Cape Bolinao Research Articles

A proposed decision support tool for prioritising conservation planning of Southeast Asian seagrass meadows: combined approaches based on ecosystem services and vulnerability analyses

AbstractSeagrass habitats provide a range of goods and benefits to coastal communities by supporting ecosystem functioning, food provisioning, and cultural values. However, they are at risk worldwide from anthropogenic activities, climate change impacts and limited resources, which hamper efforts to protect them. Effective conservation planning requires prioritisation of sites based on multiple factors, including their relative value and vulnerability (VU). The current study examines the efficacy of combining two well-established approaches – ecosystem service assessments and habitat VU analyses – to test a method for determining conservation priority for selected seagrass meadows in Southeast Asia. Seven seagrass meadows around Southeast Asia were selected and scored by the authors based on (1) the cumulative contribution of 12 ecosystem services (ES) and the condition of the meadows, (2) VU from 16 anthropogenic threats, which were each ranked against five factors (spatial scale, frequency, functional impact, resistance and recovery time) and (3) the combination of the two approaches to create a single numerical index. Prioritisation of sites differed when meadows were scored solely for the ES they provide, compared to how vulnerable they are to anthropogenic threats. The new combined analysis brought the two metrics together to give conservation priority to sites where management intervention will yield maximum conservation benefits from conservation effort, and resulted in the prioritisation of three sites: Barrang Lompo (Indonesia), Cape Bolinao (Philippines) and Beting Tanjung Kupang (Malaysia). This method is easy to use and does not require great technical expertise. It is also auditable, allowing for clear and transparent understanding of decision-making process.

Wave energy potential assessment in the central and southern regions of the South China Sea

Wave energy potential in the South China Sea was assessed and analysed based on a 31-year simulation of wave characteristics using the third generation spectral WAVEWATCH–III™ model. The model was forced by Climate Forecast System Reanalysis (CFSR) winds and ETOPO2 bathymetry data. The highest annual wave power can be found in the northern region of the study area with amplitudes exceeding 20 kW/m. The values decrease gradually towards the Sunda Shelf and reach to their minimum at coastal regions due to bathymetry complexity, shadowing and island obstruction effects. However, the wave power is strongly influenced by seasonality and inter-annual fluctuation. Nine sites representing different sub-regions were selected for further analysis on eligibility of wave farming. Various wave energy statistics including estimated electric power for a number of Wave Energy Converter (WEC) devices showed some stations (Hameau Mo in Vietnamese east coast, Spratly Island, Palawan and Cape Bolinao in west coast of Luzon) have greater eligibility for wave power farming. The estimated electric power that can be produced from these sites using Wave Dragon, an intermediate depth WEC device, ranges from 712 to 1211 kW and 935–1680 kW for annual and a six-month period from September to February, respectively.

The community composition and production of phytoplankton in fish pens of Cape Bolinao, Pangasinan: a field study

From 1995 up to the present, fish pens proliferated in the municipal waters of Bolinao, northern Philippines. Since then, fish kills and phytoplankton blooms have been recurrent. Have fishpens altered the phytoplankton community composition and production of these waters? The phytoplankton community in Cape Bolinao, Lingayen Gulf is typical of a tropical coastal area where diatoms alternate with dinoflagellates during the dry and wet seasons. In the nutrient-rich fish pens, phytoplankton in this study showed a lower diatom/dinoflagellate ratio and unusually high phytoplankton counts of 10 4 cells/l and even as high as 10 5 cells/l. Correlations between physico-chemical parameters, phytoplankton production and community composition were made in 2001. This paper tried to explain the occurrence of a Cylindrotheca closterium bloom (10 5 cells/l), during the dry season of the same year and a Prorocentrum minimum bloom (4.7 × 10 5 cells/l), which accompanied a massive fish kill during January 2002.

Spatio-temporal variation in sexual reproduction of the tropical seagrass Enhalus acoroides (L.f.) Royle in Cape Bolinao, NW Philippines

The Indo-Pacific seagrass Enhalus acoroides (L.f.) Royle can reproduce by vegetative growth as well as sexually, by the production of seeds. To assess the role of environmental conditions in the occurrence of sexual reproduction in this dioecious species, spatio-temporal variation in flowering was investigated in the reef flats off Cape Bolinao, north-western Philippines. Flowering occurred year-round, but the intensity varied temporally and correlated with mean water temperature. Spatially, differences in flowering intensity correlated with available light as affected by turbidity and water depth. Exposure duration of female flowers to air seems to be crucial for pollination and subsequent seed setting, resulting in higher numbers of fruits in shallower sites. Contrary to previous hypotheses, no effect of tidal levels on the release of male flowers was observed. It is suggested that production of gas bubbles in photosynthesis plays a key role. The great discrepancy between observed flowering and the presence of peduncle scars on the rhizomes at the deeper sites suggests that early abortion is common here. The use of these scars to quantify flowering will lead to an overestimation of reproductive effort in deep sites. The rare occurrence of flowering in deep sites supports the contention that light availability is a key factor in successful flowering in E. acoroides. Allocation of biomass and nutrients (N, P) over various plant components suggests that sexual reproduction involves high cost in E. acoroides.

Temporal changes in the abundance, leaf growth and photosynthesis of three co-occurring Philippine seagrasses.

