REVIEW | doi:10.20944/preprints202201.0220.v2
Subject: Earth Sciences, Environmental Sciences Keywords: Aquaculture; environmental impacts; PRISMA; shrimp aquaculture; socioeconomic impacts
Online: 21 February 2022 (10:48:57 CET)
Aquaculture production is under pressure to increase its production to meet the growing demand for food from a growing population. In the Philippines, aquaculture has experienced the shift from milkfish to prawn with its attractive marketable price. Its intensification has led to negative and positive impacts making its collapse inevitable in the mid-1990s and raised a range of environmental and socioeconomic problems. This paper reviewed the environmental impacts, challenges, and disease outbreaks that overtook the industry using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) method. We examined gaps and changes required to revitalize the industry to properly take-off. It considers and gives details on the impacts of shrimp culture on the environment e.g. shrimp farm management, marine pollution, disease outbreaks, climate change impacts, and socioeconomic impacts. Moreover, the presence of viral diseases such as White Spot Syndrome Virus (WSSV), Monodon Baculovirus (MBV), Infectious Hypodermal and Hematopoietic Necrosis Virus (IHHNV), Hepatopancreatic Parvovirus (HPV), and Yellow Head Virus (YHV), have caused socioeconomic impacts with approximate losses of 40,080 mt in 1997 to 51,000 mt in 2014 in the shrimp industry. Recommended strategies were considered to improve the environmental management of shrimp aquaculture, including disease management, and priorities that were highlighted for future research. This management relates to adopting good aquaculture practices on shrimp culture, proper environmental monitoring and sustainable practices at the farm level.
Online: 14 October 2021 (10:33:01 CEST)
The health status and feed conversion efficiency of farmed fish may vary according to management and production methods. Successful aquaculture requires safeguarding the health of the growing fish and optimizing the feed conversion and therefore achieving better FCE thus reducing the amount of feed required to produce farmed fish, reducing the environmental impact generated by fish feed production and reducing aquaculture wastes generated by feed wasted or poorly digested. The present review presents illustrative examples from freshwater aquaculture that suggests the potential dual benefits of focusing on the link between feed conversion and the environmental impact of fresh water fish farms. Apart from the need to support future research on new diets for farmed fish (which is mainly driven by limits in the supply of fish protein and the results price fluctuation of all ingredients used by the aquaculture, feed industry), major improvements can be expected by optimizing feeding regimes and the application of probiotics. Aside from the economic benefits and increased production of fish farms, improved feeding regimes and probiotics are expected to have a significant impact on the welfare of farmed fish as well as on digestion efficiency and the environmental impact of fresh water fish farms.
REVIEW | doi:10.20944/preprints202001.0332.v1
Subject: Biology, Agricultural Sciences & Agronomy Keywords: transcriptomics; aquaculture; genetics; next generation sequencing
Online: 28 January 2020 (05:10:55 CET)
New challenges arise in the face of global climate change which impact every ecosystem on earth, including aquatic systems. This is evident in observations made in regard to the world’s oceans, which show trends of incremental changes in ocean surface temperatures, sea levels, and ocean acidity. These environmental shifts impact human resources such as fisheries and aquaculture. In addition, according to the World Bank, the increase in human population will also require more food and nutrient production, which include industries such as aquaculture. With this increasing demand in aquaculture and fisheries, we must develop efficient and productive methods to operate these industries. We can use genetic methods, specifically transcriptomic information to better understand the biology of our source of nutrition. With the advent of RNASeq techniques, we can provide a better understanding about growth and development, immune function and stress, and adaptations. The use of population genetics or (genomics) to detect Single Nucleotide Polymorphisms (SNPs) between populations or closely related species can provide greater insight from stock structure to fishery-induced evolution. In addition, candidate loci can be investigated further to better understanding evolutionary processes, which provide clues on physiological adaptations and gene expression patterns that can help elucidate how these organisms respond to their current environment. In addition, the use of transcriptomic analyses such as differential gene expression can be used to determine resilience in various environmental conditions such as pollution, hypoxic/anoxic conditions, fluctuations in salinity, and temperature extremes. There has been an increase in transcriptomic studies for many aquaculture species, which has aimed at improving our understanding of growth, development, and metabolism, providing vital information for fisheries and aquaculture industries to make adjustments to environmental conditions such as oxygen availability, nutrition, and salinity. All of these aspects provide insightful information for advancing our knowledge of aquaculture, fisheries and conservation management.
