A Review of Unmanned System Technologies with Its Application to Aquaculture Farm Monitoring and Management

This paper aims to provide an overview of the capabilities of unmanned systems to monitor and manage aquaculture farms that support precision aquaculture using the Internet of Things. The locations of aquaculture farms are diverse, which is a big challenge on accessibility. For offshore fish cages, there is a difficulty and risk in the continuous monitoring considering the presence of waves, water currents, and other underwater environmental factors. Aquaculture farm management and surveillance operations require collecting data on water quality, water pollutants, water temperature, fish behavior, and current/wave velocity, which requires tremendous labor cost, and effort. Unmanned vehicle technologies provide greater efficiency and accuracy to execute these functions. They are even capable of cage detection and illegal fishing surveillance when equipped with sensors and other technologies. Additionally, to provide a more large-scale scope, this document explores the capacity of unmanned vehicles as a communication gateway to facilitate offshore cages equipped with robust, low-cost sensors capable of underwater and in-air wireless connectivity. The capabilities of existing commercial systems, the Internet of Things, and artificial intelligence combined with drones are also presented to provide a precise aquaculture framework.

The Influence of a Suspended Cage Aquaculture Farm on the Hydrodynamic Environment in a Semienclosed Bay, SE China

Hydrodynamic responses of the aquaculture farm structures have been increasingly studied because of their importance in informing the aquaculture carrying capacity and ecological sustainability. The hydrodynamical effect of the suspended cage farm on flow structures and vertical mixing in the Sansha Bay, SE China, is examined using observational data of two comparative stations inside and outside the cage farm. The results show that current velocities are relatively uniform in the vertical except a bottom boundary layer outside the cage farm. Within the cage farm, the surface boundary layer produced by the cage-induced friction is obvious with current velocities decreasing upward, combining the classic bottom boundary layer to form a “double-drag layers” structure in the water column. The cage-induced drag decreases with water depth in the surface boundary layer with a maximum thickness of 3/4 the water column, and the current velocities can be reduced by 54%. The cage-induced friction can also significantly hinder the horizontal water exchange in the farm. Periodic stratification phenomena exist at both stations under the influence of lateral circulation. However, the subsurface (5–10 m below the sea surface) water column below the cage facilities is well-mixed as indicated by the vertical density profile, where the velocity shear (10–3 m–2) is about 10 times higher than that of the subsurface layer outside the cage farm. Therefore, we speculate that the well-mixing of the subsurface water column results from the local turbulence induced by the velocity shear, which in turn is produced by the friction of cage structures.

Application of Ecological Indices using Macroinvertebrate Assemblages in Relation to Aquaculture Activities in Rawang Sub-basin, Selangor River, Malaysia

This study aimed to evaluate benthic macroinvertebrates assemblages using the application of ecological indices in the Rawang sub-basin of the Selangor River with reference to determining the impacts of aquaculture practices on benthic macroinvertebrates. In total, seven sampling sites were selected, namely Guntong (SR1), Guntong’s tributaries (SR2, control site), Kuang (SR3 and SR7), Gong (SR4), Buaya (SR5) and Serendah (SR6) Rivers. Sites were selected using a random sampling technique and the accessibility and proximity to aquaculture farms. Macroinvertebrates were sampled from April 2019 to March 2020 using an aquatic kick net, a hand spade, and a D-frame dip net. Water samples were also taken. Twenty-seven families belonging to the Annelida, Mollusca and Athropoda phyla were identified using taxonomic keys. Tubificidae was found to be the most dominant family (36.79%) followed by Chironomidae (28.84%). The highest number of individuals from family Tubificidae was recorded in Gong River, where effluent was discharged from an aquaculture farm. The total abundance of benthic macroinvertebrates increased with increased proximity to the aquaculture farm. Based on Biological Monitoring Working Party score value, the water quality of sampling sites in close proximity to the aquaculture farm was polluted as compared to the control location. Family Biotic Index score showed that all sites were substantially polluted with organic pollution, with the control site being much less polluted. In conclusion, benthic macroinvertebrates assemblage was affected by effluent originating from aquaculture farm outlets. It is therefore necessary to conduct aquaculture farming using methods that are deemed to be environmentally friendly.

A case study of Hangere integrated agriculture-aquaculture farm in Malawi.

