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Polyculture of sea grape (Caulerpa lentillifera) with different stocking densities of whiteleg shrimp (Litopenaeus vannamei): Effects on water quality, shrimp performance and sea grape proximate composition
Abstract
The polyculture of sea grape with whiteleg shrimp is considered as one of the strategic approaches to sustainable shrimp production. This is the first study to investigate the effects of integrating sea grape (Caulerpa lentillifera) with different densities of whiteleg shrimp (Litopenaeus vannamei) on water quality, shrimp performances and sea grape proximate composition. The experiment was executed in indoor tank systems, comprising five treatments in randomly designed triplicate tanks, with five levels of shrimp densities (100, 200, 300, 400, and 500 individuals m⁻³) integrated with sea grape (1 kg m⁻³) for 56 days. The results showed that the polyculture of sea grape with shrimp significantly enhanced sea grape biomass and proximate composition in terms of protein, lipid and ash contents while maintaining adequate levels of total ammonia nitrogen (TAN), nitrite (NO2⁻), nitrate (NO3⁻), and phosphate (PO4³⁻) in the rearing tanks at high shrimp densities. Shrimp growth rates (weight gain, daily weight gain, and specific growth rate) tended to decrease at higher density levels, but there were no statistical differences (p > 0.05) among treatments at stocking densities ranging from 200 to 400 individuals m⁻³. Although shrimp survival was significantly reduced as stocking densities increased from 400 individuals m⁻³ upward; the lowest and highest shrimp yields were obtained at densities of 100 and 400 individuals m⁻³, respectively. Feed conversion ratios were higher at higher shrimp density; however, no significant difference was not observed between 300 and 400 individual m⁻³ groups. These findings indicated that polyculture of sea grape with whiteleg shrimp can perform up to 400 individuals m⁻³ while maintaining suitable water quality parameters and sustaining improved production efficiency in the culture unit.
... Future studies could investigate the effect of co-culture on the proximate nutritional composition of the sea grapes. Previous studies have reported higher protein and lipid concentrations in sea grapes cocultured with shrimp due to the additional nutrients provided by the fed species (Anh et al., 2022;Omont et al., 2022). In the present study, it was shown that the excretion of the snails acted as a natural fertilizer, enriching the water with essential nutrients. ...
... An important aspect to consider is the potential trade-offs that may occur in co-culture systems. Studies with whiteleg shrimp Litopenaeus vannamei and Caulerpa in same-tank cultures showed that Caulerpa improved water quality and shrimp performance, but the sea grapes also showed impaired growth with increasing shrimp density due to grazing behavior and mechanical disturbance by the shrimp (Ly et al., 2021;Anh et al., 2022). Dobson et al. (2020a) showed that the integration of sea grape trays into a sandfish culture even reduced the weight gain and subsequently the yield of sea cucumbers. ...
In Van Phong Bay, Viet Nam, the economically important macroalgae sea grapes (Caulerpa lentillifera; Cau-lerpaceae, Bryopsidales) and the spotted babylon snail (Babylonia areolata) are cultivated in tidal ponds in close proximity. A co-culture in the same pond could benefit farmers by saving space and mitigating potential eutrophication. The study assessed the co-culture potential of sea grapes and spotted babylon snails held within the same system. In an outdoor experiment, three different treatments (algae and snails together, algae and snails spatially separated, only algae) were assessed for their effect on water quality, biomass properties and size increase of both organisms, photosynthetic efficiency, antioxidant activity, and total phenolic content of the macroalgae and survival of the snails. In a second (indoor) experiment, the influence of different snail densities on the physiological state of the macroalgae was investigated. In both experiments, the presence of the snails raised the concentrations of nitrogen oxides (NO x) and phosphate (PO 4). The co-culture had a positive effect on both growth and physiology of the sea grapes. Sea grapes on trays and co-cultured with Babylonia showed the highest increase in biomass. Babylonia growth and survival were not affected by spatial separation of the alga and high stocking densities could be implemented without negatively affecting the seaweed. The results are promising regarding the establishment of co-cultures and indicate the economic feasibility of integrating B. areolata snails into C. lentillifera pond cultures.
Seaweeds are a major contributor to global marine aquaculture production, with the biomass being mainly used, among others, for human nutrition, pharmaceutics, and cosmetics. However, green seaweeds are severely underrepresented, compared to red and brown macroalgae. Caulerpa lentillifera (known as “sea grapes” or “green caviar”) is an edible, green seaweed with a distinctive texture and various nutritional benefits. In this review, all articles on sea grapes published between 1900 and October 2022 and found in the scientific citation databases Scopus and Web of Science (search string: “caulerpa” AND “lentillifera”) were grouped by research topic and the intended application following the PRISMA approach. 51% of the 130 articles included in the review focused on the topic of “Biochemical composition”, followed by “Water treatment” (18%) and “Ecophysiology” (15%). The most prominent application was “Pharmaceutics”, followed by “Cultivation” and “Fundamental research”. In order to provide a knowledge base to researchers and practitioners of C. lentillifera aquaculture, research that was simultaneously grouped under one of the topics “Biochemical composition”, “Water treatment”, or “Ecophysiology” and the applications “Cultivation”, “Nutritional value” or “Post-harvest” was summarized in more detail. Light management of sea grapes, their use as a high-value co-culture species and the capacity to bioremediate nutrients, as well as their short shelf-life were identified as important areas of research interest. The assessment revealed several knowledge gaps, for example the need for intra-species comparisons of C. lentillifera biochemical composition across spatial and temporal scales.
Variations in protein, lipid, carbohydrate and astaxanthin content of Enteromorpha intestinalis, Ulva lactuca and Catenella repens were documented over a 10 months period from September 2007 to June 2008. The macroalgal species were collected from six sampling stations of Indian Sundarbans, a Gangetic delta at the apex of Bay of Bengal. On dry weight basis, the protein content varied from 4.15±0.02% (in Catenella repens) at Lothian to 14.19±0.09% (in Catenella repens) at Frasergaunge. The lipid content was low and varied from 0.07±0.02% (in Enteromorpha intestinalis) at Lothian to 1.06± 0.12% (in Ulva lactuca) at Gosaba. The level of carbohydrate was very high compared to that of lipid and protein and varied from 21.65± 0.76% (in Catenella repens) at Gosaba to 57.03± 1.63% (in Enteromorpha intestinalis) at Lothian. Astaxanthin values ranged from 97.73± 0.32 ppm (in Catenella repens) at Gosaba to 186.11± 2.72 ppm (in Enteromorpha intestinalis) at Frasergaunge. The values varied over a narrow range in the remaining stations. The results of biochemical composition of macroalgae seem to be strongly influenced by ambient hydrological parameters (surface water salinity, temperature and nitrate content) in the present geographical locale.
An integrated multi-trophic system consisting of white leg shrimp Litopenaeus vannamei and sea grape Caulerpa lentillifera was operated under various stocking densities and feeding rates to assess their effects on water quality, growth performance, and feed cost. The first experiment, which involved nursery rearing for 30 days, was designed in triplicate using a two-factor experimental design involving three stocking densities (1000, 2000, and 3000 ind. m−3) combined with two culture systems (monoculture and integrated system). Litopenaeus vannamei postlarvae 12 (PL12, mean weight: 3.33 ± 0.09 mg) and C. lentillifera (2 kg m−3) were applied in integrated tanks at a salinity of 30 g L−1. The results indicate that the integrated system of L. vannamei PL and C. lentillifera significantly decreased nitrogen and phosphorus levels and enhanced shrimp survival, growth rate, and yield. A significant synergistic effect between shrimp density and culture system was observed for shrimp survival (p < 0.05) and yield (p < 0.01). Higher shrimp density resulted in lower growth performance but increased yield. Applying stocking densities of 1000–2000 PL m−3 produced larger shrimp, while a density of 3000 PL m−3 obtained the highest production output in the integrated system. In the second experiment, the integrated system of juvenile L. vannamei (mean weight: 1.69 ± 0.07 g) and C. lentillifera was tested during the grow-out phase at different feeding rates. The six feeding treatments included a control group (monoculture) fed commercial feed (40% protein, 6% lipid) with a 100% feed ration (5% of biomass per day), while shrimp in the five integrated groups received commercial feed at 100, 75, 50, 25, and 0% feeding rations of the control. After 45 days of culture, the survival and yield of shrimp in the 100% and 75% feed ration treatments were significantly higher than those in the control group (p < 0.05). Nonetheless, shrimp growth steadily decreased with a reduction in the feeding rate from 50% downwards, and all groups grew significantly slower than the control group (p < 0.05). Interestingly, the feed conversion ratio and feed cost were lower at the lower feeding rates. This finding indicates that offering the L. vannamei—C. lentillifera integrated system at 75% feed ration can be considered the optimal feeding rate since it can reduce feed cost by 39.57% and improve water quality.
