Southeast Asian Fisheries Development Center
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Analysis of biosecurity-related policies governing the seaweed industry of the Philippines
The seaweed industry in the Philippines is a significant contributor to aquaculture production, both nationally and internationally. It out-produces the capture fisheries sector and most global producers, with the exception of China and Indonesia. Seaweed species, particularly Kappaphycus and Eucheuma spp., have been farmed throughout the country since the early 1970s. In 2017, the Philippines produced 1.4 million tonnes (fwt) and exported 35,490 tonnes of seaweed and carrageenan with a value of US$174 million. However, a decreasing trend in seaweed production has been observed since the mid-2000s as a result of pest and disease outbreaks, among other factors, which have been exacerbated by climate change. This paper is the first to analyze biosecurity-related national policies and legislation (a.k.a. ‘frameworks’ collectively), which are relevant to the seaweed industry in the Philippines. A total of 12 frameworks were identified, of which a sub-set of seven were compared using defined biosecurity themes, risks, and management measures to evaluate how seaweed biosecurity is incorporated into national policy. The inclusion of biosecurity-related activities in national frameworks was found to be limited to aquatic animal commodities or agricultural crops. Only the Code of Good Aquaculture Practices (GAqP) for seaweed specifically included seaweed cultivation, however, it did not include any biosecurity measures. The results indicated a clear gap in current biosecurity legislation and policy in the Philippines, which if addressed have the potential to reduce the impact of endemic and emergent diseases and pests and support the sustainable growth of this important industry
Oplan balik sugpo: Production of high quality postlarvae
Oplan Balik Sugpo hopes to help revive the tiger shrimp industry in the Philippines through the production of high-quality PL from the hatchery and implementation of environment-friendly strategies for grow-out culture in ponds
Tilapia culture: The basics
This new aquaculture extension manual revisits the basics of tilapia culture with updated information on the grow-out technology in cages and ponds. Updated cost and returns analyses were also included to guide farmers regarding the profitability of farming tilapia. A fresh chapter on tilapia health management is also included to promote the prevention of tilapia diseases
Nursery culture of sandfish Holothuria scabra in sea-based floating hapa nets: Effects of initial stocking density, size grading and net replacement frequency
Sea-based culture of early juvenile sandfish Holothuria scabra up to fingerling size (>2 g) using floating hapa nets has been confirmed as a viable nursery system in tropical countries such as the Philippines. However, production can be further optimized through more efficient rearing practices. In this study, we demonstrate the effects of initial stocking density, size grading and net replacement frequency during the culture of early juvenile sandfish in sea-based floating hapa nets (2 × 1 × 1 m). Testing different initial stocking density treatments ranging from 150 to 2000 early juveniles (4–10 mm; 0.02–0.06 g) per hapa net, we confirmed significantly faster growth (0.06–0.08 g d−1) and higher survival (72–97%) in low densities (≤500 hapa−1), compared to high densities (≥700 hapa−1: 0.02–0.04 g d−1; 67–80%). Low density culture can produce 2 g sandfish in about a month, while higher densities will require a 2–3 mo culture period to reach this size. Culture performance following size grading was also compared using three initial size classes (small, 0.05–0.99 g; medium, 1–1.99 g; and large, 2–3 g) and a mixed group (0.05–3.00 g). At 45 d, juveniles in pooled size-graded groups grew significantly faster (0.11–0.13 g d−1) than those in the mixed group (0.01 g d−1). Survival was significantly higher in the medium (85.3%) and large (84.7%) groups, than those in the small (54.4%) and mixed (45.6%) groups. However, size variation was not significantly mitigated by grading during the 45-d culture. Culture performance of sandfish was not significantly enhanced by more frequent net replacement for short-term rearing (30–45 d). Optimal results were gained from an initial stocking density of ≤500 early juveniles (5–10 mm) per floating hapa net which may be cultured in a month, without requiring net replacement and size grading to produce ≥2 g sandfish. However, in cases of high hatchery production, it is also feasible to adopt higher density stocking (e.g. >1000 hapa−1), but will require longer culture duration (60–85 d), monthly net replacement and size-grading to attain the same size. Results of this study can help fine-tune management practices for nursery culture of sandfish in sea-based floating hapa net nurseries in order to boost production of fingerlings needed for aquaculture and restocking.This study was funded by the Australian Centre for International Agriculture Research (ACIAR) through the project FIS/2010/042 “Expansion and Diversification of Production and Management Systems for Sea Cucumbers in the Philippines, Vietnam and Northern Australia” with counterpart funding support by SEAFDEC/AQD through study code FS-03-Y2014T. Special thanks to MRB Altamirano for valuable help in developing the manuscript in the early stages. We also appreciate the useful suggestions from M Lal and P Southgate, as well as the constructive comments from anonymous reviewers, all contributed in improving this paper. We are grateful to CP Recente, JC Rodriguez, Jr., H Figurado, and N Tibubos for the assistance in sandfish hatchery production, experimental setup and monitoring
AQD Matters 2020 March - April
In this issue: a) Turning up the heat to meet milkfish seedstock shortage; b) Deaths in farmed crab linked to bad feed, water quality; c) AQD in the time of COVID-19: Community Quarantine Storie
