Aquaculture Waste Research Articles

Performance Evaluation of Aquaponics-Waste-Based Biochar as a Cathode Catalyst in Sediment Microbial Fuel Cells for Integrated Multitrophic Aquaculture Systems

The sustainable development of aquaculture faces a significant challenge due to the need for the frequent treatment of aquacultural waste. This research presents a pioneering solution by concurrently utilizing aquacultural waste to produce biochar and enhancing a sediment microbial fuel cell (SMFC)’s treatment efficacy for waste generated from the integrated multitrophic aquaculture (IMTA) system. The water quality parameters of the aquacultural pond water were analyzed, and synthetic wastewater was prepared to validate the system’s efficiency. Over a period of more than 50 days, the SMFC was operated and monitored, yielding an average chemical oxygen demand (COD) removal efficiency of 86.31 ± 2.18%. The maximum operating voltage of the SMFC reached 0.422 V on the 21st day of operation when connected to an external resistance of 975 Ω. A novel-activated aquacultural biochar catalyst was synthesized from aquaponics waste and used as a cathode catalyst, substantially improving the SMFC’s performance. Characterization studies demonstrated that the aquacultural biochar catalyst was an active electrocatalyst, accelerating the oxygen reduction reaction rate and leading to increased power output and overall efficiency of the SMFC. The SMFC utilizing the aquacultural-waste-based biochar cathode catalyst showcased the highest maximum power density, with a range of 101.63 mW/m2 (1693.83 mW/m3), and the lowest internal resistance, indicating superior performance. These results validate the reliability of implementing SMFCs in actual aquaculture systems. A novel modular design for SMFC reactor-assisted small-scale integrated poultry–fish culture systems is proposed for further practical application in real-life aquaculture settings. This research contributes to finding sustainable and effective methods for waste treatment for aquaculture, promoting the development of environmentally friendly practices in the industry.

QUALITY OF Tetraselmis sp. CULTURED BY TIGER SHRIMP AQUACULTURE WASTE AS FERTILIZER

Tiger shrimp aquaculture waste still contained amount of nutrients needed by phytoplankton for its growth. Among nutrients was resulted from intensive aquaculture still can be used by phytoplankton. Phytoplankton used nitrates and phosphates for its growth and development. Phytoplankton requires nitrate concentration in 0,9-3,5 mg/ and phosphate in 0,27-5,51 mg/l. Utilization of tiger shrimp aquaculture waste for Tetraselmis sp. quality can be seen using fluorescence microscope with the cell of Tetraselmis sp. had to stained by acridine orange before observed using fluorescence microscope. The concept of this staining when cells of Tetraselmis sp. radiated green colour showed that cells was alive whereas cells radiated orange colour showed that cells was dead or damaged. This matter caused living cells could reducted acridine orange pigment enzymatically until become green radiated cells, instead damaged cells showed orange colour. Research procedures included cultivating Tetraselmis sp. in various dosages waste of tiger shrimp aquaculture as fertilizer. This various dosages are 2 g/l, 4 g/l, 6 g/l and 8 g/l. Culture media for Tetraselmis sp. was saltwater. Sterile saltwater was put into jars about 1 L and later added wastewater to jars. Reading of protein expression helped using imageJ software that showed histogram graphics accompanied by mean. Mean resulted by graphics indicated protein could be expressed. Based on expression of fluorescence protein with 2 g/l wastewater dosage showed that amount of protein could be ecpressed was higher than other wastewater dosage by mean value from ImageJ.

Potential Use of Oyster Shell Waste in the Composition of Construction Composites: A Review

The oyster shell is a residue rich in calcium carbonate, which can be reused as a raw material for creating building materials. For this reason, many researchers focused on the incorporation of oyster shell in the composition of composites, as it is a means of contributing to the economic sustainability by reducing the presence of pollution caused by aquaculture waste in the environment, thus increasing the value chain of the construction sector and reducing its carbon footprint. This paper intends to systematize the scientific production related to oyster shell-based composites in construction, carrying out a search using the Scopus tool and a systematic review based on the PRISMA statement. The results show that research on the incorporation of oyster shell into cementitious mortar mixtures, with a focus on its use in concrete, dominates existing scientific research. There is a lack of studies on the incorporation of the oyster shell that address its application as an aggregate or binder in the composition of coating and laying mortars. Most existing research is from Asia, and there is a lack of research in some parts of Europe. In the Americas, Africa and Oceania, no existing studies were found. Despite the growing understanding of the importance of sustainability and economic issues related to products used in the blue circular economy sector, there are still few studies that consider the incorporation of waste or by-products of aquaculture. Future investigations that cover these practical and contextual gaps can contribute to the better use of oyster shell waste and its insertion in the blue circular economy.