This paper describes for the first time the community perception and awareness of sea grapes (Caulerpa spp.) and sea grape farming, its lean and peak seasons, harvest volume and production, prices in market outlets as well as factors affecting the distribution in selected regions in the Philippines through a multi-region socio-economic survey. The majority of the respondents were aware of the presence of sea grapes in their areas since the 1980s but uninformed of their potential to be cultivated. The dry season (January–April) was perceived to be the peak season of sea grapes, both in culture and wild, in the different areas studied with Mactan, Cebu as the top producer, generating an estimated 42,222 kg per month. In market outlets, Calapan and Puerto Galera exhibited the highest market price for sea grapes (PhP 155–160 kg−1) (USD 3.23–3.33 kg−1) in the last 4 years. Socio-economic factors like gender, civil status, education, and income also affected the harvest distribution. The estimated annual income generated via farming and wild harvesting is valued at around PhP 2,259,456 (USD 47,702) during peak season. This study highlights how sea grapes are regarded as an economically important commodity in the Philippines and should be conserved to ensure availability and sustainable production. Furthermore, this research could serve as a basis for policymakers and scientists in addressing challenges and gaps in Caulerpa industry.
The study was aimed to evaluate the growth, survival rate and production of white shrimp ( L. vannamei ) culture under different stocking density in controlled tank. This research was conducted at Experimental Pond Installation. Research Institute for Coastal Aquaculture and Fisheries Extension in Maros Regency, South Sulawesi. Indonesia. Juveniles of white shrimp size in weight 0.14 g/ind were cultured for 70 days in three different stocking densities: 100, 200 and 300 ind/m ³ in a total of nine fibre tanks sized of 2 m ³ . The study used Completely Randomized Design (CRD). with three replications for each treatment. The parameters observed were growth rate, survival rate, production, feed conversion ratio of white shrimp and water quality condition. The results showed that the different stocking density had a significant effect (P <0.05) on growth, survival rate and production of white shrimp. The final weight and absolute weight of vaname shrimp decreased as density increased to 300 ind/ m ³ . The final weight of vaname shrimp in treatments A. B and C were 13.70 g/ind, 12.27 g/ind and 10.90 g/ind respectively. Survival rate and production of white shrimp in this study ranged from 80-95% and 1.24-2.42 kg/m ³ respectively. Water quality measured during the experiment was suitable for the growth of white shrimp.
The integrated aquaculture-seaweed system has been identified as a bio-mitigation strategy to overcome environmental damage, improve the efficiency of nutrient use, maintain good water quality, and ensure the system's sustainability. This study was conducted to determine the appropriate density of sea grape (Caulerpa lentillifera) in polyculture with whiteleg shrimp (Litopenaeus vannamei) in the same culture tank. Five treatments were randomly designed in triplicate tanks where shrimp was monocultured (without sea grape) as a control treatment and four polyculture treatments with different seaweed density levels (0.5, 1, 1.5, and 2 kg m −3) for 56 days. The results showed that polyculture of shrimp and sea grape significantly reduced the concentrations of total ammonia nitrogen (TAN), nitrite (NO 2 −), nitrate (NO 3 −), and phosphate (PO 4 3−) in the rearing tanks and significantly improved (p < 0.05) the growth rate (6.67-6.76% day −1), survival (73.3-78.5%), and production of shrimp (3.44-3.87 kg m −3) compared to monoculture (6.24% day −1 , 54.8%, and 2.02 kg m −3 , respectively). Applying shrimp and sea grape polyculture at a density of 1 kg m −3 provided a relatively better shrimp performance and feed conversion ratio than other seaweed densities, although not significantly different among polyculture treatments. The findings suggested that sea grape could be used at densities of 0.5-2 kg m −3 in polyculture with whiteleg shrimp, of which 1 kg m −3 resulted in higher production and feed efficiency.
Estrada JL, Bautista NS, Dionisio-Sese ML. 2020. Morphological variation of two common sea grapes (Caulerpa lentillifera and Caulerpa racemosa) from selected regions in the Philippines. Biodiversitas 21: 1823-1832. Sea grapes, locally known in the Philippines as "lato" or "ar-arusip", are economically important macroalgae belonging to the edible species of the genus Caulerpa. This study characterized and compared distinct populations of sea grapes from selected regions in the Philippines and described the influence of physicochemical parameters of seawater on their morphology. Morphometric, cluster and principal component analyses showed that morphological plasticity exists in sea grapes species (Caulerpa lentillifera and Caulerpa racemosa) found in different sites in the Philippines. These are evident in morphometric parameters namely, assimilator height, space between assimilators, ramulus diameter and number of rhizoids on stolon wherein significant differences were found. This evident morphological plasticity was analyzed in relation to physico-chemical parameters of the seawater. Assimilator height of C. racemosa is significantly associated and highly influenced by water depth, salinity, temperature and dissolved oxygen whereas for C. lentillifera depth and salinity are the significant influencing factors. Highest assimilator height of sea grapes was found in Coron and Culion in Palawan due to higher salinity and temperature while in Mactan, Cebu, it is primarily attributed to lower depth and higher salinity values.
In aquaculture systems, insufficient nutrients impede shrimp growth while excessive amounts of nutrient inputs lead to environmental degradation and unnecessary high investment. A study of in-out nutrient budgets in an intensive Litopenaeus vannamei farm was conducted in this work to measure the amount of nitrogen (N) and phosphorus (P) input and output from the system. The feed conversion ratio (FCR) was obtained to determine the level of nutrient input performance. Between September and December 2017, monthly water and sediment samples were taken within one crop cycle. Nutrient concentrations in sediment and water increased over 90 days. The total nitrogen concentration in the pond water and effluents were in accordance with wastewater quality control for aquaculture; however, the total phosphorus concentration failed to meet the water quality control from the water input through the end of the crop cycle. The nutrient budget model showed that the input/output contained 107.8 kg N and 178.4 kg P. Most of the N input came from shrimp diets (80%) while most of the P came from fertilizer (57%). Both N (46%) and P (54%) mainly deposited in the sediment as an output process. The FCR of this farm is 2.0. Based on the 1.8 FCR scenario, this farm could reduce 147 kg of feed in total, which accounts for 9.04 kg N and 2.21 kg P reduction. The farmer could save $1027 USD crop− 1 ($1 USD = 32.7 baht), as well as reducing uneaten food at the bottom of the pond. This study offers a simple and straightforward model that can practically reduce environmental impacts and increase the profitability of farms.
