UV penetration of fresh water 3-4 meters most likely less for Ocean salt water. Whales survive TK time period but Dinasaurs are bowled out.
<http://www.google.ca/search?hl=en&q=UV+ultraviolet+penetration+of+water&spell=1UV Ultra Violet penetration of
water.
Google seems like a very good search engine. Change search word format and you might get a better explanation.
ie: UV Ultra Violet penetration of ( ocean, sea ).
http://www.life.ca/nl/52/lakes.htmlUV penetration of fresh water.
regards,
