Leni Yap-Dejeto | University of the Philippines Visayas (original) (raw)

Papers by Leni Yap-Dejeto

Philippine Journal of Science

Sargassum polycystum is an economically important seaweed endemic to Southeast Asian waters. Gene... more Sargassum polycystum is an economically important seaweed endemic to Southeast Asian waters. Genetic diversity studies conducted for this alga have been based on samples from various areas in the Indo-Pacific region. Here, we examined the phylogenetic patterns of S. polycystum in Eastern Samar, Philippines using the nuclear ribosomal DNA (rDNA) region – including ITS1, 5.8S gene, and ITS2. The phylogenetic and haplotype analyses using these loci indicate that the Eastern Samar samples contain 13 haplotypes. Using the ITS2 region sequences alone (to include other Indo-Pacific samples), we found that the number of Eastern Samar haplotypes was reduced to six, with one common haplotype found in Singapore and Indonesia. Our findings indicate that the genetic diversity of Eastern Samar S. polycystum is substantially higher than previously suggested. Consistent with the previous hypothesis, the populations of S. polycystum in Southeast Asian waters indicate a range expansion. The study cou...

Philippine Journal of Science

Iodine is known as an essential mineral for thyroid hormone production in humans. It is water- so... more Iodine is known as an essential mineral for thyroid hormone production in humans. It is water- soluble and diffuses into the atmosphere, where it is thought to break ozone molecules. Caulerpa racemosa (Phylum Chlorophyta, Class Ulvophyceae, Order Bropsidales) is a common dietary seaweed believed to be a good source of iodine in the Philippines. As of this writing, there is no record of iodine concentration measurements in harvested C. racemosa from Philippine waters. There is an expected decrease in iodine concentrations from harvested C. racemosa through time. But how fast it decreases and how much of it remains in the seaweed if stored for days is also unknown. This study measured iodine concentration in C. racemosa samples from an area in the Philippines and calculated the daily changes in iodine level concentrations of harvested C. racemosa that were stored. Titration analyses were done every 24 h, with factors such as the algal age, temperature, light, among others, kept consta...

SSRN Electronic Journal, 2022

Frontiers in Marine Science

In recent years, harmful algal blooms (HABs), commonly known as red tide, have started to occur y... more In recent years, harmful algal blooms (HABs), commonly known as red tide, have started to occur year-round in the warm tropical marine waters of Eastern Visayas, Philippines. These are a threat to public safety and cause enormous loss in industries relying on marine resources. The first step in solving this problem is to establish the distribution and succession of phytoplankton communities and harmful microalgae that exist in the region. For the first time, simultaneous monthly monitoring of the phytoplankton community was conducted in five HAB-affected bays of Leyte and Samar islands. We observed spatial differences on the environmental profiles between the five bays in the two islands and these differences may, in part, influence the distribution and abundance of the phytoplankton community residing within these areas. Diatom associated groups were prevalent in all sampling sites, however, HAB causative species were abundant in the bays in Samar during the sampling period. Five (...

Revista de Biología Tropical, 2016

Since 1983, San Pedro Bay in the Philippines had been reported to be the site of episodic Pyrodin... more Since 1983, San Pedro Bay in the Philippines had been reported to be the site of episodic Pyrodinium bahamense var. compressum blooms that caused paralytic shellfish poisoning in its nearby coastal communities. This bay is also subjected to numerous storms; the strongest was super typhoon Haiyan in November 8, 2013. For the first time, the seasonal dynamics of potentially toxic and harmful phytoplankton in this bay is elucidated. This is also the first record of a bloom of the cyanobacteria, Trichodesmium erythraeum that reached 70 000 colonies/L in April 2013 in this area. There were other 19 potentially toxic and harmful phytoplankton encountered during the sampling period. These consisted of a haptophyte, Phaeocystis globosa, the diatom Pseudo-nitzschia and 17 dinoflagellates. Seven of these harmful algae had densities high enough to be traced through time. Normally, diatoms abound during the dry season. But Pseudo-nitzschia increased in abundance during the wet season of 2012 an...