The genus Caulerpa is highly diverse, especially in the Caribbean Sea, the Indo-Malay archipelago and the temperate waters of southern Australia. Currently, more than 100 species are recognized worldwide. Despite recent advances in taxonomy and phylogeny, there is still confusion about the delimitation and identification of some species due to tremendous phenotypic plasticity. Caulerpa is known to occupy a wide range of environmental niches and to have great invasive potential. More studies are necessary to understand better the ecology (invasiveness, the functional role of its microbiome) and the biology (reproduction, life cycle, and metabolism) of Caulerpa species, especially for economical species. Very few species, mainly C. lentillifera and C. racemosa known as green caviar, have been cultivated. Caulerpa is consumed mostly in Asia and Oceania, but its popularity tends to be on the increase in western countries with new nutritional practices (vegetarians, vegans, health foods). Being naturally enriched in essential nutrients and various health-promoting compounds, Caulerpa species are promising candidates for the design of functional foods and in the health and well-being sectors. The diversity of Caulerpa offers a remarkable potential for valorization with innovation opportunities. Caulerpa farming can bring significant economic and environmental (e.g., bioreme-diation, blue carbon pump) benefits if these farms are established in a sustainable approach. Identity Nomenclature Valid scientific name The genus Caulerpa J.V.Lamouroux 1809 was originally erected to include eight species previously described in the genus Fucus L., 1753. Caulerpa prolifera (Forsskål) J.V.Lamouroux was later designated by Egerod (1952) as the lectotype of the genus. The name Caulerpa means "creeping stem," from Greek καυλος (kaulos), a stem, and ερπω (erpo), to creep. Nomenclatural synonyms
This work aimed to determine the optimum stocking density of Penaeus vannamei, cultured in a photo-heterotrophic intensive circular system inlined grow-out ponds with minimal water replacement. Five intensive density levels (100, 300, 500, 700 and 900 ind m-3) were considered. The water quality measured for the 98 days grow-out period was within the adequate range for P. vannamei. TAN, nitrate and total phosphorus water quality were significantly higher (P < 0.05) at the higher density. Growth rates and survival decreased as density increased after 300 org m-3. Based on the results of this study, it was found that shrimp grows adequately in high biomass density (99.21 kg tank-1) and density of 500 ind m-3 in an intensive photo-heterotrophic system with a maximum harvest weight of 10 g.
The effects of integrating different densities of white leg shrimp Litopenaeus vannamei postlarvae (PL) and red seaweed Gracilaria tenuistipitata on water quality and shrimp performance were assessed in the nursery phase. A 3 × 4 factorial experiment with three levels of shrimp density (1000, 2000, and 3000 PL m⁻³) and four levels of red seaweed density (0, 1.0, 1.5, and 2.0 kg m⁻³) was randomly designed in triplicate. Shrimp PL12 (mean weight of 4.27 ± 0.28 mg) and red seaweed were stocked in 150-L tanks at a salinity of 15 g L⁻¹ for 30 days. The results indicated that the integration of shrimp PL and red seaweed significantly reduced the nitrogen and phosphorus contents in the culture tanks and improved the survival and growth rate of shrimp, although not significantly. A significant interaction effect (p < 0.01) between shrimp and seaweed densities was only observed for shrimp production. Notably, higher stocking density resulted in lower growth performance but enhanced production. Applying stocking densities of 1000 and 2000 PL m⁻³ reared shrimp that were bigger in size, while a density of 3000 PL m⁻³ obtained the highest production output in the integrated system. Following the 30-day growth trial, shrimp quality was examined through a bacterial challenge test using pathogenic Vibrio parahaemolyticus on the shrimp groups previously reared at a density of 3000 PL m⁻³ and integrated with different amounts of seaweed. After 14 days of immersion challenge, the cumulative mortality in the control group was significantly higher than that of other groups. This result suggests that the presence of G. tenuistipitata improved the antibacterial activity of L. vannamei against V. parahaemolyticus during the nursery phase.
Determining the optimum levels of macroalgal density and salinity for removing aquaculture effluent has gained increasing research interest in recent years because of the growing concerns over environmental sustainability. Here, we determined the effects of macroalgal density and salinity on the uptake of NO2−, NO3−, NH3, and PO43− by Caulerpa lentillifera from the effluent of Poecilia latipinna using spectrophotometry. Laboratory experiments were conducted to measure nutrient uptake at five different macroalgal density levels (10, 20, 30, 40, and 50 g/L) and three salinity levels (20, 30, and 40 ppt) with and without aeration. Quadratic regression analysis revealed significant nonlinear and linear effects of macroalgal density on the uptake of NO2−, NO3−, NH3, and PO43−, where the maximum uptake was predicted to occur at the macroalgal densities of 31.6, 33.3, 50.0, and 20.0 g/L, respectively. Likewise, the effects of salinity on the uptake of NO2−, NO3−, NH3, and PO43− were significant and nonlinear where the maximum uptake was predicted to occur at the salinity levels of 29.1, 30.7, 29.5, and 29.5 ppt, respectively. The result of the effects of aeration was mixed but somewhat indicated a positive effect on the nutrient uptake within the 24 h period. Our results could help aquaculturists to minimize the excessive nutrients by C. lentillifera from aquaculture effluent while achieving long-term sustainable aquaculture production.
In general, aquaculture wastes from traditional aquatic organism cultivation rapidly deteriorate the water quality of the surrounding ecosystems, endangering animals living in the area. The integrated multi-trophic aquaculture (IMTA) system is a bio-mitigation strategy to alleviate the adverse impacts caused by aquafarming pollutants on the environment and aquatic species. This study provides an overview of the IMTA system, explains the interactive processes among the different trophic levels, summarizes the major practices being followed around the temperate coastal waters with a field case study in Japan, and discusses the assessment of IMTA bio-mitigation efficiency through experimental greatly dependent on the customs and market values in the local IMTA practice. Bio-mitigation efficiency acquired in a land-based experiment exhibits its limitation in approach and conducts a comprehensive analysis on the possibility of applying numerical models to evaluate IMTA effectiveness. The selection of a suitable candidate organism is estimating that in the same or different culture conditions with various biomasses of extractive species. However, in open water experiments, it is difficult to evaluate the bio-mitigation effect of extractive species because the initial biomass ratio (IBR) of the extractive to target species is too small. Alternatively, the possibility of applying existing numerical models to assess IMTA is relatively low. In conclusion, an optimally designed large-scale IMTA experiment is required, in which the IBR of the extractive to target species is adequately considered, and a full-scale IMTA model should be further improved with a database of individual-based submodels for IMTA candidate organisms.
The edible seaweed Caulerpa lentillifera , a powerful natural food source that is rich in protein, minerals, dietary fibers, vitamins, saturated fatty acids and unsaturated fatty acids, has been mass cultured in some Asian countries and has been the focus of researchers in recent years. Here, the operational conditions of its culture, application in wastewater treatment, and bioactive components are summarized and comparatively analyzed. Based on previous studies, salinity, nutrient concentrations, irradiance and temperature are stress factors for algal growth. Moreover, dried Caulerpa lentillifera seaweed is efficient in the biosorption of heavy metals and cationic dyes in wastewater, and fresh seaweed can be introduced as a biofilter in aquaculture system treatment. In addition, among the rich bioactive compounds in Caulerpa lentillifera , the phenolic compounds show the potential ability for regulating glucose metabolism in vivo. Polysaccharides and oligosaccharides exhibit anticoagulant, immunomodulatory effects and cancer-preventing activity. Siphonaxanthin is a compound with attractive novel functions in cancer-preventing activity and lipogenesis-inhibiting effects. Furthermore, the antioxidant activity of siphonaxanthin extracted from Caulerpa lentillifera could be stronger than that of astaxanthin. This review offers an overview of studies of Caulerpa lentillifera addressing various aspects including cultivation, wastewater treatment and biological active components which may provide valuable information for the cultivation and utilization of this green alga.