ARTICLE | doi:10.20944/preprints202201.0067.v1
Subject: Biology, Agricultural Sciences & Agronomy Keywords: duckweed; meal; Lemnoideae,; Wolffioideae; aquaculture; carbohydrates; protein
Online: 6 January 2022 (10:24:50 CET)
Duckweeds are the smallest flowering plants on Earth. They grow fast on water's surface and produce large amounts of biomass. Further, duckweeds display high adaptability, and species are found around the globe growing under different environmental conditions. In this work, we report the composition of 21 ecotypes of fourteen species of duckweeds belonging to the two sub-families of the group (Lemnoideae and Wolffioideae). It is reported the presence of starch and the composition of soluble sugars, cell walls, amino acids, phenolics, and tannins. These data were combined with literature data recovered from 85 publications to produce a compiled analysis that affords the examination of duckweeds as possible food sources for human consumption. We compare duckweeds compositions with some of the most common food sources and conclude that duckweed, which is already in use as food in Asia, can be an interesting food source anywhere in the world.
ARTICLE | doi:10.20944/preprints202112.0130.v1
Subject: Biology, Agricultural Sciences & Agronomy Keywords: rural aquaculture; water use; emergy; fish production
Online: 8 December 2021 (14:21:43 CET)
Freshwater pond aquaculture is the prevailing fish culture system worldwide, especially in developing countries. Climate change outcomes and inadequate environmental practices challenge its sustainability. This study applies emergy synthesis to assess the environmental performance of freshwater pond aquaculture in Brazil, aiming to identify and propose practices towards sustainability. As a study model, nine semi-intensive lambari farms operating at three levels of management were evaluated: low (LC), moderate (MC) and high (HC) control. Results showed that the main inputs for LC were services (27-46%), feed (7-39%), and water (15-21%), while for the MC and HC farms, they were feed (35-49% and 17-48%, respectively) and services (33-39% and 26-36%, respectively). All farms required more than 60% of their emergy from purchased inputs, resulting in low emergy sustainability index (ESI = 0.1-0.5). Replacing animal protein and oil on diet composition by vegetal sources, using superficial water instead of springwater, increasing juvenile productivity, and controlling pond fertilization can lead all systems to higher efficiency and resilience, increasing sustainability.
REVIEW | doi:10.20944/preprints201912.0377.v1
Subject: Life Sciences, Microbiology Keywords: algae; wastewater; microalgae; biofuels; phytoplankton; aquaculture; phycology
Online: 29 December 2019 (09:34:40 CET)
Microalgae wastewater treatment has long been promoted as a sustainable method to handle the influx of human waste due to population growth. Initially, in the early 1900’s, microalgae was noted to increase wastewater treatment efficiency by aerating the water and consuming waste. By mid-century, wastewater grown microalgae was being investigated as a way to produce biomass for food, fuel, and other biomaterials. The space race in the 1960’s led to the use of microalgae in life support systems. Technological developments and political pressure in the 1970’s spurred studies of the impact of wastewater on the growth of phytoplankton in the oceans as well as methods to use microalgae wastewater treatment in aquaculture. Simultaneously, the oil crisis of that decade promoted research of alternative fuels, which included microalgae biofuels via the Aquatic Species Program. This program led to research into the use of wastewater as a feedstock for microalgae growth. By the later 2000’s, instability in the oil market caused another energy crisis which further prompted investment in microalgae biofuels, some of which involved combined wastewater treatment. Currently, microalgae wastewater treatment is being researched as a way to cut back on greenhouse gas emissions to curb global warming and produce sustainable biofuels.
ARTICLE | doi:10.20944/preprints202108.0110.v2
Subject: Life Sciences, Biotechnology Keywords: Astyanax; Macrobrachium; Prochilodus; IMTA; resources optimization; integrated aquaculture
Online: 23 August 2021 (12:56:04 CEST)
A single farmed fish species assimilates about 20% of the nutrients in the supplied diet. This study evaluated if the culture of complementary ecological-function species can recover nutrients dispersed into the water and transform them into high-valued biomass. A completely randomized experiment was designed with three treatments and four replications of each production system: monoculture of lambari (Astyanax lacustris); integrated aquaculture of lambari and Amazon river prawn (Macrobrachium amazonicum); and integrated aquaculture of lambari, Amazon river prawn, and curimbatá (Prochilodus lineatus). Fingerlings of lambari (0.8 ± 0.8 g) were stocked in twelve earthen-ponds (0.015 ha) at the density of 50 fish m-2. Eight ponds, were stocked with juveniles of Amazon river prawn (1.1 ± 0.2 g) at the density of 25 prawn m−2. Four of these eight ponds were stocked with curimbatá fingerlings (0.2 ± 0.1 g) at a density of 13 fish m-². Only lambari was fed twice a day with an extruded commercial diet. The experiment lasted 60 days when lambari attained commercial size. The inclusion of prawn increased the total species yield from 1.8 to 2.4 t ha-1 cycle-1 and reduced the feed conversion ratio (FCR) from 2.5 to 1.8. The inclusion of prawn and curimbatá increased the total yield to 3.2 t ha-1 cycle-1 and reduced the FCR to 1.4. Therefore, the integrated culture of lambari, prawn, and curimbatá improves the use of space, water, feed, and benthic species can recover the large quantity of nutrients accumulated in the bottom of lambari pond production, converting them into high-nutritional and monetary-valued biomass.
