Complex sentence: It was detected for the first time in 2014 in the Aegean Sea, where scientific divers found specimens growing on rocky substrate and on the rhizomes of the seagrass "Posidonia oceanica".
Split into simpler sentences: It was detected for the first time in 2014 in the Aegean Sea. In this location it was growing on rocky substrate and on the rhizomes of the seagrass "Posidonia oceanica".