00. Ocean Decade - Philippines

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The UNACOM Online and Digital Enabling Library and Index is developed to support the alignment of research, investments, and community initiatives toward contributing to a well-functioning, productive, resilient, sustainable, and inspiring ocean. The goal is to enable the government, partner agencies, and UNESCO to develop more robust Science-Informed Policies and facilitate a stronger Science-Policy Interface through the gathered data, information, and knowledge related to the Ocean Decade in the Philippines.

Particularly, it aims to:

Gather and index all publications, reports, policies, laws, legislations, articles, and other documents of the Philippine National Committee on Marine Sciences (NCMS) related to the Ocean Decade.
Disseminate and promote these publications, reports, policies, and other documents on the initiatives and actions to address the Ocean Decade challenges.

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Fisheries Administrative Order No. 1. Organization and functions of the Bureau of Fisheries.
(Department of Agriculture and Natural Resources, 1947-07-01)
Spontaneous maturation and spawning of milkfish in floating net cages
Marte, Clarissa L.; Lacanilao, Flor (Elsevier, 1986-04)
Milkfish (Chanos chanos Forsskal) reared from wild-caught fry and from hatchery-bred fry matured at 3.5–5.5 years (2.3–4.9 kg). Maturation and spawning of the hatcherybred fish marks the first time the milkfish life-cycle has been completed in captivity. Milkfish at various stages of gonadal development were obtained in July–October 1980 and March–June 1981 derived from wild-caught fry, and in February–June 1983 from the hatchery-bred fish. The fish were held in floating net cages 9 m and 10 m diameter by 3 m deep, located in 7 m deep water off Igang, Guimaras Island, Philippines. Annual ranges of temperature and salinity were 25–33°C and 25–38 ppt, respectively. The fish were fed commercial feed pellet (42% protein) at 1.5–2% of body weight twice daily. Sexual maturation occurred during the natural breeding season of wild milkfish in the nearby waters. Gonadosomatic index (GSI) of mature males was 0.32–3.95 (wild-caught, 0.32–3.95; hatchery-bred, 1.71–3.85). For mature females it was 1.24–8.12 (wildcaught, 1.56–7.62; hatchery-bred, 1.24–8.12). Two spawnings were recorded in August 1980 and eight in May–July 1981 from the broodstock derived from wild-caught fry, with 342–6293 eggs collected from each spawning, while 14 spawnings were observed in May–June 1983 from the hatchery-bred fish, with 770–114 000 eggs collected. The time of spawning was between 23.00 and 02.00 h. Fertilization rate was 55–99% for the broodstock from wild-caught fry and 47–100% for the hatchery-bred fish. Hatch rate varied from 9 to 80%. Factors affecting spontaneous maturation, spawning and rematuration are discussed. Although slight improvements in egg collection were obtained, further innovations in egg collecting techniques will have to be developed. The results indicate the potential for hatchery production of milkfish fry from captive broodstock and for restocking of waters deprived of naturally occurring fry.
Electrophoretic evidence for extensive hybrid gene introgression into commercial Oreochromis niloticus (L.) stocks in the Philippines
Macaranas, J. M.; Taniguchi, N.; Pante, M. J. R.; Capili, J. B.; Pullin, R. S. V. (Hindawi Limited, 1986-10)
The usefulness of isozyme and protein markers in identifying tilapia species and their hybrids is demonstrated. Genetic characterization of Oreochromis niloticus populations from commercial farms, experimental stations, and government hatcheries in Luzon, Visayas and Mindanao in the Philippines indicates well-established introgression with O. mossambicus. Genetic differentiation of the O. niloticus stocks, measured by Nei's genetic distance, was highly correlated with O. mossambicus gene content. The implications of these results for tilapia genetic improvement are discussed.
Indo-West Pacific affinities of Philippine seagrasses
Fortes, M. D. (Walter de Gruyter, 1988)
A dendrograph was developed to depict the mutual relationships among 27 Indo-Pacific countries with similar seagrass floras. Hierarchical (cluster) analysis of the resulting affinities provides strong evidence that the countries could be partitioned into seven discrete provinces. The genus Halophila represents a major connection between most of these provinces, strongly influencing the clustering of the Seagrasses. The degree of species overlap (9.5 — 46.2%) between Province A (where Philippines belongs) and Province G (Western, Southern, and Southeastern portions of Australia) favors vicariance as an explanation. The separation of Kampuchea as a discrete unit within Province A appears to be an artifact of collection rather than a reflection of the true floral affinities in the region. The lack of sufficient basic floristic information remains as the most serious limitation in any attempt to describe the phytogeographic affinities of seagrasses in the Indo-Pacific region.
