Watch Lords of the Deep

In the near future the surface of the Earth has become uninhabitable and the human race is searching for new environments to live in, including a series of underwater bases like the one inhabited by a crew of scientists studying life beneath the waves. Claire is a biologist who discovers a mass of a jelly like substance she takes back to her lab, a maintenance crew working outside the base are then attacked by large stingray type creatures. One of the crew members is attacked and begins to transform into an unimaginable sea creature.