Now showing items 1-4 of 4

    • Article

      Assessment of stocks of a natural Gracilaria population on Panay Island, Philippines 

      TR de Castro, NG Guanzon Jr. & MR Luhan - Botanica Marina, 1991 - Walter de Gruyter
      Two peaks in biomass were recorded from natural beds of Gracilaria sp. at Leganes, Iloilo and Batan, Aklan study sites. The major peak occurred in February 1989 for both areas. The minor peak occurred in September 1988 at Batan and October 1988 at Leganes. Highest biomass at Ivisan, Capiz occurred in May 1988. Lowest biomass was recorded in June at Batan and December 1988 at Leganes. At Ivisan, no biomass was recorded from November 1988 to February 1989. Correlation analysis showed no relationship between biomass and temperature or pH at all study sites. However, salinity was negatively correlated with biomass at Leganes and Batan. Rainfall was inversely correlated with biomass. Based on salinity data gathered from the three study sites, Gracilaria sp. is euryhaline and can tolerate a wide range of salinity. The results show a marked seasonality in the biomass of Gracilaria sp.
    • Article

      Polyculture of milkfish Chanos chanos (Forsskal) and the red seaweed Gracilariopsis bailinae (Zhang et Xia) in brackish water earthen ponds 

      NG Guanzon Jr., TR de Castro-Mallare & FM Lorque - Aquaculture Research, 2004 - Wiley-Blackwell
      Growth, net production, and survival rates of milkfish cultured with Gracilariopsis bailinae at two stocking density combinations (T1– 30 fingerlings 100-m−2 pond+1-kg G. bailinae 4-m−2 net cage, T2– 30 fingerlings 100-m−2 pond+2-kg G. bailinae 4-m−2 net cage) in brackish water earthen ponds over four culture periods were determined. The control (T3) was stocked at 30 fingerlings 100-m−2 pond. Specific growth and production rates of G. bailinae were also calculated. There were no significant differences in mean growth, survival, and net production rates of milkfish between the three treatments. Irrespective of stocking singly or in combination with G. bailinae, significantly higher mean growth and mean production rates for milkfish were obtained during the third culture period of year 1 than those obtained from the other culture periods. Survival rates were not significantly different among the four culture periods. There were no significant differences in mean specific growth and mean net production rates between the two stocking densities of G. bailinae. Significantly higher mean specific growth and mean net production rates of red seaweed were also obtained during the third culture period of year 1 than those obtained from other culture periods. The production of milkfish and red seaweed was higher during the dry season. Growth rates of milkfish was positively correlated with temperature and salinity, while net production rates were positively correlated with temperature and total rainfall, but was inversely correlated with dissolved oxygen. G. bailinae growth and net production rates were positively correlated with water temperature and salinity. Results show that milkfish can be polycultured with G. bailinae grown in net cages in brackish water ponds at stocking density combination of 30 fingerlings 100-m−2 pond+1-kg G. bailinae 4-m−2 net cage.
    • 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.