20 research outputs found
Diversity of Sergestid Shrimp Acetes (Order Decapoda) in Selected Sites of Sarawak Coastal Water and Its Autecology
Sergestid shrimps Acetes, locally known as ‘bubok’ in Sarawak is a valuable marine resource that supports the livelihood of the coastal communities, particularly during the blooming season (March –April). The shrimps play a significant role in transporting primary producers and consumers energy to higher trophic levels. Sergestid shrimp fishery in Sarawak depends heavily on traditional knowledge and practices, halting the sustainable utilization of this valuable resource. Therefore, the objectives of this study are to determine the diversity of Acetes living along the coastal water of Sarawak (Miri, Lundu, Telaga Air) based on morphological assessment and cytochrome oxidase subunit 1 (CO1) gene analysis and to analyse the interactions between the abundance of Acetes with selected environmental parameters namely dissolved oxygen (DO), temperature, turbidity, pH, salinity, total suspended solid (TSS) and chlorophyll a (chl a) as well as the presence of zooplankton (diet of Acetes) in coastal water of Miri, Sarawak
Checklist of sergestid shrimps, Acetes (Decapoda: Sergestidae) from selected sites along the coastal water of Sarawak, Malaysia
Acetes is exploited by the local people of Sarawak as a source of income during its bloom season, processed into local products such as fermented shrimp paste and pickle. Despite its importance in socio-economy, little is known on Acetes species composition in the coastal water of Sarawak, Malaysia. The objective of this study is to provide checklist of Acetes species found in the coastal water of Sarawak. Acetes samples were collected at three different sites namely Lundu, Telaga Air and Miri using bottom trawl net and traditional fishing gears. Four species were identified based on the morphological characters namely A. erythraeus, A. serrulatus, A. japonicus and A. indicus and A. erythraeus is the new record for Sarawak. © 2020 Malaysian Nature Society. All rights reserved
Red Seaweed Gracilaria Arcuata in Cage Culture Area of Lawas, Sarawak
Red seaweed Gracilaria sp. is known as ‘Janggut Duyong’ by the local people of Sarawak. This macroalgae is
well-distributed in both temperate and tropical seawaters. Gracilaria sp. could be processed to produce agar for
industrial purposes whereas some people consumed it directly and become part of their daily diet. In terms of
ecology, Gracilaria sp. is one of primary producer in the seawater and its presence can form habitats to support
other aquatic organisms. Despite its socio-economic and ecological importance, little is known about Gracilaria
sp. in Sarawak. Hence, this study is designed to: (i) determine the diversity and abundance of Gracilaria in cage
culture of Lawas, Sarawak (ii) assess the water quality of the cage culture area where Gracilaria is found and
(iii) determine other aquatic organisms that found within Gracilaria population. Three field samplings had been
conducted from October 2013 to November 2014 at cage culture areas of Awat-Awat Village, Lawas, Sarawak.
Only single species of Gracilaria was found namely Gracilaria arcuata. Besides G. arcuata, Acanthophora sp.
and Padina sp. were also found but in small patches. In addition, five different groups of aquatic invertebrates
were observed namely tunicates, bivalves, polychaetes, small crabs and brittle stars. The selected water quality
parameters namely temperature, pH, dissolved oxygen, salinity, turbidity, total suspended solid, orthophosphate,
silicate and chlorophyll a were significantly different (p= 0.000) during all the three field samplings except for
nitrite (p= 0.588). However, the values recorded were within normal range of standard water quality for tropical
estuarine area. Since healthy population of Gracilaria could be easily found here, therefore this area has the
potential for future seaweed aquacultur
MODELLING THE ENVIRONMENTAL AND BIOLOGICAL CUES FOR THE BLOOM OF SERGESTID SHRIMP Acetes (DECAPODA: SERGESTIDAE) IN COASTAL WATER OF MIRI, SARAWAK, MALAYSIAN BORNEO
The sergestid shrimp (Acetes spp.) show annual peak season from February to April. This krill-like shrimp, locally known as ‘bubok’, is one of the commercially important fisheries in Miri, Sarawak, Malaysian Borneo. Previous researchers had reported patchy data on the environmental factors and Acetes distribution in Miri-Bintulu adjacent areas. Moreover, insufficient analysis has led to the inability to conduct sustainable management strategies for Acetes fisheries. Therefore, this study is designed to explore the mathematical model usage to understand the interaction between selected water quality parameters and zooplankton assemblages with Acetes population in coastal water of Miri. Selected temporal biotic and abiotic data were collected using standard methods and later subjected to mathematical time series analysis called the Granger causality test. The results show bi-directional Granger causality between the abundance of Acetes and dissolved oxygen (DO). Interaction between other water quality parameters (temperature, salinity, turbidity, pH, TSS and Chlorophyll a) with the abundance of Acetes is also emerged. The number of zooplankton in the water column, namely Centropages, Euterpina, Oithona rigida, and Oncaea shows a significant causality towards the abundance of Acetes. The findings imply that complex interaction between biotic and abiotic factors exists during the bloom of Acetes in Miri; thus, relevant agencies should step up measures to ensure sustainable management of the coastal areas where Acetes bloom occurs
