Preliminary Comparison of Remote Sensing-Derived Chlorophyll a Concentration and Sea Surface Temperature with the Fisheries Resources and Ecological Data in Manila Bay

Remote sensing is used to determine the chlorophyll a concentration and the sea surface temperature. Here, obtained remote-sensed chlorophyll a and sea surface temperature data from MODIS for Manila Bay from 2014 – 2015 was analyzed and initially correlated with the results from the fisheries resources and ecological assessment (this study). Chlorophyll a concentration was generally concentrated on the eastern part of the bay all throughout 2014. Sea surface temperature was observed to be high during May, July, August, and October 2014. During the first quarter of 2015, a high concentration of chlorophyll a was generally concentrated on the eastern and southwestern part of the bay, while sea surface temperature was high and almost uniform except in the southern side of the bay. The second quarter of 2015 showed that the chlorophyll a is still concentrated in the eastern side of the bay, while the highest sea surface temperature was observed during May reaching more than 30 °C. Comparative analysis indicated that there is a correlation between remote sensing and actual chlorophyll a data vis-à-vis egg and larval aggregations. Further studies are warranted

Evolution of the Freshwater Sardinella, Sardinella Tawilis (Clupeiformes: Clupeidae), in Taal Lake, Philippines and Identification of iIts Marine Sister-Species, Sardinella Hualiensis

We identify the sister species of the world\u27s only freshwater sardinella, Sardinella tawilis (Herre, 1927) of Taal Lake, Philippines as the morphologically-similar marine Taiwanese sardinella Sardinella hualiensis (Chu and Tsai, 1958). Evidence of incomplete lineage sorting and a species tree derived from three mitochondrial genes and one nuclear gene indicate that S. tawilis diverged from S. hualiensis in the late Pleistocene. Neutrality tests, mismatch distribution analysis, sequence diversity indices, and species tree analysis indicate populations of both species have long been stable and that the divergence between these two lineages occurred prior to the putative 18th century formation of Taal Lake

Status and management of Philippine pelagic resources potentially shared with neighboring countries

The fishery sector contributes significantly to the country’s economy and continues to play an important role in providing livelihood and in attaining food security. A significant amount of the sector’s contribution comes from pelagic resources that are potentially shared with other countries such as the highly migratory species of tunas, billfishes, oceanic sharks and small pelagics. An average of 1.09 M metric tonnes have been caught from 1993 to 1997 of which a great majority is being taken by commercial fishing boats numbering to about 3,416 in 1998. In this paper, the status and management of potentially shared pelagic fishery resources are presented including the problems being encountered in research and management and also the past, present and future national resource surveys

Hidden Diversity in Sardines: Genetic and Morphological Evidence for Cryptic Species in the Goldstripe Sardinella, Sardinella gibbosa (Bleeker, 1849)

Cryptic species continue to be uncovered in many fish taxa, posing challenges for fisheries conservation and management. In Sardinella gibbosa, previous investigations revealed subtle intra-species variations, resulting in numerous synonyms and a controversial taxonomy for this sardine. Here, we tested for cryptic diversity within S. gibbosa using genetic data from two mitochondrial and one nuclear gene regions of 248 individuals of S. gibbosa, collected from eight locations across the Philippine archipelago. Deep genetic divergence and subsequent clustering was consistent across both mitochondrial and nuclear markers. Clade distribution is geographically limited: Clade 1 is widely distributed in the central Philippines, while Clade 2 is limited to the northernmost sampling site. In addition, morphometric analyses revealed a unique head shape that characterized each genetic clade. Hence, both genetic and morphological evidence strongly suggests a hidden diversity within this common and commercially-important sardine

First Record of Blacknape Large-Eye Bream \u3ci\u3eGymnocranius satoi\u3c/i\u3e (Perciformes: Lethrinidae) in the Philippines

