The Future Species of Anthropocene Seas

Averting extinctions in an increasingly affluent and populated world is the challenge of our generation. The defining features of geological epochs are the mass turnover and extinction of species, genera, and families. The oceans of the Anthropocene epoch face a multitude of problems, competing demands, and diagnoses of solutions. Here, we argue the most pressing problem is the risk of losing populations and species in the Anthropocene. A key challenge is that our interpretation of species’ status depends on what we care about and value. The prevailing mindset has been unbelieving of the possibility of marine extinctions; indeed, only the local extinction of sawfishes in South Africa has been documented in real time. Unseen and unmanaged, more than a hundred local, regional, and global extinctions have been detected retrospectively half a century after the fact. Looking to the future, we need to develop approaches to diagnose and manage marine species, recognizing a wider range of perspectives on what our future oceans could look like. To this end, we show that we can prioritize populations and species for intervention using simple rules-of-thumb grounded in evolutionary ecology. Finally, we conclude that a pressing, but overlooked, need is to protect species to avoid extinctions, thus securing the full portfolio of biodiversity.