Seasonal changes in phytoplankton composition in an extensive fish culture area in Bolinao, Pangasinan, northern Philippines

The proliferation of fish cages and pens in Bolinao, Pangasinan, northern Philippines seemed to have reached its limit in 2002 when a massive fish kill coinciding with a bloom of Prorocentrum minimum occurred. Since then, various measures have been taken by the local government to decrease the number of fish cages to allow recovery of the waters of Bolinao. Samples collected in April, June and November 2004 representing summer, southwest and northeast monsoons, respectively, from five stations were analyzed for phytoplankton composition. Diatoms generally dominated the phytoplankton and peaked during summer which can be attributed to a very high concentration of Thalassiosira sp. constituting 92% of the phytoplankton in that season. The dinoflagellates constituted a small portion of the phytoplankton composition in all seasons. The flagellates represented a small fraction of the phytoplankton and followed the trend of the dinoflagellates. Cyanobacteria thrived during the wet seasons, almost co-existing with the diatoms. The results seem to suggest that the management of the fish cages or the aquaculture ponds might have resulted to changes in the present (2004) phytoplankton composition compared to previous years (1995-2002)

Harmful Algal Bloom in Iligan Bay, Southern Philippines

We report the first occurrence of harmful algal bloom (HAB) caused by a non-toxic dinoflagellate, Cochlodinium sp. in Philippine waters, particularly, in Kalangahan Pt.-Manticao Pt., Iligan Bay on March 13-18, 2002. Two patches of Cochlodinium sp. bloom, associated with fish kills in Kalangahan Pt.-Mantacao Pt., Iligan Bay, caused localized water discoloration from the usual ocean blue to rusty brown or reddish brown to blackish. The first patch, located near fish-aggregating device (FAD) areas, spanned 2 km wide, while the second patch, located near a fish corral, spanned 500m wide. These patches occupied the water column from surface to 5 m depth, but a thick mat formed at 0.5 m to surface. Patches occupied the water column from surface to 5 m depth, but a thick mat formed at 0.5 m to surface. Patches decreased as the bloom began to decline. The observed dead demersal and pelagic fishes coincided with highest bloom density of 3.1 x 104 to 3.8 x 104 cells ml-1 of Cochlodinium. Dissected gills and stomach contents of fishes killed in HAB-affected areas did not reveal any indication of clogging of gills by Cochlodinium sp. Fishes covered by the “shading effect” of Cochlodinium bloom may have suffered anoxia or asphyxation due to oxygen depletion. No poisoning of people who consumed the dead fishes was reported. Laboratory analyses revealed lower DO values, 2.4 to 0.5 mg L-1from 2400 to 0600Hr; 14N:1P ratio; air-water temperature ranged from 28-29°C; pH 7.89-8.29; and salinity, 33-35°/oo. Favella sp., a tintinnid grazer of dinoflagellate was developing in the area at the termination of the Cochlodinium bloom on March 18

Valuing and Managing the Philippines’ Marine Resources toward a Prosperous Ocean-Based Blue Economy

The ocean-based “blue economy” is a significant part of the Philippine economy that has largely been taken for granted despite its enormous potential. It is of critical importance to a substantial segment of our population dependent on the seas and coastal resources for their livelihood and sustenance, appreciably enlarge the country’s wealth, and significantly contribute to its gross domestic product. This paper attempts to review the major issues concerning marine ecosystems in relation to the country’s pursuit of the blue economy. It discusses the economic and social activities in relation to the seas and coastal areas, and provides updated estimates of the real value of the country’s marine ecosystems’ goods and services. Based on primary and available secondary data, the marine ecosystems (excluding the continental shelf) can contribute a conservative monetary value of US$ 966.6 billion to the economy. In light of the risks and threats to the blue economy, the paper further discusses the country’s current national initiatives and involvement in regional collaborations toward ensuring its health and sustainable development. Given the Philippines’ vast largely untapped potential, a recommendation for the creation of a Department of Marine Resources, separate from the Department of Agriculture, seems in order

An inter-site study of biofouling recruitment on static immersion panels in major ports of South East Asia and India

Limited knowledge of native marine biodiversity hinders effective biodiversity management to safeguard South and Southeast Asia’s marine coastal environment against the threat of invasive species transfer through shipping. In particular, sessile marine biofouling organisms in South East Asian ports are poorly known. Through the support of the ASEAN-India Cooperation Project on the Extent of Transfer of Alien Invasive Organisms in South/South East Asia Region by Shipping, a coordinated effort to examine diversity of biofouling organisms in major port areas in Southeast Asia and India was made using polyvinylchloride (PVC) panels as recruitment surfaces in a static immersion study for a period of 12 months. Not surprisingly, the study revealed that fouling patterns differed between ports possibly as a result of dissimilar hydrographic conditions. However, there were also underlying similarities that reflected a regional uniformity in the composition of fouling communities. At the same time, the alien Caribbean bivalve Mytilopsis sallei was detected in Manila Bay (Philippines), Songkhla Port (Thailand) and Singapore. This is a first simultaneous biofouling survey involving scientists and government stakeholders from India and ASEAN nations of Brunei Darussalam, Indonesia, Lao PDR, Malaysia, Myanmar, Singapore, Thailand, Philippines and Vietnam

