Challenge 02: Protect and restore ecosystems and biodiversity
Permanent URI for this collectionhttps://repository.unesco.gov.ph/handle/123456789/21
Ocean Decade
Challenge 02:
Protect and restore ecosystems and biodiversity
Understand the effects of multiple stressors on ocean ecosystems, and develop solutions to monitor, protect, manage and restore ecosystems and their biodiversity under changing environmental, social and climate conditions.
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- Population genetic structure of the milkfish, Chanos chanos , based on PCR-RFLP analysis of the mitochondrial control region.Ravago-Gotanco, Rachel G.; Juinio-Meñez, Ma. Antonette (Springer, 2003-06-24)The milkfish, Chanos chanos (Forsskål, 1775) is a pelagic, monotypic gonorhynchiform widely distributed in the tropical Indo-Pacific. This study evaluates temporal variability of milkfish samples from the Philippine archipelago, and spatial variability at two geographic scales based on restriction fragment length polymorphism (RFLP) analysis of a portion of the mitochondrial control region. High levels of genetic diversity characterize the milkfish control region (mean h=0.908, π=1.59%), with 74 haplotypes detected among the 367 fish analyzed. For temporal analysis of Philippine samples, milkfish were collected over 2 years from three sites (inter-annual variation), and sampled twice within a year during different seasons at four sites (intra-annual variation). No significant temporal variability was detected between or within years. Significant spatial differentiation among the Philippine samples was observed (F ST=0.006, P<0.05), with two northeastern samples, Claveria and Dingalan, found to be genetically distinct. However, an hierarchical analysis of molecular variance (AMOVA), where samples were grouped into four geographic regions, revealed very low levels of genetic partitioning, with less than 1% of the total variation attributed to between-region differences, and lack of genetic structure. Nonetheless, the existence of putative northeastern Philippine populations is not discounted. Strong genetic structure across broad geographical scales was revealed by AMOVA, with 11% of the molecular variance based on haplotype frequencies allocated between three distinct groups: Indian Ocean, west Pacific (Philippines) and north central Pacific (Hawaii) The broad-scale genetic structure points to limited gene flow among disjunct Indo-Pacific populations.
- Coral responses in single- and mixed-species plots to nutrient disturbanceDizon, R. M.; Yap, H. T. (Inter-Research Science Center, 2005)Space is a limiting resource in coral reef communities causing actively growing coral colonies to come in proximity and interact with each other. Although most contact interactions among corals have been studied extensively, very few non-contact and non-aggressive interactions have been documented so far. We present results from a 3 yr field study of coral communities showing that, under unperturbed conditions, the reef-building coral Porites cylindrica exhibits significantly higher growth when transplanted together with 2 other species (P. rus and Pavona frondifera) than when grown in monoculture. However, the introduction of a chronic disturbance (nutrient enrichment) adversely affected its growth rates and survival, thus overturning the earlier trend. Furthermore, the 3 species used in the experiment exhibited different responses to the perturbation (negative, no effect, positive). Our results show that the presence of other species can enhance performance at the colony level, while differential species responses potentially provide buffering effects at the community level that may contribute to the maintenance of community structure and function during periods of disturbance.
- Understanding coral reefs as complex systems: Degradation and prospects for recoveryDizon, Raymond T.; Yap, Helen T. (Editorial CSIC, 2006-06-30)The present century is witness to unprecedented levels of coral reef degradation worldwide. Current understanding based on traditional ideas is unlikely to capture adequately the dynamics of phenomena accompanying this trend. In this regard, the ideas of complexity are reviewed. Some applications to coral reefs as complex systems have already been discussed in the literature although further progress is warranted as the search for new and more effective management tools continues, and the direction towards more holistic, integrative and large scale approaches gains wider acceptance. We distinguish between the concepts of robustness and resilience in the face of disturbance, highlight the various mechanisms that foster these stability properties and provide some coral reef examples. We identify some of the driving forces behind succession that are critical for community assembly and possible reef recovery. Finally, we consider how self-organization arises out of apparently random and chaotic processes and interactions to exhibit certain regularities and patterns especially when moving up on the scale of space and/or time.
- Growth and survival of coral transplants with and without electrochemical deposition of CaCO3Sabater, Marlowe G.; Yap, Helen T. (Elsevier BV, 2002-06)This study aims to investigate experimentally the effect of electrochemical deposition of CaCO3 on linear and girth growth, survival and skeletal structure of Porites cylindrica Dana. Transplanted coral nubbins were subjected to up to 18 V and 4.16 A of direct current underwater to induce the precipitation of dissolved minerals. Naturally growing colonies showed a significant increase in percentage longitudinal growth over the treated and untreated corals. Survival followed a similar trend as the growth rate. Lowest survival rates were found in the untreated nubbins. Phenotypic alterations were observed in the treated nubbins where the basal corallites decreased in size with a concomitant increase in their number per unit area. This was probably due to increased mineral concentration (such as Ca2+, Na−, Mg2+, CO32−, Cl−, OH− and HCO3−) at the basal region of the nubbins. These alterations were accompanied by a significant increase in girth growth rates of the treated nubbins at their basal regions. The abundance of mineral ions at the basal region thus appeared to be utilized by the numerous small polyps for a lateral increase in size of the nubbins instead of a longitudinal increase.
