Environmental friendly aquaculture key to sustainable fish farming development in Nigeria

Aquaculture production in Nigeria has increased tremendously in recent times; along with this increase is the rise in the level of waste outputs from aquaculture practices. The discharge of waste from aquaculture operations on continuous basis leads to eutrophication and destruction of natural ecosystem in receiving water body. Controlled wastes production strategies is necessary to maintain sustainable aquaculture growth into the future, as long-term sustainability of fish culture systems depends on their ability to reduce their waste outputs. The release of solid wastes is mainly a function of the digestibility of various dietary components while the release of dissolved wastes is mainly a function of the metabolism of nutrients by the fish. This paper critically reviews the impacts of aquaculture wastes on the environment and the strategies to mitigate the effect of these impacts. Future trends and research needs on aquaculture induced effluents are outlined. As the amount of nutrient discharge is typically site and operation specific, effective farm management has been identified as the most important factor to avoid effluent pollution

Marine shrimp culture industry of Thailand: operating guidelines for shrimp farms.

The marine shrimp industry in Thailand had developed a code of conduct for its operations. This code of conduct is a set of principles and processes that provides a framework to meet the industry’s goal for environmental, social, and economic responsibility. The foundation of the code of conduct is the following mission statement. The marine shrimp farming industry in Thailand is committed to producing high quality, hygienic products in a sustainable manner that provides for environmental, social, and economic benefits for the present and future generations. Policy statements have been formulated to outline actions that the industry will undertake to meet its commitments under the mission statement. These policy statements cover a broad range of topics, including: environmental protection, public consultation, regulatory compliance, location, quality and safety, continual improvement, efficiency, research and development, social responsibility, monitoring and auditing, education and training, international trade. The code of conduct is voluntary, but it has been signed by a wide variety of industry stakeholders. The code commits the signatories to specific actions, including the development of a series of operating guidelines and procedural manuals. These actions will aid the industry in carrying out its operations in a manner consistent with the objectives of the code of conduct

Growth and nutrient uptake of the seaweed Ulva ohnoi integrated in a Solea senegalensis recirculating system: influence of lighting, stocking density and CO2

The integrated production of fish and seaweeds can improve the sustainability of the marine aquaculture industry. Seaweeds remove the nutrients dissolved in fish-farm effluents and can become a good source of proteins, carbohydrates and bioactive compounds of commercial interestPostprint (published version

The Effect of Filtration with Natural Esker Sand on the Removal of Organic Carbon and Suspended Solids from the Effluent of Experimental Recirculating Aquaculture Systems

We studied the effect of sand filtration with natural esker material on the removal of total organic carbon (TOC), total suspended solids (TSS), and turbidity from the effluent of an experimental recirculating aquaculture system (RAS) farm. Separate experiments were performed with the same esker sand: (1) a soil column experiment in 2017 where the effluent (mean TOC 8.14 mg L−1) was percolated vertically through a 50-cm-thick sand column with the infiltration 1 m day−1; (2) a sand filtration experiment with watersaturated conditions in 2018 where the effluent from the woodchip denitrification (mean TOC 26.84 mg L−1) was infiltrated through a sand layer with the retention time of 1.2 days. In experiment 2, infiltration of 25 L day−1 through a 31-cm sand layer and 40 L day−1 through a 50-cm sand layer were studied. Both experiments were performed in association with rainbow trout (Oncorhynchus mykiss) grow-out trials. In sand filtration with vertical water flow through a soil column, the removal of TSS was 40%, while of TOC 6%, partly due to the small thickness of the soil column and coarse sand material. In water-saturated conditions, mean removal of TOC (3 mg L−1 1.2 day−1), TSS (1.2 mg L−1 1.2 day−1), and turbidity (0.4 FTU 1.2 day−1) reached 11% (TOC), 18% (TSS), and 15% (turbidity), even with the retention time of only 1.2 days. The removal of TOC in water-saturated conditions correlated with the removal of TSS and turbidity.202

