Gulf of Alaska Expedition Finds Abundant Life on Surface, Sea Floor

Image via Oceana.

Researchers engaged in a Gulf of Alaska expedition in late May for ocean conservation organization Oceana say they found every marine site filled with life, from the surface to the seafloor

Their initial report on the eight-day expedition exploring 23 sites in search of deep-sea corals and other seafloor habitat areas notes finding striking coral gardens in an area south of Kodiak Island in the open Gulf of Alaska, in an area still open to bottom trawling.

Large groves of sea whips, a soft coral, were found in an area closed to bottom trawling to protect king crab. Sea whip groves provide vertical structure in soft sediments on the seafloor and are used by fish and invertebrates to hide from predators. The same area also had other organisms like sea pens, another form of coral that grows in soft bottom areas. Oceana researchers said sea whips and sea pens are essential habitat as they can often be the only vertical structures in soft or sandy areas.

At the surface the expedition observed feeding humpback and fin whales, large groups of black footed albatross, Laysan albatross, tufted puffins, pupping northern sea otters, Steller sea lion haul outs and a single juvenile northern fur seal, a rare sighting in the open Gulf of Alaska.

Looking beneath the waves, researchers found the water column teeming with krill, squid, copepods, jellies and other small organisms, many of which are food for fish and other marine life.

On the seafloor they found hydrocorals, sponge beds, brittle stars, anemones, sea cucumbers and many other animals spread across boulders, cobblestones and other areas of the seafloor.

The corals sponges and other seafloor structures provide habitat for fish to feed, breed and hide from predators. Small organisms like krill and squid provide food for herring and salmon. These fish in turn are food for birds, mammals and other surface life.

Oceana biologists say that they’ve observed coral rubble in flat, hard bottom habitat in areas still open to bottom trawling. They contend that coral habitats on the offshore banks targeted by the trawl fleet are at risk of destruction.

They said they plan to present the expedition’s findings to fisheries managers with National Marine Fisheries Service and the North Pacific Fishery Management Council in coming months as they advocate for conservation of what they have identified as essential fish habitats.