[Airthumbs (OP)]

I ask this question due to a recent documentary "Planet Earth" by the BBC, where the oceans are described as being similar to desserts on land, in that there are large open spaces where little life exists. 

[CliffordK]

I didn't see the special.

Life isn't uniform in different parts of the ocean.  So, the fish living on a continental shelf, or near the shore are much different than those living in deep water.  And this would have been true throughout time.

Humans have impacted ocean life.  For example sea organisms tend to like structures to build in...  so sunken ships form "artificial reefs" which are often teaming with life (although there is some risk from toxins aboard).  Some places such as Guadalcanal have mostly recovered since the WWII environmental devastation, and now has lots of life in the artificial reefs provided by the war.

There are some "Dead Zones", in particular near the outlet of some large rivers that otherwise should have been teaming with life, but have been contaminated with agricultural runoff or such.  While disturbing to the local harbors, the impact to the 139 Million Square Miles of ocean is likely minimal.

Over the last 100 years, we have made measurable changes in our environment including nuclear fallout from atomic bombs, and various toxins and chemicals throughout the environment including the atmosphere and oceans.

There is some ability for the oceans to absorb toxins and either break them down or bury them, but the capacity isn't infinite, especially if our population growth remains unchecked.

[SteveFish]

Your response suggests that you should look at the link I posted on another thread.

http://sackler.nasmediaonline.org/2007/ile/jeremy_jackson/jeremy_jackson.html

[Airthumbs (OP)]

Stevefish, thanks for that link, it really does answer my question in more depth then I could have hoped for. As the full lecture is 44mins, I will have to listen to it all in it's entirety at some point but I know it will only be depressing and confirm what I already suspected. 

[Mingfei Shao]

the topic should be highlighted !

[Airthumbs (OP)]

Mingfei Shao, I agree totally  []

[Variola]

I ask this question due to a recent documentary "Planet Earth" by the BBC, where the oceans are described as being similar to desserts on land, in that there are large open spaces where little life exists. 

A quick google seems to confirm your question, that areas of ocean that are 'least biologically productive" are increasing in size, possibly due to climate change, or to natural changes over time.

For me it seems ludicrous to claim an area is not as biologically productive as other areas due to lack of higher vertebrates, but I am biased as I view things in terms of microbial eco systems, and I am no marine biologist! These areas could be of significant importance to some life that cannot exist in other areas.