Publications by authors named "Bryan Raveen Nelson"

15 Publications

  • Page 1 of 1

Population data and genetic characteristics of 12 X-STR loci using the Investigator® Argus X-12 Quality Sensor kit for the Kedayan population of Borneo in Malaysia.

Int J Legal Med 2021 Jul 30;135(4):1433-1435. Epub 2021 Mar 30.

Forensic Science Programme, School of Health Sciences, Universiti Sains Malaysia, Health Campus, 16150, Kubang Kerian, Kelantan, Malaysia.

DNA profiling of X-chromosomal short tandem repeats (X-STR) has exceptional value in criminal investigations, especially for complex kinship and incest cases. In this study, Investigator® Argus X-12 Quality Sensor (QS) kits were successfully used to characterize 12 X-STR loci in 199 unrelated healthy Kedayan individuals living in Sabah and Sarawak, Malaysia. The LG1 haplogroup (DXS8378 - DXS10135 - DXS10148) has the largest HD (0.9799) as compared with all other closely linked haplotype groups examined (LG2; DXS7132-DXS10074-DXS10079, LG3; DXS10103-DXS10101-HPRTB and LG4; DXS10134-DXS7423-DXS10146). Data from statistical analysis showed that high combined of PD, PD, MEC_, MEC_, MEC_, and MEC_ values (0.999999994405922, 0.99999999999999, 0.999990463834938, 0.999999975914808, 0.999999975985006, and 0.999996491927194, respectively) in the Kedayan. In a two-dimensional scaling (MDS) plot and dendrogram constructed using allele frequencies at the 12 X-STR loci, Kedayan appear to be most closely related to their other Austronesian populations including the Malays and Filipinos as compared with other reference population groups. Findings from the present study thus demonstrate high genetic variability across the 12 tested X-STR loci and can be used for population studies and forensic applications.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00414-021-02577-0DOI Listing
July 2021

A review on introduced spp. and emerging concerns.

Heliyon 2020 Nov 4;6(11):e05370. Epub 2020 Nov 4.

Institute of Tropical Biodiversity and Sustainable Development, Universiti Malaysia Terengganu, 21030 Kuala Nerus, Terengganu, Malaysia.

Peacock bass ( spp.) originates from the Neotropical environments of Brazil and Venezuela but, through trade and smuggling for aquarium keeping, sport fishing and aquaculture, it is now an emerging concern. Yet, less is known for spp. distribution and its ability to invade new environments. Aimed to communicate on spp. ecology, biology and introduction schemes from Scopus, Web of Science, Google Scholar and also National Centre for Biotechnology Information, this review also contains management strategies for invading fish species. While spp. can displace native fish populations, this concern is explained using ecological functions, physiological demands, direct and secondary invasion, disease tolerance and parasite spillover. Briefly, spp. has rapid embryogenesis (72 h) and matures in short periods (11-12 months), giving it an advantage to colonize new environments. With a large appetite, this true piscivore gains territorial control over water bodies by making it their feeding and nursery grounds. Perceived as an emerging concern after becoming introduced, seal-off or sport fishing were used to manage spp. but, this practice is not sustainable for the entire ecosystem. Hence, we recommend bottom-up management that involves community participation because they interact with the fish and have knowledge about their environment.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.heliyon.2020.e05370DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7648196PMC
November 2020

Structural Characterization and Antioxidant Potential of Chitosan by γ-Irradiation from the Carapace of Horseshoe Crab.

Polymers (Basel) 2020 Oct 15;12(10). Epub 2020 Oct 15.

School of Biotechnology, GIET University, Gunupur 765022, Odisha, India.

