Water Quality Management In Aquaculture Research Articles

Water Quality Management in Aquaculture

Water Quality Management in Aquaculture

Fuzzy comprehensive evaluation of seawater quality of Larimichthys Crocea mariculture areas in Zhoushan, China

Context Aquaculture is an essential industry and assessing its impact on the environment, particularly water quality, is crucial for sustainable practices. This study aimed to comprehensively evaluate the seawater quality in the Dongji Island yellow croaker (Larimichthys crocea) aquaculture area by using the fuzzy comprehensive evaluation method and field survey. Aims The main objective of this study was to assess the seawater quality in the aquaculture area during 2 consecutive years (2019 and 2020) on the basis of monitoring data. Methods The researchers utilised the fuzzy comprehensive evaluation method to assess seawater quality in the Dongji Island yellow croaker aquaculture area. Seawater monitoring data from 6 months in 2019 and 6 months in 2020 were collected for the evaluation. The method included an annual average evaluation, and membership degrees were calculated for each year and individual months. Qualitative interviews with 30 local fish farmers were conducted to unravel the challenges faced by aquaculture water quality management. Key results The evaluation results indicated that the seawater quality in the aquaculture area was classified as Class I water in both 2019 and 2020 on the basis of the annual average evaluation. However, the membership degrees for 2019 were higher than those for 2020, suggesting that water quality was better in 2019. Furthermore, individual monthly evaluations in 2020 showed varying membership degrees, with May and June having higher membership degrees, indicating better water quality than in other months. August had the lowest membership degree, implying poorer water quality during that month. Conclusions The study demonstrated that the fuzzy comprehensive evaluation method is effective for evaluating seawater quality in aquaculture areas. It also concluded that the water quality in 2019 was superior to that in 2020, raising concerns about potential environmental degradation. Implications The quantitative and qualitative findings of this research have important implications for aquaculture practices in the Zhoushan area. The study highlights the need for continued monitoring and management of water quality to ensure sustainable aquaculture practices and adherence to water-quality policies. Future aquaculture endeavours in the region should consider the potential impact on water quality to maintain a healthy ecosystem.

Long‐Term Changes and Influencing Factors of Water Quality in Aquaculture Dominated Lakes Unveiled by Sediment Records and Time Series Remote Sensing Images

AbstractHydraulic connectivity has great effects on water quality. Enclosure aquaculture can largely alter lake flow regime and thus deteriorate water quality. Understanding the dynamics and influencing factors of water quality in enclosure aquaculture lakes is of great significance to ecosystem restoration of degraded lakes. However, it remains challenging due to the lack of long time series data. In this study, the dynamics of water quality in aquaculture dominated lakes were captured through 210Pb and 137Cs dating based on sediment records. Meanwhile, the effects of landscape pattern within aquaculture lakes on water quality were revealed by long time series of remote sensing images. Results showed the 210Pb and 137Cs sediment dating could provide an effective way to obtain long‐term series of lake water quality data in the unmonitored area. The contents of lake sediment nutrients showed an upward trend from 1960 to 2018. The transformation of lakes from agriculture dominated to aquaculture dominated had increased sediment nutrients level. The long‐term changes of lake sediment nutrients could be well explained by the landscape pattern metrics within aquaculture lakes, with an average explain power of 87.6%. The configuration metrics at class level had the most contribution (73.6%) to the changes of lake sediment nutrients, followed by the composition metrics (48.8%) and the configuration metrics at landscape level (33.4%). This study can provide a promising method to understand water quality changes in lakes with no historical monitoring data available and is of great benefit to water quality management in aquaculture dominated lakes.

