Age Determination and Body Length Relationship of Two-Spot Red Snapper (Lutjanus bohar)

Otolith study on fifty two-spot red snappers (Lutjanus bohar) in the Davao Gulf, Philippines, was conducted to describe their growth pattern, determine the age structure, and estimate their age at sexual maturity. Samples were obtained from Toril and Bankerohan Public Markets in Davao from Februay to June 2015. Fish morphometrics, otolith extraction, and age determination followed. Length-weight relationship showed that L. bohar follows isometric growth pattern (b = 3.0015). Somatic and otolith morphometrics gave significant correlations where otolith length and total length relationship had the highest R2 value (R2= 0.9382). Out of the samples, twenty-one of the sagittal otoliths ranges from three to seven years old. The parameters obtained from the age-at-length data fitted to von Bertalanffy growth function were K = 0.81 and L∞ = 28.9 cm, with estimated age at maturity of six years old. The growth performance index (φ = 2.83) revealed that L. bohar in Davao Gulf has a faster growth rate. Faster growth rate leading to earlier maturity and smaller size-at-maturity may indicate the effects of environmental factors and fishing pressure to slow-growing fishes. We recommend studying the population ecology of L. bohar in Davao Gulf and considering a larger sample size in future researches

Spatio-temporal Distribution and Abundance of Crown-of-Thorns Starfish (Acanthaster planci L.) in Three Marine Protected Areas (MPAs) around the Island Garden City of Samal, Philippines

The spatial and temporal distribution of crown-of-thorns starfish or COTS (Acanthaster planci L.) was investigated in three marine protected areas (MPAs) around the Island Garden City of Samal (IGaCoS), Philippines, from December 2008 to December 2009. Methods include photo quadrat for the live coral cover and belt transect for the density of COTS and its predators. There was a significant difference in the spatial distribution of COTS among MPAs. Sanipaan Marine Park (SMP) had the highest COTS density while Coral Garden and Aundanao MPAs had the least. Variability of COTS density was attributed to percent coral cover and human intervention (i.e., COTS clean-up drive). At temporal scale, only data from SMP fitted for the analysis. There was no significant difference observed during the sampling periods conducted in April, August, and November 2009. The results suggest longer time of monitoring to cover the life span of COTS, taking into consideration  the probable causes for infestation, whether anthropogenic (i.e., harvesting leading to mass spawning) or natural. In conclusion, the spatial distribution of COTS depends on the abundance of their preferred food while the temporal distribution is probably influenced by environmental conditions over time

Measuring the Economic Impact of Weather Determinants on Aquaculture in the Davao Region, Philippines

Aquaculture is an important determinant of economic growth in the Davao Region in the Southern Philippines because it contributes towards increasing employment and agribusiness development opportunities. However, the industry faces various issues that affect farm productivity. One of these challenges pertains to welfare effects emanating from changing patterns of weather variables. Hence, this research aimed to measure the impact of weather determinants on aquaculture production’s net income based on surveyed farms in the Davao Region. Based on the Ricardian approach, our econometric model specifies the dependent variable as net income (PhP/ha) and this is a function of weather variables such as precipitation, humidity, and agro-climatic and socio-demographic variables. From the results, weather and agro-climatic variability have statistically significant effects on aquaculture’s net income. More specifically, a unit increase in the standard deviation of rain value increases net income by PhP12,730. However, an increase in one standard deviation of average air humidity decreased net income by approximately PhP2,940. Finally, unit increases in the standard deviation of soil moisture and soil temperature translate to increases in net income by approximately PhP16,150 and PhP16,170. Thus, given the results, strategies that would enable aquaculture farmers to mitigate and adapt to changing weather conditions should be implemented. Also, weather stations should be updated and upgraded in order to provide accurate readings and forecasts so that aquaculture farmers’ decision making will be improved with regards to their farm practices

Functional, size and taxonomic diversity of fish along a depth gradient in the deep sea

