Thursday January 11, 2024
The Conversation —
Why would oceanographers ever care about anchovies having sex? We do because these small fish can help mix different layers of the ocean when they mate. This circulates nutrients, oxygen and greenhouse gases around different layers of the ocean, thereby sustaining the ecosystem.
Mixing layers of the ocean vertically requires energy. Most of this energy is provided by winds and tides. However, research that was conducted in 1966 found a mismatch between the energy required for mixing and the energy provided by available sources.
This prompted an intriguing question: can swimming animals such as fish and crustaceans fill the energy gap and contribute to ocean mixing?
After decades of mixed and extremely scarce evidence, the oceanographic community came close to reaching a verdict on the topic in 2019. A study conducted by an American researcher called Eric Kunze concluded that biological mixing is extremely unlikely to happen.