‘Nemo’ fish threatened by global warming

This video is about orange-fin clownfish, aka orange-fin anemonefish.

Ocellaris clownfish became famous by the film Finding Nemo.

However, this species, and its clownfish (or anemonefish) relatives are now threatened by global warming. Though the fish themselves can stand warmer ocean water, the sea anemones on which they depend cannot.

As shown by research about orange-fin anemonefish (Amphiprion chrysopterus) in Moorea, French Polynesia; from Nature:

Cascading effects of thermally-induced anemone bleaching on associated anemonefish hormonal stress response and reproduction

10 October 2017

Abstract

Organisms can behaviorally, physiologically, and morphologically adjust to environmental variation via integrative hormonal mechanisms, ultimately allowing animals to cope with environmental change. The stress response to environmental and social changes commonly promotes survival at the expense of reproduction. However, despite climate change impacts on population declines and diversity loss, few studies have attributed hormonal stress responses, or their regulatory effects, to climate change in the wild. Here, we report hormonal and fitness responses of individual wild fish to a recent large-scale sea warming event that caused widespread bleaching on coral reefs.

This 14-month monitoring study shows a strong correlation between anemone bleaching (zooxanthellae loss), anemonefish stress response, and reproductive hormones that decreased fecundity by 73%. These findings suggest that hormone stress responses play a crucial role in changes to population demography following climate change and plasticity in hormonal responsiveness may be a key mechanism enabling individual acclimation to climate change.