Complex sentence: Lake Myvatn, Iceland, has dense colonies of marimo that grow to about 12 cm in diameter and form well defined patches on the lake floor at depths ranging from 2-2.5 m. The colonies were discovered in 1978 but have shrunk considerably in size since then.
Split into simpler sentences: Lake Myvatn, Iceland, has a dense colonies of marimo that grow to about 12 cm in diameter. They live in well defined patches on the lake floor at depths ranging from 2-2.5 m. The colonies were discovered in 1978 but have shrunk considerably in size since then.