Ulva prolifera is one of the most common macroalgae and is distributed widely off the coast of China. It is well known for its rapid growth rate and good reproduction and it has fast nitrogen removal efficiency. Integration of seaweed cultivation in shrimp farming water is considered a potential aquaculture practice since seaweeds can convert dissolved inorganic nitrogen into biomass and the biomass can be harvested easily. This study investigated the effect of integrating green seaweed (Ulva prolifera) with Litopenaeus vannamei (500 shrimp m−3) at varying levels of water exchange daily on water quality and shrimp growth performance. The four daily water exchange quantities were 5% (T1), 10% (T2), 15% (T3), and 20% (T4). The appropriate range of the stocking density of U. prolifera was 800 mg L−1. No significant differences were observed in total ammonia nitrogen (TAN) concentration between T2 and T3 (P > 0.05) from beginning to end. The concentrations of nitrite and nitrate in all treatment remained constant at low levels from beginning to the end. On day 35, there were no significant differences in survival rate of shrimp among T2, T3, and T4. No significant differences in FCR were observed in group T2, as compared to T1, T3, or T4. No significant differences in cumulative weight of U. prolifera were observed among T1, T2, and T3; however, they were significantly larger than that of T4. The study demonstrates that integrating U. prolifera (800 mg L−1) with L. vannamei (500 shrimp m−3) with 10% water exchange can control the water quality and enhance shrimp growth.
Some seaweed has been used as an important source of commercial application of phycocolloids, agar, and
alginate consequently some seaweeds have also been utilized as food and food ingredients due to their high
nutritive compositions such as carbohydrates, protein, lipid, amino acids, fatty acids, fibre and minerals. In different countries, including India, seaweeds are gradually taking place as food items in the market, so their biochemical components analysis will decipher their nutritional implications. In this investigation, total 33 species of seaweeds were collected from the southeast coast of India and analyzed for their biochemical composition such as carbohydrate including glucose and starch, protein and lipid. The carbohydrate content varied from 15.20 ± 0.69 mg/gm dry weight (Padina boergesenii) to 97.69 ± 2.3 mg/gm dry wt (Gracilaria edulis). The carbohydrate content of red seaweeds was comparably higher than green and brown seaweeds. The protein content was minimum in Cystoseira indica (76.23 ± 0.21 mg/gm dry wt) and maximum in Amphiroa anceps (96.06 ± 0.95 mg/gm dry wt) and lipid content was comparatively high in Valoniopsis pachynema (82.33 ± 2.51 mg/gm dry wt) and Caulerpa racemosa (81.06 ± 0.37 mg/gm dry wt). The glucose content was high in Digenea simplex (0.78 ± 0.004 mg/gm drywt) followed by Laurencia papillosa (0.61 ± 0.08 mg/gm dry wt) likewise starch content was also high in Digenea simplex (0.72 ± 0.01 mg/gm dry wt) and Laurencia papillosa (0.54 ± 0.00 mg/gm dry wt). From this study, it was concluded that the above mentioned seaweeds will be used as food after further more detailed analysis of the other biochemical components
The bioavailability of organic matter was assessed at three locations during the dry and wet seasons in the Great Barrier Reef, by measuring changes in particulate (POM) and dissolved (DOM) organic matter concentrations during laboratory incubations over 50 days. The sites did not show any difference in salinity and, therefore, observed changes could be related to factors such as disparities in the biological activity and/or the impact of sediment resuspension rather than to location. Our results demonstrate that the POM pool has a higher bioavailability than the DOM pool, with the C, N and P-containing compounds being more bioavailable than the C and N-containing molecules, which in turn are more labile than compounds containing just C. The addition of labile POM to the DOM pool did not impact the bioavailability of DOM, suggesting that priming had no major impact on the degradation of this pool in these experiments. Furthermore, our results demonstrate that 94% and 75% of the bioavailable N and P are contained in the organic fraction delivering enough nutrients to sustain phytoplankton productivity in the Great Barrier Reef. Using the obtained degradation rate constants and an average water residence time of 2 weeks we show that most bioavailable POM (> 96%) and DOM (> 83%) is degraded before reaching the outer shelf. Our results emphasize that organic matter is a key and mostly unaccounted part of the C, N and P cycles in tropical coastal waters of the Great Barrier Reef.
Farming the shrimp, fish and another commodity could produce large quantities of waste. Aquaculture waste can be formed as feces, residual feed and dead organism which are accumulated in a cultivation area. Generally, the waste is discharged directly into the water without filtration. Thus, one of the problems that are often faced by farmer is the low quality of pure water due to the high content of nutrients. Moreover, suspended solid pollutant will be formed that lead to eutrophication, oxygen depletion, and precipitation. The aim of this research is to analyze the solid waste pond tiger shrimp as fertilizer for the growth of Caulerpa lentiilifera. Here, the Random Design complete (RAL) and three times in Deuteronomy are used in the experiment. The parameters of one control and three treatment doses are used 0, 2, 4, and 6 g.L-1 respectively. The results showed that solid waste shrimp ponds can be used as fertilizer to meet the needs of Caulerpa lentillifera for growth and the results show the highest value is found in the dose of 6 g.L-1 with NO3- (4.58 ppm), NH4+ (3.34 ppm), PO43- (2.03 ppm) and the value of the rate of growth and the PH are obtained (3.64 g.day-1) and (6,4-8), respectively. Keywords: Caulerpa lentillifera, growth rate, Nitrification, solid waste, Tiger Shrimp.
Biochemical composition and antioxidant activity were assessed in seven seaweeds from Madeira Archipelago, namely, the chlorophyte (Ulva lactuca), the rhodophytes (Asparagopsis taxiformis, Chondrus crispus, Galaxaura rugosa, Grateloupia lanceola and Nemalion elminthoides), and the phaeophyte (Zonaria tournefortii). Seaweed mineral content varied from 16.60 to 84.16 g (100 g)-1 dry weight (dw). Organic matter, composed by fiber and matrix polysaccharides (8.33 to 54.04 g (100 g)-1 dw), starch (1.95 to 25.41 g (100 g)-1 dw), protein (2.80 to 17.55 g (100 g)-1 dw), and fat (1.46 to 12.04 g (100 g)-1 dw), was also determined. Asparagopsis taxiformis was found to have substantial quantities of protein, fat, fiber, and matricial polysaccharides, compared to the other analyzed seaweeds. Analysis of antioxidant components included the measurement of chlorophyll a (28.81 to 244.3 g (100 g)-1 dw), total carotenoids (0 to 297.8 g (100 g)-1 dw), total phenolic compounds (0 to 2154 mg GAE (100 g)-1 dw), and total flavonols (7.27 to 604.8 mg QE (100 g)-1 dw). Zonaria tournefortii was found to possess the highest contents of chlorophyll a, total carotenoids, total phenolic content (TPC), and antioxidant activity, determined through ferric reduction antioxidant potential (FRAP), ferrous ion chelating (FIC), free radical-scavenging assay (FRSA), and β-carotene bleaching (β-CB). Statistical analysis showed 38 significant correlations between various biochemical and antioxidant parameters or activity and determined that fat content showed the highest number of correlations. Overall, this study gives a better understanding of Madeira autochthonous seaweeds in their potential of being introduced as a raw material for nutrient supplementation in various food products or to produce functional foods using seaweed natural properties.
Water quality parameters viz., Temperature, pH, Salinity, Dissolved Oxygen, Alkalinity, Hardness,
Nitrite- Nitrogen, Nitrate-Nitrogen and Ammonia were studied in 14 shrimp culture ponds (6 at
Narsapurapupeta, 4 at Kajuluru and 4 at Kaikavolu villages) of East Godavari district, Andhra Pradesh.
