menu.header.image.unacom.logo
 

National Committee on Marine Sciences (NCMS)

Permanent URI for this communityhttps://repository.unesco.gov.ph/handle/123456789/6

Browse

Filters

1989 - 198912000 - 20012

Settings

AGROVOC Keyword: search.filters.agrovoc.geographical distribution

Search Results

Now showing 1 - 3 of 3
  • No Thumbnail Available
    Are Pyrodinium blooms in the Southeast Asian region recurring and spreading? A view at the end of the millennium
    Azanza, Rhodora V.; Max Taylor, F. J. R. (Royal Swedish Academy of Sciences, 2001-09)
    Pyrodinium bahamense (var. compressum) has been the only dinoflagellate species that has caused major public health and economic problems in the Southeast Asian region for more than 2 decades now. It produces saxitoxin, a suite of toxins that cause Paralytic Shellfish Poisoning (PSP). A serious toxicological problem affecting many countries of the world, mild cases of this poisoning can occur within 30 minutes while in extreme cases, death through respiratory paralysis may occur within 2–24 hrs of ingestion of intoxicated shellfish. Blooms of the organism have been reported in Malaysia, Brunei Darussalam, the Philippines and Indonesia. The ASEAN-Canada Red Tide Network has recorded 31 blooms of the organism in 26 areas since 1976 when it first occurred in Sabah, Malaysia. As of 1999, the most hard hit country has been the Philippines which has the greatest number of areas affected (18) and highest number of Paralytic Shellfish Poisoning (PSP) cases (about 1995). Malaysia has reported a total of 609 PSP cases and 44 deaths while Brunei has recorded 14 PSP cases and no fatalities. Indonesia, on the other hand has a record of 427 PSP cases and 17 deaths. Studies on ecological/environmental impacts of these blooms have not been done in the region. Estimates of economic impacts have shown that the loss could be up to USD 300 000 day−1. Most of the data and information useful for understanding Pyrodinium bloom dynamics have come from harmful/toxic algal monitoring and research that have developed to different degrees in the various countries in the region affected by the organism's bloom. Regional collaborative research and monitoring efforts can help harmonize local data sets and ensure their quality and availability for comparative analysis and modeling. Temporal patterns of the blooms at local and regional scales and possible signals and trends in the occurrence/recurrence and spread of Pyrodinium blooms could be investigated. Existing descriptive and simple predictive models of Pyrodinium blooms can be improved and refined to help in the management of the wild harvest and aquaculture of shellfish in a region where the people are dependent on these resources for their daily food sustainance and livelihood.
  • No Thumbnail Available
    Vegetative dynamics and sexual reproduction of monospecific Thalassia hemprichii meadows in the Kalayaan Island Group
    Rollon, Rene N.; Cayabyab, Napo M.; Fortes, Miguel D. (Elsevier BV, 2001-11)
    We surveyed eight offshore islands and shoals in the Philippine Kalayaan Island Group. The aims were to (1) map the distribution, (2) evaluate the demographic status, (3) elucidate the vegetative growth dynamics, and (4) quantify the sexual reproductive capacity of Thalassia hemprichii meadows in the region. We combined age reconstruction techniques and in situ estimations to attain such goals. We found T. hemprichii meadows only in Pag-asa Island. These meadows were generally young (mean age <1 year) and rapidly expanding (net recruitment ∼0.8 ln units per year). This was consistent with the horizontal rhizome apices being dense (162–334 apex m−2) and fast-spreading (36–56 cm per apex per year). The results for in situ measurements of plastochron interval (9.2 days), and relative leaf (3.7 cm2 cm−2 per shoot per day) and areal growth rates (2.3–2.7 cm2 per shoot per day) were similar to those of previous studies. The variation in the vertical internodal lengths showed a unimodal annual trend more distinctly in the south than in the north station, suggesting local, small-scale differences in environmental conditions between stations. Flower production was clearly seasonal, peaking around January 1999. Fruiting (128–134 m−2) and seedling recruitment (22–32 m−2) values were high, indicating a substantial contribution of sexual reproduction to the rapid expansion or meadow maintenance. The apparent disjunct occurrence of such young and highly reproductive meadows in the region merits further investigation.
  • Thumbnail Image
    Status of giant clam resources of the Philippines
    Juinio, Marie Antoinette R.; Meñez, Lambert Anthony B.; Villanoy, Cesar L.; Gomez, Edgardo D. (Oxford University Press (OUP), 1989-11-01)
    Field surveys were conducted to determine distribution and abundance of giant dam resources in the Philippines. All seven known species of giant clams were recorded with Tridacna crocea, T. maxima and T. squamosa occurring the most frequently. The larger species T. derasa, T. gigas, Hippopus hippopus and H. porcellanus were relatively rare. The reduction of giant dam stocks in the Philippines is due to the uncontrolled exploitation of this resource which is primarily gathered for shellcraft and as supplementary diet in coastal villages.