Kappaphycus alvarezii is one of the most commercially important seaweed species and is the primar... more Kappaphycus alvarezii is one of the most commercially important seaweed species and is the primary source of kappa carrageenan. Since its initial cultivation in the early 1970's, the Philippines is the largest producer of Kappaphycus until it was replaced by Indonesia in 2008. The decline in production and quality is primarily associated with the occurrence of ice-ice disease and epiphyte infestation. This study monitored the growth of epiphytes and ice-ice disease in the Kappaphycus alvarezii var. tambalang (brown) farms established in Balangiga and Lawaan, Eastern Samar. Epiphyte cover was higher in Balangiga (17±11.3%) compared to that of Lawaan (3.6±3.98%). The intensity of ice-ice disease remained low for both sites. The physico-chemical parameters measured were within normal range except for the recorded temperature in Balangiga of 19°C which is below the range recommended for optimal growth of Kappaphycus. This may explain the higher epiphyte cover in Balangiga as compare...

Cysts withstand hostile environmental conditions and are source of inoculum for recurrent blooms.... more Cysts withstand hostile environmental conditions and are source of inoculum for recurrent blooms. In the Philippines, the first recorded bloom of the phytoplankton Pyrodinium bahamense was observed in Samar-Leyte areas, including Cancabato Bay in 1983. Since then, shellfish bans in these areas have been imposed periodically. Until the present however, there is no thorough cyst study done in this bay. This study has assessed the abundance and distribution of dinoflagellate cysts in the bay. Surface sediment samples collected and processed by palynological technique have revealed a total of 21 species of dinoflagellate cysts belonging to five groups: Gonyaulacoid, Protoperidinioid, Gymnodinioid, Calciodinellid, and Diplopsalid. Cysts have been detected in all stations, with cyst densities ranging from 1-80 cysts g-1 DW; and Operculodinium centrocarpum (Protoceratium reticulatum) dominated in four stations. Low levels of P. bahamense cysts, Polysphaeridium zoharyi, have been detected i...

Phytoplankton samples were collected by bucket, 20 μm mesh size plankton net and Van Dorn water s... more Phytoplankton samples were collected by bucket, 20 μm mesh size plankton net and Van Dorn water sampler in San Pedro Bay, Leyte, Philippines from December 2006 to May 2008. Acidwashed valves of Pseudo-nitzschia were observed and critically identified using transmission electron microscopy (TEM). The following species were identified: Pseudo-nitzschia brasiliana, P. caciantha, P. micropora, P. pseudodelicatissima, and P. pungens. Morphometric measurements of valves and descriptions of species are included herein. P. pungens was the most abundant species encountered in this study with maximum density at 3.5×104cells·L-1 during February 2007. This is the first taxonomic account at the species level of this genus in Philippine waters.

This paper reports the comparison of phytoplankton composition, and cell density of whale shark f... more This paper reports the comparison of phytoplankton composition, and cell density of whale shark feeding grounds off Sogod Bay, Southern Leyte and Oslob, Cebu on November 2014, January 2015, and February 2015. All water samples were taken one meter below the surface of the water from three stations on each site. For the qualitative analysis, water samples were collected with the use of plankton net. For the quantitative analysis, 1L water samples were collected with the use of WILDCO water sampler and bucket. All physico-chemical measurement and nutrient values for phosphate and nitrate on each site were within the normal range of the ASEAN water quality criteria. The overall dominant genus in both sites was the diatoms of the genus Skeletonema . Diatoms from genus Chaetoceros , Cosinodiscus , and Cerataulina were also abundant phytoplankton seen in both sites. In the month of January 2015, the diatoms Skeletonema spp. dominated yielding the highest phytoplankton density of 6.6...

Harmful Algae, 2005

For the first time, a Prorocentrum minimum bloom at a maximum cell density of 4.7×105cells/L was ... more For the first time, a Prorocentrum minimum bloom at a maximum cell density of 4.7×105cells/L was recorded on January 31 to February 4, 2002 at Bolinao, Pangasinan, Northern Philippines where intensive and extensive aquaculture of Chanos chanos (milkfish) in fish pens and cages has been practiced for years now. The fish kill, which lasted almost simultaneously with the bloom of the organism had its peak when the organisms bloom was declining. Lack of oxygen in the cages and pens was the fundamental cause of the fish kill. Losses due to the fish kill were estimated at six million pesos (equivalent to US$ 120,000), which includes only the worth of dead cultivated fish. Lack of oxygen in the cages and pens was the fundamental cause of the fish kill, and toxicity of the Prorocentrum could not be confirmed. The cells had minute spinules equally all over the surface of valves. Intercalary striae were wide with many ridges perpendicular to valve margin. Outline of cells was rounder than typical P. minimum cells and similar to P. balticum. Recommendations for future research on the organism are incorporated together with monitoring and management interventions in order to mitigate or possibly prevent damages in similar future events.