Valorisation of aquaculture sludge into microbial protein using bioreactor with an optimised nutrients

The present study was conducted to optimise the nutrients used for producing high nutritional biofloc in bioreactor utilising aquaculture waste. Full Factorial design (23) of independent variables such as sludge quantity (20 and 30 gL−1), carbon nitrogen ratio (15:1 and 20:1) and bioflocculant (cationic starch) doses (30 and 60 ppm) were used for optimisation. The percentage of crude protein and crude lipid in biofloc was shown to be significantly influenced by the interaction between carbon nitrogen ratio and bioflocculant dose (BC) as well as the interaction between sludge quantity, carbon nitrogen ratio, and bioflocculant dose (ABC) (p < 0.05). The floc volume of biofloc was shown to be significantly influenced by the interaction between carbon nitrogen ratio and bioflocculant dose (BC) (p < 0.05). The optimised parameters were 30 gL−1 of sludge, a carbon nitrogen ratio of 20:1, and 30 ppm of cationic starch, which resulted in a maximum CP of 27.09%, a maximum CL of 4.36%, and a maximum floc volume of 132 mL L−1. Principal component analysis (PCA) resulted in a 2 principal components (PC 1, nutritional factors which decides the nutritional composition of biofloc and PC 2, nitrification factors which are needed for biofloc formation) that explained 85% of total data variation. This study found the production of nutritive biofloc in a bioreactor using aquaculture waste with optimised nutrients.

Eco-efficient biowaste and aqua waste as cementitious material in high performance concrete

The energy requirements and environmental impact of cement manufacture are key issues today. Over the years, much research has been done to improve the resilience and sustainability of the cement industry as well as to offset its carbon emissions. This work used pozzolanic materials, corncob ash (CCA), and crab shell powder (CSP) to partially replace ordinary Portlandcement in concrete mixtures. The performance of concrete mixed with agricultural and aquaculture additives was assessed by replacing the cement. Compressive strength tests were carried out on concrete specimens in which cement was replaced by agricultural and aquacultural wastes. Furthermore, microstructural analysis was conducted to understand the morphology and chemical phases in the concrete specimens blended with supplementary cementitious materials. Concrete specimens combined with agricultural and aquatic-based additives show higher compressive strength results. In contrast to the specimens mixed with corn cob ash, crab shell powder demonstrates significant strength at lower dosages. The rich silica enhances pozzolanic reaction, which helped improve the thick phases of the concrete matrix. It can be concluded that concrete made from agricultural and aquatic sources can serve as a sustainable substitute for ordinary Portland cement and a strength booster, providing a new type of building material and promoting environmentally friendly construction.

Insights from an exergy analysis of a green chemistry chitosan biorefinery

Chitosan is a biopolymer with a wide range of applications; however, its production from chitin involves using toxic chemical solvents and high energy consumption. In this study, we propose a new greener route for producing chitosan from shrimp exoskeletons. Our design reduces chemical solvents and freshwater consumption while adhering to Green Chemistry principles. Through process simulation and exergy analysis, we identified critical stages with high irreversibility and achieved a global energy efficiency of 75%, outperforming the conventional chitosan extraction process. An exergy analysis is then conducted to identify sources of energy inefficiencies and reveal process irreversibilities. With a processing capacity of 6507 kg/h of shrimp shells, our proposed biorefinery produces valuable byproducts such as astaxanthin and minerals/proteins. The exergy analysis determined drying, dilution, and washing units as critical stages with the highest irreversibility. Our results demonstrate the potential of applying Green Chemistry principles to improve the sustainability of chitosan production from aquaculture waste streams.