The case study was undertaken to assess performance and sustainability of Hangere Agriculture-Aquaculture Integrated Farm. Data was collected during a seven-day visit at the farm (carried out on 7-14 June 2009), using a semi-structured questionnaire with open ended questions and a study of farm records and cash flows. Direct observations of farm operations were also reported. Hangere integrated agriculture-aquaculture farm is located in Mzuzu City, Mzimba District, Malawi and belongs to 37-year-old Mrs Liness Chavula. The farm has a total land holding of approximately 13 ha. Of this area, only 2.2 ha are used for aquaculture with three drainable ponds with a total area of 1804 m2. Of the remaining area, 4 ha are used for maize cultivation, 1.5 ha for growing sweet potatoes, and 1 ha is used for vegetables, including cassava and Rhodes grass Chloris gayana. The farm holds Tilapia rendalli and Oreochromis karongae in polyculture and Clarias gariepinus in monoculture. The fish are fed formulated diets and the ponds are fertilized with livestock manure. The fish are harvested three times yearly and are sold to wholesalers and retail with prices of K450/kg (US $3.21) and K500/kg (US $3.5), respectively. Pigs, goats and a dairy cow are also kept on the farm. In 2008 the farm made a profit of K289,000 (US $2,064), from the sale of field crops, livestock and fish. Of the K289,000 of profit, K100,000 (US $714) came from fish sales while K70,000 (US $500) came from maize sales, K28,000 (US $200) from pig sales and K50,000 (US $357) from sweet potatoes. The farm faces several challenges including labour shortages, absence of a hatchery facility for fingerling production and lack of available extension services. The farm experiences low water levels during the hot-dry season and pest infestation in the pond vicinity, both of which lower production. Hangere farm operates at a semi-intensive level, being integrated with other on-farm agriculture activities, and is a typical example of a small scale fish farm in Malawi. The farm has also begun cultivating new crops, mainly coffee and wheat, both of which are highly priced cash crops in Malawi. C. gariepinus (catfish) has also been introduced in ponds at the farm with the potential to reach 1 kg in body weight in 6 months.

Effects of aqua drugs and chemicals on the farmed shrimp (Penaeus monodon) in southern coastal region of Bangladesh

The study was conducted to observe the effects of aqua drugs and chemicals on the health of farmed shrimp (Penaeusmonodon) in southern coastal region of Bangladesh. Samples were collected from shrimp farms and ghers in three upazilas of Cox’s Bazar district, namely Cox’s Bazar Sadar, Teknaf and Maheshkhaliupazila during March 2018 to October 2018. Data were collected through personal contact, questionnaire interview and discussion with key informants. During the study period water temperature were ranged between 26°C to 32°C in summer and 23°C in rainy season. The highest pH was 8.0 ± 0.20 recorded from Beximco Shrimp Farm of Cox’s Bazar Sadar in summer and the lowest was 7.0 ± 0.23 from the Aquaculture Farm Limited of Cox’s Bazar Sadar. Farmers in the study areas used Geotox to remove gas, TSP to proliferate algae and Zymetin to inhibit growth of pathogens and to promote shrimp growth. The highest recovery was recorded 90-96% by use of Bleaching powder in Aquaculture Farm limited of Cox’s Bazar Sadar area. On the other hand, the lowest recovery was recorded 60-65% by use of Zeolite plus in Beximco shrimp farm of Cox’s Bazar Sadarupazila. The average recovery was recorded from Beximco shrimp farm of Cox’s Bazar Sadarupazila. By use of EcodoxinZoothamniumwas 80-85% recovery. Farmers used more aqua-drugs in rainy season than summer. By use of Oxyflow instant oxygen supply was recorded 75-80% recovery. The highest recovery was recorded 90-95% by use of Lime in Unique Aquaculture of Teknaf. On the other hand, the lowest recovery was recorded 60-65% by use of Renamox in MKA shrimp farm of Teknafupazila. The average recovery was recorded Unique Aquaculture of Teknafupazila. From field and laboratory observations it was revealed that the study area had potentiality for shrimp culture, although necessary measures need to be taken specially during rainy season. Asian J. Med. Biol. Res. September 2020, 6(3): 491-498

Seasonal Variation of Culturable Benthic Soil Prokaryotic Microbiota as Potential Fish Pathogens and Probiotics from an Aquaculture Farm in East Kolkata Wetlands, India

Rising demand in the aquaculture sector tends towards finding innovative ways to promote better yield and profitability. Benthic soil microbiota can provide an insight into the potent opportunistic fish pathogens as well as probiotics present in the aquaculture system. This study reports the seasonal diversity and abundance of fifteen culturable pathogenic bacterial strains belonging to the genera of Comamonas, Aeromonas, Providencia, Klebsiella, Escherichia, Acinetobacter, Serratia, Stenotrophomonas, Staphylococcus, and Enterobacter along with nine probiotic strains native to genera of Bacillus and Pseudomonas isolated from an aquaculture farm benthic soil, located in East Kolkata Wetlands, West Bengal, India. Strains are isolated using traditional microbial culture methods and tested for their antimicrobial susceptibility against commonly available antibiotics. 16S rDNA analysis was done for the identification of the strains and the establishment of their phylogenetic relationships. Among the isolates, B. pumilus strain S8 in the pre-monsoon sample, E. coli strain M2aR1 in the monsoon sample, and A. hydrophila strain P6dF1 in the post-monsoon sample were the most abundant having MPN counts of 275±21 x 106 CFU/gram dry soil, 278±18 x 106 CFU/gram dry soil, and 321±28 x 106 CFU/gram dry soil respectively. Data on the temporal diversity, abundance, and drug-susceptibility of prokaryotic fish-pathogens and probiotics can be used to formulate measures for sustainable aquaculture practices with reduced maintenance costs.