Biodiversity is well studied in ecology and the concept has been developed to include traits of species, rather than solely taxonomy, to better reflect the functional diversity of a system. The deep sea provides a natural environmental gradient within which to study changes in different diversity metrics, but traits of deep-sea fish are not widely known, hampering the application of functional diversity to this globally important system. We used morphological traits to determine the functional richness and functional divergence of demersal fish assemblages along the continental slope in the Northeast Atlantic, at depths of 300–2,000 m. We compared these metrics to size diversity based on individual body size and species richness. Functional richness and size diversity showed similar patterns, with the highest diversity at intermediate depths; functional divergence showed the opposite pattern, with the highest values at the shallowest and deepest parts of the study site. Species richness increased with depth. The functional implications of these patterns were deduced by examining depth-related changes in morphological traits and the dominance of feeding guilds as illustrated by stable isotope analyses. The patterns in diversity and the variation in certain morphological traits can potentially be explained by changes in the relative dominance of pelagic and benthic feeding guilds. All measures of diversity examined here suggest that the deep areas of the continental slope may be equally or more diverse than assemblages just beyond the continental shelf

Urban coral reefs: Degradation and resilience of hard coral assemblages in coastal cities of East and Southeast Asia

© 2018 The Author(s) Given predicted increases in urbanization in tropical and subtropical regions, understanding the processes shaping urban coral reefs may be essential for anticipating future conservation challenges. We used a case study approach to identify unifying patterns of urban coral reefs and clarify the effects of urbanization on hard coral assemblages. Data were compiled from 11 cities throughout East and Southeast Asia, with particular focus on Singapore, Jakarta, Hong Kong, and Naha (Okinawa). Our review highlights several key characteristics of urban coral reefs, including “reef compression” (a decline in bathymetric range with increasing turbidity and decreasing water clarity over time and relative to shore), dominance by domed coral growth forms and low reef complexity, variable city-specific inshore-offshore gradients, early declines in coral cover with recent fluctuating periods of acute impacts and rapid recovery, and colonization of urban infrastructure by hard corals. We present hypotheses for urban reef community dynamics and discuss potential of ecological engineering for corals in urban areas

The moderating role of perceived teacher expectation and academic self-concept in the relationship between athletic status and academic performance

The main objective of the study was to determine the effect of perceived teacher expectation and academic self-concept to the academic performance of the student. Students academic performance is being affected by several factors. Several studies revealed that perceived teacher expectation and self-concept are factors that can affect the performance of students academically. Teachers play a vital role in making their students perform better in class. However, the students themselves can greatly influence their academic performance through their self-concept. This study utilized predictive cross-sectional quantitative research design. Two hundred (200) college students of De La Salle University were the participants of this study. The proponents used hierarchical linear regression in order to answer the research questions. The conclusion was that student athletes perform less that non-student-athletes. Perceived teacher expectation found to be significant in explaining the academic performance. When perceived teacher expectation is low, student athletes perform less that non-student-athletes in academics. Academic self-concept also found to be significant in explaining the academic performance. Interestingly, the result revealed that when academic self-concept is high, student-athletes still perform poorly in academics

Changes in the fish diversity and abundance on a heavily fished fringing reef on Santiago Island, Pangasinan, Philippines