Remediation and recovery of Kariba weed as emerging contaminant in freshwater and shellfish aquaculture system via solvothermal liquefaction

Fast growing Kariba weed causes major problems and pollution on freshwater and shellfish aquaculture systems by interfering with nutrient uptake of crops, restricting sunlight penetration, and decreasing water quality due to massive biomass of Kariba weed remnants. Solvothermal liquefaction is considered an emerging thermochemical technique to convert waste into high yield of value-added products. Solvothermal liquefaction (STL) of Kariba weed as an emerging contaminant was performed to investigate the effects of different types of solvents (ethanol and methanol) and Kariba weed mass loadings (2.5–10 % w/v) on treating and reducing the weed via conversion into potentially useful crude oil product and char. Up to 92.53 % of Kariba weed has been reduced via this technique. The optimal conditions for crude oil production were found to be at 5 % w/v of mass loading in methanol medium, resulting in a high heating value (HHV) of 34.66 MJ/kg and yield of 20.86 wt%, whereas the biochar production was found to be optimum at 7.5 % w/v of mass loading in methanol medium, resulting in 29.92 MJ/kg of HHV and 25.38 wt% of yield. The crude oil consisted of beneficial chemical compounds for biofuel production such as hexadecanoic acid, methyl ester (65.02 peak area %) and the biochar showed high carbon content (72.83 %). In conclusion, STL as a remediation for emerging Kariba weed is a feasible process for shellfish aquaculture waste treatment and biofuels production.

EFEKTIFITAS SAYURAN SELADA (Lactuca sativa L.) DALAM MEREDUKSI KONSENTRASI NITRAT PADA LIMBAH HASIL BUDIDAYA IKAN PATIN (Pangasius pangasius) DENGAN SISTEM AKUAPONIK

Background: Water is a natural resource that has a very important function for human life and other living things. Aquaculture waste produces ammonia, nitrite and nitrate waste. Nitrates can have a negative impact on the environment, among others, by contaminating water sources for various purposes, one of which is drinking water and causing health problems for humans.&#x0D; Method: This research used quasi-experimental (Quasi experiment) with Non-Equivalent Control group design. The study involved two groups, the control and the treatment by supplying 108 lettuce planting holes in three times. Data analysis used univariate and bivariate analysis with Wilcoxon test.&#x0D; Result: The lettuce (Lactuca sativa L) had no effect in reduced nitrate concentrations in the posttreatment. The results of the Wilcoxon test showed a p-value of 0.068.&#x0D; Conclusion: There was no significant difference in nitrate concentration in catfish (Pangasius pangasius) culture water at the input and output of the lettuce (Lactuca sativa L) installation.

Marine shell-based biorefinery: A sustainable solution for aquaculture waste valorization

Fossil-derived products contribute significantly to greenhouse gas emissions. Transitioning from fossil-based to bio-based products is an effective solution to this problem. There has been substantial research on how biorefinery systems can help achieve such an aim. Marine shell-based biorefinery systems have been proposed in the past, but their environmental sustainability has not been empirically proven. So, the current study examines the environmental impacts of chitosan production as a promising biomaterial in a lobster shell-based biorefinery. The life cycle assessment approach is used to estimate the environmental impact and cumulative exergy demand of chitosan production. The present study also aims at environmentally scrutinizing two non-commercial scenarios, i.e., the replacement of sodium hydroxide with potassium hydroxide (labeled as Scenario 1) and chitosan production based on the biological extraction of chitin and the replacement of sodium hydroxide with potassium hydroxide (labeled as Scenario 2) against the conventional chitosan production (labeled as the Base Scenario). The findings show that 1 kg of conventional chitosan production in the developed biorefinery leads to 8.75E-05 DALY damage to human health and 2.60E+02 PDF.m2.yr damage to ecosystem quality, mainly due to chitin and sodium hydroxide. In comparison, chitosan production based on Scenario 1 and Scenario 2 can lead to a 17% and 23% reduction in damage to human health and 6% and 11% in damage to ecosystem quality, respectively. The developed biorefinery produces chitosan with a weighted environmental impact of 43 EUR2003, which can be discounted by 8% and 13% using Scenario 1 and Scenario 2, respectively. The findings indicate that chitosan production eliminates 2.32E+02 MJ/FU exergy from nature, that approximately 54% of it is related to the “non-renewable, fossil” category. Scenarios 1 and 2 correspond to approximately a saving of 13% and a growth of 71% in exergy removal from nature than the Base scenario, respectively.

