Sreekanth, G B and Kiranya, B and Akhilesh, K V and Mayekar, Trivesh and Vasudevan, Chandrasekar and Rajkumar, Solomon and Kumar, Praveen (2023) Spatio-temporal patterns in the distribution of juvenile elasmobranchs in a tropical Indian Ocean estuary, Zuari- India. Marine Biodiversity. ISSN 1867-1624
Full text not available from this repository.Abstract
Estuarine and coastal ecosystems act as important habitats for several elasmobranchs. However, little is known about the species, spatial and temporal distribution patterns, and variability in abundance of elasmobranchs occurring in estuaries along the Indian coast. Fishery surveys in Zuari, a tropical estuary on the Arabian Sea coast of India during 2018–2019, yielded 727 individuals of 18 elasmobranchs elasmobranch species from seven families in the small-scale fisheries. The size composition showed that juvenile and sub-adults’ life stages dominated the catch. Most taxa were infrequent in the catch and the top five abundant species were Scoliodon laticaudus, Rhizoprionodon acutus, Chiloscyllium arabicum, Pastinachus sephen, Glaucostegus granulatus, and Himantura uarnak, which shared 70% of the total numerical records. The species richness and diversity of elasmobranchs were the highest in the lower reach with a salinity range (25–34 psu) and estuarine mouth width (3–5 km), whereas evenness was maximum in the upper reaches with a salinity range (20–25 psu) and estuarine mouth width (1–2 km). The numerical abundance and diversity of elasmobranchs were markedly high during dry saline phase (673) and very low counts (54) during the wet phase. Thus, a clear seasonal difference was evident in the distribution of elasmobranchs in Zuari estuary. The ecological guild of elasmobranchs in the Zuari estuarine environments can be broadly categorised into non-marine transients (five species) and others as euryhaline generalists (nine species) and estuarine generalists (four species). Spatial maps show the distribution of elasmobranch species in the estuary followed a strong salinity gradient and the lower reaches showed the highest abundance. The study highlighted the importance of conserving the estuaries of the Indian Ocean region which act as shark habitats and are being impacted by urbanisation and climate change, further provides insights into spatial estuarine use by elasmobranchs.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | Sharks; Euryhaline; Rays; Ecological guild; Small-scale ; fishery; Conservation; Spatial management; Salinity |
| Subjects: | Demersal Fisheries > Shark fisheries Elasmobranch Fisheries Demersal Fishes > Ray fisheries |
| Divisions: | CMFRI-Veraval |
| Depositing User: | Arun Surendran |
| Date Deposited: | 10 Jul 2023 05:58 |
| Last Modified: | 10 Jul 2023 05:58 |
| URI: | http://eprints.cmfri.org.in/id/eprint/17228 |
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