Enhancing adaptive capacity of wetland fishers through pen culture in the face of changing climate: A study from a tropical wetland, India

Abstract

Wetlands are among the most productive of all aquatic ecosystems. In developing countries, millions of marginal fishers rely solely on wetlands for security of both nutrition and livelihood. The decline in wetland fisheries owing to anthropogenic and climatic changes has made fishers increasingly vulnerable. Pen culture can be an effective climate-resilient technology for enhancing fish production in shallow, macrophyte-choked, and multi-stake floodplain wetlands, especially in eastern and north-eastern India. In this context, pen culture was implemented as an adaptive measure in a tropical Gangetic wetland (Mathura) to enhance fish production and increase the adaptive capacity of fishers. Indian Major Carps, Gibelion catla, Labeo rohita, and Cirrhinus mrigala of initial size 10.4±.21g, 8.2 ± 0.48g, and 6.5 ± 0.23g respectively, were stocked at the ratio of 4:4:2 and at the rate of 30 fish m-2 each in pens of 100 m2 in duplicate. For purposes of conservation, Labeo bata and Gudusia chapra, 4.3 ± 0.18g and 3.8±.34g initial size, respectively, were stocked at the rate of 20 Nos.m-2 each at the ratio of 1:1. The fish were fed with commercial feed at the rate of 4% of body weight. A net survival of 82%, 87%, and 75% was recorded in Indian Major Carps, L. bata and G. chapra. A production of 380 kg IMC was achieved during 120 days of the culture period. L. bata achieved an average weight of 21.40 ± 0.34g during the 90-day culture period, with a survival rate of 87%. G. chapra attained an average weight of 16.5 ± 0.42g during the culture period, with a recorded survival rate of 75%. G. chapra was observed to spawn in the pen. The water quality inside pens and reference sites did not differ significantly (p >0.05). The produced fish were released in the wetland for fisheries enhancement. The present communication discusses the technological suitability and economic feasibility of adopting climate-resilient pen culture as an adaptation measure for enhancing the adaptive capacity of wetland fishers in the face of a changing climate.

Ecological assessment of the Amazon sailfin catfish (Pterygoplichthysspecies) within the Indian freshwaters: a mesocosm-based approach

“…IMC that we used for our study are economically valuable food fish (Dwivedi et al, 2004) and contributes to about 58% of aquaculture production in India with a gross commercial value of ~$3.11/kg (as reported in 2021) (Karnatak et al, 2021) Among the IMC species, rohu is the most preferred aquaculture species for its considerably higher market price in comparison to catla and mrigal (Asaduzzaman et al, 2010;Rasal & Sundaray, 2020). Rohu is primarily a column feeder mostly predating upon planktons and periphytons (Majumder et al, 2020).…”