Influence of climate variability and human activities on carp spawning dynamics in Tanguar haor and the Surma river in Bangladesh
摘要
This study investigates the ecological impacts of climate variability and human activities on carp spawning dynamics in Tanguar haor and the Surma river, Bangladesh. Spawn collection was conducted using the Savar-net (spawn collection net) technique, supported by participatory rural appraisal (PRA) surveys and GIS mapping to characterize habitats. Data from 240 fishers were analyzed through principal component analysis (PCA) to identify key drivers of spawning variation. Results showed a marked increase in fish spawn harvest in the Surma river, from 1.01 kg in 2021 to 3.90 kg in 2022, while Tanguar haor yields rose from 0.40 to 0.60 kg during the same period. Notably, 41.5% of the recorded species were classified as threatened. Three minor carp species, Labeo calbasu, Labeo bata, and Labeo gonius were present in both ecosystems. Statistical analysis revealed strong positive correlations between carp spawning and water pollution (r = 0.81), weather fluctuations (r = 0.806), and brood-fish hunting (r = 0.806), while siltation showed a strong negative correlation (r = −0.772). These findings highlight the combined pressures of climate variability and human activities on spawning success. The study provides critical insights for fisheries management, ecological conservation, and the sustainable use of wetland resources in Bangladesh.