Complex sentence: Fertilizer runoff combined with the increasing salinity and inflow of highly polluted water from the New River have also resulted in large algal blooms and elevated bacteria levels in the Salton Sea; with the lack of an outlet, it is increasingly becoming an unstable system.
Split into simpler sentences: Fertilizer runoff combined with the increasing salinity and inflow of highly polluted water from the New River have resulted in large algal blooms and elevated bacteria levels. With the lack of an outlet, the Salton Sea is increasingly becoming an unstable system.