Student information

MSc thesis topic: Studying space use of Humpback Mahseer in the Cauvery river basin in Karnataka India

The Humpback Mahseer (Tor reamdevii) is a type of fish that is endemic to the Cauvery River basin in South India. It was once found abundantly across several upper and middle sub-basins, but the populations have declined with over 90% since the early 2000’s. In an effort to save this species from going extinct, the Cauvery Wildlife Sanctuary started a species recovery program with the future vision to re-populate areas where the species has already gone extinct.

The Sanctuary has the largest breeding population and the largest contiguous habitat (117 Km) that is protected on both banks. A part of the recovery project is to assess and possibly adapt areas that might be suitable for reintroducing this species based on fish behaviour and habitat use of individuals that are still living in the wild.

For the habitat use study as described above, 8 adult fish (between 6 – 23 Kilograms) are fitted with very high frequency (VHF) radio transmitters. Additionally, in previous studies, 9 habitat types have been identified in the area where the fish are still present. To characterise the suitability or identify necessary changes to be made in other areas, it is essential to study the habitat use and variation in movement patterns of the fish. This study can be divided in two sections.

  1. Classification of the current habitat in the 9 sub types that are described.

    • For this sub part high resolution drone imagery is available. The imagery needs to be classified based on descriptions as will be presented by ecological experts that know the area together with objective descriptive characteristics such as river width or river sinuosity.

  2. Statistical analysis of habitat use and how this usage changes with changing environmental variables over seasons.

    • Since January 2024, 8 fish are being tracked over varying time intervals multiple times per week, together with water quality parameters.

Relevance to research/projects at GRS or other groups

  • Spatial temporal analysis for Earth and Environment
  • Geoscripting
  • Spatial modelling and statistics

Possible Objectives and Research questions

  • How does habitat use of the Humpback Mahseer change over seasons?
  • How can we use descriptive statistics and expert knowledge for classifying habitats?
  • Can (supervised) classification be carried out using planet data instead of (more costly) UAV data?

Requirements

  • Scripting knowledge will be very useful although not entirely necessary

Literature and information

  • The legendary hump-backed mahseer Tor sp. of India’s River Cauvery: an endemic fish swimming towards extinction? - Adrian C. Pinder, Rajeev Raghavan, Robert Britton
  • Kraft, S., Gandra, M., Lennox, R. J., Mourier, J., Winkler, A. C., & Abecasis, D. (2023). Residency and space use estimation methods based on passive acoustic telemetry data. In Movement Ecology (Vol. 11, Issue 1). BioMed Central Ltd.
  • Costa-Pereira R, Moll RJ, Jesmer BR, Jetz W. Animal tracking moves community ecology: Opportunities and challenges. J Anim Ecol. 2022 Jul;91(7):1334-1344. Epub 2022 Apr 18. PMID: 35388473; PMCID: PMC10286655.

Theme(s): Modelling & visualisation