The BBC has put together a terrific guide to the world's endangered whales. It's a web resource that's well worth a look if you're interested in these magnificent mammals. It gives readers a good sense of the different species of whales with illustrations and information about distribution and physical characteristics.

The guide also provides details about the impact commercial whaling has had on each species. It includes estimates of past and current population sizes for the various breeds.

The species described in the guide include:

• Minke Whale
• Humpback Whale
• Bryde's Whale
• Sei Whale
• Sperm Whale
• Fin Whale
• Blue Whale

Find out more: Endangered Whales (BBC News)

Photo: Fin Whale (Balaenoptera physalus). Protected Resouces Division, Southwest Fisheries Science Center, La Jolla, California (swfsc.nmfs.noaa.gov/PRD).