Design Rules for Marine Fish Farms in Norway: Calculation of the Structural Response of Such Flexible Structures to Verify Structural Integrity

2004 ◽  
Author(s):  
Are Johan Berstad ◽  
Harald Tronstad ◽  
Anders Ytterland
Keyword(s):  
Marine Fish ◽  
Structural Integrity ◽  
Flexible Structures ◽  
Structural Response ◽  
Fish Farm ◽  
Practical Calculation ◽  
Fish Farms ◽  
Good Correspondence ◽  
Design Rules ◽  
Farm Structures

As of April 1st 2004 all new marine fish farms in Norway need to be certified to comply with technical criteria in a new Norwegian Standard, NS 9415 (NAS, 2003). This paper gives an overview of the design rules. Marine fish farms have a strongly flexible hydroelastic behavior. The design rules have revealed the need for calculations to verify the structural capacity of such facilities. This paper describes how loads and response are derived on the fish farm structures. In order to account for the large geometrical deflections occurring in fish farm components such as the net and anchor cables which interacts with stiffer structural components, time domain simulations analysis of such facilities is required to assess the structural integrity. This paper report a proposed practical calculation method and results from model tests have been carried out to validate calculations. Good correspondence was shown. Additionally some applications are described.

Environmental Description in the Design of Fish Farms at Exposed Locations

2017 ◽  
Author(s):  
David Kristiansen ◽  
Vegard Aksnes ◽  
Biao Su ◽  
Pål Lader ◽  
Hans V. Bjelland
Keyword(s):  
Marine Fish ◽  
Environmental Conditions ◽  
Measurement Data ◽  
Field Measurements ◽  
Fish Farm ◽  
Fish Farms ◽  
Coastal Regions ◽  
Waves And Currents ◽  
Farm Structures

This paper addresses the description of exposure from waves and currents in coastal regions for design of marine fish farms. Representative descriptions of environmental conditions are important inputs to the design and dimensioning of reliable fish farm structures. A trend with moving production to more exposed sites and introduction of new and novel fish farm structures increase the need for more precise descriptions of the marine environment to keep control of uncertainties in design. Dedicated field measurements at two exposed aquaculture sites from February to December 2016 are presented. Results from statistical analyses of the measurement data demonstrate that common practice for characterization of exposure in design of fish farms has several deficiencies that should be improved to reduce uncertainties in design.

scholarly journals Digital Droplet PCR-Based Environmental DNA Tool for Monitoring Cryptocaryon irritans in a Marine Fish Farm from Hong Kong

Diversity ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 350
Author(s):  
Hin Hung Tsang ◽  
Jose A. Domingos ◽  
Jacob A. F. Westaway ◽  
Maximilian H. Y. Kam ◽  
Roger Huerlimann ◽  
...  
Keyword(s):  
Hong Kong ◽  
Marine Fish ◽  
Environmental Control ◽  
Environmental Dna ◽  
Fish Farm ◽  
Fish Farms ◽  
Cryptocaryon Irritans ◽  
Digital Droplet Pcr ◽  
Physical Chemical ◽  
Droplet Pcr

The adoption of new investigative strategies based on environmental DNA (eDNA) can be used to monitor parasites, associated bacterial microbiomes, and physical-chemical parameters in fish farms. In this study, we used the economically important and globally distributed fish ciliate parasite Cryptocaryon irritans as a model to understand the parasite abundance and potential drivers of its presence in marine fish farms. Environmental (rainfall) and physical-chemical (temperature, oxygen, salinity, pH) data collected from a marine fish farm in Hong Kong were analyzed together with the eDNA approach targeting C. irritans abundance based on digital droplet PCR and 16S metagenomics to determine associations and triggers between parasites and specific bacterial groups. Rainfall and temperature demonstrated positive associations with high abundance of C. irritans (eDNA) at the studied marine fish cage farm. However, rainfall was the only parameter tested that demonstrated a significant association with parasite eDNA, indicating that the raining season is a risky period for fish farmers in Hong Kong. Coraliomargarita was the bacterial genus with the most significant relationship with low abundance of C. irritans in water. Understanding the environmental triggers of ciliate parasites propagation and associated bacterial microbiome could elucidate new insights into environmental control, microbial management, and promote the reduction of chemical use in marine fish farms.