Introduction. The rise of antibiotic resistance and superbugs drives the search for new antibioti... more Introduction. The rise of antibiotic resistance and superbugs drives the search for new antibiotics today. Meanwhile, the green mussel Perna viridis is a cultivated and marketed staple bivalve in the Philippines due to its fast reproduction, high protein content, and tolerance to environmental variables. Although some studies have analyzed the antimicrobial activity of P. viridis, zoochemical analyses and further evaluation of its antimicrobial activity, such as determining the minimum inhibitory concentration (MIC), remains unexplored. Objectives. The study evaluated the zoochemicals present in crude methanolic extract of P. viridis by qualitative screening and thin-layer chromatography analysis. It further evaluated the crude extract for its antimicrobial activity against common pathogenic bacteria and plant pathogenic fungi. Materials and Methods. The zoochemicals in crude methanolic extract of P. viridis were screened using qualitative spotting methods and thin-layer chromatogra...

INTRODUCTION Observations of Microzooplankton in the Vicinity of Whale Shark Rhincodon typus Aggr... more INTRODUCTION Observations of Microzooplankton in the Vicinity of Whale Shark Rhincodon typus Aggregation Sites in Oslob, Cebu and Pintuyan, S. Leyte, Philippines

Zooplankton play an important role as part of the diet of various types of organisms such as whal... more Zooplankton play an important role as part of the diet of various types of organisms such as whale sharks. This group of organisms is believed to be one of the environmental cues of whale shark migration. Sampling stations were established along the whale shark feeding grounds in Sogod Bay, Southern Leyte and Oslob, Cebu. In Sogod Bay, whale sharks migrate seasonally from November to July. In Oslob, these are found daily the whole year round. Water samples were taken one meter below water surface from three stations on each site to assess zooplankton abundance and composition between sites. All physico-chemical values were within normal ranges. A total of 27 zooplankton groups were observed in Sogod Bay and 28 in Oslob. In both sites, Order Tintinnida from Class Ciliata dominated with a cell density of 2,000 indiv/L in Sogod and 3,000 indiv/L in Oslob, respectively. Increased cell density of this order results from the decrease of their predators, the subclass Copepoda, which was b...

Revista de Biología Tropical, 2016

Since 1983, San Pedro Bay in the Philippines had been reported to be the site of episodic Pyrodin... more Since 1983, San Pedro Bay in the Philippines had been reported to be the site of episodic Pyrodinium bahamense var. compressum blooms that caused paralytic shellfish poisoning in its nearby coastal communities. This bay is also subjected to numerous storms; the strongest was super typhoon Haiyan in November 8, 2013. For the first time, the seasonal dynamics of potentially toxic and harmful phytoplankton in this bay is elucidated. This is also the first record of a bloom of the cyanobacteria, Trichodesmium erythraeum that reached 70 000 colonies/L in April 2013 in this area. There were other 19 potentially toxic and harmful phytoplankton encountered during the sampling period. These consisted of a haptophyte, Phaeocystis globosa, the diatom Pseudonitzschia and 17 dinoflagellates. Seven of these harmful algae had densities high enough to be traced through time. Normally, diatoms abound during the dry season. But Pseudo-nitzschia increased in abundance during the wet season of 2012 and 2013. The dinoflagellates and Phaeocystis globosa behaved as expected and exhibited a relative increase in cell density during the rainy season of both years too. High nutrient availability during this season must have influenced the behavior of the phytoplankton despite differences in temperature and light intensity among seasons. Other notable but rare harmful species found only in plankton net tows during the study were

Revista de biologia tropical, 2016

Since 1983, San Pedro Bay in the Philippines had been reported to be the site of episodic Pyrodin... more Since 1983, San Pedro Bay in the Philippines had been reported to be the site of episodic Pyrodinium bahamense var. compressum blooms that caused paralytic shellfish poisoning in its nearby coastal communities. This bay is also subjected to numerous storms; the strongest was super typhoon Haiyan in November 8, 2013. For the first time, the seasonal dynamics of potentially toxic and harmful phytoplankton in this bay is elucidated. This is also the first record of a bloom of the cyanobacteria, Trichodesmium erythraeum that reached 70 000 colonies/L in April 2013 in this area. There were other 19 potentially toxic and harmful phytoplankton encountered during the sampling period. These consisted of a haptophyte, Phaeocystis globosa, the diatom Pseudo-nitzschia and 17 dinoflagellates. Seven of these harmful algae had densities high enough to be traced through time. Normally, diatoms abound during the dry season. But Pseudo-nitzschia increased in abundance during the wet season of 2012 an...