Temperature ranged from 26.5 ºC to 28 ºC in the ponds. pH varied from 6.95 to 8.38.Dissolved oxygen
varied from 4.4 to 8.6 mg/l. Minimum values of dissolved oxygen were recorded at Kajuluru village
pond and maximum in Narasapurapupeta ponds. Low salinity (2 ppt) was observed in Kajuluru ponds
and high (10 ppt) in Kaikavolu ponds. The alkalinity was minimum (120 mg/l) in the ponds of
Narasapurapupeta and maximum (500 mg/l) in Kajuluru ponds. The hardness ranged from 600 mg/l to
3440 mg/l. The values of ammonia were 0.02 - 1.07 mg/l. The nitrite-nitrogen was minimum (0.01) in
Kajuluru ponds and maximum (0.80) in Narasapurapupeta ponds. The nitrate- nitrogen was minimum
(3.36) in Kaikavolu ponds and maximum (6.40) in Kajuluru ponds. The cumulative effect of these water
parameters will reflect on the shrimp production. The parameters observed were in the optimal range for
shrimp culture except salinity in which case it was found that the shrimp was acclimatized to grow at low
salinities.
The aim of this research to know how to operate and develop the Vannamei production by using biofiter technology of seaweed to the farmer, keeper, young people and leader of the society. The results showed that the Integration of Gracilaria verucosa as a biofilter agent in aquaculture pond can increase the production of Vanname shrimp. The results were obtained 5 tons/ha of seaweed from the initial density of seaweed 1 ton/ha after 3 months of culture with daily growth rate of 4.18%/day. Vannamei shrimp growth of 0.5 grams to 16.7 grams/fish, shrimp production from 1 ton/ha to 3,5 tons/ha. Based on the economic analysis showed gains with the value of R/C ratio of 1.83 and a profitability of 80.08%. Biofilter methods is more likely, given the application is very simple, high adaptability, easy maintenance, and economic value. Socialization and counseling about the application of environmental friendly biofilter system using G. verucosa needs to be carried out at farmer pond.
In the Indo-Pacific region, several species of the green seaweed genus Caulerpa Lamouroux (1809) are very popular as human food because of their delicious taste and crunchy texture, which are pleasing to the palate, and because of their health benefits: Caulerpa contains proteins, fiber, minerals, vitamins, polyunsaturated fatty acids, and bioactive anti-oxidants. The consumption of these seaweeds is well established in local traditions and, for this reason, several seaweed farms have been established, or are under assessment, with a view to providing additional sources of income for local communities and to secure their livelihoods. Currently Caulerpa species are mostly collected from the wild and sold on the markets. However, farms can use a range of culture techniques such as bottom planting, off-bottom culture, floating long lines, or land-based raceways. This paper presents an overview of the traditional consumption and nutritional values of Caulerpa in the Indo-Pacific region and the different farming methods used for Caulerpa culture.
Intensive fish aquaculture activities release large amount of nitrogen (NH4-N and NO3-N) to the surrounding waters and lead to water eutrophication. However, integrating a single species of seaweed with the fed fish usually cannot remove both forms of nitrogen efficiently. Polyculture of different seaweeds will be an effective way to reduce the nitrogen load of surrounding waters. To compare the feasibility of using Caulerpa lentillifera and Gracilaria lichenoides as biofilters to treat marine fish aquaculture effluents, nine NH4-N/NO3-N ratios were set up and the nitrogen uptake and growth rate of the two seaweeds were measured. The main results showed that: (1) In the presence of multiple N sources, C. lentillifera selectively takes up NO3-N prior to NH4-N and the NO3-N uptake rate was 7.43–50.43 μmol g−1 (dw) h−1 which was significantly higher than that of G. lichenoides. Gracilaria lichenoides selectively takes up NH4-N prior to NO3-N and the NH4-N uptake rate was 10.27–14.14 μmol g−1 (dw) h−1 which was significantly higher than that of C. lentillifera. (2) The NH4-N/NO3-N ratio had effects on the growth of the two seaweeds: 1/1 and 1/5 of NH4-N/NO3-N were favorable for the growth of C. lentillifera; 1/4 and 1/0.5 of NH4-N/NO3-N were favorable for the growth of G. lichenoides. The results preliminarily indicate that integrated culture of C. lentillifera and G. lichenoides was sufficient for bioremediation of marine fish aquaculture effluents.
This study presents the establishment of an integrated multi-trophic aquaculture (IMTA) system in the tropical open waters of southern Cebu, Philippines using a combination of locally available species, namely donkey’s ear abalone (Haliotis asinina) as fed species and seaweeds (Gracilaria heteroclada and Eucheuma denticulatum) as inorganic extractive species. The culture of Caulerpa lentillifera as a biofilter did not work in the open sea cultivation system using baskets. Monthly measurements of shell length, width and body weight of the cultured abalones, together with in situ measurements of physicochemical parameters to assess any changes in water quality, mainly nitrate, nitrite, ammonia and phosphate, were conducted over a year period from February 2013 to January 2014 in three designated stations (Abalone, Seaweed and Control Stations) at three different depths (surface, middle and bottom).
Cage culture of abalone side by side with seaweeds in the open sea did not result in any significant water quality disturbance in the area—at least not in the current volume of caged abalones being used. Of the four inorganic compounds monitored in the field, nitrate and ammonia in the Seaweed Station were shown to have relatively lower year-round average values when compared with the Abalone Station, although in the case of nitrate, it was higher in the Control Station compared with the abalone and Seaweed Stations. Although this difference was not significant, it shows the red seaweeds, G. heteroclada and E. denticulatum, to be functioning as a natural filter for these two nutrients. In contrast, nitrite, and phosphate concentrations were not reduced indicating that the seaweeds were not effective biofilter for these two nutrients.
The two-month old hatchery-bred donkey’s ear abalones can grow to a size of 53.8 × 28.2 mm (L × W) and body weight of 37.8 g after a period of 12 months. Any expansion of the farm into a much larger commercial-scale farm will have to be complimented with seaweeds stocked around it if only to mitigate possible build-up of excess inorganic wastes—to serve as both a natural filter and as a source of natural feed. The potential use of an organic extractive species has to be further studied under farm condition to achieve its full potential as an IMTA species.
The effects of stocking density and physicochemical water characteristics on the growth, survival, and production of the Pacific white shrimp, Litopenaeus vannamei, were assessed in six 500±72.5 m2 earthen ponds during two culture seasons: autumn-winter (20 weeks) and spring-summer (14 weeks). Stocking densities were 50, 60, and 70 shrimp/m2. Water turnover was approximately 15% per day. Aeration was supplied by a 3.5 hp air blower. Mean growth during the autumn-winter did not differ significantly among the stocking densities with final weights of 12.77, 12.72, and 12.40 g and yields of 3,609, 5,093, and 5,618 kg/ha at 50, 60, and 70 shrimp/m2, respectively. In contrast, there were statistically significant differences in mean growth and final yields during the spring-summer. Final mean weights were 18.63, 13.46, and 11.86 g and yields were 7,243, 7,307, and 8,011 kg/ha at 50, 60, and 70 shrimp/m2, respectively. Low water temperatures during the winter affected production. Better performance was recorded at higher spring-summer temperatures (≥23°C). Larger shrimp were associated with lower stocking density while higher stocking density produced slightly higher yields. For best performance, dissolved oxygen should be maintained above 4 mg/l.
Due to deterioration of shrimp farming environment, it is necessary to develop the technique of shrimp culture that environmentally friendly and sustainable. One of important technique to fulfill the need is integrated model with seaweeds. We investigated two different integrated model using different seaweeds species, Sargassum plagyophyllum and Gracilaria verrucosa. These two species seaweeds were cultured in tiger shrimp pond at density of 2 kg/m 3. Density of tiger shrimp was 50 juvenile /m 3. These experiments were conducted in 28 days. The shrimp productivity was evaluated from the rate of shrimp survival, final individual size, growth and biomass production. Seaweeds biomass production was also evaluated. Collected data was analyzed using one way ANOVA, continued by LSD test. Results indicated that the presence of both seaweeds tend to increase shrimp productivity, it was indicated by higher survival, individual size, growth rate and shrimp biomass production. The role of Gracilaria in increasing shrimp productivity was higher compared to Sargassum. It is recommended to use Gracilaria in integrated model with tiger shrimp.
