23 results on '"Li-Lee Chew"'
Search Results
2. Response of marine copepods to a changing tropical environment: winners, losers and implications
- Author
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Li Lee Chew and Ving Ching Chong
- Subjects
Coastal developments ,Straits of Malacca ,Man-induced effects ,Zooplankton ,Biodiversity ,Species vulnerability ,Medicine ,Biology (General) ,QH301-705.5 - Abstract
Background. Climate change concurrent with anthropogenic disturbances can initiate serial changes that reverberate up the food chain with repercussions for fisheries. To date, there is no information available concerning the combined effects of global warming and human impacts on tropical marine food webs. While temperate copepods respond differently to warming and environmental stressors, the extent to which tropical copepods can adapt to rising temperature of already warm waters remains unknown. We hypothesize that sea warming and other anthropogenic disturbances over the long term will have the greatest impact on the copepod community in nearshore waters where their effects are accentuated, and therefore vulnerable and resilient species could be identified. Methods. Zooplankton samples were collected during two time periods (1985–86 and 2014–15) interposed by marked anthropogenic disturbances, and at the same five stations located progressively from inshore to offshore in Klang Strait, Malaysia, following the asymmetrical before-after-control-impact (BACI) design. Copepods were identified to species, and results were interpreted by univariate (ANOVA) and multivariate (PERMANOVA, PCO) analyses of the computed species abundance and diversity measures. Results. Copepod total abundance was not significantly different among stations but higher after disturbance than before disturbance. However, changes in the abundance of particular species and the community structure between time periods were dramatic. Coastal large-bodied calanoid species (e.g., Acartia spinicauda, Calanopia thompsoni, Pseudodiaptomus bowmani and Tortanus forcipatus) were the most vulnerable group to disturbance. This however favored the opportunistic species (e.g., Oithona simplex, O. attenuata, Hemicyclops sp., Pseudomacrochiron sp. and Microsetella norvegica). Small-bodied copepods (e.g., Paracalanus sp., Parvocalanus crassirostris and Euterpina acutifrons) were unaffected. Centropages tenuiremis was likely an introduced species. There was no significant loss in species richness of copepods despite the dramatic changes in community structure. Discussion. Sea warming and other human-induced effects such as eutrophication, acidification and coastal habitat degradation are likely the main factors that have altered copepod community structure. The large-bodied estuarine and coastal calanoid copepods are surmised to be vulnerable to eutrophication and hypoxia, while both resilient and opportunistic species are largely unaffected by, or adaptable to, degraded coastal environments and observed sea surface temperature (SST) rise. It is forecasted that SST rise with unmitigated anthropogenic impacts will further reduce large-bodied copepod species the favoured food for fish larvae with dire consequences for coastal fish production.
- Published
- 2016
- Full Text
- View/download PDF
3. Corrigendum to 'Examination of barnacles’ potential to be used as bioindicators of persistent organic pollutants in coastal ecosystem: A Malaysia case study' [Chemosphere 263 (2021) 128272]
- Author
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Li Lee Chew, Hong Wooi Teoh, Mohamad Pauzi Zakaria, Nguyen Minh Tue, Fook Choy Yap, Gan Zhang, Choon Weng Lee, Vahab Vaezzadeh, Tatsuya Kunisue, Yang Amri Affendi, Chui Wei Bong, and Margaret William Thomes
- Subjects
Pollutant ,Environmental Engineering ,Ecology ,Coastal ecosystem ,Health, Toxicology and Mutagenesis ,Public Health, Environmental and Occupational Health ,Environmental science ,Environmental Chemistry ,General Medicine ,General Chemistry ,Bioindicator ,Pollution - Published
- 2022
4. The role of microzooplankton grazing in the microbial food web of a tropical mangrove estuary
- Author
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Yu Lin Yong, Choon Weng Lee, Chui Wei Bong, Li Lee Chew, and Ving Ching Chong
- Subjects
Aquatic Science ,Oceanography - Published
- 2022
5. Carbon stock of disturbed and undisturbed mangrove ecosystems in Klang Straits, Malaysia
- Author
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Guangcheng Chen, Shunyang Chen, Hong Wooi Teoh, RozainahMohamad Zakaria, Li Lee Chew, Ahmad Bakrin Sofawi, Heng Hing Moh, and S.Y.S.N. Adibah
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Total organic carbon ,chemistry.chemical_classification ,Hydrology ,chemistry.chemical_element ,Biomass ,Soil carbon ,Aquatic Science ,Oceanography ,Isotopic signature ,chemistry ,Isotopes of carbon ,Environmental science ,Organic matter ,Mangrove ,Carbon ,Ecology, Evolution, Behavior and Systematics - Abstract
Ecosystem carbon stocks were compared in three island mangrove forests, subjected to different anthropogenic stresses, close to Port Klang in Selangor State on the west coast of Peninsular Malaysia. Carbon stocks in living biomass, litter, deadwood and soil were quantified, and the carbon isotopic signature in mangrove soils was also measured, to estimate their carbon source. We hypothesize that carbon stock would be more readily available in undisturbed mangroves. The results indicated that, in general, soil organic carbon pool comprised the majority of the ecosystem carbon stock, while dead organic matter made a negligible contribution. The highest ecosystem carbon stock was measured in the permanent undisturbed mangrove reserve on Pulau Klang. Carbon isotope data revealed that disturbed mangroves in Pulau Ketam had a more enriched δ13C signature of soil samples compared to the other two sites. The soil organic carbon in Pulau Ketam was mostly derived from mangrove materials (92.8%). The results suggested that the organic carbon accumulated in the soils was not only regulated by the burial of mangrove-derived organic carbon, but also the site conditions.
