|
|
Article: Ocean Ecosystems: Hard Bottoms
- Article from:
- Biology
- Author:
CopyrightCOPYRIGHT 2002 The Gale Group Inc. This material is published under license from the publisher through the Gale Group, Farmington Hills, Michigan. All inquiries regarding rights should be directed to the Gale Group. (Hide copyright information)
|
Ocean Ecosystems: Hard Bottoms
The term "hard bottom" refers to the ocean region close to shore, where wave action prevents the accumulation of muddy sediment that will create a soft bottom. Plants and animals living on or in the seafloor are called benthos. Benthic epifauna reside on or attach to a rocky substrate (surface). Benthic infauna bury themselves in soft sediments or bore into the rocky bottom or shells of other animals.
Seaweeds, a kind of algae, anchor to the bottom with holdfasts. Unlike the roots of higher plants, holdfasts do not extract nutrients. Many seaweeds have pneumatocysts, gas-filled bladders that keep the photosynthetic parts of the seaweed in the photic zone, ...