Philippine Journal of Science

Sargassum polycystum is an economically important seaweed endemic to Southeast Asian waters. Gene... more Sargassum polycystum is an economically important seaweed endemic to Southeast Asian waters. Genetic diversity studies conducted for this alga have been based on samples from various areas in the Indo-Pacific region. Here, we examined the phylogenetic patterns of S. polycystum in Eastern Samar, Philippines using the nuclear ribosomal DNA (rDNA) region – including ITS1, 5.8S gene, and ITS2. The phylogenetic and haplotype analyses using these loci indicate that the Eastern Samar samples contain 13 haplotypes. Using the ITS2 region sequences alone (to include other Indo-Pacific samples), we found that the number of Eastern Samar haplotypes was reduced to six, with one common haplotype found in Singapore and Indonesia. Our findings indicate that the genetic diversity of Eastern Samar S. polycystum is substantially higher than previously suggested. Consistent with the previous hypothesis, the populations of S. polycystum in Southeast Asian waters indicate a range expansion. The study cou...

Philippine Journal of Science

Iodine is known as an essential mineral for thyroid hormone production in humans. It is water- so... more Iodine is known as an essential mineral for thyroid hormone production in humans. It is water- soluble and diffuses into the atmosphere, where it is thought to break ozone molecules. Caulerpa racemosa (Phylum Chlorophyta, Class Ulvophyceae, Order Bropsidales) is a common dietary seaweed believed to be a good source of iodine in the Philippines. As of this writing, there is no record of iodine concentration measurements in harvested C. racemosa from Philippine waters. There is an expected decrease in iodine concentrations from harvested C. racemosa through time. But how fast it decreases and how much of it remains in the seaweed if stored for days is also unknown. This study measured iodine concentration in C. racemosa samples from an area in the Philippines and calculated the daily changes in iodine level concentrations of harvested C. racemosa that were stored. Titration analyses were done every 24 h, with factors such as the algal age, temperature, light, among others, kept consta...

SSRN Electronic Journal, 2022

Frontiers in Marine Science

In recent years, harmful algal blooms (HABs), commonly known as red tide, have started to occur y... more In recent years, harmful algal blooms (HABs), commonly known as red tide, have started to occur year-round in the warm tropical marine waters of Eastern Visayas, Philippines. These are a threat to public safety and cause enormous loss in industries relying on marine resources. The first step in solving this problem is to establish the distribution and succession of phytoplankton communities and harmful microalgae that exist in the region. For the first time, simultaneous monthly monitoring of the phytoplankton community was conducted in five HAB-affected bays of Leyte and Samar islands. We observed spatial differences on the environmental profiles between the five bays in the two islands and these differences may, in part, influence the distribution and abundance of the phytoplankton community residing within these areas. Diatom associated groups were prevalent in all sampling sites, however, HAB causative species were abundant in the bays in Samar during the sampling period. Five (...

Revista de Biología Tropical, 2016

Since 1983, San Pedro Bay in the Philippines had been reported to be the site of episodic Pyrodin... more Since 1983, San Pedro Bay in the Philippines had been reported to be the site of episodic Pyrodinium bahamense var. compressum blooms that caused paralytic shellfish poisoning in its nearby coastal communities. This bay is also subjected to numerous storms; the strongest was super typhoon Haiyan in November 8, 2013. For the first time, the seasonal dynamics of potentially toxic and harmful phytoplankton in this bay is elucidated. This is also the first record of a bloom of the cyanobacteria, Trichodesmium erythraeum that reached 70 000 colonies/L in April 2013 in this area. There were other 19 potentially toxic and harmful phytoplankton encountered during the sampling period. These consisted of a haptophyte, Phaeocystis globosa, the diatom Pseudo-nitzschia and 17 dinoflagellates. Seven of these harmful algae had densities high enough to be traced through time. Normally, diatoms abound during the dry season. But Pseudo-nitzschia increased in abundance during the wet season of 2012 an...

Kappaphycus alvarezii is one of the most commercially important seaweed species and is the primar... more Kappaphycus alvarezii is one of the most commercially important seaweed species and is the primary source of kappa carrageenan. Since its initial cultivation in the early 1970's, the Philippines is the largest producer of Kappaphycus until it was replaced by Indonesia in 2008. The decline in production and quality is primarily associated with the occurrence of ice-ice disease and epiphyte infestation. This study monitored the growth of epiphytes and ice-ice disease in the Kappaphycus alvarezii var. tambalang (brown) farms established in Balangiga and Lawaan, Eastern Samar. Epiphyte cover was higher in Balangiga (17±11.3%) compared to that of Lawaan (3.6±3.98%). The intensity of ice-ice disease remained low for both sites. The physico-chemical parameters measured were within normal range except for the recorded temperature in Balangiga of 19°C which is below the range recommended for optimal growth of Kappaphycus. This may explain the higher epiphyte cover in Balangiga as compare...