Characterizations of sulfur oxidizing bacteria from extensive shrimp ponds

The aim of this study is to characterize the sulfur oxidizing bacteria (SOB) isolates from the sediments of extensive shrimp ponds for recommending the use of this group for water quality management in aquaculture. Sediment samples were collected from 12 extensive shrimp ponds located in Tra Vinh, Soc Trang, Bac Lieu, and Ca Mau provinces. To screen the potential sulfur oxidizing bacteria, medium was amended with sodium thiosulfate, and the sulfate ion production ability and sulfur oxidase enzyme activity of the isolates were measured spectrophotometrically. Results showed that 30 isolates grew on the thiosulfate agar medium. Among these, only five isolates reduced the pH of the growth medium and showed high sulfur oxidase activity and production of sulfate ion when isolates were inoculated with thiosulfate as a substrate. Physiological and biochemical tests indicated that five selected isolates were Gram negative, short rod, non-motile, non-spore forming, negative for oxidase reaction, and positive for catalase reaction. The isolates SOBTB1.1 and SOBTB6.2 showed the significantly higher sulfur oxidase activity and production of sulfate ion compared to other isolates. SOBTB6.2 isolate produced sulfate ion and exhibited higher sulfur oxidase activity at pH4-5, followed by pH6-7. It is, therefore, suggested that the SOBTB 1.1 and SOBTB6.2 could be promising sulfur oxidizers for further research and uses in aquaculture.

An Enhanced Extreme Learning Machine for Dissolved Oxygen Prediction in Wireless Sensor Networks

Water quality monitoring using Wireless Sensor Networks (WSNs) is essential in aquaculture water quality management. In the field of water quality monitoring, dissolved oxygen (DO) is a key parameter, and its prediction can provide decision support for aquaculture production, thereby reducing farming risk. However, it is difficult to build a precise prediction model, and existing methods of DO prediction neglect the importance of analyzing DO content. To address this problem, this study proposes a hybrid DO prediction model, named KIG-ELM, which is composed of K-means, improved genetic algorithm (IGA), and extreme learning machine (ELM). This model is based on edge computing architecture, in which data acquisition, processing and dissolved oxygen prediction are distributed in sensing nodes, routing nodes and server respectively. Sensing technique and clustering operation are applied in the process of data acquisition and processing. Meanwhile, an optimized extreme learning machine is implemented for DO prediction. We evaluate the efficiency and accuracy of proposed prediction approach in a practical aquaculture on massive water quality data. Experimental results show that the hybrid model achieves significant prediction results and can meet the needs of practical production and management.

Biopotentiality of High Efficient Aerobic Denitrifier Bacillus megaterium S379 for Intensive Aquaculture Water Quality Management

Excessive nitrite accumulation is a very tough issue for intensive aquaculture. A high efficient aerobic denitrifier Bacillus megaterium S379 with 91.71±0.17% of NO2--N (65 mg L-1) removal was successfully isolated for solving the problem. Denitrification of S379 showed excellent environment adaptation that it kept high nitrite removal ratio (more than 85%) when temperature ranged from 25°C to 40°C and pH varied between 7.0 and 9.0, and could endure as high as 560 mg L-1 of NO2--N. Immobilization of S379 could enhance denitrification even when NO2--N adding amount got to 340 mg L-1. Immobilized cells also showed well pollutants removal performance in aquaculture wastewater treatment. Moreover, S379 possessed positive hydrolase activities for starch, casein, cellulose and fat and bore more than 60 ppt of salinity. Totally, all the results revealed significant potentiality of immobilized S379 applied in aquaculture water quality management.

Experimental study to evaluate the efficacy of locally available waste carbon sources on aquaculture water quality management using biofloc technology

Locally available carbonaceous waste products viz. wheat flour, rice flour and tapioca flour recovered from flour industries were explored as carbon source for biofloc production and water quality management in light limited indoor aquariums without any culture species. The main objective of the study was to find out the efficacy of locally available waste carbon sources on biofloc production. Tapioca flour was found to be encompassed with more than 90% carbohydrate and was observed more suitable for microbial growth, resulting in 41.4 and 33.7% higher floc formation as compared to rice flour and wheat flour, respectively. In addition, enhanced microbial protein assimilation of 33.5% was noted in tapioca flour biofloc system with respect to wheat flour (27%) and rice flour (23.75%). All biofloc systems showed adequate water quality management in terms of nitrite and total ammonium nitrogen removal from the culture tank. The study demonstrates the effective use of waste products from flour industries in biofloc technology to obtain multi-layer benefit as waste minimization and water treatment.