- Published
- 2021
6. Automated identification of copepods using digital image processing and artificial neural network.
- Author
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Lee Kien Leow, Li-Lee Chew, Ving Ching Chong, and Sarinder Kaur Dhillon
- Published
- 2015
- Full Text
- View/download PDF
7. Effect of coastal development on larval fish abundance in Klang Strait (Malaysia)
- Author
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Li Lee Chew, Ving Ching Chong, Ching Ching Ng, Kar-Hoe Loh, Cecilia Chu, and Ai Lin Ooi
- Subjects
0106 biological sciences ,Larva ,010504 meteorology & atmospheric sciences ,Ecology ,010604 marine biology & hydrobiology ,Aquatic Science ,Ichthyoplankton ,Biology ,Sciaenidae ,biology.organism_classification ,01 natural sciences ,Fishery ,Sea surface temperature ,Taxon ,Clupeidae ,Abundance (ecology) ,Animal Science and Zoology ,Transect ,Ecology, Evolution, Behavior and Systematics ,0105 earth and related environmental sciences - Abstract
Changes in larval fish assemblages were studied before (1985–86) and after (2013–2014) rapid coastal development in the Klang Strait, Malaysia, based on a Before-After-Control-Impact (BACI) experimental design. Fish larvae were sampled by bongo-nets along an 18-km transect from the impact station at the Kapar power station (KPS) to four control stations in increasingly offshore waters. Families Gobiidae, Clupeidae, Sciaenidae and Engraulidae were most abundant at both sampling periods, demonstrating their adaptability and resilience to the natural and anthropogenic disturbances. Coastal development has reduced larval fish abundance at KPS, inevitably shifting higher larval abundance to the control stations. This shift is related to lower sea surface temperature and higher pH. Despite the coastal disturbances, there was an overall increase in total larval fish abundance attributed to the preflexion stage of the Gobiidae, Sciaenidae, Engraulidae, Cynoglossidae and Callionymidae, and the yolk-sac and preflexion larvae of unidentified taxa.