Kinetic analysis of the adsorption of glyphosate onto palm oil fronds activated carbon
Existing techniques for the treatment of pollutants include membrane separation, ion exchange, precipitation, transformation and biosorption. Of all of this technology, biosorption has several positive aspects which include low operating expenses, very efficient detoxification of toxicants at low concentrations, low amount of disposal materials and does not need nutrient requirements as in bacterial-based remediation, the latter of which is limited by the presence of heavy metals and other toxicants. The biosorption of glyphosate on palm oil fronds activated carbon can be an efficient and low-cost tool for remediation of glyphosate. The absorption kinetics data of biosorption isotherm on the biosorption of glyphosate on palm oil fronds activated carbon were analyzed using three models—pseudo-1st, pseudo-2nd and Elovich, and fitted using non-linear regression. The Elovich model was the poorest in fitting the curve based on visual observation followed by the pseudo-1st order. Statistical analysis based on root-mean-square error (RMSE), adjusted coefficient of determination (adjR2), bias factor (BF), accuracy factor (AF), corrected AICc (Akaike Information Criterion), Bayesian Information Criterion (BIC) and Hannan–Quinn information criterion (HQC) that showed that the pseudo-second order model is the best model. Kinetic analysis using the pseudo-second order model at 250 mg/L glyphosate gave a value of equilibrium sorption capacity qe of 94.12 mg g-1 (95% confidence interval from 89.913 to 98.332) and a value of the pseudo-second-order rate constant, k2 of 0.02 (95% confidence interval from 0.012 to 0.023). Further analysis is needed to provide proof for the chemisorption mechanism usually tied to this kinetic
Isothermal modelling of the adsoprtion of glyphosate onto palm oil fronds activated carbon
Glyphosate is a heavily usage herbicide in Malaysia. It inhibits amino acids synthesis in plants and microorganisms with the latter inhibition makes it difficult to find biodegradation microorganism as a bioremediation agent for this pesticide. One candidate for bioremediation is biosorption that has several positive aspects which include low operating expenses, very efficient detoxification of toxicants at low concentrations, low amount of disposal materials and does not need nutrient requirements as in bacterial-based remediation, the latter of which is limited by the presence of heavy metals and other toxicants. The biosorption of glyphosate on palm oil fronds activated carbon can be an efficient and low-cost tool for remediation of glyphosate. The absorption kinetics data of biosorption isotherm on the biosorption of glyphosate on oil palm fronds activated carbon were analyzed using modelled according to various models ranging from one to five parameters models such as Henry, Langmuir, Dubinin-Radushkevich, Freundlich, BET, Toth, Sips, Fritz-Schlunder IV, Baudu and Fritz-Schlunder V, and fitted using non-linear regression. Only the Henry, Langmuir, Freundlich, BET and Toth models can fit the data. Statistical analysis based on root-mean-square error (RMSE), adjusted coefficient of determination (adjR2), bias factor (BF), accuracy factor (AF), corrected AICc (Akaike Information Criterion) showed that the Langmuir model is the best model. The calculated Langmuir parameters bL value of 0.002 L/mg (95% confidence interval from 0.001 to 0.004) and qmL value of 255.5 mg/g (95% confidence interval from 160.90 to 350.11)
Kinetic analysis for the removal of copper using Durvillaea antarctica
Existing techniques for the treatment of pollutants include membrane separation, ion exchange, precipitation, and transformation and biosorption. Of all this technology, biosorption has several positive aspects which include low operating expenses, very efficient detoxification of toxicants at low concentrations, low amount of disposal materials and does not need nutrient requirements as in bacterial-based remediation, the latter of which is limited by the presence of heavy metals and other toxicants. The reduction of copper by Durvillaea antarctica, an alga that lives as south as the Antarctic region can be an efficient and low-cost tool for remediation of copper. In this study, the kinetics of copper biosorption is modelled according to the pseudo-first order, pseudo-second order and Elovich models. Statistical analysis based on root-mean-square error (RMSE), adjusted coefficient of determination (adjR2), bias factor (BF), accuracy factor (AF) and corrected AICc (Akaike Information Criterion) showed that the pseudo-second order model is the best model. Kinetic analysis using the pseudo-second order model at 0.15 mM copper gave a value of equilibrium sorption capacity qe of 0.150 mmol g-1 (95% confidence interval from 0.149 to 0.151) and a value of the pseudo-second-order rate constant, k2 of 8.605 (95% confidence interval from 7.016 to 10.194)
Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries
Abstract
Background
Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres.