The analysis of the temporal changes in shoot density, areal leaf biomass, leaf growth and parameters of the photosynthesis-irradiance relationship of three tropical seagrass species (Enhalus acoroides, Thalassia hemprichii and Cymodocea rotundata), co-existing in a shallow subtidal meadow in Cape Bolinao, Philippines, shows that species-specific traits are significant sources of temporal variability, and indicates that these seagrass species respond differently to a common environmental forcing. Species-specific differences are much less important as source of variability of the temporal change in chlorophyll concentration of seagrass leaves. The results indicate that the temporal changes in photosynthetic performance of these seagrasses were driven by environmental forcing and their specific responses to it mostly, but the temporal change in their abundance and leaf growth was also controlled by other factors. The significant contribution of species-specific factors in the temporal changes of biomass, growth and photosynthetic performance of co-occurring seagrass species in Cape Bolinao should contribute to the maintenance of the multispecific, highly productive meadows characteristic of pristine coastal ecosystems in Southeast (SE) Asia.

Nutrient limitation of the tropical seagrass Enhalus acoroides (L.) Royle in Cape Bolinao, NW Philippines

Experimental additions of nutrients to the sediment of Enhalus acoroides stands were performed at four sites and three times along the year in Cape Bolinao, NW Philippines to test the hypothesis that seagrass growth in tropical environments is limited by the availability of nutrients. Both the nitrogen content (as % DW) and the nitrogen incorporation of E. acoroides leaves increased after the addition of nutrients. The size (g DW per shoot) and the leaf growth rates (g DW per shoot d −1) of E. acoroides shoots also increased after the addition of nutrients. Nitrogen rather than phosphorus was the nutrient limiting shoot size and leaf growth of E. acoroides in the area. The extent of nutrient limitation of E. acoroides showed high variability both in space and time which cannot be directly linked with differences in light or nutrient availability among the experimental sites.

Species composition and plant performance of mixed seagrass beds along a siltation gradient at Cape Bolinao, The Philippines

The response of mixed Southeast Asian seagrass beds to siltation was analyzed based on field data, a transplantation experiment and experimental manipulation of light availability in seagrass populations along a silt gradient at Cape Bolinao, The Philippines. Seagrass species diversity, shoot density and depth penetration declined with increasing amounts of suspended material and increasing water column light attenuation along the silt gradient. The seagrass species could be ranked according to decreasing tolerance to siltation as: Enhalus acoroides > Cymodocea serrulata > Halodule uninervis > Thalassia hernprichii > Halophila ovalis > Cymodocea rotundata > Syringodium isoetifoliurn. A gradual decline in shoot density and depth penetration of the different species along the silt gradient suggested that changes in the vertical light attenuation coefficient in the water column, primarily caused by differences in suspended inorganic solids, was the most important factor affecting seagrass performance. However, inconsistency among the species in response to Increasing water depth, artificial shading and transplantation indicated that other factors, such as siltat~on-derived changes in sediment conditions, contribute to the sequential loss of seagrass species along the silt gradient.

Temporal Variation in the Biomass, Quantity and Quality of Agar from Gelidiella acerosa (Forsskål) Feldmann et Hamel (Rhodophyta: Gelidiales) from Cape Bolinao, NW Philippines

Article Temporal Variation in the Biomass, Quantity and Quality of Agar from Gelidiella acerosa (Forsskål) Feldmann et Hamel (Rhodophyta: Gelidiales) from Cape Bolinao, NW Philippines was published on January 1, 1997 in the journal Botanica Marina (volume 40, issue 1-6).

Nutrient limitation of Philippine seagrasses (Cape Bolinao, NW Philippines):in situ experimental evidence

Nutrient limitation of Philippine seagrasses (Cape Bolinao, NW Philippines):in situ experimental evidence

Topoisomerase II-mediated DNA cleavage by adocia- and xestoquinones from the Philippine sponge Xestospongia sp.

Investigation of an orange Xestospongia sp. sponge collected at Cape Bolinao in northern Luzon, Philippines, yielded the known compounds adociaquinones A and B (1, 2) and six new metabolites, secoadociaquinones A and B (3, 4), 14-methoxyxestoquinone (5), 15-methoxyxestoquinone (6), 15-chloro-14-hydroxyxestoquinone (7), and 14-chloro-15-hydroxyxestoquinone (8). All compounds showed inhibition of topoisomerase II in catalytic DNA unwinding and/or decatenation assays. Furthermore, adociaquinone B showed activity in a KSDS assay, suggesting it inhibits the enzyme by freezing the enzyme-DNA cleavable complex. Interestingly, adociaquinone B did not displace ethidium bromide from DNA or unwind supercoiled DNA, implying it does not intercalate DNA.

Yield estimates, catch, effort and fishery potential of the reef flat in Cape Bolinao, Philippines

Summary Catch, fishing effort and yield estimates of the Cape Bolinao reef flat fishery in Lingayen Gulf, Philippines are provided, based on data collected from May 1987 to April 1988. The dynamics of the dominant species, the rabbitfish Siganus fuscescens, suggest that such fisheries are capable of maintaining a high production in site of heavy fish in pressure. However, yield comparisons with those of other reef fisgeries in the Indo-Pacific region, along with characteristics of the catch and the use of multiple gear types, suggest that current extraction rates should not be increased.

Coral Reef Fisheries at Cape Bolinao, Philippines: Species Composition, Abundance and Diversity

Coral Reef Fisheries at Cape Bolinao, Philippines: Species Composition, Abundance and Diversity