Metal Distribution and Short-Time Variability in Recent Sediments from the Ganges River towards the Bay of Bengal (India)

The Ganges River receives inputs from highly populated cities of India (New Delhi, Calcutta, among others) and a strong influence of anthropogenic activities until reaching the Bay of Bengal. It is a seasonal river with 80% of discharges occurring between July and October during monsoon. The land-based activities next to the shore lead to discharges of untreated domestic and industrial e uents, inputs of agricultural chemicals, discharges of organic matter (cremations), and discharges of chemicals from aquaculture farms. In spite of the UNESCO declaring Human Patrimony the National Park Sundarbans, located in the delta, contamination has increased over time and it dramatically intensifies during the monsoon period due to the flooding of the drainage basin. Vertical element distribution (Cd, Co, Hg, Ni, Pb, and Zn) was studied in sediments collected in di erent stations towards the Hügli Estuary. Results determined no vertical gradient associated with the analyzed sediment samples, which informs about severe sediment dynamic in the area that probably relates to tidal hydrodynamics and seasonal variation floods. The multivariate analysis results showed di erent associations among metals and in some cases between some of them (Co, Zn, Pb, and Cu) and the organic carbon. These allow the identification of di erent geochemical processes in the area and their relationship with the sources of contamination such as discharge of domestic and industrial e uents and di use sources enhanced by the monsoons. Also, an environmental risk value was given to the studied area by comparing the analyzed concentrations to quality guidelines adopted in other countries. It showed an estimated risk associated with the concentration of the metal Cu measured in the area of Kadwip

Constructed Wetlands for Marine Aquaculture Wastewater Treatment: A New Challenge

Aquaculture is the fastest growing food production sector worldwide. Global demand for seafood continues to grow, and landbased aquaculture is expected to grow in order to meet the increasing market demand. In this context, marine aquaculture production systems are moving towards land-based farming. However, due to the large volumes of wastewater with high salinity and other fish-metabolism derived pollutants (e.g., nitrogen compounds), it remains a challenge for treatment of effluents from land-based marine aquaculture. In this scenario, development of environmental-friendly and efficient aquaculture effluent treatment system is crucial for sustainable intensification of aquaculture. Owing to low capital, operating costs, and low energy consumption, constructed wetlands (CWs) are becoming a promising technique to treat aquaculture effluents before discharge.Fil: Perez, Leonardo Martin. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Pontificia Universidad Católica Argentina "Santa María de los Buenos Aires". Facultad de Química e Ingeniería-Rosario; Argentina. Universidad Politécnica de Catalunya; España. Unesco; Argentin

Use of mangroves for aquaculture: Myanmar.

Aquaculture has only started to develop rapidly in the past few decades, due to better knowledge of culture species, improved methodologies and techniques in breeding, nutrition and increasing demand for food fish of high-value species such as shrimps, sea bass and groupers. Mangrove deforestation has an impact on shrimp culture itself, the success of the latter (when traditional culture method is used) depends on stocking of wild fry. For semi-intensive and intensive shrimp culture, the number of wild caught spawners may decrease because wild shrimp populations also use mangrove swamps as its feeding ground. Other negative effects of mangrove destruction to make way to shrimp ponds, include water pollution from pond effluents, sedimentation from the release of solid materials from pond, interruption of the tidal water flow, dwindling natural shrimp and fish stock due to increased pollution or product contamination due to indiscriminate use of chemicals. Chemicals and drugs (antibiotic) should not be used in fish and shrimp culture for prevention and control of bacteria and viral diseases. In order to ensure the sustainable development of aquaculture, it is important to bear in mind the interdependence of technology and natural resource under various socioeconomic setting

Environmental Dynamics in Animal Waste Reclamation in the Scaling up of Livestock in Thailand