The Philippines has been regarded as the center of the center of marine shorefish biodiversity, having the highest number of fish species per square area in the world. The blacknape large-eye bream, Gymnocranius satoi, has been reported to occur from Southern Japan, Taiwan to Northwestern Australia and to the Coral Sea, but has not previously been recorded from the Philippines. From 2011 – 2019, the National Fisheries Research and Development Institute (NFRDI) collaborated with the National Museum of Natural History of the Smithsonian Institution (NMNH/SI), USA, and the Old Dominion University (ODU), Virgina, USA, to inventory all commercial fish species sold in fish markets around the Philippines. During three (3) fish market surveys (Dumaguete City Market, Negros Oriental; Claveria Public Market, Cagayan, Northern Luzon; and Tabaco City Market, Albay, Southeastern Luzon in 2013, 2016 and 2017, respectively), we collected and eventually identified using morphological and DNA barcoding (COI) analysis, seven (7) specimens of G. satoi, representing the first records of this species from the country. Since the potential to discover new species and first records of fish species in the Philippines is high, further taxonomic study of the genus Gymnocranius is needed

Preliminary Inventory of Boats and Gears in Manila Bay

Recent information about the number and types of boats and gears used in Manila Bay is lacking. Here we discuss the results of the initial boat and gear inventory conducted in Manila Bay from May 2015 to October 2016. The survey was done in the coastal barangays of Cavite, Bataan, Bulacan, Pampanga, and Metro Manila. A total of 3,659 fishing boats were recorded from 84 coastal barangays or about 40% out of the 212 coastal barangays in Manila Bay. About 94.45% of the boats are municipal fishing boats and only 5.55% are commercial boats and the highest number of boats recorded was in Cavite (1,461 boats). 91.04% of the fishing boats are motorized and only 8.96% are non-motorized. The average fisher to boat ratio for the five provinces is 3.0:1, which is higher compared to the 2.4:1 result of MADECOR and National Museum Assessment (1995). There are 25 types of fishing gears recorded during the survey with a total of4, 946 units. Gillnet, specifically bottom gillnet, is the most dominant gear being used in Manila Bay

Species Composition, Distribution, Biomass Trends and Exploitation of Dominant Fish Species in Manila Bay using Experimental Trawl Survey

An experimental trawl fishing survey was conducted in Manila Bay from March 2014 to October 2015 at sixteen (16) pre-established dragging stations adapted from an earlier study (MADECOR, 1995). Using a commercial otter trawl, the average trawling speed during fishing operations was 6-7 km/hour. Analysis of catches focused on biomass trends, species composition, distribution and exploitation of dominant species. A total of 146 fish and invertebrate species belonging to 48 families were recorded during the survey period wherein most of the catches were dominated by small pelagic species such as anchovies and sardines. Exploitation rates (E) for the six (6) dominant species (Sardinella gibbosa, Sardinella fimbriata, Valamugil seheli, Mugil cephalus, Encrasicholina devisi and Stolephorous commersonnii) shows signs of overfishing. The estimated demersal fish biomass of the bay revealed that the relative decline was about 90% from the 1947 baseline study

Molecular cloning and expression of chitin deacetylase 1 gene from the gills of Penaeus monodon (black tiger shrimp)

