Socio-economic development, scientific research, and exploitation explain differences in conservation status of marine and freshwater chondrichthyans among countries

Abstract

Sharks, skates, rays and chimaeras (chondrichthyans) are of high conservation concern; especially obligate freshwater chondrichthyans, given their restricted ranges, proximity to humans, and threatened habitat. The biological traits that increase chondrichthyan susceptibility to extinction are well known. Less attention has been put on the human determinants of chondrichthyan conservation status. Socio-economic development, scientific research, and exploitation affect natural resource management and conservation. We assessed the relationship between these factors and chondrichthyan conservation. We ran generalized linear models with number of Threatened (THR), Least Concern (LC), and Data Deficient chondrichthyans as dependent variables, and indicators of socio-economic development (governance, human security, human development, and corruption indices), scientific research (number of papers on chondrichthyans), and exploitation (total, industrial, and foreign catch of chondrichthyans), as independent variables. Human density instead of exploitation was a predictor for obligate freshwater chondrichthyans. Socio-economic development (regardless of the index used) and scientific research were associated to desirable conservation status, such as low THR and high LC, for both marine and obligate freshwater species. Exploitation and human density (for obligate freshwater chondrichthyans) were associated to negative conservation status, i.e. high THR and low LC. Current human density projections translated into a 69% decrease in obligate freshwater chondrichthyans LC by 2050. Development produces desirable conservation status for chondrichthyans, but resource overconsumption must be reduced. Scientific research appears to assist sustainable use of chondrichthyan resources, and should be promoted in developing countries. Assessment and conservation of obligate freshwater chondrichthyans, and freshwater biota in general, must be pursued with urgency.