Browsing by Author "Yusoff, FM"

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    Equivalence of trophic structure between a tropical and temperate mangrove ecosystem in the Indo-Pacific
    (CSIRO Publishing, 2019-05-22) Mazumder, D; Saintilan, N; Yusoff, FM; Kelleway, JJ
    In this study we compared ecosystem trophic structure between a tropical mangrove forest at Matang, Malaysia, and a temperate mangrove forest near mangrove poleward limits at Towra Point in south-east Australia. These forests are separated by 8500 km of ocean over 45° of latitude and are of contrasting size, productivity and diversity. However, we observed a marked degree of similarity in food chain length (approximately four trophic levels in both forests), the taxonomy of key intermediate members of the food chain and the isotope signature of primary carbon sources, suggesting a strong contribution of surface organic matter rather than mangrove detritus. Common families were represented among dominant grazing herbivores, zooplanktivorous fishes, decapod crustaceans and top predators. These similarities suggest that there is some consistency in trophic interactions within two mangroves on opposite sides of the Indo-Pacific, despite a degree of evolutionary divergence in the assemblage. © CSIRO 2019
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    Feeding habits of five dominant fish species from Matang Mangrove Estuaries, Malaysia based on stomach contents and stable isotope analyses
    (Research Square, 2021-05-14) Azim, MKM; Amin, SMN; Mazumder, D; Arshad, A; Yusoff, FM; Saintilan, N
    The centres of mangrove biodiversity and productivity have been under-represented in studies of fish diet and habitat utilization, particularly in relation to environmental changes between wet and dry seasons. Feeding habits of five dominant fish species (Thryssa kammalensis, Ambassis gymnocephalus, Escualosa thoracata, Stolephorus baganensis and Johnius belangerii) were investigated from two sites in the Matang Mangrove ecosystem, Perak Malaysia, with sampling encompassing both wet and dry seasons. The stomach fullness of the fish was on average significantly higher in the wet season (48%) than in the dry season (32%) with isopods and copepods forming a more important component of the fish diet during the wet season than the dry season. The stomach contents of each species were, on average: T. kammalensis {(Animal based (A) = 50.11%, Plant based (P) = 38.24%)}, A. gymnocephalus (A = 50.35%, P = 37.99%), E. thoracata (A = 42.09%, P = 44.4%), S. baganensis (A = 38.17%, P = 46.55%) and J. belangerri (A = 25.35%, P = 58.86%). Therefore, all five fish species can be considered omnivorous. The similarity among diets varied from 60-80% during the wet and dry season. During the dry season, stable carbon and nitrogen isotope values of the samples had less variation, indicating narrow dietary sources compared to the wet season where the distribution of their isotopic values was larger. Seasons should be considered for planning mangrove management, as results of this study found contracted trophic breadth for commercially valuable fish in the dry season. This work is licensed under a CC BY 4.0 License.
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    Stable isotope analysis as a tool for determining seafood provenance
    (Triveni Enterprises, 2018-09) Gopi, K; Mazumder, D; Yusoff, FM; Sammut, J
    Aim: To determine if stable isotope analysis is a viable tool for authenticating the geographical origin of seafood purchased from the market. The carbon and nitrogen isotope values of samples were analysed to determine if they differ according to their source. Methodology: One set of barramundi samples were purchased from three different markets and another set was obtained directly from a farm. Two sets of tiger prawn samples were obtained from the same markets as the barramundi. These samples were then analysed using isotope ratio mass spectrometry to determine their carbon and nitrogen isotopic values. Results: The barramundi samples showed significant differences between sources in both the δ13C (< 0.05) and δ15N (< 0.05) values. Similarly, the tiger prawn samples also showed significant differences between sources in the δ13C (< 0.05) and δ15N (p-value < 0.05) values. Interpretation: This pilot study successfully distinguished between barramundi samples and tiger prawns from different geographical locations. We recommend that further studies be conducted with a higher number of samples, and multiple sites from different geographic regions, and to account for factors influencing the δ13C and δ15N values. This study highlights the potential of isotopic analysis as a tool for policy makers and regulatory bodies to verify seafood provenance and enforce industry compliance for source labelling of seafood products. © The Authors