- Published
- 2021
8. Respiration rates of the copepodPseudodiaptomus annandaleiin tropical waters: beyond the thermal optimum
- Author
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Li Lee Chew, Siok Mei Ting, Pascal Lehette, and Ving Ching Chong
- Subjects
0106 biological sciences ,Ecology ,biology ,010604 marine biology & hydrobiology ,Aquatic Science ,biology.organism_classification ,010603 evolutionary biology ,01 natural sciences ,Tropical waters ,Oceanography ,Pseudodiaptomus annandalei ,Respiration ,Ecology, Evolution, Behavior and Systematics ,Copepod - Published
- 2016
9. Heat shock response and metabolic stress in the tropical estuarine copepod Pseudodiaptomus annandalei converge at its upper thermal optimum
- Author
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Joyce Siew Yong Low, Pascal Lehette, Li Lee Chew, Ving Ching Chong, Ching Ching Ng, and Hao Chin Goh
- Subjects
0106 biological sciences ,0301 basic medicine ,Physiology ,Acclimatization ,01 natural sciences ,Biochemistry ,Copepoda ,03 medical and health sciences ,Animal science ,Stress, Physiological ,Heat shock protein ,Respiration ,Animals ,HSP70 Heat-Shock Proteins ,HSP90 Heat-Shock Proteins ,RNA, Messenger ,Heat shock ,Calanoida ,Tropical Climate ,biology ,Chemistry ,010604 marine biology & hydrobiology ,Temperature ,biology.organism_classification ,Hsp70 ,Salinity ,030104 developmental biology ,General Agricultural and Biological Sciences ,Estuaries ,Copepod ,Heat-Shock Response ,Developmental Biology - Abstract
Heat shock response (HSR), in terms of transcription regulation of two heat shock proteins genes hsp70 and hsp90), was analysed in a widespread tropical copepod Pseudodiaptomus annandalei. The mRNA transcripts of both genes were quantified after copepods at a salinity of 20 underwent an acclimation process involving an initial acclimation temperature of 29 °C, followed by gradual thermal ramping to the target exposure temperature range of 24-36 °C. The respective cellular HSR and organismal metabolism, measured by respiratory activity at exposure temperatures, were compared. The fold change in mRNA expression for both hsp70 and hsp90 (8-9 fold) peaks at 32 °C, which is very close to 32.4 °C, the upper thermal optimum for respiration in the species. Unexpectedly, the modelled HSR curves peak at only 3 °C (hsp90) and 3.5 °C (hsp70) above the mean water temperature (29.32 °C) of the copepod in the field. We propose that copepods in tropical waters adopt a preparative HSR strategy, early at the upper limit of its thermal optimum, due to the narrow thermal range of its habitat thus precluding substantial energy demand at higher temperatures. However, the model suggests that the species could survive to at least 36 °C with short acclimation time. Nevertheless, the significant overlap between its thermal range of hsp synthesis and the narrow temperature range of its habitat also suggests that any unprecedented rise in sea temperature would have a detrimental effect on the species.
- Published
- 2018
10. WITHDRAWN: Heat shock response and metabolic stress in the tropical estuarine copepod Pseudodiaptomus annandalei converge at its upper thermal optimum
- Author
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Joyce S.Y. Low, Li Lee Chew, Ching Ching Ng, Hao Chin Goh, Pascal Lehette, and Ving Ching Chong
- Subjects
0106 biological sciences ,0301 basic medicine ,03 medical and health sciences ,030104 developmental biology ,Physiology ,010604 marine biology & hydrobiology ,General Agricultural and Biological Sciences ,01 natural sciences ,Biochemistry ,Developmental Biology - Published
- 2017
11. Vertical migration and positioning behavior of copepods in a mangrove estuary: Interactions between tidal, diel light and lunar cycles
- Author
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Ving Ching Chong, A. Sasekumar, Li Lee Chew, and Ai Lin Ooi
- Subjects
geography ,geography.geographical_feature_category ,Ecology ,Estuary ,Euryhaline ,Aquatic Science ,Biology ,Nocturnal ,Oceanography ,biology.organism_classification ,Zooplankton ,Water column ,Diel vertical migration ,Stenohaline ,Copepod - Abstract
Two-hourly zooplankton samplings encompassing tidal (semi-diurnal), diel (24 h), and lunar (4 phases) cycles during the dry (July 2003) and wet (November 2003) monsoon periods were conducted in the Matang estuary to investigate the vertical distribution and behavior of five different groups of copepods (estuarine, euryhaline, marine euryhaline, stenohaline and nocturnal pontellids) in response to the tidal and light regime. Diel vertical migration (DVM) was evident for all copepod groups but the observed patterns differed among species and sampling period (wet or dry and neap or spring tide). Tidally-induced vertical migration (TVM), superimposed by DVM, was observed for estuarine, marine euryhaline and stenohaline copepods but not for euryhaline and nocturnal pontellid copepods. Estuarine copepods tended to ascend during night-flood tide and descent to the bottom during day-ebb tide; this suggests a selective mechanism to penetrate upstream and maintain position in the estuary. In contrast, the marine euryhaline and stenohaline copepods remained at the bottom especially during day-flood tide and ascended into the water column during night-ebb tide; this suggests a selective mechanism to avoid upstream transport. Euryhaline copepods did not respond to tidal advection probably due to their wide range of salinity tolerance, while the large nocturnal pontellid copepods have strong swimming ability. Adaptive vertical migration appears to be a major factor structuring the copepod community in tropical estuaries, and its occurrence in most copepods suggests that neritic marine zooplankton tidally-advected into estuaries and nearshore waters can survive better than previously thought.
