Mr Watson is the founder of Sea Shepherd, the conservation group based in Malibu, California, whose two ships patrol the seas challenging illegal fishing and whaling.
Trapped droplets of ancient seas are challenging long-held beliefs about the ocean's history.
For more than two years now China has been buzzing the islands by air and sea to challenge Japan's claim of control, and last November included them in an "Air Defence Identification Zone".
On Monday, the head of Egypt's state-run provider of air navigation services, Ehab Azmy, said the plane plunged directly into the sea and challenged an account by the Greek defence minister that it made "sudden swerves" before the crash.
In January 2013, Manila said it was taking China to a UN tribunal under the auspices of the UN Convention on the Laws of the Sea, to challenge its claims.
This year, the legality of this protracted detention at sea was challenged before Australia's High Court.
D'Estaing found his anchored ships were now vulnerable to attacks from land batteries, warships and fireships, and cancelled the landing, putting to sea to challenge Howe in battle.
The vastness and inaccessibility of the deep sea has challenged scientists seeking to understand its diversity [ 1, 2].
Tying down mobile species to particular sea zones is challenging, but where there is a static life-history phase (such as egglaying) it is more feasible.
The simulation model presented in this paper has been developed to rapidly progress the design, development and validation of Halcyon's autonomy management system, particularly in challenging sea conditions.
It is very similar in appearance to the slightly larger Fea's petrel, and separating these two Macaronesian species at sea is very challenging.
