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

Aquaculture facilities provide a suitable habitat for a wide group of marine species that are able to colonise and settle on artificial structures. This study aims to determine the composition of fouling communities in off-coast facilities, with special emphasis on motile epifauna and amphipods as a main group. Seventeen aquaculture sites were sampled along the Mediterranean coast, collecting samples by scraping fouling organisms directly from the ropes. Additionally, thirty publications were reviewed, in order to assess the similarity of aquaculture fouling with other fouling communities. Our results reflect that amphipods accounted for more than 80% of the epifauna associated with farms fouling communities. This characteristic epifauna was defined by seven amphipod species well-adapted to colonise and survive in these off-coast habitats. Most species common in farms have also been commonly found in harbours, marinas, and/or offshore on turtles, buoys or platforms etc., showing a great resistance to polluted areas but also to dispersal via rafting on floating objects. In this study, two exotic species were identified: Caprella scaura and Stenothoe georgiana, the latter being the first report from the Mediterranean Sea. The presence of Jassa slatteryi was also confirmed, underestimated until now in the Mediterranean

Connectivity Patterns for Direct Developing Invertebrates in Fragmented Marine Habitats: Fish Farms Fouling as Source Population in the Establishment and Maintenance of Local Metapopulations

Artificial structures can be considered as high spatially structured habitats in the marine pelagic system, where patch connectivity would be strongly dependent on the exchange of larvae or dispersing individuals. Fish-farms located offshore may alter ecological connectivity, modifying trophic resources, and species dispersal among patches. High population densities of invertebrates can be found associated with fish-farm fouling communities, which can act as a seed source, contributing to the patterns of connectivity through individuals exchange between subpopulations or with sink populations. A field experiment was performed to analyse the role of fish-farms in the colonisation of new uninhabited habitats (floating experimental units) located at different positions relative to the fish farm and the main current, containing artificial habitats with and without feed pellets similar to those used in the fish farm. Amphipods were used as example of direct developing invertebrates for studying dispersing individuals from the fish farm to the new habitats. The richest and most abundant populations in this study were found close to and downstream of the fish farm, surpassing 1,000 amphipods at their maximum. Moreover, some floating habitats located more than 2 km from the fish farm were colonised in only 15 days. Thus, the role of fish farms has been shown to extend beyond a ‘stepping-stones’ effect in species dispersal, and have an additional effect on ecological connectivity by increasing population sizes and acting as population source. Our study aims to provide recommendations for coastal zone management in order to predict potential spread from fish farms to other platforms in the future and promote solutions related to interactions and consequences of connectivity within and between marine facilities

Description, systematics and ecology of a new tanaidacean (Crustacea, Peracarida) species from mediterranean fish farms

An undescribed species of tanaidacean belonging to the genus Hexapleomera, tribe Pancolini, Hexapleomera bultidactyla sp. nov. was found in fouling community samples from off-coast fish farms cages in the western Mediterranean Sea. The species can be distinguished from other Hexapleomera species by the presence of a ventral apophysis on the dactylus of the chela in males. Other diagnostic characters (in combination) include a male antennule with five aesthetascs, the female with three, the maxillule palp with four terminal setae and maxilliped basis and coxa each with two setae; the male fixed finger with four ventral setae and proximal apophysis, the female chela fixed finger with a proximal triangular apophysis, an apophysis on the coxa of pereopod 1, a pleopod 3 basis with three outer setae, and an uropod of four segments. Although several substrata were investigated, the species was most abundant where the turf formed by Ceramiaceae algae and the hydroid Aglaophenia sp. was dominant. An updated identification key to all the species of Hexapleomera is provided.P. Esquete is supported by Fundacão para a Ciência e Tecnologia (FCT, Portugal), under postdoctoral Grant SFRH/BPD/94985/2013

Exploring changes in bacterial communities to assess the influence of fish farming on marine sediments

