First Marine Fish Declared Extinct. Mass extinction? What Mass Extinction?

I was rather miffed with myself to have completely missed an important but sad conservation biology milestone back in March this year when the IUCN Redlist of Threatened Species was updated to list the smooth handfish Sympterichthys unipennis as officially extinct. The milestone got a bit of coverage in the news but given the nature of news cycles these days it’s sort of understandable that a database updating to declare an obscure and not especially photogenic animal extinct, a fish no less, got a bit buried. But why was this particular bit of news such a landmark? The listing of Sympterichthys unipennis¬†as extinct by the IUCN is the first marine bony fish to be declared extinct in modern times. Now, that needs a bit of unpacking. There’s a bit of weaselling there to turn it into a more notable fact but given how we’re inundated with information – about biodiversity loss, changes we should all be making to benefit nature – how is it only now that the first (marine, modern etc. etc.) fish is being declared extinct? Have scientists been alarmist all this time? One extinct fish out of the tens of thousands of living species doesn’t seem too bad, does it? Surely you’d expect more if we are in the midsts of the sixth mass extinction?

Let’s unpick what this status change means and delve into a topic that genuinely keeps me up at night: how do we know a species is extinct? Hopefully this will help clarify why this is an important milestone and why it absolutely doesn’t mean that worrying claims about biodiversity loss are overly cautious or unwarranted. Continue reading