Papers by Syaizwan Zahmir Zulkifli
International Journal of Global Warming, 2016
The release of nitrous oxide (N 2 O) from agricultural activities contributes to the increase of ... more The release of nitrous oxide (N 2 O) from agricultural activities contributes to the increase of greenhouse gases in the atmosphere. In this study, the amount of nitrogen fertiliser used in an oil palm plantation of different stages (immature and mature) was estimated. Data of fertilising scheme at the oil palm plantation for oil palms varying in age (planted between 1986 and 2009) was used. Estimation of nitrous oxide emissions and the resulting CO 2equivalent (CO 2-eq) emissions were calculated for each category of the oil palm. The amounts of N-fertiliser applied were between 102137 kg N/ha. The resulting N 2 O emissions were between 19.07-22.10 kg N 2 O-N/ha, which corresponds to CO 2-eq of between 2223.53-2700.42 kg CO 2-eq/ha. It was also estimated that about 29.87-34.63 g CO 2 were emitted per MJ crop. The N 2 O emission per ha oil palm was found to decrease from immature stage until maturely-developed stage spanning 20 years. The CO 2-eq amount decreased only after ten years of oil palm development. The results were also compared for synthetic nitrogen fertiliser-induced emissions within tropical regions.
Scientific reports, 2020
The ornamental fish trade has been considered as one of the most important routes of invasive ali... more The ornamental fish trade has been considered as one of the most important routes of invasive alien fish introduction into native freshwater ecosystems. Therefore, the species composition and invasion risks of fish species from 60 freshwater fish pet stores in Klang Valley, Malaysia were studied. A checklist of taxa belonging to 18 orders, 53 families, and 251 species of alien fishes was documented. Fish Invasiveness Screening Test (FIST) showed that seven (30.43%), eight (34.78%) and eight (34.78%) species were considered to be high, medium and low invasion risks, respectively. After the calibration of the Fish Invasiveness Screening Kit (FISK) v2 using the Receiver Operating Characteristics, a threshold value of 17 for distinguishing between invasive and non-invasive fishes was identified. As a result, nine species (39.13%) were of high invasion risk. In this study, we found that non-native fishes dominated (85.66%) the freshwater ornamental trade in Klang Valley, while FISK is a more robust tool in assessing the risk of invasion, and for the most part, its outcome was commensurate with FIST. This study, for the first time, revealed the number of high-risk ornamental fish species that give an awareness of possible future invasion if unmonitored in Klang Valley, Malaysia.
Aquatic Invasions, 2020
The importation of non-native fish species into Malaysia began as early as the 19 th century, whe... more The importation of non-native fish species into Malaysia began as early as the 19 th century, when a substantial number of non-native fishes were introduced from southern China, heralding the beginning of aquaculture in Malaysia. In this review, we analyzed the available literature on the history, checklists, current status, production trends, and potential ecological and socioeconomic impacts of non-native freshwater fishes in Malaysia. We identified a total of 30 non-native food fishes belonging to 12 families, with Cichlidae occurring the most frequently. Moreover, 173 species from 40 families of non-native freshwater ornamental, recreational and biological control fishes were also listed. The aquaculture production and wholesale value were significantly higher (p < 0.05) for non-native species, as compared to native species. Approximately 93% (1,317,990 metric tonnes (MT)) of aquaculture production and 85.6% (RM 7.4 billion) of wholesale value are from non-native species. However, for inland freshwater captured fisheries, the landing and wholesale values were significantly higher (p < 0.05) for native species than the non-native species. Non-native species only occupied approximately 28.6% (18,227 MT) of the landing, and 14.2% (RM 110 million) of wholesale value, respectively. For the ornamental fish production, the highest value was recorded in the year 2012 (RM 629 million), but dipped to its lowest value in 2017 (RM 327 million). The cyprinids that are mostly represented by non-native species recorded the highest value (RM 112 million) in the year 2018, followed by osteoglossids that are mainly represented by the native Asian arowana (RM 108 million). Despite the massive economic contribution from these non-native fishes, some of these fish present important ecological and socioeconomic threats to Malaysia. Several recommendations are proposed for a win-win situation between the economic gains and environmental threats caused by these non-native fishes.