scholarly journals Development of a Hydropower Turbine Using Seawater from a Fish Farm

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 266
Author(s):  
Md Rakibuzzaman ◽  
Sang-Ho Suh ◽  
Hyoung-Ho Kim ◽  
Youngtae Ryu ◽  
Kyung Yup Kim
Keyword(s):  
Power Plants ◽  
Guide Vane ◽  
Cross Flow ◽  
Synchronous Generator ◽  
Fish Farm ◽  
Hydropower Plant ◽  
Fish Farms ◽  
Data Simulation ◽  
Small Hydropower ◽  
Hydropower Plants

Discharge water from fish farms is a clean, renewable, and abundant energy source that has been used to obtain renewable energy via small hydropower plants. Small hydropower plants may be installed at offshore fish farms where suitable water is obtained throughout the year. It is necessary to meet the challenges of developing small hydropower systems, including sustainability and turbine efficiency. The main objective of this study was to investigate the possibility of constructing a small hydropower plant and develop 100 kW class propeller-type turbines in a fish farm with a permanent magnet synchronous generator (PMSG). The turbine was optimized using a computer simulation, and an experiment was conducted to obtain performance data. Simulation results were then validated with experimental results. Results revealed that streamlining the designed shape of the guide vane reduced the flow separation and improved the efficiency of the turbine. Optimizing the shape of the runner vane decreased the flow rate, reducing the water power and increasing the efficiency by about 5.57%. Also, results revealed that tubular or cross-flow turbines could be suitable for use in fish farm power plants, and the generator used should be waterproofed to avoid exposure to seawater.

Feasibility of Repurposing Offshore Decommissioned Gas Rigs into Fish Farms

2021 ◽  
Author(s):  
Saptarshi Pal ◽  
Chengi Kuo
Keyword(s):  
North Sea ◽  
Net Present Value ◽  
Cost Benefit Analysis ◽  
Storage System ◽  
Artificial Reef ◽  
Cost Benefit ◽  
Fish Farm ◽  
Fish Feed ◽  
Offshore Platforms ◽  
Fish Farms

Abstract In the past 70 years the world has relied extensively for its energy needs based on hydrocarbons produced significantly offshore. In recent years many installations with fixed platforms and pipelines are reaching the end of their useful life and are required by law to be decommissioned and removed if an approved alternative use cannot be found. This process coincides with focus on decarbonization arising from global warming and climate change. The conventional way of decommissioning is to remove the structure and take it onshore for disposal. Such an activity costs around £28 million for smaller UKCS installations in the Southern North Sea. Possible alternative solutions include their use as a research-leisure complex and artificial reef. Such an approach would have less impact on the environment and it is therefore worthwhile to explore the feasibility of repurposing these decommissioned UKCS platforms. The paper begins by highlighting the background to UKCS offshore decommissioning and farming fish life-cycle. This is followed by a critical review of the three options of total and partial removals and leave-on-site. It is found that repurposing decommissioned platforms for aquaculture farm has not been given sufficient attention and thus offers scope for a project to explore the feasibility of such a solution. Existing offshore fish farming in various countries are examined before using a decision-making matrix to select the most suitable UKCS installation for conversion and this led to using a normally unattended gas platform for the case study. The focus for this paper is on design and operation of an unattended fish farm and its cost benefit analysis. The former covers fish cage selection, capacity calculation, fish handling procedures, fish feed characteristics, feed demand, designing feed logistics and storage system. The processing facilities are layout on two decks and power needs are generated using a hybrid system of diesel and Li-ion battery. The possibility of using renewable sources by connecting to wind energy grids was also considered. For the latter capital and operating expenditure, revenue generated and maintenance costs are estimated before performing net present value prediction of the profitability of the fish farm over 10 years with for example up to 8 cages and three discount rates. The main conclusions derived are: It is technically feasible to convert a decommissioned gas platform to a fish farm and the operation can be economic. However, liability transfer implications in a repurposed offshore decommissioned gas platforms to fish farms were not established to verify the project viability. The conversion of unattended offshore gas platforms in the UKCS to an automated offshore fish farm is a novel solution which has not been implemented in the North Sea before. The work will provide an economic and environmental friendly solution to decommissioning offshore platforms and provide with a possible profitable investment.

