moving fast in water has a positive impact on an aquatic animal's survival
fish is not aquatic_animal. treading_water is aquatic_body_movement. moving_water is not running_water. running_water is moving_water. treading_water is not aquatic_body_movement. splashing is aquatic_body_movement. fish is aquatic_animal. moving_water is running_water. splashing is not aquatic_body_movement. aquatic_ecosystem is not water.