Growth rates and primary production of Enhalus acoroides (L.f.) royle from Lag-it, North Bais Bay, the Philippines
Estacion, Janet S.; Fortes, Miguel D. (Elsevier, 1988-01)
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.
Temperature-influenced infection rates in the Chondrus crispus-Petersenia pollagaster pathosystem: A regression analysis
Molina, F. I.; Hughes, G. C.; Craigie, J. S. (Springer, 1988-03)
Cross-infection experiments were performed to determine the influence of temperature on infection rate in the Chondrus crispus Stackhouse-Petersenia pollagaster (Petersen) Sparrow pathosystem. C. crispus thalli were collected at Pubnico Harbor, Nova Scotia, Canada in the fall of 1981 to 1984. Infective zoospores were used to inoculate healthy thalli at five different temperatures. The highest infection rate was obtained at 20°C, while significantly lower rates were obtained at temperature extremes. The parasite's life cycle, consisting of infection of healthy thalli, endobiotic development, and release of zoospores, was completed in 48 to 72 h at 15° to 20°C.
Fishing mortality rates of giant clams (Family Tridacnidae) from the Sulu Archipelago and Southern Palawan, Philippines
Villanoy, Cesar L.; Juinio, Antoinette R.; Meñez, Lambert Anthony (Springer, 1988-05)
Average size frequency distributions of Tridacna squamosa, T. gigas, Hippopus hippopus and H. porcellanus harvested from the Sulu Archipelago and Southern Palawan areas from 1978–1985 were derived from export records and a warehouse inventory of giant clam shells. Average species mortality rates (Z) were estimated and were used to approximate average fishing mortality rates (F) over the period 1978–1985. Crude estimates of exploitation rates (F/Z) indicate that populations of these species are already overexploited. These findings have serious implications in view of the fact that the Sulu Archipelago and Southern Palawan are thought to be the last strongholds of giant clams in Philippine waters.
Notes on the induced spawning and larval rearing of the Asian moon scallop, Amusium pleuronectes (Linné), in the laboratory
Belda, C. A.; Del Norte, A. G. C. (Elsevier, 1988-08)
Sexual and chemical stimulations were effective in inducing the scallop, Amusium pleuronectes (Linné), to spawn sperm only, whereas thermal stimulation was not at all successful. Chemical stimulation consisted of serotonin injections into the ripe gonads. Fertilizable eggs were obtained by stripping gametes from the ovaries. Cleavage of zygotes (72.4 μm mean diameter) occured 1 h after fertilization. Trochophores (58.9–111.2 μm in length) and straight-hinge veligers or D-veligers (80.0–130.2 μm) were observed in less than 24 h. Five days after fertilization, the umbone stage (101.6–169.1 μm) was reached. Crawling pediveligers (174.0–250.0 μm) appeared after 9 days. Seawater in the culture vessels was changed 24 h after fertilization and every other day thereafter. The larvae were fed on Isochrysis galbana (Tahitian strain) at an initial concentration of 30 cells/gml.
Aspects of the growth, recruitment, mortality and reproduction of the scallop Amusium pleuronectes (Linné) in the Lingayen Gulf, Philippines
Del Norte, A. G. C. (Informa UK Limited, 1988-11)
Growth, recruitment, mortality and reproduction were investigated in the Asian moon scallop, Amusium pleuronectes (Linne) from the Lingayen Gulf, Philippines. Allometric relationships were defined by comparing different shell dimensions, as well as body weight proportions including total weight with shell, visceral weight, adductor muscle weight and gonad weight. Use of the von Bertalanffy-based ELEFAN I program yielded estimates of growth parameters equivalent to H ∞ = 106Dimshell height and K = 0.92 per year, with approximate longevity for the species of about 2 years. Recruitment, as derived using the ELEFAN II program, occurred throughout the year, but showed a pattern consisting of one major and one minor pulse separated by an 8- and 4-months interval. Fishing mortality (F = 5.3) was higher than natural mortality (M = 1.9). Spawning occurred throughout the year, with one major peak in February and one minor peak between July and September, thereby providing some biological basis to the recruitment pattern indicated. Protandry and size at sexual maturity (54 mm) in the species were confirmed.