Natural product extraction is ingenuity that permits the mass manufacturing of specific products in a cost-effective manner. With the aim of obtaining an alternative chitosan supply, the carapace of dead horseshoe crabs seemed feasible. This sparked an investigation of the structural changes and antioxidant capacity of horseshoe crab chitosan (HCH) by γ-irradiation using Co source. Chitosan was extracted from the horseshoe crab (; Müller) carapace using heterogeneous chemical -deacetylation of chitin, followed by the irradiation of HCH using Co at a dose-dependent rate of 10 kGy/hour. The average molecular weight was determined by the viscosimetric method. Regarding the chemical properties, the crystal-like structures obtained from γ-irradiated chitosan powders were determined using Fourier transfer infrared (FTIR) spectroscopy and X-ray diffraction (XRD) analyses. The change in chitosan structure was evident with dose-dependent rates between 10 and 20 kGy/hour. The antioxidant properties of horseshoe crab-derived chitosan were evaluated in vitro. The 20 kGy γ-irradiation applied to chitosan changed the structure and reduced the molecular weight, providing sufficient degradation for an increase in antioxidant activity. Our findings indicate that horseshoe crab chitosan can be employed for both scald-wound healing and long-term food preservation due to its buffer-like and radical ion scavenging ability.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/polym12102361DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7602389PMC
October 2020

Autosomal STR Profiling and Databanking in Malaysia: Current Status and Future Prospects.

Genes (Basel) 2020 09 23;11(10). Epub 2020 Sep 23.

Institute of Tropical Biodiversity and Sustainable Development, Universiti Malaysia Terengganu, Kuala Nerus 21030, Terengganu, Malaysia.

Science and technology are extensively used in criminal investigation. From the mid- to late-1980s, one of the scientific discoveries that has had a particularly remarkable impact on this field has been the use of highly variable DNA sequence regions (minisatellites) in the human genome for individual identification. The technique was initially referred to as DNA fingerprinting, but is now more widely referred to as DNA profiling. Since then, many new developments have occurred within this area of science. These include the introduction of new genetic markers (microsatellites also known as short tandem repeats/STRs), the use of the polymerase chain reaction for target amplification, the development of DNA databases (databanking), and the advancement and/or improvement of genotyping protocols and technologies. In 2019, we described the progress of DNA profiling and DNA databanking in Malaysia for the first time. This report included information on DNA analysis regulations and legislation, STR genotyping protocols, database management, and accreditation status. Here, we provide an update on the performance of our DNA databank (numbers of DNA profiles and hits) plus the technical issues associated with correctly assigning the weight of evidence for DNA profiles in an ethnically diverse population, and the potential application of rapid DNA testing in the country. A total of 116,534 DNA profiles were obtained and stored in the Forensic DNA Databank of Malaysia (FDDM) by 2019, having increased from 70,570 in 2017. The number of hits increased by more than three-fold in just two years, where 17 and 69 hits between the DNA profiles stored in the FDDM and those from crime scenes, suspects, detainees, drug users, convicts, missing persons, or volunteers were recorded in 2017 and 2019, respectively. Forensic DNA analysis and databanking are thus progressing well in Malaysia and have already contributed to many criminal investigations. However, several other issues are discussed here, including the need for STR population data for uncharacterized population groups, and pilot trials for adopting rapid DNA profiling technology. These aspects should be considered by policy makers and law enforcement agencies in order to increase the reliability and efficiency of DNA profiling in criminal cases and in kinship analysis in Malaysia.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/genes11101112DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7597947PMC
September 2020

Characterization dataset for pre- and post-irradiated shrimp waste chitosan.

Data Brief 2020 Oct 25;32:106081. Epub 2020 Jul 25.

Research Division, Association for Biodiversity Conservation and Research (ABC), Devine Colony, 756001 Balasore, Odisha, India.

This dataset presents morphological features, elemental composition and functional groups of different pre- and post-gamma (γ)-irradiated chitosan (10kGy & 20kGy) prepared from shrimp waste. The γ-irradiated chitosan was characterized using Fourier transfer infrared (FTIR) spectroscopy and X-ray diffraction (XRD) analyses. Thermogravimetry/differential thermal analysis (TG/DTA) were performed using Perkin Elmer Pyris Diamond DSC with a heating rate of 10 °C/minute and dynamic synthetic atmospheric air set at flow rate of 100 ml/minute. We observed γ-irradiated chitosan to have shorter polymer size, small pores and compacted structure with active alkyl and hydroxyl groups when compared to non-irradiated chitosan. Our data provides baseline understanding for structure of shrimp chitosan after Co exposure which means, the biopolymer becomes more stable and is considered suitable for vast food industry applications.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.dib.2020.106081DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7397402PMC
October 2020

Population data for 23 Y chromosome STR loci using the Powerplex® Y23 STR kit for the Kedayan population in Malaysia.