- Published
- 2015
12. Detection of multiple potentially pathogenic bacteria in Matang mangrove estuaries, Malaysia
- Author
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Aziz Ghaderpour, Li Lee Chew, Kwai Lin Thong, Lay Ching Chai, Khairul Nazrin Mohd Nasori, and Ving Ching Chong
- Subjects
Pollution ,media_common.quotation_subject ,Indicator bacteria ,Aquatic Science ,Biology ,Oceanography ,medicine.disease_cause ,Feces ,Aquaculture ,Water Quality ,Escherichia coli ,medicine ,Humans ,media_common ,geography ,geography.geographical_feature_category ,Bacteria ,Brackish water ,business.industry ,Ecology ,Malaysia ,Estuary ,Pathogenic bacteria ,Culture Media ,Chromogenic Compounds ,Wetlands ,Mangrove ,Estuaries ,Water Microbiology ,business ,Surface water ,Enterococcus - Abstract
The deltaic estuarine system of the Matang Mangrove Forest Reserve of Malaysia is a site where several human settlements and brackish water aquaculture have been established. Here, we evaluated the level of fecal indicator bacteria (FIB) and the presence of potentially pathogenic bacteria in the surface water and sediments. Higher levels of FIB were detected at downstream sampling sites from the fishing village, indicating it as a possible source of anthropogenic pollution to the estuary. Enterococci levels in the estuarine sediments were higher than in the surface water, while total coliforms and E. coli in the estuarine sediments were not detected in all samples. Also, various types of potentially pathogenic bacteria, including Klebsiella pneumoniae, Serratia marcescens and Enterobacter cloacae were isolated. The results indicate that the Matang estuarine system is contaminated with various types of potential human bacterial pathogens which might pose a health risk to the public.
- Published
- 2014
13. Phytoplankton fuel the energy flow from zooplankton to small nekton in turbid mangrove waters
- Author
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A. Sasekumar, Ving Ching Chong, K. Tanaka, and Li Lee Chew
- Subjects
Ecology ,Nekton ,Seston ,Juvenile fish ,Aquatic Science ,Zooplankton ,Food web ,Oceanography ,Benthic zone ,Phytoplankton ,Environmental science ,Ecology, Evolution, Behavior and Systematics ,Trophic level - Abstract
Fish, zooplankton, seston, benthic microalgae and mangrove leaves were examined to investigate the trophic role of zooplankton in the food web of Matang estuaries. Despite the high turbidity and large amounts of detrital material in the water column, the study reveals that phytoplankton fuel the energy flow to zooplankton and small nekton in mangrove-fringed estuaries. The stable carbon isotope (δ13C) values and C/N ratios (7.2 to 8.2) of fine seston (
- Published
- 2012
14. Response of marine copepods to a changing tropical environment: winners, losers and implications
- Author
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Ving Ching Chong and Li Lee Chew
- Subjects
0106 biological sciences ,010504 meteorology & atmospheric sciences ,Coastal fish ,lcsh:Medicine ,Species vulnerability ,Introduced species ,Marine Biology ,01 natural sciences ,Zooplankton ,General Biochemistry, Genetics and Molecular Biology ,Abundance (ecology) ,Straits of Malacca ,Relative species abundance ,0105 earth and related environmental sciences ,Man-induced effects ,biology ,Ecology ,010604 marine biology & hydrobiology ,General Neuroscience ,lcsh:R ,Food webs ,General Medicine ,Biodiversity ,biology.organism_classification ,Fishery ,Habitat destruction ,Coastal developments ,Aquaculture, Fisheries and Fish Science ,Species richness ,General Agricultural and Biological Sciences ,Copepod ,Environmental Sciences - Abstract
Background.Climate change concurrent with anthropogenic disturbances can initiate serial changes that reverberate up the food chain with repercussions for fisheries. To date, there is no information available concerning the combined effects of global warming and human impacts on tropical marine food webs. While temperate copepods respond differently to warming and environmental stressors, the extent to which tropical copepods can adapt to rising temperature of already warm waters remains unknown. We hypothesize that sea warming and other anthropogenic disturbances over the long term will have the greatest impact on the copepod community in nearshore waters where their effects are accentuated, and therefore vulnerable and resilient species could be