Postdoctoral Seminar Series
Scale mismatches in socio-‐ecological systems: Implementing marine reserve networks in the Philippines
Vera Horigue, PhD
James Cook University
Scholars and development groups have advocated for the establishment of marine reserve networks, because they are known and, in some cases, empirically proven to provide greater ecological, social and economic benefits compared to individual reserves. However, as in the case of individual reserves, marine reserve networks have to be well-designed and well-managed in order to provide more benefits. Still, implementing optimal marine reserve network designs is much more difficult in certain governance contexts, because ecological and governance scales are rarely congruent. Institutional arrangements that can and address scale mismatches between ecological and social systems will then be required, to provide for implementation of marine reserve networks that can span multiple governance units, or be scaled up to higher governance levels.
In this seminar, I will discuss how scale mismatches and the varying scales of planning and management can influence effectiveness of marine reserves. Specifically in this talk, I will discuss:
a.) What is a "a scale mismatch"? And, why is it important to consider when planning and establishing marine reserve networks?
b.) What are the options available to resolve scale mismatches in order to implement marine reserve networks?
c).) What are the current practices in the Philippines, and the challenges experienced in relation to design and network governance?
Various approaches and collaborative efforts are required in order to diagnose and resolve scale mismatches. This includes combining modelling and empirical research, and collaborations across different disciplines (i.e. biological, physical and social sciences).
Nitrogen limitation due to mariculture-derived phosphorus and the recurring incidence of algal blooms in Bolinao and Anda, Pangasinan, Philippines
Charissa Ferrera, PhD
Tokyo Institute of Technology
The mariculture of milkfish (Chanos chanos) has been a major source of income in the shared semi-enclosed coastal waters of Bolinao and Anda, Pangasinan. After nearly two decades of operation, degradation of water quality has been observed from long-term monitoring of Bolinao waters. Although the number of fish farming structures in Bolinao has been regulated to within the allowable limit after the massive fish kill that occurred in 2002, conditions have remained eutrophic. Results of seasonal surveys indicate that mariculture areas are nitrogen-limited as shown by nitrogen to phosphorus ratios (N/P) in the water that are consistently lower (~6.6) than the Redfield ratio (16). Decomposition of wasted fish feeds containing more P than the nutritional requirement of fish, fish feces and excretions are the major sources of nutrients in the area. At the start of the wet season, N-limitation is relieved by N-supply from the watershed, oftentimes resulting to algal blooms that lead to fish kills. The increase in fish structures in the adjacent waters of Anda, as seen through satellite images, contributes to higher amounts of mariculture-derived nutrients brought in to Bolinao by residual current during the dry season. Correspondingly, recurring blooms of dinoflagellates and diatoms that often proliferate in low N/P ratio conditions have been reported for Bolinao and Anda. Understanding the environmental-socio-economic aspect is important in the recovery of a coastal area from the harmful effects of algal blooms arising from cultural eutrophication.
A comparison between the use of sexually- and asexually-derived corals to actively restore degraded reef areas in northwestern Philippines
Maria Vanessa Baria, PhD
University of Ryukyus
Active restoration is an option to restore degraded reef areas which have insufficient larval supply and high post-settlement mortality. The primary considerations in active restoration approach are increase in live coral cover and its effort cost. Two materials used in actively restoring degraded coral reefs are asexually- and sexually-derived corals. This study was conducted to determine and compare growth and survivorship of asexually- and sexually-derived corals of Acropora granulosa in the in situ nursery and subsequently on degraded reef areas in northwestern Philippines. For sexual propagation, gametes spawned from gravid colonies of A. granulosa were collected and reared until settlement (200 days) at an outdoor hatchery facility. After 6 months, coral juveniles were reared at the in situ nursery along with coral fragments (asexual propagation) then outplanted to a degraded reef (referred to “coral bommies”). Cumulative survival of sexually-derived corals was significantly higher than asexually-derived corals reared at the in situ nursery (100% and 83%) for 200 days and coral bommies (27% and 21%) for 382 days. Growth of sexually-derived corals was also significantly higher than asexually-derived corals at in situ nursery (4.65 ± 0.77 and 2.65 ± 1.51cm3, mean ± sd, respectively) and on coral bommies (25.1 ± 11.57 and 10.25 ± 4.04 cm3, respectively). Production cost is more expensive in sexual (3.96 USD) than asexual (3.20 USD) mode of propagation. However, 14 months post-outplantation showed that individual cost of sexually derived corals is cheaper than asexual counterpart, 14.17 and 18.74 USD, respectively. Size advantage and or the genetic variability of sexually derived corals could have enhanced its survival both in in situ and on the reef. Hence, it is recommended that sexually-derived corals be used in restoration of degraded reefs in order to attain higher success rate.
Keywords: Coral restoration; Coral degradation; Sexual propagation; Asexual propagation; Acropora granulosa
A meta-analysis on long-term change in coral cover and the effectiveness of marine protected areas in the Philippines
Evangeline T. Magdaong, PhD
Although coral declines have been reported from major reefs of the world, region-specific trends still remain unclear, particularly in areas with high diversity such as the Philippines. We assessed the temporal patterns of the magnitude and trajectory of coral cover change in the Philippines using survey data collected from 317 sites. We examined the rate of change in coral cover in relation to time, effects of bleaching and protection against fishing and assessed the efficacy of marine protected areas (MPAs) using meta-analysis. Results showed an overall increase in coral cover in the Philippines from 1981 to 2010. Protection from fishing contributed to the overall increase in the mean annual rate of change as the coral cover significantly increased within MPAs than outside. The significant differences in the rate of coral cover change through time were influenced by chronic anthropogenic stresses, coinciding with the timing of thermal stress and the establishment of MPAs. The rate of change in coral cover was independent of the level of protection and the age and size of MPA.
Charina Lyn Amedo-Repollo, PhD
University of Hawai'iat Manoa
Physical Oceanography Laboratory, Marine Science Institute
University of the Philippines, Diliman, Quezon City
High Frequency Doppler Radar (HFDR), shallow pressure gauges (SPG) and Acoustic Doppler Current Profiler (ADCP) time-series observations during the Philippine Straits Dynamics Experiment (PhilEx) were analyzed to describe the tidal and mesoscale currents in Panay Strait, Philippines.
Low frequency surface currents inferred from three HFDR (July 2008 – July 2009), reveal a clear seasonal signal concurrent with the reversal of the Asian monsoon. A mesoscale cyclonic eddy west of Panay Island is generated during the winter Northeast (NE) monsoon. This causes changes in the strength, depth and width of the intraseasonal Panay coastal (PC) jet as its eastern limb. Winds from QuikSCAT and from a nearby air port indicate that these flow structures correlate with the strength and direction of the prevailing local wind.
An intensive survey in February 8-9, 2009 using 24-hour of successive cross-shore Conductivity - Temperature - Depth (CTD) sections, which in conjunction with shipboard ADCP measurement show a well-developed cyclonic eddy characterized by near-surface velocities of 50 cm/s. This eddy coincides with the intensification of the wind in between Mindoro and Panay Islands generating a positive wind stress curl in the lee of Panay, which in turn induces divergent surface currents. Water column response from the mean transects show a pronounced signal of upwelling, indicated by the doming of isotherms
and isopycnals. A pressure gradient then is set up, resulting in the spin-up of a cyclonic eddy in geostrophic balance. Evolution of the vorticity within the vortex core confirms wind stress curl as the dominant forcing.