Growth rates and primary production of Enhalus acoroides (L.f.) royle from Lag-it, North Bais Bay, the Philippines

The growth rates and primary production of the leaves of Enhalus acoroides (L.f.) Royle at Lag-it, North Bais Bay, The Philippines, were studied from August 1982 to August 1983. Randomized complete block design showed that both rates are considerably influenced by the composite effect of spatial and temporal factors. Similarly, both are markedly bimodal. Mean growth rate was 0.93 cm day −1, with peaks in September–October and May, with lowest values in November–January. Mean production was 0.92 g C m −2 day −1, with peaks in October and March–May (Station 2) and December (Station 1) and lowest values in December (Station 2) and in June (Station 1). Growth rates significantly increased with a decrease in the percent of time the seagrass beds were exposed to air and sun in the daytime ( r=−0.69), while it increased with the number of daylight hours ( r=0.72). Production showed no significant correlation with either factor. Mean turnover time for the seagrass was 67 days, producing 5.5 crops annually.