Complex sentence: By 2002 a cave survey had been completed by the Western Belize Regional Cave Project, recording a total of 6400 m of passages; dye traces at sinking streams above the cave indicated that there could be a further 6 km of cave passages beyond the terminal sumps.
Split into simpler sentences: By 2002 a cave survey had been completed by the Western Belize Regional Cave Project, recording a total of 6400 m of passages. Dye traces at sinking streams above the cave indicate that there may be a further 6 km of cave passages beyond the terminal sumps.