Impacts of a marine fish farm in Argolikos Gulf (Greece) on the water column and the sediment

Desalination ◽  
2007 ◽  
Vol 210 (1-3) ◽  
pp. 110-124 ◽  
Author(s):  
E. Mantzavrakos ◽  
M. Kornaros ◽  
G. Lyberatos ◽  
P. Kaspiris
Keyword(s):  
Water Column ◽  
Marine Fish ◽  
Fish Farm

scholarly journals ARMOUR UNIT STRUCTURAL RESPONSE - A PARAMETRIC STUDY

1988 ◽  
Vol 1 (21) ◽  
pp. 176
Author(s):  
C. David Anglin ◽  
William F. Baird ◽  
Etienne P.D. Mansard ◽  
R. Douglas Scott ◽  
David J. Turcke
Keyword(s):  
Wave Height ◽  
Parametric Study ◽  
Structural Integrity ◽  
Design Procedure ◽  
Structural Response ◽  
Design Parameters ◽  
Coastal Structures ◽  
Log Normal ◽  
Wave Induced ◽  
Hydraulic Stability

There is a general lack of knowledge regarding the nature and magnitude of loads acting on armour units used for the protection of rubblemound coastal structures. Thus, a comprehensive design procedure incorporating both the hydraulic stability and the structural integrity of the armour units does not exist. This paper presents the results of a detailed parametric study of the structural response of armour units to wave-induced loading in a physical breakwater model. The effect of the following design parameters is investigated: breakwater slope, armour unit location, wave period and wave height. This research has made a number of significant contributions towards the development of a comprehensive design procedure for concrete armour units. It has identified a linear relationship between the wave-induced stress in the armour units and the incident wave height. In addition, it has shown that the conditional probability of waveinduced stress given wave height can be estimated by a log-normal distribution. Finally, a preliminary design chart has been developed which incorporates both the structural integrity and the hydraulic stability of the armour units.

scholarly journals Histamine Level in Freshwater and Marine Fish Sold in Bulgarian Markets

2020 ◽  
Author(s):  
D. Bangieva ◽  
D. Stratev ◽  
T. Stoyanchev
Keyword(s):  
Marine Fish ◽  
Enzyme Linked Immunosorbent Assay ◽  
Fish Farms ◽  
Histamine Concentration ◽  
Microbial Decomposition ◽  
Fish Samples ◽  
Low Levels ◽  
Processing And Storage ◽  
Seafood Processing ◽  
And Storage

Background: Histamine is an essential biogenic amine produced as a result of microbial decomposition of histidine during seafood processing and storage. The objective of this study was to evaluate histamine concentration in freshwater and marine fish marketed in Stara Zagora region, Bulgaria. Methods: Forty fish samples were purchased from local fish farms and retail stores in Stara Zagora, Bulgaria. Enzyme-Linked Immunosorbent Assay was used to determine histamine levels. The data were processed using GraphPad Software InStat 3. Results: Histamine was detected in 26 out of 40 (65%) samples, and none of them exceeded the regulatory limit of 200 mg/kg. The average histamine content in marine fish (6.965±3.187 mg/kg) was insignificantly (p>0.05) higher than that in freshwater fish (4.503±1.133 mg/kg). Conclusion: The results reveal low levels of histamine in freshwater and marine fish indicating their good quality. However, its presence in seafoods remains a major food safety problem that requires permanent regulation of histamine concentration in fish.  

Floc and sediment properties and their environmental distribution from a marine fish farm

2004 ◽  
Vol 35 (5) ◽  
pp. 483-493 ◽  
Author(s):  
E Kate Schendel ◽  
Susanne E Nordstrom ◽  
Les M Lavkulich
Keyword(s):  
Marine Fish ◽  
Fish Farm ◽  
Environmental Distribution ◽  
Sediment Properties

Assessing changes in the toxicity of effluents from intensive marine fish farms over time by using a battery of bioassays

2018 ◽  
Vol 25 (13) ◽  
pp. 12739-12748 ◽  
Author(s):  
Carlos Carballeira ◽  
Alesandra Cebro ◽  
Rubén Villares ◽  
Alejo Carballeira
Keyword(s):  
Marine Fish ◽  
Fish Farms ◽  
Over Time ◽  
Battery Of Bioassays
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