Phytoplankton are essential to aquatic life zones because: they provide the basis of food chains. Log in for more information. Added 5/22/2016 9:52:12 AM This answer has been confirmed as correct and helpful.
Explanation:One of the reasons for this is that there is little or no magma available at the plate boundary. The most common magmas at constructive plate margins are the iron/magnesium-rich magmas that produce basalts.