Fish assemblages on the reef slope, reef flat, and seagrass beds on Santiago Island were sampled over 18 months in 1992-1993 as part of a 6-year reef monitoring project started in 1986. Abundance and species diversity were analyzed by a variety of indices, and by multi-dimensional scaling and correlated ordered similarity matrix. The monitoring showed a distinct shift in the reef slope fish composition during the first half of 1988. Of the 100 most abundant species, 21 species showed significant reductions in abundance, and 20 species showed significant increases. Differences were not due to depth preference or feeding habits. Fishing pressure was apparently responsible for declines in Cheilinus trilobatus, Acanthurus nigricauda, and Naso literatus, as well as a general decline in the family Acanthuridae (surgeonfishes). However, analysis of site preferences of the decreasing species and the increasing species indicated a shift in community composition from those species preferring more coral cover to those preferring more sand, rock, and possibly Sargassum seaweed. Site preferences were determined from benthic life form transects done in 1992. Of 35 significantly changing species for which habitat data was obtained, 24 fit the hypothesis of habitat change. This supports the proposition from previous studies that the major cause of change in the reef slope fish community was the destructive fishing activity associated with Malthusian overfishing. Similar analyses of the fish assemblages on the reef flat and on the seagrass beds showed seasonal effects, particularly in the latter, but no strong shift comparable to that of the reef slope. These latter areas had been subjected to greater fishing pressure for a longer period. Reef fish populations such as those in Bolinao tend to be highly resilient provided the larval supply is not adversely affected. However, subtle changes in the cover of coral on a reef can lead to major changes in the composition of the fish community. Coral cover is being widely diminished on Philippine reefs, and substantial changes in the fish communities may be anticipated, even on reefs with initially low coral cover. These changes may affect the utility and immediate value of the fish to local fishers and the market systems they supply. It is of great urgency to stop destructive fishing practices such as blasting and use of cyanide, and to develop anchoring methods that are minimally destructive. There is a strong predictive relation between the numbers of fish (abundance) in an area and the numbers of species (biodiversity) they include. As fish populations decline due to destructive fishing, or highly concentrated non-destructive fishing, the local species richness may be expected to decline. This decline may have serious short-term social and economic consequences, as well as far-reaching long-term environmental effects. Efforts to reduce overfishing must be intensified—though reduction of birth rate, provision of alternative livelihoods, and curbing of destructive fishing — in order to prevent a very distressing future for the Philippine marine environment and the people it supports

Priority reef areas in the Pacific Coast of the Philippines for marine protected area deployment

The present paper seeks to provide a scientific basis for the establishment of marine protected areas (MPA) through an integrated and objective analysis of biodiversity survey data, which permits ranking of various sites in order of their importance as potential MPA. The approach proposed here involves the determination of biodiversity values for each of the four taxonomic groups (corals, reef fishes, seagrasses and seaweeds) and an assessment of the levels of risk for each of the survey sites to human degradation and natural disturbance. The biodiversity and risk scores were then combined into one MPA priority score using a conversion table. Five of the 17 geographic units (mostly small islands) stand out as high priority sites for conservation: Biri in Northern Samar; Ticao and Palaguigue Islands in Masbate; Pujada Bay, Davao Oriental; Homonhon and Suluan Islands, Eastern Samar; and Laoang, Northern Samar. The approach described here provides a framework by which an objective, repeatable prioritization of conservation value of various areas could be undertaken. Although the final measures are not absolute, it allows one to make explicit the assumptions made about the characters and measures used in prioritization and assign relative weights to various species, taxonomic groups and data sets, thereby reducing the impact of an observer\u27s subjectivity

DNA barcoding of marine teleost fishes (Teleostei) in Cebu, the Philippines, a biodiversity hotspot of the coral triangle

Abstract A morphology-based barcoding library of market teleost fishes (Teleostei) in Cebu is built based on cytochrome c oxidase subunit I (COI) sequences and voucher specimens which aimed to establish a reliable reference of frequently traded fishes in the province, a biodiversity hotspot at the center of the Philippine archipelago. A total of 1721 specimens were collected from 18 fish markets and landing sites around the province, in which 538 specimens were sequenced belonging to 393 species from 229 genera, 86 families, and 37 orders. Most speciose families are coral reef or reef-related shallow-water species. Twelve species from 11 families are newly recorded in the Philippine waters, among which 7 species are deep-sea inhabitants, while 3 species have expanded their distribution range. Only 20 taxa could not be identified to the species level due to the difficulty in morphological examinations, absence of matched reference sequences in online databases, and/or problematic species awaiting further studies. This first comprehensive DNA barcoding survey of Cebu fishes can facilitate further taxonomic research as well as the conservation and management of fisheries in the Philippines