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How do aquatic animals use lift to steer underwater?

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Least tern, Sternula antillarum, flying with wings raised and its yellow-tipped black bill pointed forward. — Locomotion These birds largely reside in coastal areas of North America, although some populations live in the continent's interior along large rivers.

In aquatic environments, animals utilize lift primarily as a steering aid rather than a source of propulsion. This lift is generated by the flow of water across specific body surfaces, similar to the principles of flight in air, where pressure differentials are created by water flowing at different speeds across surfaces.1

For many aquatic vertebrates, such as fish, whales, and seals, the anterolateral fins serve as the major steering organs, helping to counteract pitching (dorsoventral seesawing) movements. In some invertebrates, such as scallops, the body form of a closed shell acts as an airfoil. When combined with the downward ejection of water, this shape produces lift to assist in their movement.23

While some animals like penguins and sea turtles use their bladelike flippers to provide both lift and thrust through synchronous, wing-like movements, these mechanisms are specialized for propulsion and maneuvering within the water column.4