Rapid assessment of the physiological impacts caused by catch‐and‐release angling on blue‐finned mahseer ( Tor sp.) of the Cauvery River, India

Abstract

Forty‐nine blue‐finned mahseer ( Tor sp.; mean total length 458 ± 20 mm) were angled using a range of bait/lure types, angling and air exposure times in water that averaged 27 ± 2 °C over the course of the assessment. No cases of mortality were observed, and rates of moderate and major injury were low, with 91% of mahseer hooked in the mouth. More extreme physiological disturbances (i.e. blood lactate, glucose, pH ) in mahseer were associated with longer angling times. Sixteen fish (33%) exhibited at least one form of reflex impairment. Moreover, longer air exposures and angling times resulted in significant likelihood of reflex impairment. Findings suggest that blue‐finned mahseer are robust to catch‐and‐release, but that anglers should avoid unnecessarily long fight times and minimise air exposure to decrease the likelihood of sub‐lethal effects that could contribute to post‐release mortality.

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