Evaluating sea cucumbers as extractive species for benthic bioremediation in mussel farms

Filter-feeding mussels blend suspended particles into faeces and pseudo-faeces enhancing organic matter flows between the water column and the bottom, and strengthening benthic-pelagic coupling. Inside operating farms, high bivalve densities in relatively confined areas result in an elevated rate of organic sinking to the seabed, which may cause a localized impact in the immediate surrounding. Deposit-feeding sea cucumbers are potentially optimal candidates to bioremediate mussel organic waste, due to their ability to process organic-enriched sediments impacted by aquaculture waste. However, although the feasibility of this polyculture has been investigated for a few Indo-Pacific species, little is known about Atlanto-Mediterranean species. Hence, for the first time, in the present study, we conducted a comparative investigation on the suitability of different Mediterranean sea cucumber species, to be reared in Integrated Multitrophic Aquaculture (IMTA) with mussels. A pilot-scale experiment was accomplished operating within a mussel farm where two sea cucumbers species, Holothuria tubulosa and Holothuria polii, were caged beneath the long-line mussel farm of Mytilus galloprovincialis. After four months, H. tubulosa showed high survivorship (94%) and positive somatic growth (6.07%); conversely H. polii showed negative growth (− 25.37%), although 92% of specimens survived. Furthermore, sea cucumber growth was size-dependent. In fact, smaller individuals, independently from the species, grew significantly faster than larger ones. These results evidenced a clear difference in the suitability of the two sea cucumber species for IMTA with M. galloprovincialis, probably due to their different trophic ecology (feeding specialization on different microhabitats, i.e. different sediment layers). Specifically, H. tubulosa seems to be an optimal candidate as extractive species both for polycultures production and waste bioremediation in M. galloprovincialis operating farms.

Environment-friendly floating net cage culture research in Indonesia

Reservoirs and lakes are widely used for fisheries, both capture fisheries and aquaculture. Aquaculture fisheries that develop in reservoirs or lakes include floating net cages culture (FCC) and pen culture. Besides impacting the economy and employment opportunities, aquaculture activities through FCC can decrease water quality from uneaten feed and fish metabolism residue. For this reason, an environmentally friendly FCC is needed to reduce aquaculture waste. This paper reviews the development of ecologically friendly FCC research in Indonesia. Several studies on environmentally friendly FCC include double net FCC, bio-cages, carpel FCC, windowed, and triple layer FCC. Double net FCC still allows the remaining uneaten feed and feces to settle. Bio-cage research is in the innovation model stage and has no prototype or laboratory tests. Windowed FCC, made with a closed system and a few gaps for circulation, can accommodate aquaculture waste and not spread into the waters, but fish grow slower than other FCC. The loop bio-phytoremediation of FCC or Smart FCC has three layers that can accommodate waste, and the waste will be used for plants that function as filters and phytoremediators of waste. Smart FCC is an aquaponic system modified to be applied in reservoirs/lakes.

Upflow Anaerobic Floating Filter (UAFF) Improved the Performance of the Anaerobic Treatment of Brackish Aquaculture Waste

