National Committee on Marine Sciences (NCMS)
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- Associated effects of shading on the behavior, growth, and survival of Stichopus cf. horrens juvenilesRioja, Rose Angeli; Palomar-Abesamis, Nadia; Juinio–Meñez, Marie Antonette (Springer Science and Business Media LLC, 2021-07-07)Stichopus cf. horrens is an emergent culture species. It is known to be nocturnal and negatively phototactic; hence, determining its behavioral and growth responses to different light regimes is essential in optimizing culture protocols. This study examined the interactive effects of shading and relative food availability on the feeding pattern, absolute growth rates, and survival of juvenile S. cf. horrens. Six-month-old juveniles (4.27 to 19.41 g) were reared in replicate aquaria with three different shading treatments (covered, exposed, and half-covered aquaria) under ambient light conditions for 30 days. Juveniles in the exposed treatment with high microalgal biomass (13.44 ± 4.57 mg/g) had the highest growth rates (0.10 ± 0.05 g/day) but also the highest mortality (50%). In contrast, juveniles in the covered treatment had the lowest growth (−0.07 ± 0.03 g/day) but the highest survival (100%). Growth rates in the half-covered treatment were comparable with the exposed, and survival was higher than in the covered treatment. These indicate a trade-off between growth associated with more food and mortality risks due to light-induced stress. Juveniles in the half-covered treatment showed a significant preference to stay in the shaded portion whenever they were inactive during the day, suggesting avoidance to high light intensities (4726.51 ± 1582.43 Lux). Results of this study suggest that careful calibration of light intensities in nursery systems may help enhance juvenile growth. For indoor systems that may have limited space or surfaces for microalgal growth, cultured benthic diatom can be added to the partially covered tanks to increase the food available for the juveniles.
- Sargassum sp. juice as an early juvenile supplemental feed for Stichopus cf. horrensIbañez, Glaiza; Cabanayan-Soy, Rona; Baure, Jerwin; Juinio-Meñez, Marie Antonette (Springer, 2022-09-28)The development of an efficient and low-cost feed is important to reduce the production and maintenance costs of microalgae. In this study, two experiments were conducted to evaluate the feasibility of using Sargassum sp. juice (SARG) to boost the growth and survival of post-settled Stichopus cf. horrens juveniles. Experiment 1 tested whether SARG improves growth compared with live microalgae diets, Chaetoceros calcitrans (Cc), combined Cc and Navicula ramosissima (Nr), and an unfed treatment. Experiment 2 determined the best SARG concentration—high feeding regime (HFR; 1 mL ind−1), medium (MFR; 0.5 mL ind−1), or low (LFR; 0.25 ml ind−1), relative to live microalgae Chaetoceros muelleri (CM). Juveniles in both experiments were reared for 30 days. In Experiment 1, the average daily growth rate (DGRL) of juveniles in SARG (0.04 ± 0.01 cm d−1) was the highest although not significantly different from Cc and Cc + Nr, but was significantly higher than the control. In Experiment 2, DGRL at day 14 in HFR (− 0.02 ± 0.02 cm d−1) was significantly lower than LFR (0.01 ± 0.01 cm d−1) and MFR (0.02 ± 0.02 cm d−1). Survival was higher in all SARG treatments compared with CM, while a significant decrease in feeding activity was observed in HFR by day 30. Results indicate that concentrations of 0.25–0.5 mL SARG per juvenile can boost growth and be an alternate diet for post-settled juveniles during early rearing. However, SARG alone is not sufficient to maintain growth beyond 3 weeks. With SARG feed supplementation and water quality management, the scaling-up of juvenile production of this emergent culture species can be accelerated.Our sincere gratitude to Mr. Tirso Catbagan and Mr. Garry Bucol for their assistance in the set-up of the experiments. We also thank Ms. Rose Angeli Rioja and Ms. JayR Gorospe for providing inputs to improve this paper. We also thank the Sea cucumber Research Team and the staff of the University of the Philippines—Marine Science Institute, Bolinao Marine Laboratory for their support and assistance during the conduct of the study.
- ₱12.3-M tilapia lost in Taal Lake fish kill: BFAR monitoring waters off 3 lakeshore townsCinco, Maricar (Philippine Daily Inquirer, Inc., 2019-06-01)At least 150 tons or P12.3 million worth of cultured tilapia turned belly-up in fish cages in Taal Lake in Batangas province due to a low level of dissolved oxygen in the water. The Department of Environment and Natural Resources and the local government of Laurel town in Batangas continued to closely monitor the remaining fish cages after the fish kill occurred in the villages of Gulod and Buso-buso in the last two days. As of Friday, provincial environment officer, Jose Elmer Bascos, said they had yet to dispose all of the dead fish as they needed a larger area to bury them.
- Taal fish feeding resumes as water quality improvesSimeon, Louise Maureen (Philippine Star Printing Co., Inc., 2019-02-09)Fish cage operators can now resume feeding their fish stocks in Taal Lake after tests showed improvements in the quality of water. Agriculture Secretary William Dar said tests conducted by the Bureau of Fisheries and Aquatic Resources (BFAR) from Jan. 14 to 30 revealed that the level of dissolved oxygen in Taal Lake, which is essential to fish growth and survival, had already improved. BFAR Calabarzon director Sammy Malvas said Taal water quality tests also showed that the sulfide level is within normal.
- Whale nursed back to health in La UnionSotelo, Yolanda (Philippine Daily Inquirer, Inc., 2017-05-08)Sto. Tomas, La Union—In a concrete tank, “Agustina” swims feebly, aided by an orange floater from which it tries to wriggle away. Agustina is a female melon-headed whale that was stranded on a beach in the coastal village of San Agustin in San Fernando City on April 30. The 6.2-foot- (1.89 meters) long whale was rescued and brought to a Bureau of Fisheries and Aquatic Resources (BFAR) facility here on a Sunday when its tanks were empty and its staff was not around. The whale bore scratch marks all over its body and fins. It also had wounds which could have been inflicted by other creatures like sharks or when it hit rocks or was caught by a net, according to the BFAR staff.