Procedia Environmental Sciences, 2015
This study aimed to determine the concentration of butyltin and the physic-chemical factors in ma... more This study aimed to determine the concentration of butyltin and the physic-chemical factors in marine sediment after five years of total global banning. Level of butyltins namely tributyltins (TBT), dibutyltin (DBT) monobutyltin (MBT) and the physicochemical parameters of sediments (sediment texture, pH and total organic carbon (TOC)) were measured in sample collected from nine stations at Kong Kong Laut. Concentrations of tributyltin were varied from undetected to 945.7 µg kg-1 dry weight, undetected to 188 µg kg-1 dry weight for DBT, and undetected to 55.2 µg kg-1 dry weight for MBT. The highest levels of TBT and DBT were found at station number 1, which is in the vicinity of dock yard. Level of pH and type of sediment are almost uniform in all nine stations except for TOC. No significant relationships were found between physicochemical parameters and the three butyltins. These findings suggest that TBT in station number 1 was freshly introduced and that the main source was suspected from maintenance work conducted in the dockyard.
The present study used a food chain model of the giant mudskipper (Periophthalmodon schlosseri) t... more The present study used a food chain model of the giant mudskipper (Periophthalmodon schlosseri) to demonstrate the mobility of the trace elements (Cr, As, Cd and Pb) in a mangrove ecosystem. Samples of sediments, P. schlosseri and its food items were collected, digested and determine the trace elements concentration. The mean concentrations of the trace elements were relatively low. In sediments, the concentration of As was found to exceed the Interim Sediment Quality Guideline-low (ISQG-low). The concentrations were correlated to nitrogen stable isotope ratios (δ 15 N) to investigate mobility patterns. Data on δ 15 N demonstrated clear separation of trophic levels in the food chain. Integration of P. schlosseri and its stomach contents data showed a strong relationship with r=0.89 for Cr, r=0.75 for As, r=0.93 for Cd and r=0.95 for Pb. These elements are in biomagnification pattern along the food chain of P. schlosseri. In this study, the stable isotope ratio is used to investigate the mobility of trace elements and other pollutants along the food chain in mangrove ecosystems.
The coastal environment of the Johor Strait is gradually being altered, thus degrading the ecosys... more The coastal environment of the Johor Strait is gradually being altered, thus degrading the ecosystem's health. The present study was conducted to determine the food web in mangrove-mudflat ecosystem in vicinity to Sungai Pulai estuary as revealed by stable isotope analysis. A wide range of biota and sediments were collected and analyzed for δ 13 C and δ 15 N isotopic ratios. Results showed δ 13 C and δ 15 N values were ranged between-14‰ to-31‰ and 2.5‰ to 17.5‰, respectively. These data revealed that there are four trophic levels (primary producers up to tertiary consumers) that exist within the mangrove-mudflat ecosystem. Hence, a stable isotope analysis could be used to verify trophic structure in tropical mangrove ecosystem.
Procedia Environmental Sciences, 2015
This study was conducted to develop a preliminary food web model of aquatic environment at the No... more This study was conducted to develop a preliminary food web model of aquatic environment at the North Selangor Peat Swamp Forest (NSPSF) using stable isotope markers (δ 13 C and δ 15 N). The samples were collected from two selected points of peat swamp area representing disturbed and undisturbed areas. Samples collected then underwent analytical procedures before being analysed using an Isotope Mass Ratio Spectrometry (IRMS). Results showed that there are differences in trends of the food web between disturbed and undisturbed area. A consumer in the higher trophic level had significantly higher δ 13 C and δ 15 N values compared to the lower consumer. Hemibagus nemurus has become the top predator in disturbed areas while Channa lucius becomes the top predator in undisturbed areas. Sampling throughout the year is highly recommended as different species are only available for a certain period of time due to the water input from the rainfall.
Procedia Environmental Sciences, 2015
Diuron is an alternative biocide to replace tributyltin in antifouling paints. However, its effec... more Diuron is an alternative biocide to replace tributyltin in antifouling paints. However, its effect on non-targeted organisms are not fully studied, hence this study was conducted to investigate toxicological effects of Diuron in the early life stage (24hr post-hatch nauplii) of brine shrimp Artemia salina. The lethal concentration 50 (LC 50 ) of Diuron on A. salina nauplii was determined after 24 hours, 48 hours and 72 hours exposure after conducting a range definitive tests. Additional investigations on morphological abnormalities and total length were also conducted. Results showed that LC 50 of Diuron were 23.27 mg.L -1 , 12.19 mg.L -1 , 6.00 mg.L -1 in 24, 48 and 72 hours, respectively. Some external abnormalities were also observed. The total length was found to decrease with the increase in Diuron concentration. These results indicate that Diuron is an environmentally toxic substances. Furthermore, in-depth investigation should be conducted to establish A. salina as a bioindicator for Diuron contamination.
