Ocean Warming Causes Sharp Decline in Fish Populations

A study published in Nature Ecology & Evolution reveals that for every 0.1°C increase in ocean temperature per decade, fish populations decline by an average of 7.2%. The faster the temperature rises in the deep ocean, the more severe the fish losses become. The study indicates that bottom-water warming is a more critical long-term stressor than surface-water warming. Bottom-water heating compresses cold-water fish habitats, reduces dissolved oxygen levels, disrupts bottom-feeding food chains, and directly impacts egg hatching rates and juvenile survival, further accelerating population decline.