Offshore Aquaculture System Research Articles

Navigating offshore aquaculture: Efficient strategies for policymakers in transition

Coastal aquaculture faces significant environmental challenges, prompting consideration of relocating mariculture activities further offshore, termed offshore aquaculture (OA). However, the associated risks and costs have impeded the OA's growth, underscoring the need for sound policy direction. Utilizing game models, we evaluate the advantages of various policy strategies and explore the complex dynamics between stakeholders, which enhances policymakers' decision-making abilities regarding the OA's evolution. Data-driven insights reveal that: 1) A lack of policy intervention in the OA can lead to fierce market competition and unequal resource distribution, adversely affecting societal prosperity. 2) Policies centered around direct government investment in OA system or subsidizing enterprise-led initiatives can paradoxically compromise both societal welfare and the OA's sustainable growth. 3) Our analysis shows that subsidizing OA product production and consumption effectively mitigates the constraints observed in the previously mentioned policies, promoting societal welfare, and expanding the OA sector. Additionally, this approach stimulates the maximum enterprise investment in OA system, even if other policies might seem more directly supportive. 4) Policy enactment often witnesses erratic strategies from decision-makers. Within this spectrum, OA enterprises are highly susceptible to strategic chaos, with government missteps having the gravest repercussions on market equilibrium. In summary, this paper examines the theoretical advantages and challenges of various policies, coupled with paying attention to the intricate interactions and potential chaos phenomena of decision-makers in different scenarios. These findings are then used to offer corresponding policy insights, thereby empowering policymakers to better guide OA development.

Marine algae biomass energy source is increasing getting approval from policy maker and community. Beside production of seaweed for biomass energy, seaweed plantation has benefit for food, cosmetic, gelatin and pharmaceutical products. Large production of biomass will require deployment of very large multibody floating structure offshore. To ensure that the system is reliable, design needs to be built, a mooring

Marine algae biomass energy source is increasing getting approval from policy maker and community. Beside production of seaweed for biomass energy, seaweed plantation has benefit for food, cosmetic, gelatin and pharmaceutical products. Large production of biomass will require deployment of very large multibody floating structure offshore. To ensure that the system is reliable, design needs to be built, a mooring component for the mooring system, need to be properly sized to provide reliable strength for position keeping. This paper present, result of hydrodynamic test carried in UTM lab to determine coefficient required for the design and simulation of mooring system for very large floating structure for offshore aquaculture structure for ocean plantation, the paper also present safety and efficiency of the mooring system. Hydrodynamic test is traditionally used to secure coefficient require for design for environment for ship structure and offshore platform hydrodynamic interaction. The case of seaweed biomass is unique because the seaweed interacts directly and moves with the environment. The obtained the coefficient is used to model the static moorings system that assess the tension, tilt, safe mass and motion of the mooring components. Interpolated time dependent currents from the towing tank are used to estimate dynamic response of the mooring as well as the draft of the mooring components, the overall analysis is use to select required mooring components of the system. The outcome of the test presented in this paper will help for future development of offshore aquaculture system and multibody system deployment and analysis

Analysis of static structural of ocean FARMITS offshore cage due to environmental load

Consumption of fish in Indonesia continuously increase from 2000 to 2014. Particularly fish farming in Java from 2006-2014 is quite high, so there need to be adequate facilities for fish farming. Responding to these challenges, we developed Offshore Cage Ocean FARMITS technology specifically designed For the southern waters of Java Island. This paper discusses the static structure strength analysis of deformation and maximum yield strength that occurs on the offshore cage structure of Ocean FARMITS. The frame structure made of hollow pipe made from HDPE will be placed at 4,41m Wave Height, with a period of 19s. Numerical simulations are performed to obtain a motion response RAO and structural response due to random waves. This Structure is then analyzed under mooring conditions with the Catenary Mooring configuration. Rope stress that occur due to environmental loads will give tension stress to the structure, resulting in the offshore cage structure to occur maximum stress and deformation. The result of this research is to prove that the structure that is made by HDPE able to restrain the tension force of mooring line stress. This has been validated by the standard of Practical Aspects of Offshore Aquaculture System Design from Aquaculture America, so this structure can be said to be operating safely under Indonesian Irregular Wave.