The increase in global demand for fishery products has led to a fivefold increase in aquaculture production since 1990. Commercial feed is the highest production cost in intensive aquaculture, and residual commercial feed leads to eutrophication; hence it is important to find a low-cost alternative that has less environmental impact. We investigate the use of the filamentous green algae, Chaetomorpha sp., as a raw feed for giant tiger prawns. The giant tiger prawn, Penaeus monodon was grown in monoculture, and in co-culture with Chaetomorpha sp. to investigate the potential benefits of co-culturing. Five 20-day-old giant tiger prawn juveniles were released in 70-L monoculture and co-culture tanks, and the specific growth rate (SGR) and feed conversion ratio (FCR) were measured after 10 weeks. The final mean body weight of co-cultured prawns was approximately 50 % heavier than that of monocultured prawns. The SGR in co-culture tanks was 4.79 ± 0.08 % day−1, which was higher than that in monoculture tanks (4.14 ± 0.27 % day−1). The FCR was 38.9 % lower in co-culture than in monoculture tanks. The protein content of Chaetomorpha sp. obtained from proximate analysis was almost the same or a little lower than other filamentous green seaweeds; however, the Chaetomorpha sp. has higher fiber and gross energy. These results show that Chaetomorpha sp. has potential for reducing feed costs in prawn intensive aquaculture through co-culturing.
China’s aquaculture industry accounts for the largest share of the world’s fishery production, and provides a principal source of protein for the nation’s booming population. However, the environmental effects of the nutrient loadings produced by this industry have not been systematically studied or reviewed. Few quantitative estimates exist for nutrient discharge from aquaculture and the resultant nutrient enrichment in waters and sediments. In this paper, we evaluate nutrient discharge from aquacultural systems into aquatic ecosystems and the resulting nutrient enrichment of water and sediments, based on data from 330 cases in 51 peer-reviewed publications. Nitrogen use efficiency ranged from 11.7% to 27.7%, whereas phosphorus use efficiency ranged from 8.7% to 21.2%. In 2010, aquacultural nutrient discharges into Chinese aquatic ecosystems included 1044 Gg total nitrogen (184 Gg N from mariculture; 860 Gg N freshwater culture) and 173 Gg total phosphorus (22 Gg P from mariculture; 151 Gg P from freshwater culture). Water bodies and sediments showed high levels of nutrient enrichment, especially in closed pond systems. However, this does not mean that open aquacultural systems have smaller nutrient losses. Improvement of feed efficiency in cage systems and retention of nutrients in closed systems will therefore be necessary. Strategies to increase nutrient recycling, such as integrated multi-trophic aquaculture, and social measures, such as subsidies, should be increased in the future. We recommend the recycling of nutrients in water and sediments by hybrid agricultural-aquacultural systems and the adoption of nutrient use efficiency as an indicator at farm or regional level for the sustainable development of aquaculture; such indicators; together with water quality indicators, can be used to guide evaluations of technological, policy, and economic approaches to improve the sustainability of Chinese aquaculture.
Caulerpa lentillifera is a green algae that distributes worldwide and is cultivated for food. We assessed vegetative propagation of C. lentillifera by measuring the specific growth rate (SGR) and chlorophyll fluorescence of the green algae cultured at different salinities and nutrient levels. The results indicated that C. lentillifera can survive in salinities ranging from 20 to 50, and can develop at salinities of 30 to 40. The maximum SGR for C. lentillifera occurred at a salinity of 35. Both chlorophyll content and the ratio of variable to maximum fluorescence (F
v/F
m) were also at a maximum at a salinity of 35. Photosynthesis was inhibited in salinities greater than 45 and less than 25. Both the maximum SGR and maximum chlorophyll content were found in algae treated with a concentration of 0.5 mmol/L of NO3-N and 0.1 mmol/L of PO4-P. The photosynthetic capacity of photosystem II (PSII) was inhibited in cultures of C. lentillifera at high nutrient levels. This occurred when NO3-N concentrations were greater than 1.0 mmol/L and when PO4-P concentrations were at 0.4 mmol/L. As there is strong need for large-scale cultivation of C. lentillifera, these data contribute important information to ensure optimal results.
The green algae genus Caulerpa is coenocytic, and the thallus consists of only one cell with many nuclei. It is widely distributed in the tropical seas. In the Southeast Asian waters, there are at least ten known species. Three species, particularly Caulerpa racemosa var. clavifera f. macrophysa (Kützing) Weber-van Bosse, C. racemosa var. laetevirens (Montagne) Weber-van Bosse, and Caulerpa lentillifera J. Agardh are widely consumed. The proximate analysis and secondary metabolite composition of these three species were determined to describe their lipid and nutritional values. Glycolipids and phospholipids were the major lipid classes, with significant levels of triacylglycerol. Polyunsaturated fatty acids (PUFA) were the major fatty acids of all the three species. Typical n-3 and n-6 PUFA such as 18:3n-3, 18:4n-3, 20:5n-3, 18;2n-6, and 20:4n-6 were found in significant amount in all these three species. All three species contained a red-pigmented secondary metabolite determined as caulerpin. All three extracts exhibited potent antimicrobial activity against human food pathogenic bacteria and anti-inflammatory activity against the murine macrophage cell line, RAW 264.7.
See www.cambridge.org/9780521145954. Buy this from the publisher, the authors do not have full-text copies to distribute!
In coastal seas, from the tropics to the poles, seaweeds supply the energy required to support diverse coastal marine life and provide habitat for invertebrates and fish. Retaining the highly successful approach and structure of the first edition, this is a synthesis of the role of seaweeds in underpinning the functioning of coastal ecosystems worldwide. It has been fully updated to cover the major developments of the past twenty years, including current research on the endosymbiotic origin of algae, molecular biology including 'omics', chemical ecology, invasive seaweeds, photobiology and stress physiology. In addition to exploring the processes by which seaweeds, as individuals and communities, interact with their biotic and abiotic environment, the book presents exciting new research on how seaweeds respond to local and global environmental change. It remains an invaluable resource for students and provides an entry into the scientific literature of a wide range of topics.
Variations in protein, lipid, carbohydrate and astaxanthin content of Enteromorpha intestinalis, Ulva lactuca and Catenella repens were documented over a 10 months period from September 2007 to June 2008. The macroalgal species were collected from six sampling stations of Indian Sundarbans, a Gangetic delta at the apex of Bay of Bengal. On dry weight basis, the protein content varied from 4.15±0.02% (in Catenella repens) at Lothian to 14.19±0.09% (in Catenella repens) at Frasergaunge. The lipid content was low and varied from 0.07±0.02% (in Enteromorpha intestinalis) at Lothian to 1.06± 0.12% (in Ulva lactuca) at Gosaba. The level of carbohydrate was very high compared to that of lipid and protein and varied from 21.65± 0.76% (in Catenella repens) at Gosaba to 57.03± 1.63% (in Enteromorpha intestinalis) at Lothian. Astaxanthin values ranged from 97.73± 0.32 ppm (in Catenella repens) at Gosaba to 186.11± 2.72 ppm (in Enteromorpha intestinalis) at Frasergaunge. The values varied over a narrow range in the remaining stations. The results of biochemical composition of macroalgae seem to be strongly influenced by ambient hydrological parameters (surface water salinity, temperature and nitrate content) in the present geographical locale. INTRODUCTION Far East, where they are used in the food industry [7].