REVIEW | doi:10.20944/preprints202104.0549.v1
Subject: Biology, Anatomy & Morphology Keywords: Fisheries; Aquaculture; Food security; SDGs; COVID-19; Bangladesh
Online: 20 April 2021 (14:12:18 CEST)
Bangladesh has achieved tremendous progress in the fisheries sector that is making evidential contribution to food security, nutrition and livelihoods. Based on secondary data collected from the Department of Fisheries, Bangladesh and related un-published grey literature, this paper highlights the performance and challenges of the fisheries with emphasis on COVID-19 impact as well as the significance of this sector for achieving the Sustainable Development Goals (SDGs). The total fish production is increased more than six times over the last three decades (7.54 to 43.84 lakh MT) due to the dissemination of improved culture techniques and extension services. Inland closed water contributions have been increasing to 16.24%, while inland open water have declined 10.23% and marine fisheries have dropped 6.27% over the past 18 financial years (2000-2001 to 2018-2019). COVID-19, a major health crisis has also affects various issues associated with aquatic resources and communities. Transportation obstacles and complexity in the food supply, abstraction to start production, labour crisis, sudden illness, poor consumer demand, commodity price hike, creditor's pressure and reduced income were identified as affecting COVID-19 drivers. The combined effect of these drivers poses a significant threat to people’s income (SDG1- eliminate poverty), nutrition (SDG2- erase hunger), food security (SDG3- good health and wellbeing, and SDG12- responsible consumption and production) that demands comprehensive actions. Several recommendations have been elicited, which are important to implement for the achievement of SDGs as well management and imprvement of the aquatic sector (SDG14- life below and SDG16- life above water) .
Subject: Earth Sciences, Atmospheric Science Keywords: Geohazards; Comau Fjord; landslides; tsunamis; aquaculture; Austral highway
Online: 3 November 2020 (14:10:51 CET)
In this paper we study natural hazards and their potential impacts on productive activities in the Comau Fjord in Chilean Northern Patagonia. We carried out a hazard mapping to identify areas with evidence of geomorphological activity on slopes in terms of landslides, fluvial/tsunami flooding and glacial retreat. The assessment of different geomorphic process was carried out by both fieldwork and remote image processing. We performed a geodynamic hotspot identification overlapping different hazard maps to derive spatially distributed multihazard terrain units. This information was overlain with spatial data of economic activities in the area in order to establish the impacts of such natural hazards on the local salmon and mussel farming infrastructure. The results suggest significant exposure levels for these productive activities and potential damages due to the ocurrence of natural hazards. The extension of a major highway (CH-7 Austral Highway) on the east coast of Comau Fjord will be a new incentive for economic development in the area. However, the highway cosntruction sites itself have the highest level of exposure to natural hazards. 2 CITRID, Risk Reduction and Disaster Program, University of Chile 3 Physical Geography Lab. Department of Geography, University of Chile, Chile. 4 Postgraduate School, Faculty of Architecture and Urbanism, University of Chile, Chile 5 Institute of Engineering Sciences, University of O´Higgins, Rancagua, Chile. 6 Department of Geology, University of Chile. 7 Department of Earth and Environmental Sciences, University of Pavia, Italy. firstname.lastname@example.org Summary In this paper we study natural hazards and their potential impacts on productive activities in the Comau Fjord in Chilean Northern Patagonia. We carried out a hazard mapping to identify areas with evidence of geomorphological activity on slopes in terms of landslides, fluvial/tsunami flooding and glacial retreat. The assessment of different geomorphic process was carried out by both fieldwork and remote image processing. We performed a geodynamic hotspot identification overlapping different hazard maps to derive spatially distributed multihazard terrain units. This information was overlain with spatial data of economic activities in the area in order to establish the impacts of such natural hazards on the local salmon and mussel farming infrastructure. The results suggest significant exposure levels for these productive activities and potential damages due to the ocurrence of natural hazards. The extension of a major highway (CH-7 Austral Highway) on the east coast of Comau Fjord will be a new incentive for economic development in the area. However, the highway cosntruction sites itself have the highest level of exposure to natural hazards. Our study highlight that the geohazard potential might have a high negative impact on future productive activity in the fjord as well as on the new highway infrastructure.
