Burrowing crayfish (Crustacea: Decapoda: Parastacidae) as a tool for biomonitoring groundwater quality in South America.

Groundwater-dependent ecosystems are among the most important and least understood natural environments on the planet and are currently known as components of the connected groundwater systems that are in turn a part of complex socioecological systems. In these ecosystems in South America, contamination processes are little studied, but contamination infiltration can be fast and hard to manage, which makes them particularly vulnerable and puts their ecological structure and function at risk. Ecotoxicological studies in groundwater environments are few and scattered, with most assessing the occurrence of trace elements in crustaceans of subterranean habitats. Therefore, the implementation of biological indicators as a tool to assess the ecological impacts of human associated environmental risks is an important step for the management of these vulnerable ecosystems. Here we use a combination of literature review and the compilation of distribution information to build a case for the suitability of the burrowing crayfish of the family Parastacidae as a candidate biological indicator of groundwater associated environments in South America. Our investigation found that these burrowing crayfish meet a number of criteria for their utility in this context, including their key role in the transfer of energy between different trophic groups, serving as a good model to assess the levels of bioaccumulation of trace elements and other contaminants and their consequent effects on the food chain and the food security and economy of human communities that depend on this crayfish as a resource. Therefore, these burrowing crayfish can serve as valuable tools for understanding complex socioecological systems, biomonitoring groundwater quality, and improving management of ecosystem services provided by groundwater-dependent ecosystems. We conclude by outlining a framework for moving toward implementation of this biomonitoring tool into surveillance and conservation efforts for these native and endemic species in South America.