Benthic community response to sediment organic enrichment by Mediterranean fish farms: Case studies

AbstractNutrient enrichment is a significant cause of ecosystem change in coastal habitats worldwide. This study focuses on the change in a benthic macroinvertebrate community and environmental quality as assessed through different biotic indices following the construction of a sewage outfall pipe in the west of Scotland, from first implementation to seven years after operation of the pipe. Benthic macroinvertebrates are an important part of marine ecosystems because they mediate ecosystem processes and functions, are a key part of food webs and they provide many ecosystem services. Results indicated a clear change in benthic communities over time with an increase in species richness and changes to benthic community composition (specifically feeding type, bioturbation mode and ecological group) towards those indicative of organic enrichment. No clear spatial zonation was observed because organic carbon content increased over the entire area. According to a suite of benthic indices calculated, some negative changes were detectable following the start of sewage disposal, but largely negative community changes, and a change from ‘good’ to ‘moderate’ quality, only occurred seven years after implementation. The increase in species richness in response to increasing disturbance reduced the utility of a multi-metric index, the Infaunal Quality Index, which, instead of amplifying the signal of negative impact, dampened it. We suggest that any change in communities, regardless of direction, should be heeded, and species richness is a particularly sensitive and early warning indicator for this, but a suite of approaches is required to understand benthic community changes.

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Genetic identification of farmed and wild Atlantic cod, Gadus morhua, in coastal Norway

ICES Journal of Marine Science ◽

10.1093/icesjms/fsr048 ◽

2011 ◽

Vol 68 (5) ◽

pp. 901-910 ◽

Cited By ~ 30

Author(s):

Kevin A. Glover ◽

Geir Dahle ◽

Knut E. Jørstad

Keyword(s):

Case Studies ◽

Gadus Morhua ◽

Atlantic Cod ◽

Genetic Interactions ◽

Genetic Identification ◽

Fish Farms ◽

Multiple Sources ◽

Farmed Fish ◽

Farmed Escapees

Abstract Glover, K. A., Dahle, G., and Jørstad, K. E. 2011. Genetic identification of farmed and wild Atlantic cod, Gadus morhua, in coastal Norway. – ICES Journal of Marine Science, 68: 901–910. Each year thousands of Atlantic cod escape from Norwegian fish farms. To investigate the potential for the genetic identification of farmed–escaped cod in the wild, three case studies were examined. Samples of farmed, recaptured farmed escapees, and wild cod were screened for ten microsatellite loci and the Pan I locus. Variable genetic differences were observed among cod sampled from different farms and cages (pairwise FST = 0.0–0.1), and in two of the case studies, the most likely farm(s) of origin for most of the recaptured escapees were identified. In case study 2, wild cod were genetically distinct from both farmed fish (pairwise FST = 0.026–0.06) and recaptured farmed–escaped cod (pairwise FST = 0.029 and 0.039), demonstrating the potential to detect genetic interactions in that fjord. Genetic identification of escapees was more challenging in case study 3, and some morphologically characterized wild cod were found to most likely represent farmed escapees. It is concluded that where cod are farmed in the same region as their own parents/grandparents were initially sourced, or where farmed escapees originate from multiple sources, quantifying genetic interactions with wild populations will be challenging with neutral or nearly neutral markers such as microsatellites.

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Carriage of potentially fish-pathogenic bacteria in Sparus aurata cultured in Mediterranean fish farms

Diseases of Aquatic Organisms ◽

10.3354/dao054119 ◽

2003 ◽

Vol 54 ◽

pp. 119-126 ◽

Cited By ~ 39

Author(s):

MJ Pujalte ◽

A Sitjà-Bobadilla ◽

P Álvarez-Pellitero ◽

E Garay

Keyword(s):

Pathogenic Bacteria ◽

Sparus Aurata ◽

Fish Farms ◽

Mediterranean Fish

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Experience From Introduction of the Design Code NS 9415 to the Aquaculture Industry in Norway and Expanding the Scope to Cover Also Operations

Volume 9: Offshore Geotechnics; Torgeir Moan Honoring Symposium ◽

10.1115/omae2017-62426 ◽

2017 ◽

Cited By ~ 1

Author(s):

Are Johan Berstad ◽

Line Fludal Heimstad

Keyword(s):

Case Studies ◽

Design Code ◽

Fish Farms ◽

Current State ◽

Aquaculture Industry

This paper presents the current state of regulations, guidelines and the engineering in the Norwegian aquaculture industry. The statistics of fish escapes is evaluated and the need for further developments of the regulations, in planned revisions, of the Norwegian standard, are laid. Simplified case studies are shown to present the main forces acting on fish farms.

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