"Sea grapes" is a collective term for the edible varieties of the green seaweed genus Caulerpa. Here we conduct comparative analyses of the biomass productivities and biochemical properties of C. lentillifera and C. racemosa from tropical Australia. Commercial-scale production was evaluated using 1 m(2) culture units with high stocking densities (> 5 kg m(-2)). Productivity of C. lentillifera in a 6-week period yielded, on average, 2 kg week(-1), whereas C. racemosa yielded < 0.5 kg week(-1). Morphometric comparisons of the harvestable biomass revealed that C. lentillifera had a higher proportion of fronds (edible portions) to horizontal runners (stolons) and a higher density of fronds per unit area. C. racemosa fronds, however, were significantly longer. The nutritional value of C. racemosa was higher than C. lentillifera for both polyunsaturated fatty acids (10.6 vs. 5.3 mg g(-1) DW) and pigments (9.4 vs. 4.2 mg g(-1) DW). The content of eicosapentaenoic acid (EPA) and beta-carotene decreased with increasing frond size in both species. Trace element contents also varied substantially between the species, including higher levels of zinc, magnesium and strontium in C. lentillifera, and higher levels of selenium in C. racemosa. Some less desirable elements were higher in C. lentillifera, including arsenic (1 vs. 0.1 ppm) and cadmium, whereas others were higher in C. racemosa, including lead, copper and vanadium. Overall C. lentillifera has a high biomass production potential in monoculture and distinct nutritional properties that warrant a focus on its commercialisation as a new aquaculture product in tropical Australia and in Southeast Asia more broadly.
The Canadian Integrated Multi-Trophic Aquaculture Network (CIMTAN) is a Natural Sciences and Engineering Research Council strategic network that was initiated in 2010. It was triggered by the fact that aquaculture, though the world fastest growing food production sector, is associated with environmental, economic, and societal issues. Integrated multi-trophic aquaculture (IMTA) offers an innovative solution for the environmental sustainability, economic stability, and societal acceptability of aquaculture by taking an ecosystem-based management approach. IMTA is the farming, in proximity, of aquaculture species from different trophic levels, and with complementary ecosystem functions, so that one species’ excess nutrients are recaptured by the other crops and synergistic interactions among species occur. CIMTAN is providing the interdisciplinary research and development and highly qualified personnel training in the following linked areas: (1) ecological design, ecosystem interactions, and biomitigative efficiency; (2) system innovation and engineering; (3) economic viability and societal acceptance; and (4) regulatory science. By mitigating organic and inorganic enrichment of fed aquaculture operations and producing additional extractive crops, IMTA should transform environmental and socioeconomic issues into benefits, trusted quality seafood, and novel seafood-based products. CIMTAN is going beyond addressing questions of a natural science and engineering nature and is addressing socioeconomic, policy, and regulatory governance components.
Integrated multi-trophic aquaculture (IMTA) has been proposed as a concept that combines the cultivation of fed aquaculture species (e.g., finfish/shrimp) with extractive aquaculture species (e.g., shellfish/seaweed). In seaweed-based integrated aquaculture, seaweeds have the capacity to reduce the environmental impact of nitrogen-rich effluents on coastal ecosystems. Thus, selection of optimal species for such aquaculture is of great importance. The present study aimed to develop a seaweed species-selection index for selecting suitable species in seaweed-based integrated aquaculture system. The index was synthesized using available literature-based information, reference data, and physiological seaweed experiments to identify and prioritize the desired species. Undaria pinnatifida, Porphyra yezoensis and Ulva compressa scored the highest according to a seaweed-based integrated aquaculture suitability index (SASI). Seaweed species with the highest scores were adjudged to fit the integrated aquaculture systems. Despite the application of this model limited by local aquaculture environment, it is considered to be a useful tool for selecting seaweed species in IMTA.
This work aimed to evaluate the effects of integrated culture of sea lettuce (Ulva fasciata) on the shrimp (Litopenaeus vannamei) and mullet (Mugil liza) rearing in a biofloc technology (BFT), on water quality, animal performance and seaweed growth, nitrogen and phosphorus recovery, seaweed bioactive compounds. Two groups were compared: i) Ulva group: cultivation system integrating shrimp and mullet with seaweed, ii) control group: the same without seaweed, both groups used BFT. Each group had four replicates; initial biomass was 618 ± 8 g and 246 ± 34 g for the shrimp and mullet, respectively. Additionally, in the Ulva group, 120 g of sea lettuce per tank was included every two weeks. After 55 days, the integration of seaweed in the system did not influence the shrimp and mullet performance. Shrimps grew, on average, 1.22 g week−1, with 90.6% survival, 2.91 kg m−3 yield and 1.84 FCR. Mullets grew, on average, 1.035 g week−1, with 99.17% survival, and 4.08 kg m−3 yield. At the end 317.01 ± 32.02 g of seaweed per experimental unit was harvested. The total final biomass and yield, considering the whole system, were 12.2% higher in the Ulva group than in the control group. Nitrogen and phosphorus recovery were respectively 5.5% and 7.6% higher in the Ulva group than in the control group. The nitrogen, phosphorus, chlorophyll-a and carotenoids contents in the Ulva group were also higher at the end of the experiment. In conclusion, the integration of sea lettuce can increase the total yield, nitrogen and phosphorus recovery in the biofloc system. Furthermore, the integration of sea lettuce in this system can increase the content of chlorophyll-a and carotenoids, without affecting the yield of ulvan extract.
Searching for potential increases in shrimp yields, this study evaluated the effects of different stocking densities on water quality and production performance of juvenile shrimp, Litopenaeus vannamei, reared on a biofloc‐dominated system throughout 77 days. The organisms (1.27 ± 0.54 g) were stocked at three densities, 400 (T400), 500 (T500), and 600 (T600) shrimp/m2 corresponding to 500, 625, and 750 shrimp/m3, with three replicates each, in nine 35 m2 tanks with 28 m3 of workable volume inside a greenhouse. Shrimp were maintained at optimal conditions for the species with an average temperature of 28.9 ± 0.1°C, dissolved oxygen average above 6.0 mg/L, and pH above 7.3. Significant differences in yields (3.52 ± 0.05, 4.02 ± 0.06 and 4.22 ± 0.40 kg/m2 or 4.39 ± 0.07, 4.48 ± 0.08, and 5.27 ± 0.49 kg/m3) were observed between treatments (T400, T500, and T600, respectively), and for final mean weights (12.3 ± 5.53, 12.2 ± 3.89, and 10.2 ± 3.49 g, respectively). These results suggest that 500 shrimp/m2 or 625 shrimp/m3 is the optimum stocking density for Biofloc Technology culture under the defined study conditions.
Inorganic carbon, nitrogen and phosphorus are the main elements required by seaweeds for photosynthesis and growth. This review focusses mainly on nitrogen, but the roles of carbon and phosphorus, which may interactively affect seaweed physiological processes, are also explored. Fundamental concepts such as limiting nutrients, sources, and ratios, mechanisms of nutrient uptake, nutrient assimilation and storage, patterns of uptake and preferences for different nitrogen sources are discussed. The roles of abiotic (water motion, light, temperature, salinity and desiccation) and biotic (life stages and age class) factors in nutrient (nitrogen, phosphorous, carbon) uptake are also reviewed. Understanding species-specific nitrogen physiologies and nitrogen source preferences will enable polyculture of different seaweed species and the use of seaweeds as biofilters in integrated multitrophic aquaculture systems.
Aquaculture is responsible for almost 50% of the global production of aquatic organisms. However, the activity generates residues that cause environmental impacts. Several strategies can be adopted from the planning stage to the residue treatment to reduce these negative impacts. Alternative rearing systems, such as integrated multi‐trophic aquaculture (IMTA), integrated aquaculture‐agriculture systems, recirculation systems (RAS) and biofloc (BFT), can be implemented in place of the traditional monocultures. At the residue treatment stage, the solids particles can be removed by the settlement of suspended solids in tanks or mechanical filters. The reduction in dissolved nutrients is used in biological filters, constructed wetlands or the irrigation of agricultural crops. Finally, we describe the methodologies that are used to estimate the aquaculture environmental impacts. These methodologies allow the stages and processes that have a higher environmental impact in the production chain to be identified. Among them, we can highlight the life‐cycle assessment (LCA), emergy analysis and ecological footprint. The strategies described in this study can contribute to increasing aquaculture sustainability; however, studies should be developed that focus on more than just productivity and profitability, as it is necessary to include social and environmental issues.