Highlights Fish hatchery RAS thickened wastewater was successfully treated by anaerobic digestion. Traditional complete mix digester (CSTR) configuration was compared to the UAFF, an upflow anaerobic floating filter. UAFF start-up resulted faster and more productive than in conventional reactors (188 compared to 100 NmL CH4/g VS). At steady conditions, yields of 190.5 and 180.9 NmL CH4/g VS were recorded, for UAFF and CSTR respectively. Abstract. Thickened wastewater from a fish hatchery recirculating water system (RAS) was successfully treated by anaerobic digestion, showing a high methane potential in brackish and marine conditions. To optimize the process and establish operational criteria for a full-scale transfer, pilot-scale tests were carried out in a BioReactor Simulator System (BRS, Bioprocesscontrol, Sweden). The BRS consists of 6 reactors with a volume of 1.8 L each: 3 reactors operated in conventional configuration (CSTR, continuous stirred tank reactor), while the other 3 were modified with an up-flow fixed bed layout, with floating plastic filling elements (UAFF, upflow anaerobic floating filter). The objective of the present paper was the comparison of the performance of the UAFF and the CSTR anaerobic systems both in the initial colonization batch process, and in the following continuous process. The batch test was performed in 72 days by treating aquaculture sludge inoculated with brackish digestate, for the CSTRs, and with the biofilm of the plastic media for the UAFFs. The following continuous loading phase was characterized by start-up and steady steps. The tests were performed in mesophilic conditions. The start-up in the UAFF reactors resulted significantly faster and more productive than in conventional reactors, with specific yields reaching 187.9 NmL CH4/g VS compared to 100.0 NmL CH4/g VS. During the following steady phase, with the retention time of 20 days, the specific yields increased in all digesters but the differences between the 2 types of reactors were not significant, even if favorable for the UAFF (190.5 and 180.9 NmL CH4/g VS, respectively for UAFF and CSTR). Keywords: Anaerobic digestion, Anaerobic filter, Aquaculture, Biogas, Biomethane, Brackish and marine wastewater, Fish farm effluents.

Factor affecting the willingness to adopt good aquaculture practices (GAPs) in traditional shrimp farming in Pinrang Regency, South Sulawesi Province, Indonesia

This study explores the factors influencing shrimp farmers’ adoption of Good Aquaculture Practices (GAPs) in traditionally managed aquaculture ponds cluster in Pinrang Regency, South Sulawesi Province, Indonesia. The factors influencing shrimp farmers’ decision to apply GAPs to traditional ponds in Pinrang Regency were analyzed using the Theory of Planned Behavior (TPB) with structural equation modeling (SEM). The analysis results showed that shrimp farmers’ willingness to adopt GAPs was strongly influenced by their attitude that GAPs can increase their production or income, improve a positive reputation in society, and contribute to improving the aquaculture environment. Meanwhile, the main impetus for adopting GAPs came from exporters or local entrepreneurs and directives and assistance from the relevant government, universities, and academics. The shrimp farmers believe that to maximize the level of application and the adoption of GAPs, improving pond engineering and managing environmental limiting factors are of high priority. The decline in aquaculture pond water quality is closely related to the condition of ponds with problems exchanging water, particularly disposing of aquaculture waste after the operation.

Composition, Technological, and Microstructural Aspects of Concrete Modified with Finely Ground Mussel Shell Powder.

Reducing the negative environmental impact of a widely spread building material such as concrete is possible by decreasing the amount of cement in this composite material, especially when specific waste is included as a substitution for the binder. Another important environmental issue is accumulated aquaculture waste. This work justifies the possibility of achieving modified concrete with improved properties based on sea mussel shell powder (MSP). An improved environmentally friendly concrete was obtained and modified with MSP as a result of experimental studies. The dosage of MSP in the amount of 6% instead of part of the cement turned out to be optimal and most effective. Because of the modification, it was possible to increase the strength properties: the increments were up to 12% for the compressive strength (CS), up to 13% for the axial CS, up to 14% for the tensile strength (TS) in bending, and up to 12% for the axial TS. The ultimate strains under axial compression and tension decreased to 9% and 12%, respectively, and the elastic modulus increased to 15%. SEM analysis showed a more integral microstructure without voids and cracks in this composite with a modifier content of 6% compared with the sample of the ordinary composition. Economic efficiency is expressed in reducing the total cost of new concrete compared to traditional ones by about 17% and the cost of building construction by up to 15% due to a decrease in the percentage of defects.