Simulation of offshore aquaculture system for macro algae (seaweed) oceanic farming

ABSTRACTLarge-scale cultivation of seaweed has become one of the most important aquaculture activities in Malaysia which may help increase farmers’ incomes as well as seaweed itself can be processed into many beneficial end products. The present location of seaweed farming selected by farmers is situated close proximity to the coastline which is between 100 and 200 m from the seashore. The unfavourable condition of sea during rough sea with high wave and high speed of current is always a problem to the farmers since this environmental condition destroys their seaweed planting lines. To avoid the above problem, especially in monsoon prone area, a thorough analysis needs to be done in order to prevent environmental load from destroying seaweed platform on its mooring line when subjected to greater stress. The main objective of this study is to perform a simulation study which will allow analysis of the best mooring system for multi-body floating seaweed farm, together with understanding of the reliability and effectiveness of the system. This paper presents the design of seaweed platform model with mooring assessment in order to obtain a comprehensive and reliable seaweed mooring platform with the aid of mooring simulation software and model tests.

Perceived impact of offshore aquaculture area on small-scale fisheries: A fuzzy logic model approach

Recently an action plan has been put in place off southeastern Portugal, consisting in an offshore aquaculture area off the Armona sandy barrier island, Armona Pilot Production Aquaculture Area (APPAA). The infrastructure was created after the initiative of the Portuguese Government aiming to stimulate local employment opportunities related to seafood production. The APPAA aims to improve resilience of finfish and shellfish production for the future. However, the delimited infrastructure is located nearby some fishery-dependent communities. Therefore, such proximity may cause friction with some fishermen due to the limitations post APPAA development (e.g. may feel their jobs are threatened). In this study, we queried the reasoning rules elicited by local fishing communities and their perceived impact of the APPAA implementation. In that scope, a fuzzy logic expert system approach was used to investigate the interaction between three input variables (namely, ‘availability of fishable area’, ‘navigational disturbance’, and ‘catch variation’) and the output variable (i.e., overall ‘fishing community satisfaction’). The results from the fuzzy logic expert system showed that ‘catch variation’ was the input that most affected ‘fishing community satisfaction’ and seemed to be the one that suffered most changes. The results also show that, for the analyzed years, where the catch was higher, the degree of satisfaction tended to follow the trend, independently of the fishing community. The other two input variables were more conditioned by governmental arrangement (‘availability of fishable area’) and by small-scale fishermen reaction (‘navigational disturbance’). The fuzzy logic expert system proved to be a valuable tool, facilitating the analysis of governance arrangements, particularly those dealing with the interaction between the fisheries–offshore aquaculture system as a whole.

Effect of acoustic environment on gilthead sea bream (Sparus aurata): Sea and onshore aquaculture background noise

The present study evaluated the impact of sea background noise (the acoustic environment of the offshore aquaculture system) and onshore aquaculture system's ambient noise on the welfare of gilthead sea bream juveniles (Sparus aurata) through primary, secondary (biochemical and haematological indexes) and tertiary (growth performances) stress responses. The experiment lasted 120days during which two different playlists of acoustic stimuli were projected inside six experimental tanks (each condition was replicated in three tanks). Offshore aquaculture noise conditions were recreated as the typical acoustic field in proximity of an offshore sea cage for fish farming using a random sequence of quiet sea background and boat noises. The acoustic field inside an onshore open concrete tank for fish farming represented the onshore aquaculture noise conditions. The other three tanks were used as a control condition without acoustic projection. The weights and lengths of fish exposed to offshore aquaculture noise were higher than the specimens in the control and onshore aquaculture groups. Moreover, higher levels of serum cortisol, glucose, red blood cell count, haematocrit value and haemoglobin content and lower levels of white blood cells were recorded in fish groups from the control and onshore treatments. These results allow us to hypothesise that offshore aquaculture noise and the sea soundscape in particular positively influence growth performance and could reduce stress and improve the welfare of the sea bream.