Procedia Environmental Sciences, 2015
Sediment core collected from Tanjung Pelepas harbour was analyzed to determine the concentrations... more Sediment core collected from Tanjung Pelepas harbour was analyzed to determine the concentrations of trace metals e.g., Al, Fe, Ti, Pb, Zn, Cu and natural radionuclide 210 Pb. The aim of this study was to predict the origin of trace metals and date the deposition of sediment that occurred at Tanjung Pelepas harbour using the vertical profile of 210 Pb. The estimated sedimentation rate derived from 210 Pb profile was 0.57 cm/year. The entire datasets of trace metals were analyzed statistically using the Pearson correlation coefficient and principal component analysis (PCA) to predict their origins. The results showed that Al, Fe and Ti originated from natural sources while Zn and Cu came mainly from anthropogenic sources. Pb was dominated with both anthropogenic and natural sources. The enrichment factors (EF) were also calculated to estimate the level of contamination. The EF indicated that Tanjung Pelepas harbour is considered to have minor enrichment (EF<3) of Pb, Zn and Cu. Historical variations of Zn and Cu show the highest EF values estimated in late 1990's when the harbour was being developed. The EF values of Zn and Cu increased slightly from the past to the recent years which may correlate to the increased development at the harbour area.
Malaysian Applied Biology
This study reported the ranging behavior of a group of long-tailed macaques (Macaca fascicularis)... more This study reported the ranging behavior of a group of long-tailed macaques (Macaca fascicularis) that inhabit the area near Kuala Selangor Nature Park, Selangor, Malaysia. The data on the ranging behavior were collected daily through scan sampling from February to December 2011 on all significant individuals in the focus group. Observations were focusing on the moving distance and usage of canopy level by the study group in the exploiting habitat. They often travelled in the range between 100 and 600 m per day, and the ranging patterns were influenced by the food distribution, sleeping site, predation and territorial factors. The study group seems to use areas that are close to human settlements because of the availability and high distribution of food. The study group does not seem to move far from their home range because they will be returning to the trees along the roadside to sleep. Avoiding predators and territorial factor are the main reasons why they are using the same sleeping sites. The most frequent forest canopy strata used by the study group are the ground level (36.78%), followed by the lower canopy (35.46%), middle canopy (17.93%), upper canopy (7.74%), and the lowest is emergent (2%). Overall, ranging behavior of the study group is not only influenced by food distribution but also by other factors such as avoiding predators and territorial possession at the studied area.
Kuala Lumpur International Airport (KLIA) was built on a site that was primarily a peat swamp for... more Kuala Lumpur International Airport (KLIA) was built on a site that was primarily a peat swamp forest, part of which had already been converted to oil palm and rubber plantations. Beginning in 1992, it was changed into an area of modern infrastructures, highways and open landscapes. The changes in the environment have altered the diversity of vertebrate populations including birds. Reports have highlighted that the threat of busy airport and birds' population, and the tendency of birds using airports for feeding, roosting and nesting activities have resulted in risks of bird strikes. This creates an important safety issue for any airport. Therefore, a survey of the bird species in vegetated areas around KLIA was carried out and a total of 56 bird species from 27 families were identified. Of these, 40 species were resident species, 11 were migrant species and the remaining 5 species were both resident and migrant. Shannon-Wiener Index shows, H' -3.14 (with n = 874) for year 20...
Malayan Nature Journal
This study was conducted in order to seek potential microorganisms which are able to biodegrade T... more This study was conducted in order to seek potential microorganisms which are able to biodegrade TBT in sediments. Sediment samples were obtained from three seagrass beds (Merambong, Tanjung Adang, and Tanjung Kupang) and a fishing pier (Jeti Pendas). Microorganisms that are resistant to TBT concentration of more than 4.2µM were isolated and identified based on gram staining methods. The total numbers of colonies isolated from Tanjung Kupang, Tanjung Adang and Merambong were five, six, and nil, respectively. The surface sediments of all seagrass beds comprised of sandy clay. The total number of colonies from the pier's sediments which were resistant to TBT at concentrations of 4.2µM, 8.4µM, and 12.6µM were 59, ten, and five respectively. A total of 26 colonies were selected for this study, including all of the colonies from Tanjung Kupang and Tanjung Adang, as well as colonies that were resistant to 8.4µM, and 12.6µM TBT from the pier's sediment. All of the colonies were foun...