Chitin deacetylases have been identified and studied in several fungi and insects but not in crustaceans. These glycoproteins function in catalyzing the conversion of chitin to chitosan by the hydrolysis of N-acetamido bonds of chitin. Here, for the first time, the full length cDNA of chitin deacetylase (CDA) gene from crustaceans was fully cloned using a partial fragment obtained from a transcriptome database of the gills of black tiger shrimp Penaeus monodon that survived White Spot Syndrome Virus (WSSV) infection employing Rapid Amplification of cDNA Ends (RACE) PCR. The shrimp CDA, named PmCDA1, was further characterized by in silico analysis, and its constitutive expression determined in apparently healthy shrimp through reverse transcription PCR (RT-PCR). Results revealed that the P. monodon chitin deacetylase (PmCDA1) is 2176 bp-long gene with an open reading frame (ORF) of 1596 bp encoding for 532 amino acids. Phylogenetic analysis revealed that PmCDA1 belongs to Group I CDAs together with CDA1 and CDA2 proteins found in insects. Moreover, PmCDA1 is composed of a conserved chitin-binding peritrophin-A domain (CBD), a low-density lipoprotein receptor class A domain (LDL-A) and a catalytic domain that is part of CE4 superfamily, all found in group I CDAs, which are known to serve critical immune function against WSSV. Finally, high expression of PmCDA1 gene in the gills of apparently healthy P. monodon was observed suggesting important basal function of the gene in this tissue. Taken together, this is a first report of the full chitin deacetylase 1 (CDA1) gene in crustaceans particularly in shrimp that exhibits putative immune function against WSSV and is distinctly highly expressed in the gills of shrimp

Quorum quenching activity of lysates from bioluminescent bacteria isolated from selected Philippine marine and freshwater organisms

Pathogens use cell density dependent gene expression known as Quorum Sensing (QS) to launch virulent factors. Targeting the QS circuit without killing the pathogens is a very promising alternative to using antibiotics which generate antibiotic resistance. The identity and diversity of bioluminescent bacteria associated with Philippine aquatic organisms, and their potential as sources of anti-QS or quorum quenching (QQ) molecules remain unknown. In this study, out of 43 organisms, 30 were observed to harbor bioluminescent bacteria with 26 from marine and four from freshwater sources. Purified bioluminescent bacterial cultures were screened for QQ activity using motility assay and the membrane fractions (MF) of 5 isolates from marine organisms namely Johnius sp. (croaker), Sillago sp. (golden-lined sillago), Variola louti (yellow-edged lyretail), Strombus variabilis (variable conch), Cistopus indicus (octopus), and one from a freshwater host, Chanos chanos (milkfish), inhibited the QS-mediated swarming of Pseudomonas aeruginosa strain NSRI based on statistical analysis using Paired t-test and Univariate Analysis of Variance (p \u3c 0.05). Despite the host differences, the bacterial isolates shared evolutionary relationship with commonly known bioluminescent genera based on 16S rRNA gene sequence analysis with five strains belonging to the genus Photobacterium (P. leiognathi and P. mandapamensis, 99-100% identity), and two to the genus Vibrio (V. harveyi and V. campbellii, with 99% identity)

Profile of Salinity, Temperature, Heavy Metal (Pb, Cd, Hg) and Sediment Hydrogen Sulfide Concentration of Manila Bay, Philippines from 2012 to 2015

The physical parameters of seawater are important determinants of water quality. Heavy metals are components that are naturally present in a considerable amount in the ocean but are observed to be rising above the allowable level due to pollution outputs of industrialization. Heavy metal contamination is among the environmental pollution problems that the world faces. Additionally, hydrogen sulfide (H2S) is also a toxic compound that accumulates in the ocean floor posing threat to the marine organisms when present in high concentrations. The objective of this study is to document the distribution of temperature and salinity in the water column, heavy metals (Pb, Cd, Hg) and sediment H2S in Manila Bay from 2012 to 2015. Stratification in the bay was generally a factor of salinity and less of temperature. Stratification due to salinity was consistently observed in September with the halocline occurring around 10 m to 15 m. Most of the time, the bay had evenly distributed temperatures, but the slightly higher temperatures were usually recorded near the coast. Inverse trends were observed for the salinity and temperature of the bay. Pb, Cd, and Hg concentrations in the bay occasionally exceeded the permissible limits especially the lead concentration in January 2013 (ave: 809.81 µg/L), March 2013 (ave: 1102.88 µg/L) and November 2015 (1507.50 µg/L). Cd and Hg concentrations were generally below the permissible limit and the reported limit of analysis. H2S concentration ranged from < 4 mg/kg to 9.99 mg/kg for all the survey months. Distribution was higher in the northwestern part and southeastern areas of the bay