EXPLORING WATER QUALITY AS A DETERMINANT OF THE EXISTENCE OF SOFT SHELL CRAB (SCYLLA OLIVACEA) IN DIFFERENT HABITATS OF THE LARGE MARINE ECOSYSTEM IN THE BAY OF BENGAL.
The present study determined the concentration of semicarbazide (SEM) in water and soil samples from diverse habitats of mud crabs encompassing natural breeding grounds, mangrove-associated rivers, different commercial farms and the tissue samples in soft-shell crabs. Semicarbazide is a residue of...
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| Format: | Thesis |
| Language: | English English English |
| Published: |
ZIBELINE INTERNATIONAL
2024
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| Online Access: | http://ir.unimas.my/id/eprint/49878/ http://doi.org/10.26480/wcm.04.2024.495.500 |
| Abstract | Abstract here |
| Summary: | The present study determined the concentration of semicarbazide (SEM) in water and soil samples from
diverse habitats of mud crabs encompassing natural breeding grounds, mangrove-associated rivers, different
commercial farms and the tissue samples in soft-shell crabs. Semicarbazide is a residue of banned veterinary
drug nitrofurazone that can be found in some natural crustaceans that have never been exposed to
nitrofurazone. Analysis of water and soil sediment confirmed the presence of SEM in natural habitat,
however the concentrations was very low as <0.1 ng/g throughout the study. The extraction and analysis of
nitrofuran metabolites was conducted by using liquid chromatography-tandem mass spectrometry (LCMS/
MS) methods. The commercial farms of mud crabs were also exhibited the lowest levels of SEM in both
water (0.0003 ng/g) and soil sediment (0.0005 ng/g). Tissue-specific SEM analyses encompassing muscle,
shell-muscle composite, and shell revealed a distinct spatial gradient in which shell tissues exhibiting the
highest concentration of SEM (3.51±0.03 ng/g) in commercial farms, surpassing those observed in muscle
tissues (0.33±0.01 ng/g). Remarkably, crabs from commercial farms exhibited higher SEM concentrations
across all tissue types compared to those from natural breeding grounds. However, no SEM was detected in
crab feed snail and tilapia fish in commercial farms, suggesting feed composition may not be a major
contributor. The lowest concentrations of SEM in water and soil sediments towards physiological processes
rather than environmental contamination as the source. This study highlights limitations of SEM as a sole
nitrofuran abuse marker, advocating for broader regulatory frameworks and calls for reevaluating
regulations to ensure public health and responsible aquaculture. |
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