Three from Science Alert this week with the first being "Rare aerial footage reveals a pod of whales chasing down a shark" here.
Also, "Scientists have tracked where whale sharks go after tourist season." Find out more here.
Finally, early this month, "Scientists [were] streaming a live video feed of the Mariana Trench." Grab some info on it and some pictures here then check out footage of Okeanos on their YouTube channel here.