Erika M. D. Porporato

Making space for shellfish farming along the Adriatic coast

Making space for shellfish farming along the Adriatic coast Daniele Brigolin*, Erika Maria Diletta Porporato, Giuseppe Prioli, and Roberto Pastres Department of Environmental Sciences, Informatics and Statistics, Universit a Ca’ Foscari Venezia, Via Torino 155, Venice Mestre 30170, Italy Bluefarm S.r.l, Via delle Industrie 15, Venezia Marghera 30175, Italy M.A.R.E. S.c. a r.l. – 47841, via Enrico Toti 2, Cattolica (RN), Italy *Corresponding author: tel: þ39 042348528; fax: þ39 0412348594; e-mail: brigo@unive.it

The effectiveness of fish feeding behaviour in mirroring trawling-induced patterns

The ability to observe and predict trawling-induced patterns at spatial and temporal scales that are relevant to inform realistic management strategies is a challenge which scientists have consistently faced in recent decades. Here, we use fish feeding behaviour, a biological trait easily impaired by trawling disturbance, to depict alterations in fish condition (i.e. individual fitness) and feeding opportunities. The benthivorous fish Mullus barbatus barbatus was selected as a model species. The observed trends of responses to trawling in prey species confirmed the effectiveness of a non-trawled zone in sustaining higher levels of diet diversity (e.g. quantity and quality of ingested prey) and fish condition values (e.g. morphometric and physiological Condition Index). Changes observed in fish prey selection confirmed the role of trawling disturbance in modifying the local soft bottoms community, producing alterations of prey availability that trigger shifts in fish diet. Trawling-induced feeding patterns, mirrored through stomach contents, can positively or negatively affect fish condition, the main driver of population dynamics in maintaining carrying capacity levels. Due to the widespread socio-economic value of the red mullet fishery, and the current exploitation status, evidence gathered by the proposed bottom-up trait based approach might inform future trawling adaptation strategies, and tailor spatial conservation measures supporting an Ecosystem-Based Fisheries Management.

Spatial distribution of Decapoda in the Strait of Sicily (Central Mediterranean Sea) based on a trawl survey

The spatial representation of decapod crustaceans (Crustacea, Malacostraca) of the Strait of Sicily (Central Mediterranean Sea) is presented for the first time, together with comments on their vertical and horizontal distributions. The most relevant trawlable species were analysed using quantitative data gathered in 260 daylight lasting hauls, which covered a large portion (about 100 000 km2) of the investigated area. The index of local abundance, standardized to 1 km2, both in weight (Biomass Index), number (Density Index) and mean body weight were obtained for each species and for all species combined. A spatial representation of the Density Index was produced for all decapod crustaceans combined and for the most frequent species. In particular, the indices were transferred under a GIS system and spatial maps produced by applying the program ArcView™ 9.0. Different interpolators were tested and the most exact interpolator (IDW Inverse Distance Weighting) was chosen. Both historical (i.e., doubts about the presence or identification of the species) and spatial (i.e., differential distribution among different fishing areas) heterogeneity were detected and commented upon. Concerning the trawlable bottoms, very few species (such as Parapenaeus longirostris (Lucas, 1846), Aristaeomorpha foliacea (Risso, 1827), Aristeus antennatus (Risso, 1816), Nephrops norvegicus (Linnaeus, 1758) and Plesionika martia (A. Milne-Edwards, 1883)) are consistently and largely represented in the catches. A high spatial heterogeneity, likely reflecting the complex interaction between fishing pattern, hydrological features and bottom typology, was made evident.

An R package for simulating growth and organic wastage in aquaculture farms in response to environmental conditions and husbandry practices

A new R software package, RAC, is presented. RAC allows to simulate the rearing cycle of 4 species, finfish and shellfish, highly important in terms of production in the Mediterranean Sea. The package works both at the scale of the individual and of the farmed population. Mathematical models included in RAC were all validated in previous works, and account for growth and metabolism, based on input data characterizing the forcing functions—water temperature, and food quality/quantity. The package provides a demo dataset of forcings for each species, as well as a typical set of husbandry parameters for Mediterranean conditions. The present work illustrates RAC main features, and its current capabilities/limitations. Three test cases are presented as a proof of concept of RAC applicability, and to demonstrate its potential for integrating different open products nowadays provided by remote sensing and operational oceanography.

Relationships between plastic litter and chemical pollutants on benthic biodiversity

Five Descriptors (D) of Marine Strategy Framework Directive (MSFD): marine litter (D10), non-indigenous species (D2) and organic and inorganic pollutants (D8), were estimated in a coastal area of GSA 16 (Augusta harbour, Central Mediterranean Sea) in order to study their effects on the biodiversity (D1) of the benthic community D6) and to improve data for the MSFD. Investigation of plastic debris had led to the identification of 38 fragments divided into four categories, among which microplastics resulted as the most abundant. Six non-indigenous species, belonging to Polychaeta (Kirkegaardia dorsobranchialis, Notomastus aberans, Pista unibranchia, Pseudonereis anomala, Branchiomma bairdi) and Mollusca (Brachidontes pharaonis) were found. Biodiversity and benthic indices suggested a generalised, slightly disturbed ecological status. Anthracene, Zinc and Chrome were the most abundant chemical compounds in analysed sediments. Significant correlations were found between the abundance of trace elements vs biotic indices and between plastic debris vs biodiversity and benthic indices. This study represents the first report about the abundance of plastic debris and its relationship to contaminants and infauna in Augusta harbour. Our results can provide useful information for national and international laws and directives.