Oceans

Artificial coral reefs
3D-printed artificial coral reefs could save coastal fish
3D ocean farming
3D ocean farming: creating food while cleaning the ocean 
Atlantic horseshoe crab at St. Lucie County Marine Center in Fort Pierce, St. Lucie County, Florida, U.S.A.
Horseshoe crabs are drained for their blue blood. That practice will soon be over.
Nuku'alofa, Tonga, as the island nation has been cut off from the world due to a break in an undersea cable.
Undersea cable laws have hardly changed since 1884 – Tonga shows they need modernizing 
bycatch
Green lights reduce bycatch in fishing nets by 63%
The return of sail power
jellyfish nervous system
What the ancient, alien jellyfish can tell us about the human brain
Magical coral spawning event gives reefs renewed hope
reef restoration
Underwater speakers draw fish to restore coral reefs