Int J Legal Med 2020 Jul 2;134(4):1335-1337. Epub 2020 Jan 2.

Forensic Science Programme, School of Health Sciences, Universiti Sains Malaysia, Health Campus, 16150, Kubang Kerian, Kelantan, Malaysia.

Genetic polymorphisms at 23 Y chromosome short tandem repeat (STRs) loci included in the Powerplex® Y23 PCR kit were successfully scored in 128 unrelated Kedayan individuals living in Sabah, East Malaysia. Complete haplotypes were recorded for all individuals and included 92 different types with 72 being unique to single male subjects. Three important forensic statistics were calculated from these data; haplotype diversity = 0.993, discriminating capacity = 0.719, and match probability = 0.015. The Kedayan appear to be most closely related to Malays and Filipinos in a multidimensional scaling plot and are separated from other mainland Asia populations including Thais and Hakka Han. These new data for Kedayan have been deposited in the YHRD database (accession number: YA004621). Our statistical analyses showed the reliability of Y-STR loci for geographically extended use in forensic casework and for studying human population history.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00414-019-02237-4DOI Listing
July 2020

Violent crime datasets: Incidence and patterns in Malaysia from 2006 to 2017.

Data Brief 2019 Oct 3;26:104449. Epub 2019 Sep 3.

School of Health Sciences, Universiti Sains Malaysia, Health Campus, 16150, Kubang Kerian, Kelantan, Malaysia.

This article provides violent crime data in Malaysia from 2006 to 2017. The violent crimes include murder, rape, gang robbery, robbery and voluntarily causing hurt cases. A total of 330,395 violent crime cases were reported in this 12 year period and the data were tabulated state by state for all thirteen states of Malaysia, including two states in Borneo (Sabah and Sarawak) and one federal territory (Kuala Lumpur). In general, violent crimes show a decreasing trend from 2006 to 2017 in Malaysia. However, armed gang robbery and armed robbery show a fluctuating pattern from 2008 to 2011. A similar pattern was also recorded for unarmed gang robbery from 2008 to 2010. The violent crime data deposited here are available for further analysis, e.g., for identifying risk factors such as demography, lifestyle, socio-economic status, government policies etc. which may be associated with violent crime incidence and pattern across the country.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.dib.2019.104449DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6811922PMC
October 2019

Human neutrophil antigen frequency data for Malays, Chinese and Indians.

Transfus Apher Sci 2020 Apr 4;59(2):102651. Epub 2019 Oct 4.

School of Health Sciences, Universiti Sains Malaysia, Health Campus, Kelantan, Malaysia. Electronic address:

Background: Human neutrophil antigens (HNAs) are implicated in several clinical disorders and their allelic variations have been reported for many populations. This new study was aimed to report the genotype and alleles frequencies of HNA-1, -3, -4 and -5 loci in Malays, Chinese and Indians in Peninsular Malaysia.

Methods: A total of 222 blood samples were collected from healthy, unrelated Malay, Chinese and Indian individuals. Their HNA-1, -3 and -4 and HNA-5 loci were genotyped using polymerase chain reaction-sequence specific primer (PCR-SSP) or PCR-restriction fragment length polymorphism (RFLP) assays.

Results: All HNA loci are polymorphic, except for HNA -4. Geneotypes HNA-1a/1b, -3a/3b and -4a/4a were observed most frequently at these three loci in all three ethnic groups. In contrast, HNA-5a/5b and -5a/5a were observed as the predominant genotypes in Malays vs. Chinese and Indians, respectively. The Malays, Chinese and Indians shared HNA -3a (0.505-0.527), HNA -4a (1.000) and -5a (0.676-0.854) as the most frequent alleles. However, HNA-1a was found to be the most common in Malays (0.506) and Chinese (0.504) and HNA-1b for Indians (0.525).