Effective valorization of precision output of algaquaculture towards eco-sustainability and bioeconomy concomitant with biotechnological advances: An innovative concept

Both input resources and ecosystem stability are critical to the long-term viability and sustainability of the aquaculture business, which is booming while supporting global food security. Over the past few decades, technical advancements have been made to help achieve both economic and environmental goals. Among these, “algaquaculture,” which combines algae culture with aquaculture, is seen as a revolutionary concept with numerous advantages. The only difference between this system and aquaponics is that algae are used instead of leafy plants. In aquaponic systems, this integration is innovative because of algae’s superior ability to utilize waste-derived nutrients, such as nitrate, nitrite, and total ammonia nitrogen (TAN). An additional benefit of algae is that they promote growth, stimulate the immune system, and even enhance the color of fish. Some algae with human health benefits and biodiesel sources have a high market price, which can be used to compensate for an integrated aquaculture-based system’s higher economic value. While aquaculture waste bioremediation can greatly improve environmental sustainability, it is important to note that algae can play a significant part in bioremediation because of their ability to minimize environmental disruptions. This review aims to highlight the new concept of algaquaculture, functional role of algae in aquaculture, and biotechnological advancements for the bioeconomy to establish microalgae-based food production systems, including aquaculture, by citing the role and benefits of such an integrated algal-aquaculture system. For this reason, the review intends to disseminate an idea like this over the globe, focusing on how to preserve the sector in the coming years. • Algaquaculture, which combines algae culture with aquaculture, is seen as a revolutionary concept with numerous advantages. • Algaquaculture has great impact on circular and bioeconomy. • The biotechnological advances makes algaquaculture a sustainable strategy for frontiers industrial applications.

Estimasi Daya Dukung Perairan Pesisir Kabupaten Pamekasan dalam Menerima Limbah Budidaya Udang Vannamei

Vannamei shrimp cultivation business is an aquaculture business that has increased every year, both from the amount of production and the cultivation technology used. Vannamei shrimp cultivation in Madura is one type of work that develops by utilizing unproductive land and salt ponds being converted into vannamei shrimp ponds. Pamekasan Regency is one of the regencies that carry out the development of vannamei shrimp farming business with an intensive system. The development of vannamei shrimp cultivation is not in line with the conditions of the aquatic environment, this is because aquaculture activities produce waste in which aquaculture waste is directly discharged into the waters. The research was carried out on February 1, 2022 to April 1, 2022 in Candi Village, Galis District, Pamekasan Regency. Based on the results of the study, it was found that the load of organic waste in the form of TSS that was discharged into the waters during one maintenance cycle was 137.25 kg and 143.38 kg/0.3 ha when pouring the entire volume of pond water (3000 m3) into the waters. Based on the carrying capacity of coastal waters, the maximum amount of waste in the form of TSS that can be accommodated by the coastal waters of Pamekasan Regency is 441.39 tons/day. The amount of waste generated from intensive system vannmei shrimp farming activities in Pamekasan Regency is 55,983.26 tons for one year and 153.38 tons/day. The results showed that the waste produced was still below the maximum waste that could be accommodated by the waters of Pamekasaan Regency.

Silver carp (Hypophthalmichthys molitrix) by-product hydrolysates: A new nitrogen source for Bifidobacterium animalis ssp. lactis BB-12

Appropriate utilization of silver carp by-products is critical for enhancing industry profit and sustainability of aquaculture. This study explored the effect of the silver carp by-product hydrolysates on the growth of Bifidobacterium animalis ssp. lactis BB-12. Results indicated that papain recovered more nitrogen and < 1 kDa components from silver carp by-products than neutrase and alcalase. Papain-2 h (by-products hydrolyzed by papain for 2 hrs) was more effective in promoting the growth of BB-12. The content of < 1 kDa components, sulfhydryl-containing amino acids, and peptides composed of all the hydrophobic amino acids in hydrolysates was positively correlated to the growth of BB-12. BB-12 cultured by papain-2 h substituted medium exhibited a thinner and shorter morphology at 4 hrs of cultivation. This study provided a new nitrogen source for Bifidobacterium animalis ssp. lactis BB-12 and possible strategy for converting by-products to reduce aquacultural waste.