ARTICLE | doi:10.20944/preprints201805.0421.v1
Subject: Social Sciences, Economics Keywords: aquaculture; fisheries; food security; water; Tonle Sap; Cambodia
Online: 29 May 2018 (09:04:52 CEST)
Fisheries in Cambodia play an important role in supporting household food security and livelihoods throughout the country. Inland fisheries production is largely dependent on numerous ecosystem services, particularly the flood waters of the Tonle Sap Lake basin, which has been degraded from increased fishing pressure because of population growth and a rising demand for fish. To address the dual problem of food insecurity and overfishing, an integrated food security and climate change program involved the promotion of small-scale aquaculture through semi-intensive pond management. The objective of this study is to examine perceptions of small-scale aquaculture by participants in this program in order to assess the potential for aquaculture to contribute to household food security and conservation of the Tonle Sap Lake ecosystem. Focus group discussions and a household survey were conducted among current and previous fish farmers. Results demonstrate that most farmers continue to practice small-scale aquaculture as a means to supplement household food availability and income. Numerous barriers to adoption of small-scale aquaculture were identified, including access to water, prices of commercial fish feed, selling price of fish in markets, and concerns about profitability. Seasonal water scarcity is the most prominent challenge in promoting aquaculture technologies, so aquaculture development should be expanded in areas where there are abundant supplies of water, or where use of water storage techniques are feasible. Aquaculture technology appears to have the potential to contribute to food security, nutrition, and household income, and the expansion of the practice of small-scale aquaculture has the potential to reduce fishing pressure on the wild fisheries of the Tonle Sap Lake.
ARTICLE | doi:10.20944/preprints201709.0114.v1
Subject: Mathematics & Computer Science, Information Technology & Data Management Keywords: WSN; IoT; seawater temperature prediction; marine aquaculture support
Online: 23 September 2017 (11:31:13 CEST)
Aquaculture is growing ever more important due to the decrease in natural marine resources and increase inworldwide demand. To avoid losses due to aging and abnormalweather, it is important to predict seawater temperature in order to maintain a more stable supply, particularly for high value added products, such as pearls and scallops. The increase in species extinction is a prominent societal issue. Furthermore, in order to maintain a stable quality of farmed fishery, water temperature should be measured daily and farming methods altered according to seasonal stresses. In this paper, we propose an algorithm to estimate seawater temperature in marine aquaculture by combining seawater temperature data and actual weather data.
ARTICLE | doi:10.20944/preprints202112.0036.v1
Subject: Biology, Ecology Keywords: pathogens; water quality; biofloc; stagnant aquaculture; bacteria; public health
Online: 2 December 2021 (12:46:59 CET)
Bacteriological and physic-chemical analysis of fish pond water is very important in aquaculture as this gives insights into likely threats to aquaculture and associated personnels. Bacteriological and physico-chemical profiles of selected fish ponds in the Ilorin West area of Kwara State, Nigeria were investigated to evaluate the water quality of rearing enclosures. Physico-chemical analyses revealed quality parameters were within the recommended range for aquaculture. Following bacteriological analyses of static water pond culture, the TVC and TCC showed temporal variations with concentration increasing with sampling time. However, the FCC showed fluctuation. Totally, 8 bacteria groups were isolated from both rearing enclosures. Of these, Gram negative bacteria showed dominance. In which 5 Gram negative (Escherichia coli, Proteus spp, Serratia spp, Enterobacter spp and Pseudomonas spp) and 3 Gram positive (Staphylococcus spp, Streptococcus spp, and Bacillus spp) were encountered. Estimates of bacteria occurrence in both rearing facilities respectively gave: Staphylococcus spp (20%), Streptococcus spp (12%) Proteus spp (8%) Enterobacter spp (20%) Serratia spp (16%), Bacillus spp (9%), Escherichia coli (8%), Pseudomonas spp (7%) from earthen pond water sampled. While Staphylococcus spp (18%), Streptococcus spp (16%), Proteus spp (8%), Enterobacter spp (22%), Serratia spp (8%), Bacillus spp (15%), Escherichia coli (8%), Pseudomonas spp (6%) from concrete water sampled. Conclusively, although there is the presence of bacteria groups of public health concern, the static water exchange provides benefits of natural processing of wastes and restoration of the pond ecosystem. Notably, the presence of Escherichia coli gives indication of presence of pathogenic organisms of enteric origin. The presence of these organisms has been associated with a lack of tentative pond management and effective biosecurity procedures. One recommendation to this culture system (static water aquaculture) is the consideration of adaptation of concepts in biomimicry or biofloc technology which operates on similar principles.
ARTICLE | doi:10.20944/preprints202009.0518.v1
Subject: Mathematics & Computer Science, Information Technology & Data Management Keywords: aquaculture water quality; dissolved oxygen (DO); forecasting; EEMD; LSTM
Online: 22 September 2020 (10:02:09 CEST)
Dissolved Oxygen (DO) concentration is a vital parameter that indicates water quality. DO short term forecasting using time series analysis on data collected from an aquaculture pond is presented here. This can provide data support for an early warning system for an improved management of the aquaculture farm. The conventional forecasting approaches are commonly characterized by low accuracy and poor generalization problems. In this article, we present a novel hybrid DO concentration forecasting method with ensemble empirical mode decomposition (EEMD) based LSTM (Long short-term memory) neural network (NN). With this method, first, the sensor data integrity is improved through linear interpolation and moving average filtering methods of data preprocessing. Next, the EEMD algorithm is applied to decompose the original sensor data into multiple intrinsic mode functions (IMFs). Finally, the feature selection is used to carefully select IMFs that are strongly correlated with the original sensor data and integrate both into inputs for the NN. The hybrid EEMD-based LSTM forecasting model is then constructed. Performance of this proposed model in training and validation sets was compared with the observed real sensor data. To obtain the exact evaluation accuracy of the forecasted results of the hybrid EEMD-based LSTM forecasting model, three statistical performance indices were adopted: MAE, MSE, and RMSE. Results presented for short term (12-hour period) and long term (1-month period) give a strong indication of suitability of this method for forecasting DO values.
