Economic feasibility study of organic and conventional fish farming systems of Indian major carps.

Organic aquaculture is a new approach in the modern farming system. As the capital investment is higher for setting up the organic aquaculture, it is essential to conduct an economic feasibility study with compare the conventional farming system. In the current study, economic feasibility of culturing Indian major carps (IMC) using conventional culture system and organic culture system (OCS) were evaluated. IMC was cultured for three consecutive years from 2017 to 2019 in experimental ponds of 0.015 hectare (ha) area each. The crude protein content of the organic and conventional feed was maintained at the same iso-nitrogenous level (32% crude protein) but the highest production to the tune of 19 tons per ha was obtained in OCS. Further, in case of OCS, apart from fish production, vermicomposting to the tune of 45,000 kg ha-1 in the first year, and 90,000 kg ha-1 from second year onward is achievable by installing a vermicomposting unit of 200 tons annual capacity. Economic analysis of the culture systems assuming a project period of 10 years showed that the highest net present value (NPV) of 1.06 million USD, a payback period of one year and nine months and an internal rate of return (IRR) of 51% are achievable per ha of fish culture pond for OCS. Sensitivity analysis of various costs performed for OCS revealed that profitability of the organic fish farming investment is most sensitive to the total fish production and sale price of the organic fishes. In terms of production of fish and economics of organic culture system is proved to be the best available technique.

Investigating the performance of a perforated pooled circular stepped cascade aeration system for intensive aquaculture.

Aeration plays a crucial role in aquaculture to maintain adequate dissolved oxygen (DO) levels in water, which is essential for supporting aquatic life. However, traditional aeration systems such as paddlewheel aerators or diffused air aerators often come with high energy consumption, frequent maintenance, and greater operational costs. To address these challenges, this research paper presents the development and evaluation of a more sustainable and cost-effective aerator, named the perforated pooled circular stepped cascade aerator (PPCSC), for intensive aquaculture. Laboratory experiments were conducted in a masonry tank to assess the performance of the PPCSC aerator with different bottom radii (Rb) and discharges (Q). The results showed that the highest standard aeration efficiency (SAE) of 4.564 ± 0.6662 kg O2/kWh was achieved with a bottom radii (Rb) of 0.75 m and a discharge (Q) of 0.016 m3/s. A developed regression model was found to effectively evaluate the standard oxygen transfer rate (SOTR) and SAE for different Rb and Q values used in the PPCSC system. Both Rb and Q were found to significantly impact the SOTR and SAE of the PPCSC aerator. Overall, the PPCSC aerator is a promising option for small-scale tank-based intensive aquaculture due to its high performance and lower operational costs.

Economic feasibility study of aerators in aquaculture using life cycle costing (LCC) approach.

Selection of aerator is a very important aspect in aquaculture operations. The selected aerator must be economically efficient and should be able to fulfil the requirement of oxygen supply in the pond water. In the present study, economic feasibility of nine different types of aerators, namely, perforated pooled circular stepped cascade (PPCSC), pooled circular stepped cascade (PCSC), circular stepped cascade (CSC), paddle wheel (PWA), spiral aerator (SA), propeller-aspirator-pump (PAA), submersible (SUBA), impeller aerator (IA) and air-jet aerator (AJA) was assessed based on capitalization method, a life cycle costing (LCC) approach. The results revealed that the PPCSC aerator can be considered as the most suitable aerator when dissolved oxygen (DO) content in the pond water is less than equal to 3 mg/L, and pond water volume (V) is less than 2100 m3. In other situations, mostly when pond water volume is more, IA proves to be the most suitable aerator, followed by PWA, PPCSC, and other available aerators. The sensitivity analysis conducted by using varying stocking density and capital cost also showed the same trend with regard to selection of aerators. This life cycle costing approach for selection of aerator can be implemented for any types of cultured species at any prevailing environmental conditions.