identified.Methods.Zooplankton samples were collected during two time periods (1985–86 and 2014–15) interposed by marked anthropogenic disturbances, and at the same five stations located progressively from inshore to offshore in Klang Strait, Malaysia, following the asymmetrical before-after-control-impact (BACI) design. Copepods were identified to species, and results were interpreted by univariate (ANOVA) and multivariate (PERMANOVA, PCO) analyses of the computed species abundance and diversity measures.Results.Copepod total abundance was not significantly different among stations but higher after disturbance than before disturbance. However, changes in the abundance of particular species and the community structure between time periods were dramatic. Coastal large-bodied calanoid species (e.g.,Acartia spinicauda,Calanopia thompsoni,Pseudodiaptomus bowmaniandTortanus forcipatus) were the most vulnerable group to disturbance. This however favored the opportunistic species (e.g.,Oithona simplex,O. attenuata,Hemicyclopssp.,Pseudomacrochironsp. andMicrosetella norvegica). Small-bodied copepods (e.g.,Paracalanussp.,Parvocalanus crassirostrisandEuterpina acutifrons) were unaffected.Centropages tenuiremiswas likely an introduced species. There was no significant loss in species richness of copepods despite the dramatic changes in community structure.Discussion.Sea warming and other human-induced effects such as eutrophication, acidification and coastal habitat degradation are likely the main factors that have altered copepod community structure. The large-bodied estuarine and coastal calanoid copepods are surmised to be vulnerable to eutrophication and hypoxia, while both resilient and opportunistic species are largely unaffected by, or adaptable to, degraded coastal environments and observed sea surface temperature (SST) rise. It is forecasted that SST rise with unmitigated anthropogenic impacts will further reduce large-bodied copepod species the favoured food for fish larvae with dire consequences for coastal fish production.
- Published
- 2016
15. Isolation and Characterization of Aquatic-Borne Klebsiella pneumoniae from Tropical Estuaries in Malaysia
- Author
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Li Lee Chew, Lay Ching Chai, Chui Wei Bong, Aziz Ghaderpour, Ving Ching Chong, Kwai Lin Thong, and Anis Barati
- Subjects
0301 basic medicine ,Geologic Sediments ,Klebsiella pneumoniae ,Health, Toxicology and Mutagenesis ,030106 microbiology ,virulence factors ,lcsh:Medicine ,Virulence ,Article ,Microbiology ,03 medical and health sciences ,Antibiotic resistance ,anthropogenic contamination ,aquatic ,antimicrobial resistance ,Drug Resistance, Bacterial ,Humans ,Tropical Climate ,geography ,geography.geographical_feature_category ,biology ,Aquatic ecosystem ,lcsh:R ,Malaysia ,Public Health, Environmental and Occupational Health ,Biofilm ,Estuary ,Isolation (microbiology) ,biology.organism_classification ,Hospitals ,Klebsiella Infections ,Community-Acquired Infections ,Mangrove ,Estuaries ,Water Microbiology - Abstract
Klebsiella pneumoniae is an opportunistic pathogen that is responsible for causing nosocomial and community-acquired infections. Despite its common presence in soil and aquatic environments, the virulence potential of K. pneumoniae isolates of environmental origin is largely unknown. Hence, in this study, K. pneumoniae isolated from the estuarine waters and sediments of the Matang mangrove estuary were screened for potential virulence characteristics: antibiotic susceptibility, morphotype on Congo red agar, biofilm formation, presence of exopolysaccharide and capsule, possession of virulence genes (fimH, magA, ugE, wabG and rmpA) and their genomic fingerprints. A total of 55 strains of K. pneumoniae were isolated from both human-distributed sites (located along Sangga Besar River) and control sites (located along Selinsing River) where less human activity was observed, indicated that K. pneumoniae is ubiquitous in the environment. However, the detection of potentially virulent strains at the downstream of Kuala Sepetang village has suggested an anthropogenic contamination source. In conclusion, the findings from this study indicate that the Matang mangrove estuary could harbor potentially pathogenic K. pneumoniae with risk to public health. More studies are required to compare the environmental K. pneumoniae strains with the community-acquired K. pneumoniae strains.
