Impacts of Invasive Fishes on Fishery Dynamics of the Yamuna River, India

Abstract

Invasion, spread and predominance of alien invasive fishes were studied in 950-km-long stretch of the Yamuna River. The fish yield ranged between 32 t/km/yr to 240 t/km/yr and the catch of alien invasive fishes dominated over local fishes in the fishery, which was over 96% at Etawah. The calculated Invasion Coefficient Index (I xi) of alien invasive fishes was in the range of 0.12 to 0.31 indicating a major loss to the local fish diversity. The calculated Pearson's correlation coefficient was found to have positive correlation of 0.757 and 0.710 for common carp and tilapia respectively with locally captured Indian major carps (IMC). The results of this study highlighted how unintentional spread of alien invasive fishes due to rapid aquaculture diversification and intensification has invaded into the Yamuna River causing severe loss to the local fishery. The invasion of alien fishes has been mapped for the Yamuna River at different locations using GIS tools. The results of this study invite attention on the management and sustainability of the local fishery and ecosystem health of the river.

Sighting of Red-breasted Parakeet Psittacula alexandri (Linnaeus, 1758) (Psittaciformes: Psittaculidae) from Vellayani, Thiruvananthapuram, Kerala, India

“…African Catfish Clarias gariepinus, Red-bellied Piranha Pygocentrus nattereri and South American Suckermouth Armoured Catfish (Pterygoplichthys spp.) have invaded our fresh water ecosystem and depleted populations of our endemic fish species pushing them to extinction (Krishnakumar et al 2011;Singh et al 2014). Lantana camara, Wedelia trilobata, Mimosa diplotricha and other floral invasive species have replaced many native species in (Raghubanshi et al 2005).…”

Changing foodwebs of Indian aquatic ecosystems under the threats of invasive species: An overview

“…India has different climatic zones that support diverse aquatic habitats rich in aquatic biodiversity (Sarkar et al, 2017). In recent decades, the introduction of invasive fish is considered to be a major cause of species extinction posing a major ecological threat to the inland aquatic systems through the displacement of native fauna and alteration in the dynamics (Singh et al, 2014;David et al, 2017). The invasions will profoundly influence the function of the whole foodweb, and as a consequence the trophic relationships are impaired.…”

Occurrence of Ornamental Fishes:A Looming Danger for Inland Fish Diversity of India

“…Studies in the mid-1990s had clearly shown that 20% of the world's freshwater fish fauna is already extinct or is on the verge of extinction 9 . Globally, invasive alien species are considered as one of the major factors for devastation of freshwater ecosystem, and have emerged as a great threat for the existing indigenous aquatic diversity, in particular ichthyo fauna 5,10 . India is one of the regions that supports unique and immense aquatic diversity.…”

“…Besides, the exotic species have also paved the way for the entry of new pathogens, which has resulted in the outbreak of new diseases 6,7,12,13 . Recent studies in several parts of India have highlighted the fact that freshwater fish biodiversity is depleting at an alarming rate due to invasion of commercially important and ornamental, exotic fish species 3,6,7,10,14 . Many native species, especially Indian major carps in various riverine systems have been critically depleted due to the introduction of commercially important exotic species such as Nile/red tilapia (Oreochromis niloticus), African catfish (Clarias gariepinus), Thai pangus (Pangasiandon hypophthalmus) and common carp (Cyprinus carpio) 3,10,15 .…”

“…For instance, studies from the Yamuna and Ganga rivers have shown that there is a constant increase in the yield of alien varieties. In Yamuna, the occurrence of tilapia, African catfish, silver carp and Gambusia is higher and the yield is spiralling every year 10,15 . Singh et al 15 reported the highest yield of exotic variety of 384.27 kg/km in the Ganga.…”