Cysts withstand hostile environmental conditions and are source of inoculum for recurrent blooms.... more Cysts withstand hostile environmental conditions and are source of inoculum for recurrent blooms. In the Philippines, the first recorded bloom of the phytoplankton Pyrodinium bahamense was observed in Samar-Leyte areas, including Cancabato Bay in 1983. Since then, shellfish bans in these areas have been imposed periodically. Until the present however, there is no thorough cyst study done in this bay. This study has assessed the abundance and distribution of dinoflagellate cysts in the bay. Surface sediment samples collected and processed by palynological technique have revealed a total of 21 species of dinoflagellate cysts belonging to five groups: Gonyaulacoid, Protoperidinioid, Gymnodinioid, Calciodinellid, and Diplopsalid. Cysts have been detected in all stations, with cyst densities ranging from 1-80 cysts g-1 DW; and Operculodinium centrocarpum (Protoceratium reticulatum) dominated in four stations. Low levels of P. bahamense cysts, Polysphaeridium zoharyi, have been detected i...

Phytoplankton samples were collected by bucket, 20 μm mesh size plankton net and Van Dorn water s... more Phytoplankton samples were collected by bucket, 20 μm mesh size plankton net and Van Dorn water sampler in San Pedro Bay, Leyte, Philippines from December 2006 to May 2008. Acidwashed valves of Pseudo-nitzschia were observed and critically identified using transmission electron microscopy (TEM). The following species were identified: Pseudo-nitzschia brasiliana, P. caciantha, P. micropora, P. pseudodelicatissima, and P. pungens. Morphometric measurements of valves and descriptions of species are included herein. P. pungens was the most abundant species encountered in this study with maximum density at 3.5×104cells·L-1 during February 2007. This is the first taxonomic account at the species level of this genus in Philippine waters.

This paper reports the comparison of phytoplankton composition, and cell density of whale shark f... more This paper reports the comparison of phytoplankton composition, and cell density of whale shark feeding grounds off Sogod Bay, Southern Leyte and Oslob, Cebu on November 2014, January 2015, and February 2015. All water samples were taken one meter below the surface of the water from three stations on each site. For the qualitative analysis, water samples were collected with the use of plankton net. For the quantitative analysis, 1L water samples were collected with the use of WILDCO water sampler and bucket. All physico-chemical measurement and nutrient values for phosphate and nitrate on each site were within the normal range of the ASEAN water quality criteria. The overall dominant genus in both sites was the diatoms of the genus Skeletonema . Diatoms from genus Chaetoceros , Cosinodiscus , and Cerataulina were also abundant phytoplankton seen in both sites. In the month of January 2015, the diatoms Skeletonema spp. dominated yielding the highest phytoplankton density of 6.6...

Harmful Algae, 2005

For the first time, a Prorocentrum minimum bloom at a maximum cell density of 4.7×105cells/L was ... more For the first time, a Prorocentrum minimum bloom at a maximum cell density of 4.7×105cells/L was recorded on January 31 to February 4, 2002 at Bolinao, Pangasinan, Northern Philippines where intensive and extensive aquaculture of Chanos chanos (milkfish) in fish pens and cages has been practiced for years now. The fish kill, which lasted almost simultaneously with the bloom of the organism had its peak when the organisms bloom was declining. Lack of oxygen in the cages and pens was the fundamental cause of the fish kill. Losses due to the fish kill were estimated at six million pesos (equivalent to US$ 120,000), which includes only the worth of dead cultivated fish. Lack of oxygen in the cages and pens was the fundamental cause of the fish kill, and toxicity of the Prorocentrum could not be confirmed. The cells had minute spinules equally all over the surface of valves. Intercalary striae were wide with many ridges perpendicular to valve margin. Outline of cells was rounder than typical P. minimum cells and similar to P. balticum. Recommendations for future research on the organism are incorporated together with monitoring and management interventions in order to mitigate or possibly prevent damages in similar future events.