Review of waste phosphorus from aquaculture: Source, removal and recovery

AbstractThe contribution of phosphorus to water body eutrophication is a global environmental problem, and rapid increases in aquaculture are considered a significant source of phosphorus discharged into the environment. The current review focuses on the source of aquaculture waste phosphorus and measures to decrease phosphorus release into the environment. Because diets are a significant source of phosphorus in fed aquaculture systems, improving the utilization efficiency of dietary phosphorus can reduce the amount of waste phosphorus at the source. A wide range of removal and recovery technologies has been identified, including adsorption, crystallization, enhanced biological phosphorus removal (EBPR), denitrifying phosphorus removal, heterotrophic nitrification aerobic denitrification (HAND) and photosynthetic organism removal. Recovery technologies were also reviewed, particularly sludge phosphorus from recirculating aquaculture systems. A new method using bacteria to immobilize waste nitrogen and phosphorus into bioflocs has been proposed as a better solution. However, most of these technologies have only been implemented at the lab scale to pilot scale. Further studies are necessary to determine the working conditions and removal capacities of related technologies on a commercial scale. Moreover, phosphorus removal methods must be selected based on a consideration of recyclability.

Nitrogen Absorption Rate in Kappaphycus alvarezii with a Longline System in the IMTA (Integrated MultiTrophic Aquaculture) Area at Ekas Bay

The rapid growth of the aquaculture sector can indirectly lead to the accumulation of unresolved aquaculture waste in the sea. The IMTA cultivation system is one of the innovations developed in aquaculture activities to overcome aquatic environmental problems, such as the accumulation of waste from feed used in aquaculture activities. The concept combines the cultivation of several species with different trophic levels, such as fish that are fed and combined with seaweed that can absorb inorganic materials in the water. The purpose of this study was to determine the level of nitrogen absorption in Kappaphycus alvarezii using a longline system in the IMTA area in the waters of Ekas Bay. This study used a Randomized Block Design (RAK) with 4 treatments and each treatment was divided into 4 groups (North, South, East, and West). The treatment given was planting seaweed at different depths, namely 50 cm, 100 cm, 150 cm, and 200 cm. The results showed that Kappaphycus alvarezii reared with an integrated cultivation system at different planting depths gave significantly different results in absolute weight growth with values ​​ranging from 120,31 grams – 195,58 grams and specific growth rates ranging from 2.67% - 4, 35%, but did not have a significant effect on the rate of nitrogen uptake in all treatments, but the highest absorption value was at a depth of 2 meters. So the researchers suggest the cultivation of Kappaphycus alvarezii at a depth of 2 meters in the waters of Ekas Bay, East Lombok with a longline system in the IMTA area.

Handling Fruit And Vegetable Waste By Breeding BSF Larvae at the Penebel Village Waste Management Center, Tabanan

The Penebel Berlian KSM Waste Management Center is a non-governmental group with the aim of managing waste from households and from the traditional market of Penebel Village, which is in the form of organic waste and inorganic waste. In a day about 10 cubic feet of waste enters the KSM Penebel Berlian, 60% of which is organic waste. So far, organic waste is processed into compost, but it takes a long time while the waste is sent every day so that there is more and more organic waste and has not had time to be processed. It was also tried to process organic waste into eco-enzymes but failed because the community did not understand how it was made and the process of hardening the eco-enzym until it matured took a minimum of three months. The group wants to cultivate maggots intensively in KSM because the raw materials for maggot feed are adequate, can handle the problem of organic waste faster, odorless and involve group members. Maggot cultivation results will be used as poultry feed and fish feed, aquaculture waste will be used as organic fertilizer. Maggots are very positive to be developed into an alternative solution to the problem of organic waste without causing odors. Maggot larva of the BSF Fly (Black Shoulder Fly) which has the Latin name Hermetia illucens or black soldier fly is a large black fly and is not pathogenic. This cycle takes 40 to 45 days only. Community service activities have been running smoothly. Members of KSM Penebel Berlian have been able to independently produce BSF maggots from vegetable and fruit waste. Thus, the problem of organic waste in Penebel Village is also resolved, does not cause odors, waste does not accumulate, is handled in a shorter time with the concept of zero waste, and produces a product, namely BSF maggots that can be used as fish and poultry feed.