Flood-Pulse Variability and Climate Change Effects Increase Uncertainty in Fish Yields: Revisiting Narratives of Declining Fish Catches in India’s Ganga River

River-floodplains support a significant number of small-scale capture fisheries despite having undergone degradation due to human modification of river flows by dams, pollution, and climate change. River fish production is underpinned by the annual flood-pulse and associated environmental changes th...

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Main Authors: Nachiket Kelkar, Rohan Arthur, Subhasis Dey, Jagdish Krishnaswamy
Format: Article
Language:English
Published: MDPI AG 2022-03-01
Series:Hydrology
Subjects:
Online Access:https://www.mdpi.com/2306-5338/9/4/53
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author Nachiket Kelkar
Rohan Arthur
Subhasis Dey
Jagdish Krishnaswamy
author_facet Nachiket Kelkar
Rohan Arthur
Subhasis Dey
Jagdish Krishnaswamy
author_sort Nachiket Kelkar
collection DOAJ
description River-floodplains support a significant number of small-scale capture fisheries despite having undergone degradation due to human modification of river flows by dams, pollution, and climate change. River fish production is underpinned by the annual flood-pulse and associated environmental changes that act as cues for spawning and dispersal for most species. However, studies on fish stock declines have focused more on overfishing than on hydroclimatic variability. Therefore, understanding how changes in flood-pulse variability influence fishing effort and yields is critical to inform adaptive fisheries’ management. We investigated hydroclimatic factors driving flood-pulse variability and fish catch–effort dynamics in India’s Ganga River over two decades (2000–2020). We compiled fishers’ narratives of changing fish catches through semi-structured interviews to compare them with our observed trends. Flood amplitude showed increasing variability, longer duration, and earlier rise timings, linked to La Niña and El Niño phases. Catches per unit effort were correlated with total yield and effort but did not decline as fishers thought, despite overall declines in yield over time. Hydroclimatic variability was a more significant driver of changing yields than local fishing pressure. Rising uncertainty in fisheries’ production, in response to increasing flood-pulse variability and altered flows in the Gangetic Plains, may be affecting fishing behaviour and underlying resource conflicts.
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spelling doaj.art-b5e14abf266a4011a215ad0f23cb3abd2023-12-01T21:00:53ZengMDPI AGHydrology2306-53382022-03-01945310.3390/hydrology9040053Flood-Pulse Variability and Climate Change Effects Increase Uncertainty in Fish Yields: Revisiting Narratives of Declining Fish Catches in India’s Ganga RiverNachiket Kelkar0Rohan Arthur1Subhasis Dey2Jagdish Krishnaswamy3Riverine Ecosystems and Livelihoods Programme, Wildlife Conservation Trust, Mumbai 400001, IndiaNature Conservation Foundation, Mysore 570017, IndiaRiverine Ecosystems and Livelihoods Programme, Wildlife Conservation Trust, Mumbai 400001, IndiaSchool of Environment and Sustainability, Indian Institute for Human Settlements, Bangalore 560080, IndiaRiver-floodplains support a significant number of small-scale capture fisheries despite having undergone degradation due to human modification of river flows by dams, pollution, and climate change. River fish production is underpinned by the annual flood-pulse and associated environmental changes that act as cues for spawning and dispersal for most species. However, studies on fish stock declines have focused more on overfishing than on hydroclimatic variability. Therefore, understanding how changes in flood-pulse variability influence fishing effort and yields is critical to inform adaptive fisheries’ management. We investigated hydroclimatic factors driving flood-pulse variability and fish catch–effort dynamics in India’s Ganga River over two decades (2000–2020). We compiled fishers’ narratives of changing fish catches through semi-structured interviews to compare them with our observed trends. Flood amplitude showed increasing variability, longer duration, and earlier rise timings, linked to La Niña and El Niño phases. Catches per unit effort were correlated with total yield and effort but did not decline as fishers thought, despite overall declines in yield over time. Hydroclimatic variability was a more significant driver of changing yields than local fishing pressure. Rising uncertainty in fisheries’ production, in response to increasing flood-pulse variability and altered flows in the Gangetic Plains, may be affecting fishing behaviour and underlying resource conflicts.https://www.mdpi.com/2306-5338/9/4/53river flowflood-pulsemonsoon rainfallglobal climate changeatmospheric teleconnectionsfishery yields
spellingShingle Nachiket Kelkar
Rohan Arthur
Subhasis Dey
Jagdish Krishnaswamy
Flood-Pulse Variability and Climate Change Effects Increase Uncertainty in Fish Yields: Revisiting Narratives of Declining Fish Catches in India’s Ganga River
Hydrology
river flow
flood-pulse
monsoon rainfall
global climate change
atmospheric teleconnections
fishery yields
title Flood-Pulse Variability and Climate Change Effects Increase Uncertainty in Fish Yields: Revisiting Narratives of Declining Fish Catches in India’s Ganga River
title_full Flood-Pulse Variability and Climate Change Effects Increase Uncertainty in Fish Yields: Revisiting Narratives of Declining Fish Catches in India’s Ganga River
title_fullStr Flood-Pulse Variability and Climate Change Effects Increase Uncertainty in Fish Yields: Revisiting Narratives of Declining Fish Catches in India’s Ganga River
title_full_unstemmed Flood-Pulse Variability and Climate Change Effects Increase Uncertainty in Fish Yields: Revisiting Narratives of Declining Fish Catches in India’s Ganga River
title_short Flood-Pulse Variability and Climate Change Effects Increase Uncertainty in Fish Yields: Revisiting Narratives of Declining Fish Catches in India’s Ganga River
title_sort flood pulse variability and climate change effects increase uncertainty in fish yields revisiting narratives of declining fish catches in india s ganga river
topic river flow
flood-pulse
monsoon rainfall
global climate change
atmospheric teleconnections
fishery yields
url https://www.mdpi.com/2306-5338/9/4/53
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AT subhasisdey floodpulsevariabilityandclimatechangeeffectsincreaseuncertaintyinfishyieldsrevisitingnarrativesofdecliningfishcatchesinindiasgangariver
AT jagdishkrishnaswamy floodpulsevariabilityandclimatechangeeffectsincreaseuncertaintyinfishyieldsrevisitingnarrativesofdecliningfishcatchesinindiasgangariver