ARTICLE | doi:10.20944/preprints201909.0219.v1
Subject: Biology, Agricultural Sciences & Agronomy Keywords: aquaculture; computational biology; differential equation; ion transport; systems biology
Online: 19 September 2019 (05:03:11 CEST)
A mathematical expression to describe cation absorption of root is expressed with simulation results. The root cells selectively emit H+ ions with active transport consuming ATPs to establish electrical gradient. The gradient promotes external positive ions to flow into the roots, while carries negatively charged particles with symport. In this paper, a mathematical model whose independent variables are the concentrations of external and internal cation is presented. This differential equation is induced from Ohm’s law. The equation has terms for plant physiology, ion’s physical and electrical properties, growth of plant, and interaction between the root and the surroundings. Simulation showed that the physiology-related coefficient has important role on nutrition absorption.
ARTICLE | doi:10.20944/preprints202203.0137.v2
Subject: Earth Sciences, Environmental Sciences Keywords: Aquaculture; Davao Oriental; management; Mati City; shrimp farms; water quality
Online: 25 April 2022 (05:52:22 CEST)
The shrimp industry in the Philippines play a vital role in the local and national economy through exports with markets abroad such as in South Korea, Japan, the USA, and others. This study aimed to describe the various cultural and operational characteristics of small-holder and commercial shrimp farms (P. vannamei) in the Davao region. It also evaluated the current risks and challenges faced by the shrimp farmers. A semi-structured questionnaire that focused on shrimp farmers, and operators in the region was used to collect data with N=41 farmers and operator. The results showed that respondents were engaged in small-holder farming activities which had an average yield of 10 tons/ha. On the other hand, the commercial farms that operate intensively had an average yield of 24 tons/ha. Most small-holder operators used electric generator machines to conduct aeration in their farms using paddlewheels and blowers. For the commercial farms, more paddlewheels and blowers were employed per pond compared to small-holder farms. Generally, the income of a farm was related to the yield of farms or the number of fries rather than social factors or size of farms cultivated. In terms of input costs, feeds were found to have the highest input costs, followed by the fry, fuel, labor, and others (fertilizers and water treatment chemicals). Most of the farmers mentioned that they are affected by diseases such as white spot syndrome (60%), black gills (35%), and red tail (5%). They perceived that the main contamination come from the water source (31%). The main threats mentioned are declining shrimp prices in the market, source of fry, water disposal, and overstocking, and water quality. Based on this study, farmers should follow good shrimp aquaculture practices and there is a need for them to regularly monitor their water quality.
ARTICLE | doi:10.20944/preprints202111.0352.v1
Subject: Biology, Animal Sciences & Zoology Keywords: skeletal abnormalities; vertebral column; quality index; body shape; finfish aquaculture
Online: 19 November 2021 (12:43:54 CET)
The lordosis of the haemal part of the vertebral column is a frequent abnormality in reared fish. Haemal lordosis develops during the late larval and early juvenile period, mainly due to the high swimming activity of the fish in the rearing tanks. In the present study we examined whether haemal lordosis recovers during the growth of European sea bass. Furthermore, we aimed to develop simple morphometric indices (PrAn1 and PrAn2) that could link the severity of lordosis at the juvenile stage with fish morphological quality at harvesting. At 111 days post-hatching (dph, 53±4 mm standard length, SL), 600 seabass juveniles with lordotic (L, 200 fish) or normal (N, 400 fish) external morphology were selected and introduced in a common tank. At 150 dph (75±7 mm SL), 350 fish were randomly selected, pit-tagged and transferred in a sea cage for on-growing up to 502 dph (234±16 mm SL). The morphological examination of the fish at 150 and 502 dph revealed that the 60% (46 out of 77) of L juveniles turned into normal phenotype by the end of on-growing period. Interestingly, 56% of the fish with recovered external morphology (N-Rec) presented either a completely normal vertebral column (31%) or minor abnormalities of individual vertebrae (25%). Following the results of geometric morphometric analysis, the differences in the body shape between N-Rec and N fish were not significant (p>0.05, canonical variate analysis). The examined morphometric indices were effective in discriminating the normal fish from the 58% (PrAn1) to 65% (PrAn2) of lordotic juveniles. Results are discussed with respect to the mechanism of lordosis recovery, as well as to their application for the quality control and cull out of the abnormal fish in the commercial hatcheries.