Introduction. The rise of antibiotic resistance and superbugs drives the search for new antibioti... more Introduction. The rise of antibiotic resistance and superbugs drives the search for new antibiotics today. Meanwhile, the green mussel Perna viridis is a cultivated and marketed staple bivalve in the Philippines due to its fast reproduction, high protein content, and tolerance to environmental variables. Although some studies have analyzed the antimicrobial activity of P. viridis, zoochemical analyses and further evaluation of its antimicrobial activity, such as determining the minimum inhibitory concentration (MIC), remains unexplored. Objectives. The study evaluated the zoochemicals present in crude methanolic extract of P. viridis by qualitative screening and thin-layer chromatography analysis. It further evaluated the crude extract for its antimicrobial activity against common pathogenic bacteria and plant pathogenic fungi. Materials and Methods. The zoochemicals in crude methanolic extract of P. viridis were screened using qualitative spotting methods and thin-layer chromatogra...

INTRODUCTION Observations of Microzooplankton in the Vicinity of Whale Shark Rhincodon typus Aggr... more INTRODUCTION Observations of Microzooplankton in the Vicinity of Whale Shark Rhincodon typus Aggregation Sites in Oslob, Cebu and Pintuyan, S. Leyte, Philippines

Zooplankton play an important role as part of the diet of various types of organisms such as whal... more Zooplankton play an important role as part of the diet of various types of organisms such as whale sharks. This group of organisms is believed to be one of the environmental cues of whale shark migration. Sampling stations were established along the whale shark feeding grounds in Sogod Bay, Southern Leyte and Oslob, Cebu. In Sogod Bay, whale sharks migrate seasonally from November to July. In Oslob, these are found daily the whole year round. Water samples were taken one meter below water surface from three stations on each site to assess zooplankton abundance and composition between sites. All physico-chemical values were within normal ranges. A total of 27 zooplankton groups were observed in Sogod Bay and 28 in Oslob. In both sites, Order Tintinnida from Class Ciliata dominated with a cell density of 2,000 indiv/L in Sogod and 3,000 indiv/L in Oslob, respectively. Increased cell density of this order results from the decrease of their predators, the subclass Copepoda, which was b...

Revista de Biología Tropical, 2016

Since 1983, San Pedro Bay in the Philippines had been reported to be the site of episodic Pyrodin... more Since 1983, San Pedro Bay in the Philippines had been reported to be the site of episodic Pyrodinium bahamense var. compressum blooms that caused paralytic shellfish poisoning in its nearby coastal communities. This bay is also subjected to numerous storms; the strongest was super typhoon Haiyan in November 8, 2013. For the first time, the seasonal dynamics of potentially toxic and harmful phytoplankton in this bay is elucidated. This is also the first record of a bloom of the cyanobacteria, Trichodesmium erythraeum that reached 70 000 colonies/L in April 2013 in this area. There were other 19 potentially toxic and harmful phytoplankton encountered during the sampling period. These consisted of a haptophyte, Phaeocystis globosa, the diatom Pseudonitzschia and 17 dinoflagellates. Seven of these harmful algae had densities high enough to be traced through time. Normally, diatoms abound during the dry season. But Pseudo-nitzschia increased in abundance during the wet season of 2012 and 2013. The dinoflagellates and Phaeocystis globosa behaved as expected and exhibited a relative increase in cell density during the rainy season of both years too. High nutrient availability during this season must have influenced the behavior of the phytoplankton despite differences in temperature and light intensity among seasons. Other notable but rare harmful species found only in plankton net tows during the study were

Revista de biologia tropical, 2016

Since 1983, San Pedro Bay in the Philippines had been reported to be the site of episodic Pyrodin... more Since 1983, San Pedro Bay in the Philippines had been reported to be the site of episodic Pyrodinium bahamense var. compressum blooms that caused paralytic shellfish poisoning in its nearby coastal communities. This bay is also subjected to numerous storms; the strongest was super typhoon Haiyan in November 8, 2013. For the first time, the seasonal dynamics of potentially toxic and harmful phytoplankton in this bay is elucidated. This is also the first record of a bloom of the cyanobacteria, Trichodesmium erythraeum that reached 70 000 colonies/L in April 2013 in this area. There were other 19 potentially toxic and harmful phytoplankton encountered during the sampling period. These consisted of a haptophyte, Phaeocystis globosa, the diatom Pseudo-nitzschia and 17 dinoflagellates. Seven of these harmful algae had densities high enough to be traced through time. Normally, diatoms abound during the dry season. But Pseudo-nitzschia increased in abundance during the wet season of 2012 an...