The objective of this research was to evaluate the growth, oxidative stress and HSP70 of pacific white shrimp under different stocking densities. Juvenile shrimps (average weight 2 g) were stocked under three densities (30，40，50 ind/cage, expressed as S30, S40 and S50 respectively) for 60 days. All treatment groups setting in net cages (size 40 cm × 40 cm × 40 cm) were submerged in a pond to ensure the same rearing conditions. At the end of the experiment, the survival rate decreased with increasing stocking density, ranged 83.3%, 79.2% and 78.7% respectively. The finial average size of shrimp in S30 was higher than that of the group S50. SGR, WG and FCR of shrimps in S30 group were better compared to that of the S40 and S50. Furthermore, antioxidant abilities in the hemolymph, hepatopancreas and muscle of shrimp were higher at low stocking density. HSP70 increased in hepatopancreas with increasing stocking density. The results of this study demonstrated that, when juvenile shrimps were reared under high stocking density, growth, feed utilization, antioxidant capability and stress resistance ability was decreased, indicating that high stocking density would affect growth and welfare of juvenile white shrimp. © Published by Central Fisheries Research Institute (CFRI) Trabzon, Turkey.
Growth parameters of whiteleg shrimp Litopenaeus vannamei and red seaweed Gracilaria corticata were measured using integrated culturing method under zero-water exchange system in a 45-day period. A 2 × 3 factorial design was used with two levels of shrimp stocking densities and three levels of seaweed weight densities. G. corticata was cultured on a net tied to a round polyethylene frame. Culture tanks were filled with 750-L filtered seawater. A 40-W compact fluorescent lamp was hung over each tank to provide adequate and sufficient light for seaweed growth. Growth parameters of shrimp and seaweed such as specific growth rate (SGR), weight gained (WG) and average daily growth (ADG) were computed based on the initial and final weight of shrimp and seaweed. The maximum and minimum SGR of L. vannamei (1.97 and 1.69%/day) were observed in treatment S1A3 (25 shrimp/m2 and 400 g seaweed/m2) and S2A1 (50 shrimp/m2 without seaweed) respectively. The best survival rate (94.67 ± 1.33%), WG (129.9 ± 2.9%) and feed conversion ratio (1.67 ± 0.04) were also observed in treatment S1A3. The SGR of G.corticata in the treatment S1A3 (1.97 ± 0.00%/day) was significantly higher, compared to others. Strong positive correlations were obtained between the density of G. corticata and the growth parameters of L. vannamei. The red seaweed G. corticata could boost the growth parameters, survival rate and total production of L. vannamei under zero-water exchange system.
The shrimp industry of Vietnam has developed rapidly and became an
important sector in socio-economics of the country. Most recent data show
that shrimp farming accounts for 655,156 ha of farms which produce 487,960 T
annually. Mekong Delta is the main shrimp producing area where 90% of
production farms are located and 60% of the country’s shrimps are produced.
Shrimp farming systems are highly diversified which include improvedextensive,
integrated mangrove -shrimp, rotational rice-shrimp, and intensive
shrimp farming systems. Recently, white leg shrimp is dominantly used for
intensive systems, while tiger shrimp is still the main species for the other
systems. Shrimp hatcheries have been decreasing in number but increasing in
scale, with a total of 1715 hatcheries producing 67 billion postlarvae in 2012.
Shrimp feed production and shrimp processing sectors are also very dynamic
with different local and foreign investors. Certification along the production
chain is one of important trends of the industry. To address several issues and
emerging problems, and to contribute more significantly to the socio-economic
development, a strategic plan for sustainable development of shrimp industry
to year 2020 and vision for year 2030 have been issued by the government for
implementation.
In light of the increasing demand for fish, the challenge for planners now is to accelerate aquaculture development and to plan for new production, making urban areas not only centres of marketing and distribution, but also of production, particularly using urban wastewater. This book includes papers from authors in the USA, Europe and Asia that review these developing issues from the perspective of both developed and developing countries. Urban aquaculture education is also considered. The book is intended for those researching in aquaculture, water resources, urban planning and geography. It has 19 chapters and a subject index.
Integrated aquaculture has been proposed as an environmentally friendly way of recycling wastes, especially those produced through the cultivation of high trophic level species, which require the supply of exogenous energy (food). The cultivation of filter-feeders and seaweeds around fish culture cages has been tested for waste recycling. However, success has not been total, partly because the amount of filter-feeders and seaweed needed to remove a significant proportion of the wastes produced from intensive large scale cultivation systems is very large. Thus, semi-closed and land-based systems have been proposed as a technological alternative for integrated aquaculture. The latter type of systems are technically feasible. although, the high investments needed at present, prevent its more general use. In Chile, salmon cultivation is well established, and produces over 200,000 tons yr-1. As a result of the rapid expansion of salmon farming, the concern regarding the environment is rising. Thus we have made experiments to integrate the cultivation of the agarophyte Gracilaria, with salmon farms. Our results indicate that this alga is capable of removing a significant proportion of the ammonium excreted by fish. Studies in land-based integrated culture systems indicate that fish production can reach over 30 kg m-3, with an associated Gracilaria production of 49 kg (wet weight) m-2 y-1. The environmental benefits associated with the development of integrated tank cultivation were assessed by analysing previously published and unpublished data. With these production results, a profitability analysis was made, internalizing the environmental benefits. As the waste discharge is highly reduced by integrating seaweed cultivation into a fish farm, the economic profitability of a commercial project is almost not affected by internalizing the environmental costs as compared to a situation without environmental requirements.
There is a consensus among aquaculturists that water circulation in ponds is beneficial. Water circulation prevents thermal and chemical stratification. This makes the entire pond volume habitable for aquatic animals, and it eliminates the danger of thermal overturns in deep ponds. Water circulation devices create surface turbulence and this causes a small degree of aeration. Air-lift pumps use air bubbles to move water, and some oxygenation is affected by the rising bubbles. Water circulators should not be considered aerators in the usual sense. The greatest influence of water circulators on dissolved oxygen concentration is the blending of surface water with subsurface water. During daylight hours, surface water in ponds often is supersaturated with dissolved oxygen, and water at greater depths may have a low dissolved oxygen concentration. By mixing pond water, a uniform dissolved oxygen profile can be established. Oxygen produced by phytoplankton is partially conserved by water mixing, because the high degree of dissolved oxygen supersaturation normally found at pond surfaces during daylight is eliminated. Circulation of pond water also may stimulate phytoplankton growth (Sanares et al. 1986), and this could possibly increase dissolved oxygen production by photosynthesis.
The tolerance of Litopenaeus vannamei larvae to increasing concentrations of total ammonia nitrogen (TAN) using a short-term static renewal method at 26°C, 34 g L−1 salinity and pH 8.5 was assessed. The median lethal concentration (24 h LC50) for TAN in zoea (1-2-3), mysis (1-2-3) and postlarvae 1 were, respectively, 4.2-9.9-16.0; 19.0-17.3-17.5 and 13.2 mg L−1TAN (0.6-1.5-2.4; 2.8-2.5-2.6 and 1.9 mg L−1NH3-N). The LC50 values obtained in this study suggest that zoeal and post-larval stages are more sensitive to 24 h ammonia exposure than the mysis stage of L. vannamei larvae. On the basis of the ammonia toxicity level (24 h LC50) at zoea 1, we recommend that this level does not exceed 0.42 mg L−1 TAN – equivalent to 0.06 mg L−1NH3-N – to reduce ammonia toxicity during the rearing of L. vannamei larvae.