ARTICLE | doi:10.20944/preprints202202.0207.v2
Subject: Earth Sciences, Environmental Sciences Keywords: Aquaculture; Climate change; Davao Oriental; FishVool; Management; Mati City; Shrimp culture
Online: 17 March 2022 (10:58:39 CET)
The impacts of climate change on shrimp aquaculture can vary widely and can have environmental and socioeconomic consequences. This study assessed the vulnerability to climate change impacts of selected small-scale shrimp farms of Penaeus vannamei and shrimpfish market vendors in Davao region, Philippines using a modified Fisheries Vulnerability Assessment Tool (FishVool). Shrimp farmers and vendors were interviewed using two separate semi-structured questionnaires. A total of thirty-nine (N=39) shrimp farmers and forty-eight (N=48) market vendors from various market areas within the region were interviewed. Data regarding exposure (E), sensitivity (S), and adaptive capacity (AC) were collected following the FishVool parameters with modifications. Results revealed that overall climate change vulnerability of the shrimp farmers was medium (M), where both exposure and adaptive capacity were low (L) while sensitivity was medium (M). In addition, the shrimp market vulnerability of the various sites examined revealed medium (M) scores for markets in Pantukan, Mabini, Tagum, Maco, Lupon, Davao City, and Digos. But high (H) vulnerability scores for the markets in Panabo and Sta Cruz. Overall, the study provided a better understanding about shrimp farming in relation to climate change impacts and vulnerability and provided information for future shrimp farm management, marketing and climate change adapation in the region.
ARTICLE | doi:10.20944/preprints201904.0108.v1
Subject: Life Sciences, Microbiology Keywords: aquaculture; fish; foodborne disease, antimicrobial resistance; pond water; total bacteria count
Online: 9 April 2019 (12:11:35 CEST)
Fish currently provide 6.7% of all protein consumed by humans globally, nevertheless, aquaculture system has been linked to fish and environmental contamination and disease outbreak. This study aims to isolate, identify, and characterise, bacteria in fish and pond water as well as the antibiotic profile of detected Coliforms. The susceptibility of the isolates was tested using the Kirby-Bauer disc diffusion method on Mueller Hinton agar. A total of forty (40) isolates were isolated from the water samples of which (5) species were Gram Positive bacteria and 35 species of Gram Negative bacteria. The temperature for all ponds ranged from 25°C to 28°C. The mean bacteria count for pond C1 to T2 were 4.9 × 102, 4.9 × 102, 5.4 × 102, 2.5 × 102, 2.2 × 102, and 1.9 × 102 CFU/ml respectively. All isolates were 100% resistant to ceftazidime, cefuroxime and augmentin. More resistance to cefixime (80%) and gentamicin (73.3%) and nitrofurantoin (66.7%) was recorded. However, only 16.6% and 8.3% of the isolates were resistant to ciprofloxacin and ofloxacin respectively. The multiple antimicrobial resistance index (MARI) ranged from 0.5 to 0.9. The water quality parameters (temperature and pH) and the type of bacteria detected in all pond type did not differ significantly. The Multi-drug resistance bacteria detected could be pathogenic to fish and consumers.
REVIEW | doi:10.20944/preprints202203.0052.v1
Subject: Earth Sciences, Environmental Sciences Keywords: Mangroves; Drivers; Anthropogenic activities; Climate change; Extreme events; Wetlands; Interaction; Aquaculture; Agriculture
Online: 3 March 2022 (04:39:35 CET)
Globally mangrove forests are substantially declining and a globally synthesized database of the drivers of deforestation and drivers’ interaction is scarce. Here we synthesized the key social-ecological drivers of global mangrove deforestation by reviewing about two hundred published scientific studies over the last four decades (from 1980 to 2021). Our focus was on both natural and anthropogenic drivers with gradual and abrupt impacts and their geographic ranges of effects and how these drivers interact. We also summarized the patterns of global mangrove coverage decline between 1990 and 2020 and identified the threatened mangrove species and their geographic ranges. Our consolidated studies reported a 8,600 km2 decline in the global mangrove coverage between 1990 and 2020 with the highest decline occurring in South and Southeast Asia (3870 km2). We could identify 11 threatened mangrove species, two of which are critically endangered (Sonneratia griffithii and Bruguiera hainseii). Our reviewed studies pointed to aquaculture and agriculture as the predominant driver of global mangrove deforestation though the spatial distribution of their impacts varied. Gradual climate variations, i.e. seal-level rise, long-term precipitation and temperature changes and driven coastline erosion, constitute the second major group of drivers. Our findings underline a strong interaction across natural and anthropogenic drivers with the strongest interaction between the driver groups aquaculture and agriculture and industrialization and pollution. Our results suggest prioritizing globally coordinated empirical studies linking drivers and mangrove changes and a global development of policies for mangrove conservation.