Conclusion: Combined with HNA data that have been published for Malay subethnic and Orang Asli groups, this study provides the first fully comprehensive HNA dataset for populations to be found in Peninsular Malaysia. Overall, our findings provide further evidence of genetic complexity in the region. This now publicly available HNA dataset can be used as a reliable reference source for improving medical outcomes.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.transci.2019.09.004DOI Listing
April 2020

Compendium of hand, foot and mouth disease data in Malaysia from years 2010-2017.

Data Brief 2019 Jun 20;24:103868. Epub 2019 Mar 20.

Institute of Tropical Biodiversity and Sustainable Development, Universiti Malaysia Terengganu, 21030 Kuala Nerus, Terengganu, Malaysia.

This data article is constructed using information from hand, foot and mouth disease outbreaks in every Malaysian state. Important information like total number of cases from every state and age group, humidity, air temperature and wind as well as types of viruses isolated from patients infected with hand, foot and mouth disease were gathered and sorted into four tables. The information sources include Malaysian Administrative Modernisation and Management Planning Unit (MAMPU), National Centre for Biotechnology Information (NCBI) and National Oceanic and Atmospheric Administration (NOAA). Since the Ministry of Health Malaysia only begun archiving hand, foot and mouth disease cases between years 2010-2017 in MAMPU, weather data extractions are following the similar timeline. Conversely, published data on viruses and their serotypes associated to hand, foot and mouth disease were extracted from NCBI but, data availability were limited between the years 2010 and 2014.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.dib.2019.103868DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6441719PMC
June 2019

Avian data from Kenyir rainforest trail.

Data Brief 2018 Dec 28;21:2633-2637. Epub 2018 Nov 28.

Bird Group Taman Negara (BGTN), Kuala Tahan, 27000 Jerantut, Pahang, Malaysia.

This data article is constructed using avian (bird) counts from a recently identified trail in Kenyir rainforest, East Peninsular Malaysia. Avian chirps and naked eye visual were simultaneously used to locate the birds. After visual binocular and digital image inspection, identification of avian species were carried out using reference books. Data tabulation are divided by monsoon seasons and months before interpret using Shannon and Evenness indices. The highlights like feeding guilds, nativity, iconic species and statuses in the wild are presented with the data to increase its value. Within these, a total of 457 avian individuals from 36 avian family groups were recorded from which, 25 of these avian species occur as near threatened, vulnerable, endangered and critically endangered in the wild. Having these, the tabulated data becomes a calendar for seasonal availability of avian species which considers the 1.0 km trail suitable for bird watching, scientific study and ecotourism purposes.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.dib.2018.11.119DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6290243PMC
December 2018

Citizen science frontiers horseshoe crab population regain at their spawning beach in East Peninsular Malaysia.

J Environ Manage 2019 Feb 12;232:1012-1020. Epub 2018 Dec 12.

Department of Marine Science, Kulliyyah of Science, International Islamic University Malaysia Kuantan, Jalan Sultan Ahmad Shah, 25200, Kuantan, Malaysia.

Carcinoscorpius rotundicauda and Tachypleus gigas may co-exist and share common spawning grounds elsewhere but at Balok (East Coast of Peninsular Malaysia), C. rotundicauda is an understudied species. Neglected as research candidate because of inaccessible spawning grounds, smaller size and less commercial value than T. gigas and also, difficulty to attain from the wild has made C. rotundicauda population status remaining unidentified at Balok. This standpoint drove the present attempt because anthropic activities like structure placement and mining are point-source for runoffs that load sediments into Balok River. While erosion-accretion events have altered Balok River width, the shore sediments in Balok Beach were transitioned between medium-fine and fine sand between years 2012 and 2016. Eventually by year 2016, the C. rotundicauda were depositing 5117 eggs in 91 nests from 200 to 1000 m range along this corridor facing South China Sea. From this yield, C. rotundicauda released 2880 eggs in 56 nests during the Southwest monsoon, 1254 eggs in 19 nests during the Northeast monsoon and 983 eggs in 16 nests during the Inter-monsoon seasons. Though female C. rotundicauda opted to lay their eggs in shallow burrows at lower shorelines, the absence of erosion and substantial silt and clay (>20%) deposition facilitates C. rotundicauda embryogenesis with brief periods of temperature and salinity shocks during day-time falling tides. This encourages C. rotundicauda to emerge with increasing abundance and carry out bi-monthly spawning at Balok Beach. In short, shore restoration initiatives like systematic boat docking, proper disposal of nets and waste and, periodic fish-catching operations were effectively led by the Balok fisher citizen scientist. This successful community joint-cooperation proves that citizen-led caretaking of degraded beaches offers marine life protection and are practical for coastal area management especially at areas where other oviparous animals such as turtles and crocodiles are harboured.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jenvman.2018.12.002DOI Listing
February 2019