Thailand has seen a scaling up of pig production in numbers and structure. Nonetheless, in-house separation and agricultural reclamation of pig solid waste are common practice. Waste reclamation is not taking place under small-scale farming and its environmental dynamics cannot be simply understood as a direct projection to larger scales. Scaling up has transformed the environmental significance of waste reclamation, including waste transfer from livestock to agriculture farmers. Waste transfer benefits pig farmers by trade and removal of waste by agriculture and aquaculture farmers and is key to the environmental dynamics of pig production. However, waste reclamation is not clearly defined as a management option in environmental frameworks. Waste management is mainly addressed as in-farm wastewater with limited attention to agro-environmental values of present practices. To recognise present practices in agro-environmental policies this thesis suggests a descriptive strategy focused on the transfer of waste. Such strategy would avoid command-and-control norms, avoid conflicting with an environmental culture centered in biogas technology and support knowledge transfer in agriculture. A focus on waste transfer from animal farms to agriculture [and aquaculture] plots is interpreted as off-site waste management. Off-site waste management calls for the inclusion of geographical variables beyond animal farms. This leads to an extended area of environmental influence (EAEI). Resulting environmental dynamics allows an interpretation of environment beyond resource in classical agricultural geography to a connotation where environment is also significant to agriculture and livestock because of the impacts from production. The recognition of reclamation practices and, consequently, of the integral environmental dynamics, and hence the connotation of environment, would contribute to connect livestock with agriculture through environmental geography. Intensive livestock is then defined as distribution and not location. Formalisation of reclamation practices entails the acknowledgment of agro-ecological cycles in livestock

Juncus emmanuelis

This species is endemic to a small area in the southwestern Iberian Peninsula, with subpopulations scattered in approximately 16 localities. It is assessed as Endangered (EN B2ab(ii,iii,iv)) because it has an Area of Occupancy (AOO) of less than 500 km2 and shows signs of severe fragmentation due to the ongoing transformation of its specific habitat of sandy soils with an impermeable underlayer in temporary pools, as a result of several ongoing major threats associated with intensive agricultural activities. Based on this information, a continuing decline in the AOO, habitat quality and number of subpopulations has been inferred. Additional research and conservation action is needed for this species

Interactive effects of solar UV radiation and ammonium on the biomass andnutritional compound production in tank cultivated Hydropuntia corne (Rhodophyta)