- A comparison between sites of growth, physiological performance and stress responses in transplanted Tridacna gigasElfwing, Tina; Blidberg, Eva; Sison, Marilou; Tedengren, Michael (Elsevier BV, 2003-04)The continuous increase of human activities in the tropical coastal zones threatens the water quality necessary for cultivating giant clams. In order to investigate the potential for disturbances, of natural and/or anthropogenic origin, to affect growth in giant clams, transplantation experiments were conducted in the north of the Philippines. After 6 months, there were significantly lower values for both wet weights (wwt) and shell lengths (SL) at the “disturbed sites”, where the clams had experienced both natural turbidity and impacts from human settlement and fish pens, compared to the reference site. Differences between sites were also manifested as impaired physiological performance under identical light regimes and water quality in a laboratory experiment: gross production and respiration (Pg/R) ratios were lower, Rapid Light Curves (RLC) showed lower maximal production at light saturation, chlorophyll (chl) a levels per cell was higher and the degree of epibionts increased with over 90% compared to controls. The suggested explanation to this is reduced light penetration as a result of both natural higher turbidity and nutrient loading brought about by, e.g. intensive fish aquaculture in the channel. Light penetration will be further reduced in the future with present development of fish pens in the channel. To assess tolerance to additional anthropogenic impacts, such as release of copper from antifouling treatment of fish cages, clams from different sites were exposed to a sublethal dose of copper (5 μg Cu2+ l−1) under laboratory conditions. Clams from all sites showed lowered Pg/R ratios when exposed to the metal, although the control clams displayed a larger percentage decrease than clams from the channel. This could be interpreted as higher tolerances in those clams already adapted to a stressful environment, or merely reflect an overall energy conservation through reduced metabolic activity.
- Monitoring and evaluation of reef protected areas by local fishers in the Philippines: Tightening the adaptive management cycleUychiaoco, Andre J.; Arceo, Hazel O.; Green, Stuart J.; De La Cruz, Margarita T.; Gaite, Paulyn A.; Aliño, Porfirio M. (Springer, 2005-10)Monitoring by local community managers tightens the adaptive management cycle by linking management more closely with its evaluation, so management actions become more responsive to the field situation. Local community volunteers, usually fishers, managing coral reef protected areas in the Philippines used simple methods (e.g. snorkeling fish visual census) to periodically monitor and evaluate reef protection together with professional marine biologists. Except for estimates of hard coral, data collected by local volunteers were not significantly correlated with data collected by biologists (specifically abundance estimates of sand, major reef fish carnivores, and fish herbivores). Community-collected fish data generally have higher variance and show higher abundances than biologist-collected data. Nonetheless, though the data was less precise, the locally based monitoring identified or confirmed the need for management actions that were generic in nature (e.g. stronger enforcement, organizational strengthening, etc.). The locally based monitoring also encouraged cooperation among stakeholders and prompted a management response. Little time and financing is required after initial establishment and replication has been increasing. However, sustainability depends upon the communities’ perceived added-value of undertaking the monitoring and input from a paid and/or more committed local person (e.g. government) who occasionally conducts monitoring himself/herself and supervises the community monitoring. Management impact depends heavily upon good integration with active management interventions outside the monitoring effort per se
- Effects of coral transplantation in sites of varying distances and environmental conditionsDizon, Raymond T.; Yap, Helen T. (Springer, 2005-11-29)Several scleractinian coral species with different growth forms and life history strategies were studied in terms of colony growth (expressed as projected linear increment) and survivorship over a range of distances and environmental conditions in the Philippines. The experimental design consisted of 1 m2 plots grouped within a reef site, to several sites within reef systems separated by a distance of about 340 km. There were distinct differences among species, with submassive and massive forms displaying slower growth but better survival, confirming results of other studies. They probably play the role of framework builders of the reef. In contrast, the delicate branching and foliose species had higher growth rates but poor survivorship. This observation, plus their ease of fragmentation, suggests they act more as fillers of the reef matrix. There was high variability in colony increment of a species among the square meter plots, but not among sites within a reef system. Thus, more regular pattern could be observed at this level. In contrast to growth, survivorship differed significantly among sites, being lowest in the site which harbored the greatest amount of dead coral. Growth and survival, however, are not sufficient performance measures to evaluate the success of coral transplantation. Reproduction and subsequent recruitment must also be taken into account. It is recommended that coral transplant and restoration studies consider the broad environmental context of restoration and seek to develop assembly rules that will allow practitioners to match coral types and sequence of interventions to each unique context.
- Fisheries Administrative Order No. 168-2: Series of 1996. Suspension of the effectivity of FAO No 168-1. s 1991(Department of Agriculture, 1996-03-14)