Determining oxygen consumption rate and asphyxiation point in Chanodichthys mongolicus using an improved respirometer chamber

Knowledge of oxygen consumption rates and asphyxiation points in fish is important to determine appropriate stocking and water quality management in aquaculture. The oxygen consumption rate and asphyxiation point in Chanodichthys mongolicus were detected under laboratory conditions using an improved respirometer chamber. The results revealed that more accurate estimates can be obtained by adjusting the volume of the respirometer chamber, which may avoid system errors caused by either repeatedly adjusting fish density or selecting different equipment specifications. The oxygen consumption rate and asphyxiation point of C. mongolicus increased with increasing water temperature and decreasing fish size. Changes in the C. mongolicus oxygen consumption rate were divided into three stages at water temperatures of 11–33°C: (1) a low temperature oxygen consumption rate stage when water temperature was 11–19°C, (2) the optimum temperature oxygen consumption rate stage when water temperature was 19–23°C, and (3) a high temperature oxygen consumption rate stage when water temperature was > 27°C. The temperature quotients (Q10) obtained suggested that C. mongolicus preferred a temperature range of 19–23°C. At 19°C, C. mongolicus exhibited higher oxygen consumption rates during the day when the maximum values were observed at 10:00 and 14:00 than at night when the minimum occurred at 02:00.

Biofilters for water reuse in aquaculture

Aquaculture is a rapidly expanding industry in Australia and around the world. The majority of aquaculture operations employ flow through systems whereby residual feed and metabolic products are discharged to a nearby water body. In many countries, the discharge of nutrients rich aquaculture waters has contributed to the degradation of water quality in receiving water bodies. Aquaculture's dependency on water resources ultimately makes water recycling an attractive waste management option. Submerged flow biofilters, utilising a filter media with specific surface area of approximately 141m2/m3, were used to remove nitrogen and phosphorus from a synthetic fish farm water. Three biofilter systems were tested for nitrification, nitrification followed by denitrification, and combined nutrients removal. Successful carbon removal and nitrification were achieved in the nitrification system. The nitrification/denitrification biofilters achieved complete denitrification and nitrogen removal. The cyclic aerated/unaerated combined nutrients removal system achieved approximately 40 percent phosphorus removal, complete nitrification and 40 percent denitrification. The study demonstrated the viability of using biofilters for nutrients removal from fish farm waters. Biofilters are readily designed and constructed in modular form which makes such systems particularly useful for water quality management in aquaculture.

Biofilters for water reuse in aquaculture

Aquaculture is a rapidly expanding industry in Australia and around the world. The majority of aquaculture operations employ flow through systems whereby residual feed and metabolic products are discharged to a nearby water body. In many countries, the discharge of nutrients rich aquaculture waters has contributed to the degradation of water quality in receiving water bodies. Aquaculture's dependency on water resources ultimately makes water recycling an attractive waste management option.Submerged flow biofilters, utilising a filter media with specific surface area of approximately 141 m3/m3, were used to remove nitrogen and phosphorus from a synthetic fish farm water. Three biofilter systems were tested for nitrification, nitrification followed by denitrification, and combined nutrients removal. Successful carbon removal and nitrification were achieved in the nitrification system. The nitrification/denitrification biofilters achieved complete denitrification and nitrogen removal. The cyclic aerated/unaerated combined nutrients removal system achieved approximately 40 percent phosphorus removal, complete nitrification and 40 percent denitrification. The study demonstrated the viability of using biofilters for nutrients removal from fish farm waters. Biofilters are readily designed and constructed in modular form which makes such systems particularly useful for water quality management in aquaculture.