Complex sentence: Lough Lene had a notable population of Fresh water crayfish, a species that is listed on Annex II of the E.U. Habitats Directive, this species disappered from Lough Lene in 1987 following an outbreak of crayfish fungus plague.
Split into simpler sentences: Lough Lene had a notable population of fresh water crayfish, a species that is listed on Annex II of the E.U. Habitats Directive. This species disappeared from Lough Lene in 1987 following an outbreak of crayfish fungus plague.