Dilemma on the ban on exotics in Indian subcontinent: A systematic review in a socio-economic perspective

This paper overviews the role of exotic fishes in providing ecosystem services such as employment, economy, efficiency, exchange and equity using various case studies in the Indian subcontinent in a socio-economic perspective. Case study I identified that the culture period of exotics especially Tilapia species (i.e., 180-200 days) created a total labour requirement of 840 labour days compared to agricultural labour. Case study II identified a 20% increase in contribution of share of the fisheries sector during 2010-2019 to the country's national Gross Value Added (GVA) due to exotics. Case III found that the fisheries export earnings of exotics in fiscal year 2019-20 increased to over 6678.69 million USD from 2132.84 million USD in 2009-2010. Case study IV identified greater involvement of women in fish farming activities, especially 2% in intensive aquaculture and 50% in extensive aquaculture. The current systematic review attempted to highlight that exotic fishes have a productive role in steering the regional economy through providing basic tangible ecosystem services that may be identified in monetary terms. The identification and evaluation of aquaculture-based ecosystem services provided by exotic fishes often leads to a dilemma whether to ban or promote the culture of such exotic fish species. Previous studies revealed that the economic impacts of aquatic exotic species are significantly positively correlated with their ecological impacts. Unfortunately, assessment of ecological impacts required evaluation of losses due to exotics or ecosystem services offered by exotics, which was greatly lacking across globe. This review summarizes the positive effects of exotics taking ecosystem services into account, despite the need for controlling invasive species for the ecology.