Whales are more than good looking, they’re good eating!

As I’ve said to several of you, you don’t have to decide between being an invert person or a mammal lover; you can be both!  Just study whale falls.  I find them absolutely amazing.   Almost immediately upon sinking, hagfish to amphipods to sleeper sharks converge to this feast of the deep removing from 40 to 60 kilograms/day.  An average sized whale can be striped to the bone within a few months.  After a year, the whale bones and organically enriched sediment host 1000′s of polychaete worms (some estimates of up to 45,000 per square meter), crustaceans and molluscs.  Many of these whale fall specialists are new to science so if you study these perhaps you’d get to name your own species.

A year or two after the whale fall, when the organic matter has been consumed, sulfur reducing bacteria will feed on the fats and oils deep within the whale bones.  This third stage is a self contained food web getting most of its energy from chemosynthetic bacteria.   These are animals that graze on the chemosynthetic bacteria as well as critters that live off the bacteria living within their own bodies.  This stage may have up to 190 species of macroscopic animals feasting on a single whale.  At least one of these whale falls has lasted 50 years.

Thirty million year old piles of fossil whale bones and clams hint that whale falls have been happening as long as there have been whales.  And they might not be all that uncommon today.  Craig Smith (University of Hawaii) estimates there may be a dead whale every 5 to 16 km  along the seafloor of the Pacific. Another estimate gives the number of active whale falls in the world’s oceans as 600,000 at any one time.  The environmental problem here is that whaling has reduced whale populations by up to 75% in some of the world’s oceans meaning whale fall specialist that have evolved over millions of years may be facing extinction due to lack of ‘habitat.’

For a video of a whale see the following web site: http://www.youtube.com/watch?v=vQbGk4sHROg

Info for this blog came mainly from an online article by Kim Fulton-Bennett , Whale falls – islands of abundance and diversity in the deep sea and also the book The Deep by Claire Nouvian.

Were I to chose a marine biology topic  I’d really like to study, whale falls would surely be at or near the top of the list.

Phil

Comments

comments

This entry was posted in Uncategorized. Bookmark the permalink.