Wound healing in cultured Eucheuma alvareziivar. tambalang Doty
Azanza-Corrales, R.; Dawes, C. J. (Walter de Gruyter GmbH, 1989)
Wound healing in segments of Eucheuma alvarezii var. tambalang grown in enriched media in the laboratory can be divided into four stages based on histological and cytological changes. During the first stage, approximately 2—4 days after wounding, proteinaceous and phenolic substances concentrate on pit plugs of cells adjacent to the wounded surface. In the second stage, about the sixth day, cellular extensions are produced from the pits of medullary and cortical cells of sub-wound layer. During the third stage, about the 8th day, the cellular extensions divide several times and elongate towards the surface. A new cortical or wound tissue is formed during the fourth stage beginning on the 12th day. The wound tissue is continuous with the old cortex within 3 weeks.
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.
Water quality bioassays in two Bermudan harbours using the ciliate Euplotes vannus, in relation to tributyltin distribution
Slabbing, A. R. D.; Soria, S.; Burt, G. R.; Cleary, J. J. (Elsevier, 1990-01)
Laboratory cultures of the ciliate Euplotes vannus were used to bioassay water samples taken from the sea surface, 0.5 m and near bottom at stations along contamination gradients in Castle Harbour and Hamilton Harbour on Bermuda. Inhibition of population growth rate was used as an index of exposure to toxic contaminants. Significant differences in growth rates from near-bottom water samples taken at two stations in Castle Harbour were reflected in differing sediment concentrations of metals and petroleum hydrocarbons. Bioassays of four Hamilton Harbour samples indicated significant differences between control and contaminated sites when results from all three depths were pooled. Highest concentrations of tributyltin (⩽ 307 ng TBT·1−1) occurred in the surface microlayer, though measurements varied widely on the two sampling occasions. At 0.5 m, concentrations were much less variable and showed a steady decline from the head of Hamilton Harbour (41 ng TBT· 1−1) seawards to the control site (0.9 ng TBT · 1−1). While these concentrations are high enough to be toxic to some species, it is known from experimental work that TBT alone could not have accounted for the depression of ciliate growth rates in these bioassays.
The farmed Euchema species in Danajon Reef, Philippines: Vegetative and reproductive structures
Azanza-Corrales, R. (Springer, 1990-03)
As part of the information needed for applied research on hybridization of these economically important species, the vegetative and reproductive structures of Eucheuma denticulatum (Burman) Collins and Hervey, and Eucheuma alvarezii Doty being farmed in Danajon Reef, were studied. All cultured ‘strains’ suspected to have developed from original stocks apparently introduced into the area about twelve years ago were sampled monthly from February 1987 to November 1988. Analyses of fresh free-hand and plastic embedded sections revealed the sexual (male, female) and asexual (tetrasporic) structures in E. alvarezii var.tambalang Doty and the absence of the female in E. denticulatum, indicating the suitability of the former species for future manipulative experiments.
Seasonality of standing crop of a Sargassum (Fucales, Phaeophyta) bed in Bolinao, Pangasinan, Philippines
Trono, Gavino C.; Lluisma, Arturo O. (Springer, 1990-09)
The seasonality of standing crop of a Sargassum bed was investigated by conducting monthly sampling from February 1988 to July 1989. Environmental parameters of water movement, salinity, number of daytime minus tides, and water temperature were also measured. An intra-annual pattern of variation in standing crop of Sargassum crassifolium, S. cristaefolium, S. oligocystum, and S. polycystum was observed. Standing crop was generally lowest in February, March, April, or May, and highest in November through January. Sargassum accounted for about 35 to 85% of the monthly algal standing crop of the bed, and the observed variation in overall standing crop of the bed generally reflected the standing crop of Sargassum. The seasonality of the standing crops of the associated algal divisions also followed an annual cycle, but their maximum and minimum standing crops did not coincide with those of Sargassum. Individually, as well as collectively, the standing crops of the Sargassum spp. were poorly correlated with the environmental factors observed.
The farmed Eucheuma species (Gigartinales, Rhodophyta) in Danajon Reef, Philippines: Carrageenan properties
Azanza-Corrales, R.; Sa-a, P. (Springer, 1990-09)
Six cultured ‘strains’ of Eucheuma denticulatum and E. alvarezii, from which stocks can be selected for the development of a Eucheuma ‘seedling bank’, were tested for their carrageenan quality from June to November 1988. Percent yield of all the varieties taken together was apparently higher in June, becoming lower in November (regression, r −0.785, probability, p ⩽ 0.001). Stepwise regression analysis was done to determine the existence of any relationship between any of the following parameters: gel strength, viscosity, sulfate content, month of sampling, and yield, whether taken individually or in combination. Results show variations of the yield with the month of sampling. ANOVA was performed to test whether there are differences in sulfate levels, gel strength, and viscosity between the Eucheuma alvarezii morphotypes. There was no significant difference between the green and the brown types.