- Published
- 2016
- Full Text
- View/download PDF
16. Monsoonal and lunar variability in microzooplankton abundance and community structure in the Terusan mangrove creek (Malaysia)
- Author
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Yu Lin Yong, Ving Ching Chong, Choon Weng Lee, and Li Lee Chew
- Subjects
0106 biological sciences ,geography ,geography.geographical_feature_category ,010504 meteorology & atmospheric sciences ,Strombidiidae ,Ecology ,010604 marine biology & hydrobiology ,Community structure ,Estuary ,Aquatic Science ,Biology ,Oceanography ,Monsoon ,01 natural sciences ,Taxon ,Abundance (ecology) ,Phytoplankton ,Mangrove ,Ecology, Evolution, Behavior and Systematics ,0105 earth and related environmental sciences - Abstract
This study documents the monsoonal and lunar effects on species composition and abundance of microzooplankton in a tropical estuary. We investigated microzooplankton abundance in relation to the various environmental and biotic parameters, sampled in the Matang mangrove (Malaysia) from April 2013 to February 2014. A total of 39 microzooplankton taxa comprising four major groups, i.e. loricate ciliates (37.72%), aloricate ciliates (29.46%), dinoflagellates (24.33%) and meroplanktonic nauplii (8.49%) were identified. The loricate ciliates were the most diverse group with 31 taxa recorded. Four major species of loricate ciliates were identified, i.e. Tintinnopsis beroidea, Tintinnopsis rotundata, Stenosemella avellana and Tintinnidium primitivum, while Strombidiidae and Strobilidiidae dominated the aloricate ciliates. Although small loricate ciliates were ubiquitous, redundancy analysis shows marked shifts in microzooplankton community structure, from one that was dominated by loricate ciliates during the drier SW monsoon, to aloricate ciliates at the onset of the wet NE monsoon, and then to dinoflagellates towards the end of the drier NE monsoon period. These shifts were associated with rainfall, dissolved inorganic nutrients, salinity, temperature and microbial food abundance. There was no clear lunar effect on abundance of microzooplankton except for Favella ehrenbergii and copepod nauplii, which were more abundant during neap than spring tides.
- Published
- 2016
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17. Copepod community structure and abundance in a tropical mangrove estuary, with comparisons to coastal waters
- Author
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Li Lee Chew and Ving Ching Chong
- Subjects
geography ,geography.geographical_feature_category ,Ecology ,Species diversity ,Estuary ,Aquatic Science ,Biology ,biology.organism_classification ,Zooplankton ,Abundance (ecology) ,Phytoplankton ,Mangrove ,Acartia ,Copepod - Abstract
Zooplankton, sampled at five stations from the upper Sangga estuary (7 km upstream) in Matang Mangrove Forest Reserve (MMFR), Malaysia, to 16 km offshore, comprised more than 47% copepod. Copepod abundance was highest at nearshore waters (20,311 ind m−3), but decreased toward both upstream (15,572 ind m−3) and offshore waters (12,330 ind m−3). Copepod abundance was also higher during the wetter NE monsoon period as compared to the drier SW monsoon period, but vice versa for copepod species diversity. Redundancy analysis (RDA) shows that copepod community structure in the upper estuary, nearshore and offshore waters differed, being influenced by spatial and seasonal variations in environmental conditions. The copepods could generally be grouped into estuarine species (dominantly Acartia spinicauda Mori, Acartia sp1, Oithona aruensis Fruchtl, and Oithona dissimilis Lindberg), stenohaline species (Acartia erythraea Giesbrecht, Acrocalanus gibber Giesbrecht, Paracalanus aculateus Giesbrecht, and Corycaeus andrewsi Farran) and euryhaline species (Parvocalanus crassirostris Dahl, Oithona simplex Farran, and Bestiolina similis (Sewell)). Shifts in copepod community structure due to monsoonal effects on water parameters occurred at the lower estuary. Copepod peak abundance in mangrove waters could be associated with the peak chlorophyll a concentration prior to it. Evidence of copepod consumption by many species of young fish and shrimp larvae in the MMFR estuary implies the considerable impact of phytoplankton and microphytobenthos on mangrove trophodynamics.
- Published
- 2010
18. Three decades of sea water abstraction by Kapar power plant (Malaysia): What impacts on tropical zooplankton community?