ARTICLE | doi:10.20944/preprints202203.0012.v1
Subject: Chemistry, Analytical Chemistry Keywords: aquaculture; fish; salmon; feces; deconjugation; hydrolysis; extraction; chromatography; mass spectrometry; LC-MS/MS
Online: 1 March 2022 (09:36:18 CET)
The aquaculture industry has become a sustainable provider of food to humans. Remaining challenges include disease issues, as well as ethical concerns for discomfort and stress among farmed fish. There is a need for reliable biomarkers to monitor welfare in fish, and the stress hormone cortisol has been suggested as a good candidate. This study presents a novel method for measurement of cortisol in fish feces based on enzymatic hydrolysis, liquid-liquid extraction, derivatization, and finally instrumental analysis by liquid chromatography coupled with tandem mass spectrometry. Hydrolysis and extraction conditions were optimized. Cortisol appeared to be mostly conjugated to sulfate and less conjugated to glucuronic acid in the studied samples of feces from farmed Atlantic salmon. The method was suitable for quantification of cortisol after enzymatic deconjugation by either combined glucuronidase and sulfatase activity, or by glucuronidase activity alone. The limit of detection was 0.15 ng/g and the limit of quantification was 0.34 ng/g, and the method was linear (R2>0.997) up to 380 ng/g, for measurement of cortisol in wet feces. Method repeatability and intermediate precision were acceptable, both with a CV of 11%. Stress level was high in fish released into seawater, and significantly reduced after eight days.
ARTICLE | doi:10.20944/preprints201809.0593.v1
Subject: Earth Sciences, Environmental Sciences Keywords: mariculture; aquaculture; community restoration; conservation ecology; Native Hawaiian fishpond; microbes; microbial source tracking
Online: 30 September 2018 (04:49:28 CEST)
In Hawaiʻi, the transition from customary subsistence flooded taro agroecosystems, which regulate stream discharge rate trapping sediment and nutrients, to a plantation-style economy (c. the 1840s) led to nearshore sediment deposition - smothering coral reefs and destroying adjacent coastal fisheries and customary fishpond mariculture. To mitigate sediment transport, Rhizophora mangle was introduced in estuaries across Hawai’i (c. 1902) further altering fishpond ecosystems. Here, we examine the impact of cultural restoration between 2012-2018 at Heʻeia Fishpond, a 600-800-year-old walled fishpond. Fishpond water quality was assessed by calculating water exchange rates, residence times, salinity distribution, and abundance of microbial indicators prior to and after restoration. We hypothesized that R. mangle removal and concomitant reconstruction of sluice gates would increase mixing and decrease bacterial indicator abundance in the fishpond. We find that Heʻeia Fishpond’s physical environment is primarily tidally driven; wind forcing and river flux are secondary drivers. Post-restoration, two gates in the northeastern region account for >80% of relative flux in the fishpond. Increase in exchange rates during spring and neap tide and shorter minimum water residence time corresponded with the reconstruction of a partially obstructed 56 m gap together with the installation of an additional sluice gate in the fishpond wall. Lower mean salinities post-restoration suggests increased freshwater influx due to R. mangle removal. Spatial distribution of microbial bio-indicator species inversely correlated with salinity. Average abundance of Enterococcus and Bacteroidales did not significantly change after restoration efforts, however, average abundance of a biomarker specific to birds nesting in the mangroves decreased significantly after restoration. This study demonstrates the positive impact of biocultural restoration regimes on water flushing and water quality parameters, encouraging the prospect of revitalizing this and other culturally and economically significant sites for sustainable aquaculture in the future.
REVIEW | doi:10.20944/preprints202102.0168.v1
Subject: Biology, Anatomy & Morphology Keywords: aquaculture; shellfish; future food; nursery stage; mud crab; juvenile; seed production; hatchery; crablet; breeding
Online: 5 February 2021 (16:18:19 CET)
This study attempted to explain the definition, objectives, and key stages in mud crab nursery activities. The nursery stages of Scylla spp was started from megalopa stage to several crablet instar stages or started from earlier crablet stage to several crablet stages. Direct stocking of megalopa into ponds is not recommended due to their sensitivity. Instead, nursery rearing is needed to produce mud crab of larger size before stocking. Individual nursery rearing results in higher survival rate (up to 100%), but with reduced growth rate, and a more complicated maintenance process compared with communal rearing. Nursery of mud crab can be done indoors, or outdoors, with adequate shelter and feed required to obtain good survival and growth performance. Artemia nauplii are the main, established nursery feed, particularly at megalopa stage, while survival rate may be improved if combined with artificial feed, such as micro bound diet formulations. Water quality parameters, identical to those proposed in tiger shrimp culture, can followed. Crablets may be transported to the pond location with, or without water. The provision of monosex seeds from mud crab hatcheries is expected to become more common, increasing seed price, and thus improving income of farmers. Numerous aspects of mud crab nursery, including nutrition, feeding strategies, understanding of their behaviour, i.e., cannibalism, control of environmental factors, and practical rearing techniques, still need further improvement.