Horseshoe crab bio-ecological data from Balok, East Coast Peninsular Malaysia.

Data Brief 2019 Feb 13;22:458-463. Epub 2018 Dec 13.

Department of Marine Science, Kulliyyah of Science, International Islamic University Malaysia Kuantan, Jalan Sultan Ahmad Shah, 25200 Kuantan, Malaysia.

The data available in this repository were gathered from Balok, the only most productive spawning site for horseshoe crabs and in East Coast of Peninsular Malaysia. The mangrove horseshoe crab, population and spawning data are available in the first table. The horseshoe crabs were retrieved from Balok River using 11.43 cm mesh size gill nets installed at the river mouth, the confluence and last meander. The arthropods were inspected for damage, abnormality and growth before their release into Balok River, particularly at the site of capture. Sediment samples were retrieved at their spawning grounds to ascertain sediment composition and size classifications which were also processed using Logarithmic Method of Moments. Water parameters like temperature, pH and salinity were also investigated during year 2016. All these information are compiled into the second table and arranged according to the period of data availability. The horseshoe crab catch data of years 2012, 2013, 2014, 2015 and 2016 were made available by artisanal fisher and compiled in the third and fourth table for inter-species comparison.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.dib.2018.12.027DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6312785PMC
February 2019

Linkages between Chiropteran diversity and ecosystem services for sustainable fragmented forest conservation.

Data Brief 2018 Dec 14;21:2089-2094. Epub 2018 Nov 14.

School of Marine and Environmental Sciences, Universiti Malaysia Terengganu, 21030 Kuala Nerus, Terengganu, Malaysia.

This data article informs about Chiropteran diversity, new records, ecosystem services and possible pathogen carriers in fragmented forests (sub-divided by utility corridors, man-made structures, untouched and secondary plantations) within districts Setiu (Setiu Research Station), Hulu Terengganu (Saok and Lasir waterfalls) and Besut (Gunung Tebu Forest Reserve) of state Terengganu, Peninsular Malaysia. These bats were captured using harp traps and mist nets that were set 10 m apart across flyways, streams and less cluttered trees in the 50 m × 50 m transect zones (identified at each site). All animals were distinguished by morphology and gender before their release at the site of capture. The data comprise of five bat family groups Hipposideridae, Megadermatidae, Pteropodidae, Rhinolophidae and Vespertilionidae. It is interesting to note that untouched Saok Waterfalls is home to wide variety of bats listed (68.8%), followed by secondary forests of Gunung Tebu Forest Reserve (24.8%), untouched Lasir Waterfalls (4.8%) and lastly, Setiu Research Station as least favored (1.6%). Chiroptera like ( = 23, 37.7%), ( = 6, 9.8%) and ( = 6, 9.8%) were most dominant in the checklist whereas , and are new data records in the fragmented forests of Terengganu. The data were interpret into Shannon, Simpson, Margalef, Menhinik and Evenness indices to individually or collectively distinguish chiropteran variety in Terengganu State whereas weight-forearm length (W/FA) informs about chiropteran Body Condition Index (-0.25 to 0.25). The function of bats were also identified to distinguish service providers (pollination and forests regeneration) and zoonotic pathogen carriers (in particular to Leptospira bacteria, Nipah virus and Sindbis virus).
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.dib.2018.11.058DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6262155PMC
December 2018

Non-volant small mammal data from fragmented forests in Terengganu State.

Data Brief 2018 Dec 24;21:1514-1520. Epub 2018 Oct 24.