- Author
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Ving Ching Chong, Richard C.S. Wong, Kar-Hoe Loh, Li Lee Chew, Ching Ching Ng, and Pascal Lehette
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Meroplankton ,Aquatic Science ,Biology ,Oceanography ,Zooplankton ,Crustacea ,Metals, Heavy ,Animals ,Seawater ,Polycyclic Aromatic Hydrocarbons ,Ecology ,fungi ,Community structure ,Fishes ,Malaysia ,Temperature ,Eutrophication ,Hydrogen-Ion Concentration ,biology.organism_classification ,Pollution ,Crustacean ,Sea surface temperature ,Water quality ,Microbial loop ,Water Pollutants, Chemical ,Environmental Monitoring ,Power Plants - Abstract
Zooplankton samples collected before (1985-86) and after (2013-14) the establishment of Kapar power station (KPS) were examined to test the hypothesis that increased sea surface temperature (SST) and other water quality changes have altered the zooplankton community structure. Elevated SST and reduced pH were detected between before and after impact pairs, with the greatest impact at the station closest to KPS. Present PAHs and heavy metal concentrations are unlikely causal factors. Water parameter changes did not affect diversity but community structure of the zooplankton. Tolerant small crustaceans, salps and larvaceans likely benefited from elevated temperature, reduced pH and shift to a more significant microbial loop exacerbated by eutrophication, while large crustaceans were more vulnerable to such changes. It is predicted that any further rise in SST will remove more large-bodied crustacean zooplankton, the preferred food for fish larvae and other meroplankton, with grave consequences to fishery production.
- Published
- 2015
19. Respiration rates of the copepod Pseudodiaptomus annandalei in tropical waters: beyond the thermal optimum.
- Author
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LEHETTE, PASCAL, SIOK MEI TING, LI-LEE CHEW, and VING CHING CHONG
- Subjects
COPEPODA physiology ,RESPIRATION ,TEMPERATURE effect ,BODY mass index ,ACCLIMATIZATION ,PLANKTON - Abstract
We investigated the effects of temperature on weight-specific respiration rates (R
sp ) of the euryhaline calanoid copepod Pseudodiaptomus annandalei collected from the Matang Mangrove Forest Reserve (Malaysia). We employed a simple experimental approach consisting of a short temperature exposure time from 24 to 36°C. The relationship between temperature and Rsp of acclimated copepods under conditions of excess food fitted an exponential function and indicated a complete lack of acclimation at the higher temperature range. Both fine-scale temperature measurements and piecewise linear regression enabled the detection of a breakpoint produced by a significant increase in respiratory rates. It is argued that thermally stressed copepods can be detected by both a higher Q10 above 32°C and monitoring this breakpoint in the metabolic response (Rsp ). Similarly, the lower Q10 (⩽2) indicates some degree of independence of their metabolic rates between 26 and 32°C, which likely corresponds to their optimal thermal window. Results are discussed in relation to body mass, feeding status and gender. [ABSTRACT FROM AUTHOR]- Published
- 2016
- Full Text
- View/download PDF
20. Isolation and Characterization of Aquatic-Borne Klebsiella pneumoniae from Tropical Estuaries in Malaysia.
- Author
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Barati, Anis, Ghaderpour, Aziz, Li Lee Chew, Chui Wei Bong, Kwai Lin Thong, Ving Ching Chong, and Lay Ching Chai
- Published
- 2016
- Full Text
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21. Diverse and abundant multi-drug resistant E. coli in Matang mangrove estuaries, Malaysia.
- Author
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Ghaderpour, Aziz, Wing Sze Ho, Li-Lee Chew, Chui Wei Bong, Ving Ching Chong, Kwai-Lin Thong, and Lay Ching Chai
- Subjects
ESCHERICHIA coli ,ESTUARIES ,MULTIDRUG resistance - Abstract
E.coli, an important vector distributing antimicrobial resistance in the environment, was found to be multi-drug resistant, abundant, and genetically diverse in the Matang mangrove estuaries, Malaysia. One-third (34%) of the estuarine E. coli was multi-drug resistant. The highest antibiotic resistance prevalence was observed for aminoglycosides (83%) and beta-lactams (37%). Phylogenetic groups A and B1, being the most predominant E. coli, demonstrated the highest antibiotic resistant level and prevalence of integrons (integron I, 21%; integron II, 3%). Detection of phylogenetic group B2
3 downstream of fishing villages indicates human fecal contamination as a source of E. coli pollution. Enteroaggregative E. coli (1%) were also detected immediately downstream of the fishing village. The results indicated multi-drug resistance among E. coli circulating in Matang estuaries, which could be reflective of anthropogenic activities and aggravated by bacterial and antibiotic discharges from village lack of a sewerage system, aquaculture farms and upstream animal husbandry. [ABSTRACT FROM AUTHOR]- Published
- 2015
- Full Text
- View/download PDF
22. Copepod community structure and abundance in a tropical mangrove estuary, with comparisons to coastal waters.
- Author
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Li-Lee Chew and Chong, V. C.
