Tranquil underwater scene with vibrant coral reef and schools of tropical fish in clear blue water

underwater coral reef tropical fish marine life scuba diving snorkeling ocean biodiversity aquatic ecosystem conservation marine biology clear water blue tranquility undersea wildlife natural habitat coral fish ecology environmental diving sea life saltwater adventure nature exploration sustainable tourism marine conservation aquamarine vibrant ecofriendly underwater world snorkelers paradise oceanography submerged coral bleaching reef sustainability flora and fauna ocean depth