The conservation of biodiversity through the use of information contained in The IUCN Red List is especially tailored towards the conservation of species that are threatened with extinction. It is natural that the affinity and resources for conservation would turn towards these species and in this regard The IUCN Red List has been exceptionally valuable in guiding conservation work that helps prevent extinction. But, if the goal is holistic biodiversity conservation (it is!) then it is essential that conservation seeks to conserve species as part of larger assemblages, like ecosystems. In this regard, common native species are often in a prime position to provide critical information on the health of broad species assemblages and ecosystems.
Perhaps one of the most challenging aspects of modern species conservation is the shifting perspective of what constitutes a healthy ecosystem. Generally, what you would consider a healthy ecosystem is based on your experiences with nature as children, although the wealth of historical accounts on the extent of species show a very different picture of life on Earth. For instance, when Europeans first began fishing the Grand Banks off the Canadian East Coast, there were so many fish that they literally fished with weighted buckets, hauling up round after round of enormous, 200 pound codfish. Each generation has a different perspective on what a healthy ecosystem looks like and there is evidence that the erosion of global biodiversity combined with the typical human lifespan have produced a situation where conservation is aimed at conserving biodiversity to acceptable levels that are far less than their historical maximums.
Although we have made tremendous advances in conservation science and policy in the past 50 years, the baselines of global biodiversity have shifted faster than the pace of species discovery or measurement, especially in the oceans. It wasn’t until the Decade of Biodiversity from 2000–2010 that science began to accumulate a truly global picture of biodiversity through coordinated national analyses of biodiversity—much of which has been based upon or influenced by IUCN Red List assessments.
As baselines are measured and information about species accumulates, it is becoming clearer that threatened species should not be the sole focus of our conservation attention; there are also measurable declines in many once common species. Perhaps some of the most ironic examples of the decline in common species are those threatened species that still have “common” names. For example, the Common Skate (Dipturus batis) was once one of the most abundant animals in the North Atlantic Ocean and Mediterranean Sea, but is now classified as Critically Endangered on The IUCN Red List. Similarly, the Common Hippopotamus (Hippopotamus amphibius), Common Seahorse (Hippocampus kuda), and Common Tortoise (Testudo graeca), all listed as Vulnerable, are threatened species that were once so plentiful that they were self-titled.
The IUCN Red List is not only a list of threatened species, it is one of the only ways that humanity is able to scientifically account for species that are currently of Least Concern—the more common species. The IUCN Red List can be a valuable tool for conserving threatened species, but perhaps its greatest utility is that it also provides measurements on the status of common species and by extension, the broader ecosystems they form. This provides a more comprehensive outlook of species conservation that makes it possible to amplify current biodiversity towards increasing baselines and establish the momentum to conserve the once and future common species.