Seasonal changes in phytoplankton composition in an extensive fish culture area in Bolinao, Pangasinan, northern Philippines

The proliferation of fish cages and pens in Bolinao, Pangasinan, northern Philippines seemed to have reached its limit in 2002 when a massive fish kill coinciding with a bloom of Prorocentrum minimum occurred. Since then, various measures have been taken by the local government to decrease the number of fish cages to allow recovery of the waters of Bolinao. Samples collected in April, June and November 2004 representing summer, southwest and northeast monsoons, respectively, from five stations were analyzed for phytoplankton composition. Diatoms generally dominated the phytoplankton and peaked during summer which can be attributed to a very high concentration of Thalassiosira sp. constituting 92% of the phytoplankton in that season. The dinoflagellates constituted a small portion of the phytoplankton composition in all seasons. The flagellates represented a small fraction of the phytoplankton and followed the trend of the dinoflagellates. Cyanobacteria thrived during the wet seasons, almost co-existing with the diatoms. The results seem to suggest that the management of the fish cages or the aquaculture ponds might have resulted to changes in the present (2004) phytoplankton composition compared to previous years (1995-2002)

Preliminary Results On The Use Of Clay To Control Pyrodinium Bloom - A Mitigation Strategy

The frequent and expanded occurrence of Pyrodinium bahamense var compressum blooms in thePhilippines since 1983 has prompted the need to find mechanisms to control the harmful effects of thesetoxic dinoflagellates. A promising method now being explored is the use of powdered clay mineralswhich when added to the growth media is capable of flocculating with the algal cells. In this study, theefficiency of ball clay, brown bentonite, and Malampaya Sound sediments to remove Pyrodinium cellsin seawater was tested. The addition of 1 g/L of suspended ball clay to 50 mL of cultured Pyrodiniumcells (~1.037 x106 cells/L) removed 99.56% of the algal cells after 2.5 hours. Prolonging the exposuretime to 5 and 24 hours showed no significant increase in flocculation. Brown bentonite and MalampayaSound sediments showed low to moderate removal efficiency not exceeding 70% and 50%, respectively.The effect of ball clay addition on seawater chemistry showed no change in ammonia concentration butnitrate decreased after 5 and 24 hours of clay addition. Results for nitrite and phosphate were howevermore variable

Review of geographical distribution of dinoflagellate cysts in Southeast Asian coasts

Dinoflagellate cysts play an important role in the initiation, recurrence and geographical expansion of harmful algal blooms (HABs). The horizontal distribution and abundance of dinoflagellate cysts in marine sediments provide very essential information in giving early warnings of the presence of toxic species and possible continuing recurrence of HABs in a given area. A review of available bio-geographical information on dinoflagellate cyst assemblages and distributions from the surface sediments of the tropics and Southeast Asian (SEA) waters mainly on the context of HAB dynamics is also provided. Results of review on such studies revealed how cyst mapping activities contributed to understand HAB expansion in SEA region. Pyrodinium bahamense var. compressum cysts are the most common in the sediments of SEA region, explaining partly the relative wide occurrence of this PSP causative organism in the area. Cysts of Alexandrium spp. have also been found in some areas of the region, indicating the risk from the bloom of some toxic species of the genus. The factors and mechanisms of algal bloom expansion in the SEA region, involving the resting stage of causative HAB species, remain to be well understood. High priority should be given to continuing cyst mapping research in the entire SEA region, as the knowledge is so essential in comprehending HABs dispersal and occurrence thereby aiding in HABs management in the area.Proceedings of the Horiba International Conference "New Direction of Ocean Research in the Western Pacific" : Past, Present and Future of UNESCO/IOC/WESTPAC Activity for 50 years and the JSPS Project "Coastal Marine Science"Section I: Research Articles/Harmful microalga

Inter- specific and subspecific genetic divergences of freshwater eels, genus Anguilla including a recently described species, A. luzonensis, based on whole mitochondrial genome sequences

We examined general characteristics and genetic divergences of whole mitochondrial genome sequences for all 19 species/subspecies of the genus Anguilla including a recently described new species, A. luzonensis. The entire genome ranged from 16,550 (A. borneensis) to 16,833 base pairs (A. nebulosa labiata), and general characteristics such as length of each gene and gene order were very conservative across the genus and also similar with other anguilliform and bony fishes. Pairwise comparisons of sequence differences showed that interspecific divergences did not overlap with intersubspecific variations and found a clear hierarchical structure in the genus Anguilla, in which the two subspecies of A. australis and A. nebulosa had slight and the smallest differences among all species/subspecies pairs, followed by the two subspecies of A. bicolor, the A. anguilla and A. rostrata pair, and the other species pairs in order. A. luzonensis showed considerable sequence differences from all other species in all genes and was appeared to be genetically close to A. interioris. The present study analyzed the whole mitochondrial genome of A. luzonensis for the first time and genetic divergences for all anguillid species and subspecies, and provided basic information for revision and reaching agreement about the taxonomy of the genus Anguilla using molecular characteristics, which have been discussed recently