Showing items related by title, author, creator and subject.

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  Conference paper

  Effects of CO2-induced ocean environmental changes on marine life: implications for aquaculture. 

  A Ishimatsu & H Kurihara - In BO Acosta, RM Coloso, EGT de Jesus-Ayson & JD Toledo (Eds.), Sustainable aquaculture development for food security in Southeast Asia towards 2020. Proceedings of the Regional Technical Consultation on Sustainable Aquaculture Development in Southeast Asia Towards 2020, 2011 - Aquaculture Department, Southeast Asian Fisheries Development Center

  The world's oceans are becoming warmer and acidic. The atmospheric carbon dioxide concentration has increased from 280 ppm at pre-industrial revolution to above 380 ppm today. The 4th IPCC report predicts that it will range from 540 to nearly 1,000 ppm by the end of the century. The increased CO₂ not only warms surface seawater, but also acidifies it (usually termed as ocean acidification) by diffusing across the ocean surface and forming carbonic acid. Our knowledge is still scarce as to how these ocean environmental changes will affect marine life. The early studies on the impact of ocean acidification focused on corals aiming to clarify effects of high-CO₂ seawater on their calcification processes. However, more recent studies have revealed that in fact ocean acidification, either alone or coupled with warming, could have detrimental impacts on a variety of biological processes in different taxa. We have shown that early development of marine bivalves (oysters and mussels) could be severely disrupted under elevated CO₂ conditions (ca. 2,000 ppm). When a marine shrimp was exposed to seawater equilibrated with air containing 1,000 ppm CO₂ for 30 weeks, survival was only 55% as compared with 90% in the control. Gonad maturation of a sea urchin was delayed by one month under the same CO₂ conditions at ambient temperature, but when accompanied with increased temperature of 2 degree C above ambient, gonad maturation was not only delayed but also significantly suppressed; the number of eggs in the ovary was reduced to only 20% of the control. It has been shown that tropical animals already live near their thermal tolerant maxima, and therefore even small increases of environmental temperature could reduce their environmental fitness. These recent findings bear significant implication in aquaculture and fisheries production, in particular, in tropical countries. This paper will summarize recent data on these topics and discuss possible adaptation measures.
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  Technical Report

  Weather observation at Tigbauan, Iloilo, Philippines from 1977 to 1980 

  H Motoh, N Solis, E Caligdong, M Gelangre & F Boblo - 1981 - Aquaculture Department, Southeast Asian Fisheries Development Center
  Series: Technical report / SEAFDEC Aquaculture Department; no. 8

  The observations include: (1) air and sea water temperatures; (2) cloud cover; (3) rainfall; (4) wind direction and speed; (5) salinity; (6) sea wave condition.
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  Article

  Transport of hatchery-reared and wild grouper larvae, Epinephelus sp. 

  CB Estudillo & MN Duray - Aquaculture, 2003 - Elsevier

  Optimum packing conditions for the transport of hatchery-reared and wild grouper larvae were investigated under simulated condition or actual air transport. Simulation of transport motion was done through the use of an electric orbit shaker to identify the best packing conditions for the transport of grouper larvae at various ages. Simulated transport was conducted in hatchery-reared grouper larvae at day 35 (mean TL=14.73 mm), 45 (mean TL=15.23 mm) and 60 (mean TL=28.16 mm) at packing densities of 50, 100 and 200 larvae l⁻¹ and at high (28 °C) or low (23 °C) temperatures. Packing density of 50 larvae l⁻¹ was best for 45- and 60-day-old larvae 8 h transport at low temperature. However, packing density could be increased to a maximum of 100 larvae l⁻¹ 8 h transport at 23 °C with mortality rates ranging from 2.3% to 5.3%. The increase in total NH₃ level was dependent on temperature, packing density and size of larvae. High packing density (100–200 larvae l⁻¹) and temperature (28 °C) resulted in increased NH₃ level and mortality rates during transport. In addition, regardless of the temperature, NH₃ levels were consistently higher for 60-day-old larvae. Day-60 grouper larvae displayed strong resistance to handling/mechanical stress compared to 35-day-old larvae probably because most are already fully metamorphosed at this stage. Based on these results, a packing density of 50 larvae l⁻¹, a temperature of 23 °C and larval age of 60 days were considered as the best transport conditions for hatchery-reared grouper larvae. When these transport conditions were used in experiment 2, for 26-day-old hormone-metamorphosed, 60-day-old naturally metamorphosed or 60-day-old pre-metamorphosing hatchery-reared grouper larvae, a 100% survival rate was attained in all treatments. Seven days of hormone (T3) treatment did not accelerate metamorphosis of wild-caught transparent grouper larvae (tinies) significantly. Survival rates of hormone-treated transparent tinies (H-tinies), untreated black tinies (B-tinies) and untreated transparent tinies (T-tinies) were also similar after 8–9 h air transport (experiment 3). The results of the current study suggest that T3 treatment did not affect the performance of hatchery-reared and wild-caught transparent tinies/larvae during transport. In addition, mass mortalities of these transported tinies during the nursery phase were associated with nutritional aspect and the sudden confinement of these undomesticated wild-caught grouper to small space rather than transport or hormone treatment effects.