Page 39 - living-ice

PHOTO: Shawn Harper, UAF
The sea ice as a nursery
for benthic organisms
The sea ice is a habitat for some benthic (or bottom-dwelling) organisms for phases of their lives. The bristle worm is a good example of this. In the larval stage, the bristle worm is microscopic (less than 1 millimeter long) and lives with tens of thousands of other larvae and juveniles in the maze of tunnels that forms the crystal palace in the sea ice. In early spring, a banquet is served inside this palace and the bristle worm can feast on the incredible algal bloom. Without leaving the sea ice, the bristle worm gets a head start on the organisms that are waiting for an equivalent algal bloom in the water column beneath the ice. The bristle worm juveniles grow faster inside the ice than in the water below, and at the same time the maze of channels inside the crystal place protects the bristle worm larvae from the predators in the underlying water column. During its early phases, the polar cod also lives in the sea ice. Young polar cod can nd suf cient food and protection from predators in the nooks and cracks of the ice. Polar cod is a small but fat-rich sh, the staple food for many Arctic seals and the most abundant food in the entire Arctic ocean.