Figueroa et al. (2016) Acta Aquaculture 16, 331-332Introduction Hydropuntia cornea is a red alga species cultivated in tanks under nitrogen enrichment with high biomass production and content of high value bioactive compounds (Figueroa et al., 2012; Robledo et al, 2014). In this study, the combined effects (2 × 2 factorial design) of solar radiation (in door (I), green house cutting off the UV radiation and out-door (O) with UV radiation) and nitrogen (ammonium) under high (HN) and low (LN) levels on biomass production (g DW m-2 d-1), biofiltration as Nitrogen uptake efficiency (NUE, %) and Nitrogen uptake rate (NUR, mmol N m-2 h-1), photosynthetic activity as maximal electron transport rate (ETRmax), starch content and antioxidant activity were analyzed in H.cornea grown in tanks for 35 days in the above mentioned conditions. Material and methods The red seaweed Hydropuntia cornea was cultivated in cylindrical tanks of 90 L (0.17 m2 superficial area) with open flow-through N and P-enrichment (5 NH4Cl: 1 KHPO4, in a concentration ranges between 50 - 250 µM). Seaweed density assayed in tanks was 9 g FW L-1. Turnover rates were 64 and 6.4 vol d-1 in high and low flow rate, respectively. Photosynthetic activity was measured by using in vivo chlorophyll a fluorescence associated to photosystem II i.e. Electron transport rate (ETR) expressed as μmol electrons m-2 s-1. Starch (%) was determined according to anthrone method (Brooks et al. 1986) and antioxidant activity was evaluated following ABTS method (Ree et al., 1999) and expressed as Trolox equivalent (μM TEAC g-1 DW). Results Maximal photosynthetic production (ETRmax) increased throughout the culture time. (Fig. 1.A). After 35 d culture, ETRmax was higher under HN than that under LN both under in door and out door conditions (Fig.1A). However, biomass production expressed as g DW m-2 d-1 decreased throughout the experimental time (Fig 1.B). After 35d culture the highest biomass production was reached under HN-O and the lowest under LN-O although the differences were not so high (Fig.1B). The maximal efficiency of N assimilation (NUE %) was greater under LN (98%) than that under HN treatment (72%). NUE decreased throughout the time although after 35 d a clear increase was observed (Table 1). In contrast, the maximal nitrogen uptake rate (NUR) was higher under HN (45.5 mmol N m-2 h-1) than that under LN (25.8 mmol N m-2 h-1). The highest values of both NUE and NUR were obtained under solar radiation (outdoor treatments). Starch ranged from 25.1% (LN-I, 21 d) to 49.6 % (LN-O, 28 d) whereas the highest antioxidant activity was reached under LN-O after 21 d culture (68.5 μM TEAC g-1 DW). After 35d the highest level was again under LN-O (65.2 μM TEAC g-1 DW) followed by HN-O treatment (57.3 μM TEAC g-1 DW).Discussion and conclusions Ammonium supply, simulating fishpond effluents, and full solar irradiation (presence of UV radiation) have a positive effect on photosynthetic rate as ETRmax. The decrease in biomass production in spite of the increase of photosynthetic activity and nitrogen uptake rate is explained because the algae through the time could inverse more energy for the accumulation of metabolites (starch and antioxidant compounds) that that for growth. In any case the highest accumulation of starch and antioxidant activity were observed in the treatments associated to the greatest stress conditions i.e LN and outdoor culture due to UVR can negatively affect biological processes related to growth. As expected, under HN supply NUE was lower than that under LN but NUR was the reverse. H. cornea grown in simulated fishpond effluents displays a high biofiltration rate of inorganic N and accumulates commercially N compounds, as the photoprotector-antioxidant substances, mycosporine-like aminoacids (Figueroa et al., 2012) and C-compounds for nutritional uses or bioethanol production. In this study, the antioxidant activity was much higher than that reported in other seaweeds (Matanjun et al., 2008). H. cornea can be cultured and used to remove nutrient-rich fishpond effluents from aquaculture industries and besides, this biomass provides compounds of high added value for the biotechnology industry. References Brooks, J.R., Griffin, V.K., Kattan, M.W. 1986.A modified method for total carbohydrate analysisof glucose syrups, maltodextrins and other starch hydrolysis products. Cereal Chem 63:465-466. Figueroa, F. L., Korbee, N., Abdala, R., Jerez, C. G., López-de la Torre, M., Güenaga, L., Gómez-Pinchetti, J. L. 2012. Biofiltration of fishpond effluents and accumulation of N-compounds (phycobiliproteins and mycosporine-like amino acids) versus C-compounds (polysaccharides) in Hydropuntia cornea (Rhodophyta). Marine Pollution Bulletin, 64(2), 310-318. Matanjun, P., Mohamed, S., Mustapha, N.M., Ming, C.H. 2008. Antioxidant activities and phenolics content of eight species of seaweeds from north Borneo. J Appl Phycol 20:367–373. Re, R., Pellegrini, N., Proteggente, A., Pannala, A.,Yang,M., Rice-Evans, C. 1999. Antioxidant activity applying an improved ABTS radical cation decolorization assay. Free Radic Biol Med 26:1231–1237. Robledo, D., Navarro‐Angulo, L., Valdes Lozano, D., Freile‐Pelegrín, Y. 2014. Nutrient removal efficiency of Hydropuntia cornea in an integrated closed recirculation system with pink shrimp Farfantepenaeus brasiliensis. Aquaculture Research, 45(10), 1648-1658Universidad de Málaga.Campus de Excelencia Internacional Andalucia Tech