Rucha Karkarey
Other projects
19 Nov 2010
Assessing the Effects of Mass Coral Bleaching on an Apex Predator Guild (Groupers) of the Lakshadweep Islands
3 Sep 2012
Conserving Top Benthic Predators in the Lakshadweep Reefs: Identifying Priority Areas for Grouper Conservation and Ecosystem Functioning
12 Dec 2016
The Status and Growth of a Coral Reef Fishery Targeting Groupers (Epinephelids) in the Lakshadweep Archipelago, India
Climate-change disturbances can have far reaching consequences for reef fish populations. Persisting under change depends on a species’ ability to cope with the disturbance. This project studies the coping mechanisms (flexibility in foraging ecology, physiology and demography) of a keystone predatory grouper (Cephalopholis argus) and assesses its vulnerability to mass-bleaching disturbances in Lakshadweep.
Squaretail grouper. © Shreya Yadav
Coral reefs in Lakshadweep have been subjected to repeated mass bleaching events since the world-wide catastrophe of 1998. Mass bleaching events are associated with reef structural decline, which can have major consequences for structure-dependent fish species like groupers (serranids). Therefore, a question we often ask is which species will survive under such future disturbances?
Surviving repeated and increasing mass-bleaching disturbances will depend upon a species’ ability to rapidly cope with changes in their habitats. Changing composition of prey and ambush /shelter sites can impact foraging behaviour and thus survival of species in degraded habitats. Therefore, species that have suitable traits or the behavioural flexibility to modify foraging strategies and diet may persist, while species with limited abilities will quickly get filtered out of the assemblage in disturbed habitats. Previous work from Lakshadweep indicates that the peacock hind (Cephalopholis argus) is ubiquitous to all reefs (healthy – degraded) in Lakshadweep. While the densities of several species of groupers have declined dramatically since 1998, the peacock hind appears to have become a keystone and dominant grouper species in these reefs over the years.
In this project, we study the persistence (coping mechanisms) of a ubiquitous species of grouper; the peacock hind (Cephalopholis argus) in reefs along a gradient of structural degradation. We will specifically study the ability of the peacock hind to modify it’s foraging behaviour: diet composition, prey selectivity, foraging modes and diet source along a gradient of structural degradation, in order to survive.
While behavioural flexibility may be essential for short-term survival after disturbances, persisting in sub-optimal habitat condition can have long-term impacts on individual physiology as well as the population. In this project, we will study the consequences of living in degraded habitats in the peacock hind at the level of individual physiology (growth rates, age at maturity, fecundity, body consition) and population (density, size-structure). We aim to broadly study the thresholds for resilience in a ubiquitous grouper and assess its vulnerability to reef structural degradation.