Life Science Journal
Acute toxicity of cadmium (Cd) on Java medaka (Orizyas javanicus) fish was studied. To obtain the... more Acute toxicity of cadmium (Cd) on Java medaka (Orizyas javanicus) fish was studied. To obtain the results, the experiments were carried out in 3-liter aquariums (15-20 fish for each aquarium) with static condition based on O.E.C.D method with 5 treatments, and 1 blank in two repetitions. During the experiment, water physicochemical parameters were pH = 7.7 to 7.9, salinity = 19.3 to 19.7 ppt, temperature = 29.1 to 30.8˚C and conductivity = 13.54 to 13.94 mS/m. On the basis of obtained results, the LC50-96 h for Cd were determined 6.02 (5.83 to 6.21) mg/L for juveniles and 6.63 (6.31 to 6.95) mg/L for adults, respectively. Also, the MAC (maximum allowable concentration) values for Cd on Orizyas javanicus juveniles and adults were determined at 0.60 mg/l for juveniles and 0.63 mg/l for adults. These results will be helpful for future ecotoxicology studies based on heavy metals pollution in estuary areas.
Journal of Environmental Biology
The morphological expressions and histopathological analysis of the gonads of a tropical marine n... more The morphological expressions and histopathological analysis of the gonads of a tropical marine neogastropod species (Thais sp.) from the East Malaysia revealed new evidence of mechanical sterility in the imposex affected females. The gradual development of imposex was classified into five stages (Stage 0 to Stage 4) with three types of sterility conditions; Type A caused prohibition of copulation and capsule formation; Type B prohibits the releasing process of eggs; and gonads in Type C are infertile. Further analysis is needed to confirm if the gonad malformation in imposex affected snails is generated specifically by the tributyltin (TBT) or by other possible factors. The levels of imposex incidence (stages and percentages) were greater in a marina and decreased with increasing distance from the marina. Organotin tissue burdens across the sexes showed that dibutyltin (DBT) as well as TBT might be the elements inducing imposex in Thais sp. from Miri in East Malaysia.
Present study utilized stable isotope markers of carbon-13 ( 13 C) and nitrogen-15 ( 15 N) to ind... more Present study utilized stable isotope markers of carbon-13 ( 13 C) and nitrogen-15 ( 15 N) to indicate existing food web in an intertidal mudflat of Sungai Janggut, Selangor, Malaysia and also the relative contribution of primary producers to the diets of consumers. The δ 13 C values of algae was -18.69 ± 0.7‰, detritus -24.38 ± 0.9‰, invertebrates -15.25 ± 0.1 to -21.39 ± 0.1‰ and fishes -16.17 to -21.45 ± 0.2‰. The δ 15 N values of algae was 2.52 ± 0.1‰, detritus 1.53 ± 0.1‰, invertebrates 4.33 ± 0.4 to 8.97 ± 0.5‰ and fishes 9.54 ± 0.3 to 12.81 ± 0.4‰. This showed the assimilation of carbon and nitrogen from variety of sources in mangrove ecosystem. In general, organisms had more positive value of carbon than algae and detritus, indicating a metabolic shift in isotope ratios. This was particular; the average carbon in animal isotope ratio was 0.4‰ and 5.9‰ more positive than mean ratio of algae and detritus. Although there have no obvious systematic trophic enrichment in δ 13 C, the value of δ 15 N is good enough to demonstrate the existence of a food web in mangrove ecosystem of Sungai Janggut. Further investigations are needed to gather enough information in order to design an accurate and comprehensive model of the food web in a mangrove ecosystem.
From Sources to Solution, 2013
The main objective in this study is to determine Cu and Zn concentration in edible tissues (skin ... more The main objective in this study is to determine Cu and Zn concentration in edible tissues (skin and muscle) of paddy eels, Monopterus albus. The collection of M. albus samples was based on four paddy seasons (plowing, seedling, growing and harvesting). A total of 163 individuals of M. albus were collected. Edible tissues were dissected, digested and analyzed using an atomic absorption spectrometer (AAS) for metal concentration. Results showed bioaccumulation of Cu and Zn in skin was higher than in muscle tissues. Comparison with the Malaysian Food Regulation showed Cu and Zn concentrations in muscle and skin tissues were within the permissible limits. The estimation of chemical doses was calculated in order to evaluate the health risk of Malaysian population via the consumption of M. albus. Result showed Cu and Zn levels were low in muscle and skin tissues, thus suggesting edible tissues of M. albus are safe for consumption.
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Papers by Syaizwan Zahmir Zulkifli