algae are often restricted to the top 100 meters of the ocean
abyssal_zone is ocean_stratification_zone. abyssal_zone is not ocean_stratification_zone. ocean_zone is water. find_underwater is not algae. ecosystem_extreme is ecosystem. ocean_zone is not ocean_stratification_zone. find_underwater is algae. ocean_zone is ocean_stratification_zone. multicellular_algae is algae. unicellular_algae is algae.