important feeding items to fishes and yet, the costs of its fouling control added to the associated mussel spat loss make this fouling removal of questionable value. R E S U M OSementes de Perna perna foram colocadas em cordas suspensas em long-line na Praia do Coqueiro, Anchieta, ES, objetivando-se determinar a estrutura da comunidade de incrustantes e seu efeito sobre o desenvolvimento dos mexilhões. Metade das cordas teve os incrustantes removidos mensalmente, na outra metade eles foram deixados até o final do experimento. Mensalmente, 30 mexilhões de cada grupo foram retirados e medidos e a biomassa aferida. Os incrustantes foram identificados, quantificados e a biomassa de cada taxon determinada. Após 10 meses de cultivo, os mexilhões sem incrustantes eram significativamente maiores e mais pesados (ANOVA; P < 0,05; Bonferroni: sem incrustantes > com incrustantes), demonstrando que os incrustantes interferiram negativamente no desenvolvimento dos mexilhões. Os incrustantes mais abundantes em termos de biomassa foram as algas Polysiphonia subtilissima (29%) e Ulva rigida (10,3%), seguidas pelos briozoários Bugula neritina (13,6%) e sementes de Perna perna (10,6%). Foram registrados 97 taxa e 42.646 indivíduos, sendo Crustacea o grupo mais abundante, principalmente o anfípodo Cheiriphotis megacheles (12.980 ind.). A abundância de indivíduos foi positivamente correlacionada com a biomassa de algas, revelando a influência das algas na fauna vágil, provendo abrigo e alimentação. Os benefícios da remoção dos incrustantes são discutidos, uma vez que a maioria dos incrustantes são importantes como itens alimentares para os peixes; além disso, os custos desta remoção somados à perda de sementes de me...

Impacts of the invasive ascidian Didemnum vexillum on green-lipped mussel Perna canaliculus aquaculture in New Zealand

“…However, as the worst case is generally of most interest, many studies of biofouling attempt to infer potential impacts from a comparison of areas of high versus low levels of fouling (e.g. de Sa et al 2007, Daigle & Herbinger 2009, Fitridge 2011. Such assessment approaches can lead to ambiguous results, especially when the spatial and temporal variation of infestation and stochastic nature of the invasion process are considered (Forrest & Taylor 2002, Padilla 2010.…”

Implications of Extracellular Polymeric Substance Matrices of Microbial Habitats Associated with Coastal Aquaculture Systems

“…In marine aquaculture, biofouling is a major problem and expense factor, whose damage includes both the target culture species and/or cultivation infrastructure, which are exposed to a diverse array of fouling organisms with significant production impacts [62]. For example, in shellfish aquaculture, the key impact is the direct fouling of stock causing physical damage [63,64], mechanical interference [65], biological competition and environmental modification [48,66,67], while infrastructure is also impacted. Regarding finfish aquaculture, biofouling affects infrastructure causing restriction of water exchange [68], which increases disease risk [69] and causes deformation of cages and structures [67].…”

Composition and seasonal variation of brachyura and anomura (Crustacea, Decapoda) associated with brown mussel farms at Praia da Cocanha, Brazil

“…In the sites with low hydrodynamics and conditions of constant immersion, mussel farms are a suitable secondary substrate for the colonization of epibionts, providing shelter and food for large numbers of associated organisms (Bayne 1976;Marenzi and Manzoni 1998;Vaquero 2006;Sá et al 2007). Studies of the biodiversity and heterospecific associations of the organisms with shellfish farms are scarce, although of great importance because they provide a better understanding of biological phenomena and the role that each species performs in this system, contributing to livestock improvement and providing useful information for farm management in order to maximize productivity (Bayne 1976;Marenzi and Manzoni 1998;Vaquero 2006;Sá et al 2007).…”

“…Studies of the biodiversity and heterospecific associations of the organisms with shellfish farms are scarce, although of great importance because they provide a better understanding of biological phenomena and the role that each species performs in this system, contributing to livestock improvement and providing useful information for farm management in order to maximize productivity (Bayne 1976;Marenzi and Manzoni 1998;Vaquero 2006;Sá et al 2007). Previous studies cite decapods crustaceans as frequently associated with bivalve farms (Uribe et al 2001;Carvalho 2007).…”

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