SHORT NOTE | doi:10.20944/preprints202111.0497.v1
Subject: Earth Sciences, Environmental Sciences Keywords: fatty acids; lipid content; invasive species; Kjeldahl; Gas chromatography; Integrated Multi Trophic Aquaculture; Pagasitikos Gulf
Online: 26 November 2021 (10:24:14 CET)
The total lipid and protein content of the invasive caprellid amphipod Caprella scaura, from the biofouling communities of fish farm cages in the Pagasitikos Gulf were analyzed and compared among seasons. Proteins were the most abundant component (48.5 – 49.3%). Lipid content was relatively lower, with a wider range (6.7 – 34%) and showed a distinct seasonal fluctuation with high values in the winter population and a gradual decrease in spring and summer, with the lowest values in Autumn. Composition of the fatty acids profile was consistent among the seasons, with palmitic (16:0), Oleic (18:1n-9), Eicosapentanoic (20:5n-3)(EPA) and Docosahexanoic acid (22:6n-3 )(DHA) being the most abundant fatty acids. The presence of high levels of EPA and DHA fatty acids makes the species a potential candidate for use of these organisms in aquaculture.
ARTICLE | doi:10.20944/preprints202008.0395.v1
Subject: Biology, Animal Sciences & Zoology Keywords: economic analysis; conservation; P.monodon; by-catch; livelihood; seed collector; post larvae collector; coastal aquaculture; Indian Sundarbans
Online: 19 August 2020 (02:53:11 CEST)
The livelihood of most of the fishers in Indian Sundarbans is dependent on Penaeus monodon post larvae fishing. These post larvae collectors are socially backward lacking economic security. The activity of collecting Penaeus monodon post larvae for rearing in aquaculture, destroy other aquatic species. Many other juveniles of shellfish and fin fish were destroyed in the process of collection of Penaeus monodon post larvae. The removal of juveniles before they reach maturity disturbs the ecological chain by hampering breeding processes and may cause extinction of some fish species in the long run. The present study is an attempt to estimate the economic value of juveniles destroyed in the collection of (Penaeus monodon) post larvae. In total 32 species were identified in P.monodon the post larval by-catch. The economic loss is assessed based on estimating biomass by taking a length-weight relationship from published literature. Further, the paper illustrates how does a profit enterprise is linked with natural resource exploitation. The paper explores government policy and nature conservation issues for social justice and effective conservation.In conclusion, suggestions are given to reduce the burden of livelihood on natural resources to the extent of exploitation and to strengthen institution and policy-making considering socio-ecological vulnerabilities of the area.
ARTICLE | doi:10.20944/preprints201811.0326.v2
Subject: Life Sciences, Biochemistry Keywords: cellular agriculture; cell-based seafood; fish tissue culture; bioreactor; serum-free media; ocean conservation; marine cell culture; aquaculture
Online: 25 January 2019 (11:36:58 CET)
Cellular agriculture is defined as the production of agricultural products from cell cultures rather than from whole plants or animals. With growing interest in cellular agriculture as a means to address the public health, environmental, and animal welfare challenges of animal agriculture, the concept of producing seafood from fish cell- and tissue-cultures is emerging as a means to address similar challenges with industrial aquaculture systems and marine capture. Cell-based seafood - as opposed to animal-based seafood - can combine developments in biomedical engineering with modern aquaculture techniques. Biomedical engineering developments such as closed-system bioreactor production of land animal cells create a basis for large scale production of marine animal cells. Aquaculture techniques such as genetic modification and closed system aquaculture have achieved marked gains in production that can pave the way for innovations in cell-based seafood production. Here, we present the current state of innovation relevant to the development of cell-based seafood across multiple species as well as specific opportunities and challenges that exist for advancing this science. The authors find that the physiological properties of fish cell- and tissue- culture may be uniquely suited to cultivation in vitro. These physiological properties, including hypoxia tolerance, high buffering capacity, and low-temperature growth conditions, make marine cell culture an attractive opportunity for scale production of cell-based seafood; perhaps even more so than mammalian and avian cell cultures for cell-based meats. This, coupled with the unique capabilities of crustacean tissue-friendly scaffolding such as chitosan, a common seafood waste product and mushroom derivative, presents great promise for cell-based seafood production via bioreactor cultivation. To become fully realized, cell-based seafood research will require more understanding of fish muscle culture and cultivation; more investigation into serum-free media formulations optimized for fish cell culture; and bioreactor designs tuned to the needs of fish cells for large scale production.