These normally play an important role in controlling the growth of algae and also forage on detritus that accumulates as sediment on the bottom.
ðiːz nˈoːɹməli plˈeɪ ɐn ɪmpˈoːɹtənt ɹˈoʊl ɪn kəntɹˈoʊlɪŋ ðə ɡɹˈoʊθ ʌv ˈælɡiː ænd ˈɔːlsoʊ fˈɔːɹɪdʒ ˌɔn dᵻtɹˈaɪɾəs ðæt ɐkjˈuːmjʊlˌeɪts æz sˈɛdɪmənt ɔnðə bˈɑːɾəm.