A review of reported seaweed diseases and pests in aquaculture in Asia
Seaweeds have been used as a food for centuries in Asia and are increasingly exploited as a source for dietary supplements, animal feed, chemicals, and biofuels. In recent years, there has been an increase in the prevalence of diseases and pests in these aquaculture crops, with a subsequent reduction in their quantity and commercial value. In this article, we review diseases that have been reported in the scientific literature for species of red and brown seaweeds. We have focused on the major seaweed crops grown in Asia, where much of this production is centered. We also provide information on disease management and biosecurity and some observations on future directions
Effects of replacing dietary fish oil with beef tallow on growth performance, serological parameters, and fatty acid composition in juvenile olive flounder, Paralichthys olivaceus
This study evaluated the effects of replacing fish oil (FO) with beef tallow (BT) in juvenile olive flounder, Paralichthys olivaceus (3.93 ± 0.07 g), over 8 weeks. Seven diets, consisting of 0, 25, 50, 75, and 100% replacement of FO with BT and 63 and 75.9% replacement supplemented with docosahexaenoic acid (DHA) at 0.9 and 1.1% of 100 g diet, respectively, were distributed into 21 tanks in a semi‐recirculation system with 15 fish per tank. The replacement of FO with BT at the given levels showed no significant changes (p > .05) in growth performance and whole‐body proximate composition. Fish fed the diet of 75.9% replacement with 1.1% DHA supplementation showed the best performance in these measurements among the treatments. Plasma glutamic pyruvic transaminase, cholesterol, high‐ and low‐density lipoproteins, and total protein were not significantly influenced by the replacement of FO with BT. The FO replacement generally resulted in a reduction of eicosapentaenoic acid, DHA, and n‐3/n‐6 polyunsaturated fatty acid ratio in the whole body, whereas the DHA supplementation recovered the level of DHA and the n‐3/n‐6 ratio to those observed in the group fed the 0% replacement diet. Taken together, BT along with DHA supplementation can potentially be a cost‐effective alternative for FO in olive flounder culture
Bacterial microbiota of hatchery-reared freshwater prawn Macrobrachium rosenbergii (de Man, 1879)
Quantitative and qualitative analyses of bacterial microbiota associated with hatchery of freshwater prawn Macrobrachium rosenbergii (de Man, 1879) were conducted over three larval cycles, along with important water quality parameters. Physicochemical parameters (temperature, DO, salinity, pH and total ammonia) of culture water were within the optimum level required for the hatchery phase of M. rosenbergii. Aerobic plate count (APC) (log10 CFU.mL-1) ranged from 4.2 ± 0.18–8.7 ± 0.01 in rearing water and (log10 CFU.g-1) 3.3 ± 0.12–9.1 ± 1.1 in eggs and larvae. Significant differences in APCs among larval stages were observed. Ten genera and 17 species were identified with the predominance of Gram-negative bacteria constituting 63 % of all isolates (n = 706). Acinetobacter baumannii, Acinetobacter lwoffii, Chryseobacterium indologenes, Enterobacter aerogenes, Enterobacter cloacae, Vibrio furnissii, Vibrio cholerae non-01, Plesiomonas shigelloides, Pseudomonas aeruginosa, Pseudomonas pseudoalcaligenes, Bacillus cereus, Staphylococcus haemolyticus, Staphylococcus warneri and Staphylococcus xylosus were predominantly present in culture water. These bacteria likewise dominated in eggs and larvae except for the absence of Ps. aeruginosa, Ps. pseudoalcaligenes, V. cholerae non-01, Staphylococcus epidermidis and Staph. xylosus in eggs, clearly indicating that resident bacteria in water affect the composition of bacteria in eggs and larvae. Some of these are opportunistic pathogens. Thus, control measures to reduce influx of pathogenic microbes in the system by maintaining good water quality and good farm management practices through disinfection of culture facilities, rearing water, Artemia cysts, the practice of good hygiene of personnel, regular water exchange and feed regulation among others and cautionary use of antibiotics can be adopted
SEAFDEC/AQD highlights 2019
SEAFDEC/AQD highlights 2019 is SEAFDEC/AQD's annual report updating on its accomplishments and progress for the year 2019
Point-of-no-return and delayed feeding mortalities in first-feeding larvae of the silver therapon Leiopotherapon plumbeus (Kner) (Teleostei: Terapontidae)
This study examined the incidence of mortalities among first-feeding post-yolk sac silver therapon Leiopotherapon plumbeus (Kner) larvae deprived of live food in the hatchery. Starting after their yolk was consumed at 40 h post-hatch (hph) and every 2 h thereafter until 54 hph, larvae were fed and exposed to live food for an hour only and their performance was observed after initial feeding at 25 °C. Feeding incidence progressively increased until 48 hph as larval mouth gape increased during exogenous feeding, but oil globule volume progressively declined until full exhaustion at 52 hph. All starved larvae fed at 48 hph but feeding incidence progressively declined until larvae ceased to feed at 54 hph to coincide with a significant reduction in survivorship, indicating that larvae have reached their point-of-no-return (PNR) at 50 hph despite the availability of food. Delayed initial feeding of un-fed post-yolk sac larvae starting at 46 hph until 54 hph resulted in significantly higher feeding incidence among 46−48 hph larvae than those fed after 50 hph, which did not survive longer than 10 h after initial feeding. These results demonstrate that silver therapon larvae have a very brief transitional or mixed-feeding period of 12 h after yolk exhaustion so that initial feeding beyond 50 hph when larvae have reached their PNR results in early onset of death