School of Marine and Environmental Sciences, Universiti Malaysia Terengganu, 21030 Kuala Nerus, Terengganu, Malaysia.

This data article is about non-volant small mammal (squirrel, rat and tree shrew) capture from fragmented forest understories within sub-urban areas of Setiu (Peladang Agro Resort and Setiu Wetland Research Station) and inhabited areas of Hulu Terengganu (Saok and Lasir waterfalls) that are situated in Terengganu State, Peninsular Malaysia. Fruits like banana and oil palm were individually placed into each cage before the cages were fastened onto three to five meter height tree branches. The traps were also spatially distributed about ten meters from each other. Under this installation, fifty baited traps were used during the twenty-four nights of sample collection. All animals caught were distinguished by morphology and released at the same location it was caught. The understory data comprise of seven non-volant mammal species from family groups Sciuridae, Muridae and Tupaiidae. Overall, ( = 17, 39%) were dominant in the capture pool from all sites. Comparatively, ( = 2, 4%) and ( = 4, 9.3%) were restricted to Saok Waterfalls and Setiu Wetland. Banana and oil palm fruits did not attract any small mammals during the Lasir Waterfall (Hulu Terengganu) survey. All data were interpret into Shannon, Simpson, Margalef, Menhinik and Evenness indices to individually or collectively distinguish small mammal variety in Terengganu State.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.dib.2018.10.061DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6240627PMC
December 2018

The final spawning ground of Tachypleus gigas (Müller, 1785) on the east Peninsular Malaysia is at risk: a call for action.

PeerJ 2016 19;4:e2232. Epub 2016 Jul 19.

Institute of Kenyir Research (IPK), Universiti Malaysia Terengganu-UMT, Kuala Terengganu, Terengganu, Malaysia.

Tanjung Selongor and Pantai Balok (State Pahang) are the only two places known for spawning activity of the Malaysian horseshoe crab - Tachypleus gigas (Müller, 1785) on the east coast of Peninsular Malaysia. While the former beach has been disturbed by several anthropogenic activities that ultimately brought an end to the spawning activity of T. gigas, the status of the latter remains uncertain. In the present study, the spawning behavior of T. gigas at Pantai Balok (Sites I-III) was observed over a period of thirty six months, in three phases, between 2009 and 2013. Every year, the crab's nesting activity was found to be high during Southwest monsoon (May-September) followed by Northeast (November-March) and Inter monsoon (April and October) periods. In the meantime, the number of female T. gigas in 2009-2010 (Phase-1) was higher (38 crabs) than in 2010-2011 (Phase-2: 7 crabs) and 2012-2013 (Phase-3: 9 crabs) for which both increased overexploitation (for edible and fishmeal preparations) as well as anthropogenic disturbances in the vicinity (sand mining since 2009, land reclamation for wave breaker/parking lot constructions in 2011 and fishing jetty construction in 2013) are responsible. In this context, the physical infrastructure developments have altered the sediment close to nesting sites to be dominated by fine sand (2.5Xφ ) with moderately-well sorted (0.6-0.7σφ), very-coarse skewed (-2.4SKφ), and extremely leptokurtic (12.6Kφ) properties. Also, increased concentrations of Cadmium (from 4.2 to 13.6 mg kg(-1)) and Selenium (from 11.5 to 23.3 mg kg(-1)) in the sediment, and Sulphide (from 21 to 28 µg l(-1)) in the water were observed. In relation to the monsoonal changes affecting sheltered beach topography and sediment flux, the spawning crabs have shown a seasonal nest shifting behaviour in-between Sites I-III during 2009-2011. However, in 2012-2013, the crabs were mostly restricted to the areas (i.e., Sites I and II) with high oxygen (5.5-8.0 mg l(-1)) and moisture depth (6.2-10.2 cm). In view of the sustained anthropogenic pressure on the coastal habitats on one hand and decreasing horseshoe crabs population on the other, it is crucial to implement both conservation and management measures for T. gigas at Pantai Balok. Failing that may lead to the loss of this final spawning ground on the east coast of P. Malaysia.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.7717/peerj.2232DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4957986PMC
August 2016