Influence of Bass Strait water on the Tasman Sea thermocline
Villanoy, C. L.; Tomczak, M. (CSIRO Publishing, 1991)
Volumetric analysis of the Tasman Sea Central Water for different temperatures and salinities was used to determine the degree of influence of the seasonal outflow from Bass Strait on the observed strong positive anomalies in the Tasman Sea thermocline. The absence of a systematic decrease of salinity and Bass Strait Water content away from the coast suggests that the observed high-salinity anomalies are not entirely manifestations of Bass Strait Water alone and that some local processes may be involved in modifying the water properties. It is suggested that the seasonal Bass Strait Water intrusions may act as a trigger to overturn the environment, entraining high-salinity water from the upper layers by double-diffusive convection.
Seagrass-mangrove ecosystems management: A key to marine coastal conservation in the ASEAN region
Fortes, Miguel D. (Elsevier, 1991-01)
Seagrass beds and mangrove forests are intimately linked by functional interactive processes which are as yet little understood. These high-order interactions form a major basis which justifies an integrated management scheme for the two ecosystems. However, while dominating enclosed coastal areas in the ASEAN region, seagrass and mangrove habitats are being degraded and destroyed at an alarming rate, raising serious doubt on their capacity for biological sustainability and normal recovery within this generation. An integrated approach towards seagrass and mangrove ecosystems management in the ASEAN region is discussed within a framework of known ecological principles. Recommendations are made for the conservation and sustainable use of the ecosystems and their resources.
Benthic energy dynamics in a southern Baltic ecosystem
Yap, H. T. (Springer, 1991-10)
Benthic components and metabolic activity at two stations in the Darss-Zingst estuary (eastern German Baltic coast) were investigated over a seasonal cycle from April 1985 to August 1986. As has been established for temperate and boreal ecosystems, peaks in the biomass of benthic microphytes occurred in the spring and late autumn to winter, presumably caused by settling phytoplankton blooms. Metabolic activity of the benthos did not increase with rising ambient temperatures. Rather, the highest values of oxygen consumption were recorded during the cooler months (spring and winter), when increased numbers of organisms were also observed. This may be a response to a greater food supply to the sediment in the form of settling phytoplankton during these times of year.
Trends in growth and mortality of three coral species (Anthozoa: Scleractinia), including effects of transplantation
Yap, H. T.; Alino, P. M.; Gomez, E. D. (Inter-Research Science Center, 1992)
Three ecologically dominant coral species in a northern Philippine reef were compared in terms of growth and mortality and responses to transplantation. The purpose of this study was to examine the feasibility of using the species concerned in establishing new coral populations through deliberate fragmentation. The species, Acropora hyacinthus, Pocillopora damicornis and Pavona frondifera, displayed distinct differences which could be related to their respective life-history strategies. A. hyacinthus showed tendencies towards an r-mode, with rapid linear growth but also high mortality rates. Response to transplantation was poor. Pocillopora damicornis had intermediate linear growth rates and relatively high mortality. Transplants fared poorly in the initial part of the experiment though they showed successful adaptation after a year. Mortality rates of both A. hyacinthus and P. damicornis were increased by high temperatures during certain times of the year. Pavona frondifera had the highest linear growth rates and no mortality, tending towards a K-mode of life history strategy. It showed the best response to transplantation This species is thus a suitable candidate for large-scale reef restoration.
Marine environmental problems: Experiences of developing regions
Yap, Helen T. (Elsevier BV, 1992-01)
The marine environmental problems of developing regions are a particular cause for concern because of the great dependence of their human populations on marine resources for survival, and because a significant portion of the world's natural heritage is threatened. Of the problems, the destruction of shallow-water ecosystems and organic (sewage) pollution are the most prominent. The environmental issues typical for Third World countries are clearly related to their socioeconomic conditions, so that attempts at solutions must possess an adequately broad perspective, i.e. they must consider all relevant aspects of a problem. There is also a great need to strengthen the capabilities of developing nations to care for their own environment.