A scuba diver takes measurements of a Starfish on a coral reef underwater scuba diving in the ocean

starfish sea star arms asyeroidea scuba diver scuba diver person hand underwater soft coral coral reef citizen science marine research data collection study ruler measurement underwater research marine scientist ocean great barrier reef gbr scuba scuba diving diver tropical destination tropics marine conservation marine park animal encounter fish nature wildlife water activity ecosystem creature animal behaviour colourful blue planet aquarium collector unique 4k resolution underwater light sea creature behavior