Changes in bacterial assemblages along an environmental gradient determined by the distance to aquaculture installations were analysed, using denaturing gradient gel electrophoresis to assess the influence of fish farming on marine sediments. Our findings show that changes in the structure of the bacterial community are a useful indicator for determining the environmental impact of aquaculture farms, due to the rapid response to changes in nutrient load, and could be an alternative strategy for monitoring programmes. Delta and Epsilonproteobacteria linked to the sulphur cycle were detected in the sediments beneath the cages. Since these groups were not found in the sediments at control stations, they serve as indicators for assessing the impact of the organic load from fish farming on marine sediments.This study forms part of the ‘Selección de indicadores, determinación de valores de referencia, diseño de programas y protocolos de métodos y medidas para estudios ambientales en acuicultura marina’ project funded by the ‘Spanish National Plans of Aquaculture’ (JACUMAR). The research was supported by Spanish Ministry of Economy and Competitiveness project CLG2015_66686-C3-3 (JA), which was also supported by financing from the European Regional Development Fund (FEDER). ERP thanks the Generalitat Valenciana for a postdoctoral grant (APOSTD-2016-091)

Los anfípodos y la acuicultura

Diseño: Olas y colores.Esta publicación se produce enmarcada dentro del proyecto “Anfípodos como innovación para el reciclado de nutrientes dentro de la acuicultura multitrófica. Valorización de producto (AIRAM)” con la colaboración de la Fundación Biodiversidad, del Ministerio para la Transición Ecológica y el Reto Demográfico, a través del Programa Pleamar, cofinanciado por el Fondo Europeo Marítimo y de Pesca (FEMP)

Epibiontic associations between apostomid ciliates Conidophrys spp. and amphipods associated with fish farms fouling in the western Mediterranean Sea

Fish farms commonly support high abundances of invertebrates, especially amphipods, associated with fouling communities developed over nets, ropes and buoys. Protozoan epibiont ciliates of the genus Conidophrys were observed on three of the most abundant amphipod species collected from ropes of a fish farm in the western Mediterranean Sea. The amphipod species were Ericthonius punctatus that presented the epibiont Conidophrys pitelkae, and Jassa marmorata and Jassa slatteryi with the epibiont C. pilisuctor. The epibionts were found in numbers fluctuating between 1 and 119 individuals in Jassa spp. (median value = 8), higher than the number of epibionts found on E. punctatus that varied between 1 and 39 individuals (median value = 3). The epibiosis on Jassa spp. also showed prevalence values (34.33 %) superior to those of E. punctatus (24 %). Differential distribution of the epibiont species on the surface of basibionts was detected: Conidophrys pilisuctor were more frequently found on the head and gnathopods of Jassa spp., while C. pitelkae were mainly counted on the head of E. punctatus. This is the first time that Conidoprhys were found on these amphipod species

Evolution, Metabolism and Molecular Mechanisms Underlying Extreme Adaptation of Euryarchaeota and Its Biotechnological Potential

Archaeal organisms harbor many unique genotypic and phenotypic properties, testifying their peculiar evolutionary status. Thus, the so‐called extremophiles must be adequately adapted to cope with many extreme environments with regard to metabolic processes, biological functions, genomes, and transcriptomes to overcome the challenges of life. This chapter will illustrate recent progress in the research on extremophiles from the phylum Euryarchaeota and compile their evolutive history, metabolic strategies, lipid composition, the structural adaptations of their enzymes to temperature, salinity, and pH and their biotechnological applications. Archaeal organisms have evolved to deal with one or more extreme conditions, and over the evolution, they have accumulated changes in order to optimize protein structure and enzyme activity. The structural basis of these adaptations resulted in the construction of a vast repertoire of macromolecules with particular features not found in other organisms. This repertoire can be explored as an inexhaustible source of biological molecules for industrial or biotechnological applications. We hope that the information compiled herein will open new research lines that will shed light on various aspects of these extremophilic microorganisms. In addition, this information will be a valuable resource for future studies looking for archaeal enzymes with particular properties

