Successional dynamics of marine fouling hydroids (Cnidaria: Hydrozoa) at a finfish aquaculture facility in the Mediterranean Sea.

Luis Martell,Ferdinando Boero,Jennifer E Purcell,Stefano Piraino,Cinzia Gravili,Roberta Bracale,Steven A Carrion,Marco Lezzi,Erik V Thuesen

doi:10.1371/journal.pone.0195352

Abstract

Aquaculture is increasing rapidly to meet global seafood demand. Some hydroid populations have been linked to mortality and health issues in finfish and shellfish, but their dynamics in and around aquaculture farms remain understudied. In the present work, two experiments, each with 36 panels, tested colonization (factors: depth, season of immersion) and succession (factors: depth, submersion duration) over one year. Hydroid surface cover was estimated for each species, and data were analyzed with multivariate techniques. The assemblage of hydrozoans was species-poor, although species richness, frequency and abundance increased with time, paralleling the overall increase in structural complexity of fouling assemblages. Submersion duration and season of immersion were particularly important in determining the species composition of the assemblages in the succession and colonization experiments, respectively. Production of water-borne propagules, including medusae, from the hydroids was observed from locally abundant colonies, among them the well-known fouling species Obelia dichotoma, potentially representing a nuisance for cultured fish through contact-driven envenomations and gill disorders. The results illustrate the potential importance of fouling hydroids and their medusae to the health of organisms in the aquaculture industry.

Highlights

Aquaculture is playing an increasing role in meeting the protein needs of the growing world population [1]
The objectives of the present work were to describe the colonization and succession of fouling hydrozoan assemblages on panels immersed beside an aquaculture facility at Taranto, Italy (Central Mediterranean Sea) to test the roles of seasonality, submersion duration, and depth in the structuring of the fouling hydroid assemblages and to identify the species of fouling hydrozoans potentially harmful to the farmed fish in the aquaculture facility
The study was conducted at an aquaculture facility that produces sea bass (Dicentrarchus labrax (Linnaeus, 1758)) and sea bream (Sparus aurata Linnaeus, 1758) located in an area of Hydroid succession dynamics in a fish farm muddy and sandy bottoms at the eastern sector of the Mar Grande basin in the Gulf of Taranto, NW Ionian Sea (40 ̊ 25’ 46.1” N, 17 ̊ 14’ 23.7” E)

Summary

Introduction

Aquaculture is playing an increasing role in meeting the protein needs of the growing world population [1]. The development of new aquaculture facilities has led to an increase in submerged structures such as floats, ropes, cages and nets that inadvertently provide favourable substrates for fouling organisms [2]. Hydroid succession dynamics in a fish farm analysis, decision to publish, or preparation of the manuscript

Objectives

Methods

Results

Conclusion