When I'm brainstorming ideas, I like to use the organizational chart (in Word) - or you can do it just as easily by hand.
Start with a main subject, then branch out to what you may know or have heard of regarding that subject. You may have one branch or twenty off the same main subject.
Looking at the website you posted I noticed articles about sharks. I don't know much about Fish, but had one thing pop in my head immediately.
1. Main subject - FISH
A. Branching off - the fish (not sure what its called, but I've seen one) that is born with two eyes and stays on the bottom of the ocean until both eyes move into one socket & it ends up with one eye on one side of its head.
2. Main subject - nature cleaning up after itself
A. Again, I don't know the name of them, but there is a small fly of some type that you get started and they eat what we call stable flies or house flies
B. Maggots cleaning up dead flesh
C. Buzzards taking care of road kill
Those aren't great examples by any means, but you get the drift. Sometimes it is just a matter of getting an order to your thoughts.