Methods
This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries.
Results
In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia.
Conclusion
This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries
Ecology, Diversity and Molecular Studies of Red Seaweed Gracilaria spp. in Lawas, Santubong and Asajaya, Sarawak
Red seaweed Gracilaria (Gracilariaceae, Rhodophyta) is known as ‘Janggut Duyong’ by the
local people of Sarawak, widely distributed in both temperate and tropical seawater zones.
Gracilaria plays important roles as food materials and income for local people, provide
protection and source of foods for diverse aquatic organisms, one of the primary producer in
marine ecosystem and main contributor of agar worldwide. Despite the importance of
Gracilaria in terms of ecology and socio-economy, little is known about Gracilaria species in
Sarawak. Hence, this study was designed to: (i) assess selected water quality parameters in
Gracilaria habitats, (ii) examine the abundance of Gracilaria in Lawas, Santubong and
Asajaya, Sarawak as well as the aquatic organisms associated with it and (iii) identify species
of Gracilaria using morphological characteristics and molecular approaches. Three field
samplings were conducted in Lawas, Santubong and Asajaya from April 2013 to December
2014. Selected water quality was measured in-situ and ex-situ, whole thallus of Gracilaria and
other aquatic organisms found within it were collected. Identification of Gracilaria using
molecular analysis was done using cytochrome oxidase subunit 1 (CO1) gene marker. Four
species of Gracilaria (Gracilaria blodgettii, G. changii, G. arcuata, G. coronopifolia) were
identified based on morphological characteristics whereas only two species (G. blodgettii,
Hydropuntia edulis) were found using molecular analysis. Both of the data were contradicted
due to: (i) CO1 gene marker may not be suitable to resolve taxanomy of Gracilaria in Sarawak
and (ii) high similarity in terms of morphology between G. coronopifolia and H. edulis. Other
flora (Acanthophora sp. and Padina sp.) and fauna namely bivalves, polychaetes, shrimps,
tunicates, small crabs and brittle stars were found living together in Gracilaria population. The
water quality in Lawas and Santubong were under Class 2 of the Malaysian Marine Water
Quality Criteria and Standard (MWQCS). In contrast, Asajaya’s water qualities fall under Class
iv
E of MWQCS. Overall, the values of water qualities recorded were within normal range of
standard water quality for mangrove water and mariculture in Malaysia. Approximately 80%
to 90% of the cage net in Lawas was covered by seaweeds and pH was the only parameter that
show negative correlation with percentage cover of seaweeds (p= 0.000). In comparison,
percentage cover of seaweeds in Santubong and Asajaya could not be determined due to regular
collection by local people. Healthy population of Gracilaria could be easily found at all the
sampling sites, thus they have the potential for future seaweed aquaculture. It is recommended
that the state government agencies, Department of Fisheries Sarawak and other nongovernmental organisations to introduce and assist the local people embarking in seaweed
cultur
Meiofauna Community Structure in Maludam River, Sarawak
Maludam River is one of the rivers located in Sarawak and it is the habitat for many
aquatic animals and plants. The main objective of the study was to determine the
relationship between meiofauna community and environmental parameters. The sampling
was done on 24th and 25th August 2013. Six stations were selected which runs from
freshwater to estuarine regions. Eight taxa were recorded in Maludam River such as
Nematoda, Polychaeta, Oligochaeta, Tardigrada, Copepoda, Insecta, Gastropoda larvae and
Bivalvia larvae. Copepoda was the common meiofauna found in all stations. Station 6 had
recorded the highest species density (182.46 ind./10 cm2
) while the lowest species density
was recorded in station 2 (10.61 ind./ 10 cm2
). Chlorophyll a shows a strong positive
correlation with species diversity (r= 0.917, p= 0.005) and species richness (r= 0.883, p=
0.010). The data gathered from the study could be used as baseline data for future
management of Maludam River