- Subjects
- *
COPEPODA , *MANGROVE plants , *MANGROVE ecology , *INTRACOASTAL waterways , *ZOOPLANKTON - Abstract
Zooplankton, sampled at five stations from the upper Sangga estuary (7 km upstream) in Matang Mangrove Forest Reserve (MMFR), Malaysia, to 16 km offshore, comprised more than 47% copepod. Copepod abundance was highest at nearshore waters (20,311 ind m), but decreased toward both upstream (15,572 ind m) and offshore waters (12,330 ind m). Copepod abundance was also higher during the wetter NE monsoon period as compared to the drier SW monsoon period, but vice versa for copepod species diversity. Redundancy analysis (RDA) shows that copepod community structure in the upper estuary, nearshore and offshore waters differed, being influenced by spatial and seasonal variations in environmental conditions. The copepods could generally be grouped into estuarine species (dominantly Acartia spinicauda Mori, Acartia sp1, Oithona aruensis Früchtl, and Oithona dissimilis Lindberg), stenohaline species ( Acartia erythraea Giesbrecht, Acrocalanus gibber Giesbrecht, Paracalanus aculateus Giesbrecht, and Corycaeus andrewsi Farran) and euryhaline species ( Parvocalanus crassirostris Dahl, Oithona simplex Farran, and Bestiolina similis (Sewell)). Shifts in copepod community structure due to monsoonal effects on water parameters occurred at the lower estuary. Copepod peak abundance in mangrove waters could be associated with the peak chlorophyll a concentration prior to it. Evidence of copepod consumption by many species of young fish and shrimp larvae in the MMFR estuary implies the considerable impact of phytoplankton and microphytobenthos on mangrove trophodynamics. [ABSTRACT FROM AUTHOR]
- Published
- 2011
- Full Text
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23. Automated identification of copepods using digital image processing and artificial neural network
- Author
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Lee Kien Leow, Ving Ching Chong, Li Lee Chew, and Sarinder Kaur Dhillon
- Subjects
Artificial Neural Network ,copepods ,Databases, Factual ,Biology ,digital image processing ,Biochemistry ,Copepoda ,Food chain ,Automation ,Species level ,Structural Biology ,Digital image processing ,Image Processing, Computer-Assisted ,Animals ,automated image recognition ,Molecular Biology ,Artificial neural network ,business.industry ,Applied Mathematics ,Research ,Community structure ,Discriminant Analysis ,Pattern recognition ,biology.organism_classification ,Linear discriminant analysis ,Computer Science Applications ,Identification (biology) ,Artificial intelligence ,Neural Networks, Computer ,business ,Copepod - Abstract
Background Copepods are planktonic organisms that play a major role in the marine food chain. Studying the community structure and abundance of copepods in relation to the environment is essential to evaluate their contribution to mangrove trophodynamics and coastal fisheries. The routine identification of copepods can be very technical, requiring taxonomic expertise, experience and much effort which can be very time-consuming. Hence, there is an urgent need to introduce novel methods and approaches to automate identification and classification of copepod specimens. This study aims to apply digital image processing and machine learning methods to build an automated identification and classification technique. Results We developed an automated technique to extract morphological features of copepods' specimen from captured images using digital image processing techniques. An Artificial Neural Network (ANN) was used to classify the copepod specimens from species Acartia spinicauda, Bestiolina similis, Oithona aruensis, Oithona dissimilis, Oithona simplex, Parvocalanus crassirostris, Tortanus barbatus and Tortanus forcipatus based on the extracted features. 60% of the dataset was used for a two-layer feed-forward network training and the remaining 40% was used as testing dataset for system evaluation. Our approach demonstrated an overall classification accuracy of 93.13% (100% for A. spinicauda, B. similis and O. aruensis, 95% for T. barbatus, 90% for O. dissimilis and P. crassirostris, 85% for O. similis and T. forcipatus). Conclusions The methods presented in this study enable fast classification of copepods to the species level. Future studies should include more classes in the model, improving the selection of features, and reducing the time to capture the copepod images.
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