The influence of the moisture content on the electrical resistance of two types of cork stoppers

The relationship between the log of the electrical resistance (ER; measured using pin electrodes) and the moisture content (MC) have not been reported in any form of cork. That is important for the cork stoppers industry because it should help in the design and verification of more precise devices for measuring cork moisture content. In this study, using linear regression techniques, different regression models of the type log(Log(R) + 1) = axh + b were derived to describe the relationship ERMC, that was measured using pin electrodes on two types of cork stoppers [natural (N) and agglomerate(AG)]. The results obtained show that in the models proposed, the moisture content of AG cork stoppers can be estimated with an error of ± 0.3%, while that of N stoppers can be estimated with an error of 0.5%. Neither the geographical origin of the N corks nor the surface treatment to which the AG corks were subjected significantly affected the proposed models. Therefore, the moisture content of cork stoppers could be measured at the industrial scale using electrical resistancetype moisture meter

Chitosan from Marine Amphipods Inhibits the Wilt Banana Pathogen Fusarium oxysporum f. sp. Cubense Tropical Race 4

In this work, we extracted chitosan from marine amphipods associated with aquaculture facilities and tested its use in crop protection. The obtained chitosan was 2.5 ± 0.3% of initial ground amphipod dry weight. The chemical nature of chitosan from amphipod extracts was confirmed via Raman scattering spectroscopy and Fourier transform infrared spectroscopy (FTIR). This chitosan showed an 85.7–84.3% deacetylation degree. Chitosan from biofouling amphipods at 1 mg·mL−1 virtually arrested conidia germination (ca. sixfold reduction from controls) of the banana wilt pathogenic fungus Fusarium oxysporum f. sp cubense Tropical Race 4 (FocTR4). This concentration reduced (ca. twofold) the conidia germination of the biocontrol fungus Pochonia chlamydosporia (Pc123). Chitosan from amphipods at low concentrations (0.01 mg·mL−1) still reduced FocTR4 germination but did not affect Pc123. This is the first time that chitosan is obtained from biofouling amphipods. This new chitosan valorizes aquaculture residues and has potential for biomanaging the diseases of food security crops such as bananas.This project was funded by PID2020-119734RB-I00 (Spanish Ministry of Science and Innovation), EU H2020 MUSA no. 727624, and AIRAM (Biodiversity Foundation, Spanish Ministry for Ecological Transition, and the Demographic Challenge) projects

Potential retention effect at fish farms boosts zooplankton abundance

Coastal aquaculture activities influence wild macrofauna in natural environments due to the introduction of artificial structures, such as floating cages, that provide structural complexity in the pelagic system. This alters the abundance and distribution of the affected species and also their feeding behaviour and diet. Despite this, the effects of coastal aquaculture on zooplankton assemblages and the potential changes in their abundance and distribution remain largely unstudied. Traditional plankton sampling hauls between the farm mooring systems entail some practical difficulties. As an alternative, light traps were deployed at 2 farms in the SW Mediterranean during a whole warm season. Total zooplankton capture by traps at farms was higher than at control locations on every sampling night. It ranged from 3 to 10 times higher for the taxonomic groups: bivalvia, cladocera, cumacea, fish early-life-stages, gastropoda, polychaeta and tanaidacea; 10–20 times higher for amphipoda, chaetognatha, isopoda, mysidacea and ostracoda, and 22 times higher for copepoda and the crustacean juvenile stages zoea and megalopa. Permutational analysis showed significant differences for the most abundant zooplankton groups (copepoda, crustacean larvae, chaetognatha, cladocera, mysidacea and polychaeta). This marked incremental increase in zooplankton taxa at farms was consistent, irrespective of the changing environmental variables registered every night. Reasons for the greater abundance of zooplankton at farms are discussed, although results suggest a retention effect caused by cage structures rather than active attraction through physical or chemical cues