Scholarly Works, Institute of Aquaculture (IA)
Permanent URI for this collectionhttps://hdl.handle.net/20.500.14583/362
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Item Effects of light quality and temperature on the photosynthesis and pigment content of a subtidal edible red alga Meristotheca papulosa (Solieriaceae, Gigartinales) from JapanBorlongan, Iris Ann; Suzuki, Sayuri; Nishihara, Gregory N.; Kozono, Jumpei; Terada, Ryuta (Springer Science and Business Media LLC, 2020-02-11)This study investigated the effects of different light spectral qualities and temperature on the photosynthesis and pigment content of a subtidal edible red alga, Meristotheca papulosa. Photosynthesis–irradiance (P–E) experiments were carried out under red (660 nm), blue (450 nm), green (525 nm, light-emitting diodes), and white light (visible light, metal halide lamp), and at 12, 20, and 28 °C, respectively. Maximum net photosynthetic rates (NPmax) were highest under green light. Other P–E parameter estimates were similar among algae under red, blue, and green light, including their lower initial slope (α) and higher saturation irradiances (Ek) as compared to those under white light. Additionally, NPmax and Ek under white light were highest at 28°C, and lowest at 12°C with characteristic photoinhibition at irradiances greater than 150μmol photons m−2s−1. Photosynthesis–temperature (P–T) experiment revealed that the maximum gross photosynthetic rate (GPmax) occurred at 22.1°C, which was within the optimal temperature range of Fv/Fm (21.5–23.6°C). Exposures to the different light qualities at 100μmol photons m−2s−1 for 7days showed increased phycoerythrin (PE) concentration of algae under blue and green light, while chlorophyll-a and phycocyanin (PC) showed little variation in all light qualities. Therefore, considering future management prospects for M. papulosa mariculture, we suggest that green light could be utilized to enhance photosynthesis. Furthermore, if the aim is to achieve high PE content for an improved reddish-color fresh product, exposure to blue or green light could be a good alternative.Item Understanding biosecurity: Knowledge, attitudes and practices of seaweed farmers in the PhilippinesMateo, Jonalyn P.; Campbell, Iona; Cottier-Cook, Elizabeth J.; Luhan, Maria Rovilla J.; Ferriols, Victor Marco Emmanuel N.; Hurtado, Anicia Q. (Springer, 2021)Farmers are one of the most important components of any plant-based cultivation industry. The Philippines is one of the world’s major producers of red carrageenophyte algae and has tens of thousands of farmers involved in this industry. The production of algae such as Kappaphycus and Eucheuma increased significantly from the early 1970s, when the industry was established, before declining from the mid-2000s, due to a number of reasons, including disease and epiphyte outbreaks. The introduction of biosecurity measures has been one approach used to tackle this decline. Biosecurity-related knowledge, attitude and practices (KAP) of the seaweed farmers were assessed in the four highest seaweed producing regions in the Philippines: (1) Tawi-Tawi, (2) Palawan, (3) Zamboanga and (4) Bohol. Analyses showed that seaweed farmers from Tawi-Tawi had relatively higher KAP mean scores than the other three sites. Palawan and Bohol farmers, however, scored lower on their knowledge, higher on their attitude and highest on their practices compared with the other areas. Farmers from Zamboanga scored the lowest in both their attitude and practice mean scores, although their knowledge score was one of the highest. This is the first KAP assessment applied to the seaweed farming industry globally and the results, in which the farmers’ biosecurity-related knowledge and practices, which scored “Fair” (50–75%) across all the regions, and their attitudes, which scored predominantly “Good” (> 75%) suggest that there is potential to raise the score for biosecurity practices. This assessment highlights how biosecurity challenges are currently addressed by seaweed farmers in the Philippines and suggests how the KAP survey could be used as a tool by policymakers and scientists to address gaps in biosecurity management practices.Item Effects of Vinegars and Sodium Acetate on the Growth Performance of Pacific White Shrimp, Penaeus vannameiJamis, Jhumar O.; Tumbokon, Barry Leonard M.; Caigoy, Jant Cres C.; Bunda, Marj Gem B.; Serrano, Augusto E. (Israeli Journal of Aquaculture - Bamidgeh, 2018)Vinegars and their salts have the potential to act as growth promoters and prophylactics against bacterial pathogens. This study aims to evaluate the effects of various vinegars and sodium acetate on the growth performance of white shrimp Penaeus vannamei. Groups of shrimps were fed diets containing 2% of either apple cider vinegar (ACV), coconut sap vinegar (CSV), sugar cane vinegar (CaV), or sodium acetate, and a diet with no vinegar (i.e. a control diet). Total acidity data of the diet showed that only the sodium acetate diet resulted in the highest total acidity after 60 min immersion in salt water (20 ppt). Attractability tests using customized repartitioned aquaria showed that the CSV diet attracted the highest significant percentage of shrimps after 10 min of feed placement in the feeding chamber. In the feeding trial that lasted for 60 days, results showed that the ACV and CSV groups of shrimps consumed significantly more feed than the other groups. All vinegar groups exhibited significantly higher final average body weight, weight gain, and specific growth, rate than either the control or sodium acetate group. The CSV group exhibited the significantly best feed conversion ratio and protein efficiency ratio. Survival was statistically similar among all groups. Conclusion: the CSV group exhibited the significantly best growth performance and efficiency while both the control and sodium acetate groups exhibited the poorest. © 2018, Israeli Journal of Aquaculture - Bamidgeh. All rights reserved.