IUCN makes bold claim that heightened extinction risk of African freshwater biodiversity threatens livelihoods
Today IUCN launched the results of a 5-year project to apply Red List extinction risk categories to 5,167 species of African freshwater biodiversity. The results are worrying – 21% of freshwater species were classed as threatened with extinction. Interestingly the IUCN press release explicitly states that this trend puts “the livelihoods of millions of people at risk” citing as evidence estimates of 7.5 million people in Sub-Saharan African depending on inland fisheries and the case of overfishing a group of fish know as ‘chambo’ in Lake Malawi (link for full details). Whilst the tactic of aligning extinction risk with threats to livelihoods is clearly intended to gain policy attention in relation to water extraction, dams and invasive alien species, I wonder whether the claimed causal link is as solid or clear cut as suggested. For instance, to what extent are ‘replacement’ fisheries composed of ubiquitous species dependent on the biodiversity in the system, or put another way what happens to other fresh water biodiversity with human use value when native fish assemblies are eradicated and replaced with a few food fishes? In short, is there a scientific basis for using the outputs of a threshold-based categorisation scheme to predict that millions of people will lose a key source of income, food and materials? This is not intended to suggest that the IUCN are being alarmist, rather it is to prompt discussion on the evidence we have, or the future research we need, to test causal links between the maintenance of freshwater biodiversity and the maintenance of freshwater ecosystem services. With water development set to increase massively across Africa, with for example, a doubling of irrigated land area by 2025 there is clearly an urgent need to marshal evidence and arguments.