Fish and zooplankton carry carbon into the deep ocean

Zooplankton and fish carry carbon into deep ocean water on their daily dives. A new study reported from Palma, Mallorca, on 21 October 2026 shows how those journeys help move carbon down. Many of the animals feed near the surface at night, then descend during the day.

Researchers at the Spanish Institute of Oceanography (IEO-CSIC) say the animals’ breathing, excretion and other bodily processes carry carbon into deeper water. The journeys are part of what scientists call the biological carbon pump: carbon taken up near the surface can reach the deep ocean and remain there for long periods.

Movement connects sea habitats in other ways, too. Currents carry eggs and larvae, linking populations and helping organisms reach new habitats. Animal migrations and the movement of waste and organic remains also spread nutrients and energy between open water, the seabed and other habitats.

The study, published in Aquatic Conservation: Marine and Freshwater Ecosystems, warns that changes to currents or migration routes can have effects far beyond where they occur. Climate change and other human pressures may alter how larvae spread and how habitats exchange nutrients and other material.

That matters for marine protection. Protected areas can depend on larvae or nutrients arriving from beyond their borders. The researchers say these links between habitats — known as marine functional connectivity — should play a bigger part in planning and managing sea areas.

Topics: Nature & wildlife · Environment · Pollença

Source: Europa Press / Mallorca.com