Pelagic Ecosystems Overview

A tufted puffin searches for fish. Tufted puffins are one of several species of marine birds monitored in the Gulf Watch Pelagic Ecosystems projects.

The Pelagic Ecosystems component encompasses six projects focused on collecting long-term predator and prey species data from sites centered in Prince William Sound. Pelagic refers to the open seas, as opposed to waters adjacent to land (nearshore). Many of these projects have long-term data sets and publications that contain decades of information ranging from the abundance of whale groups, or pods, to the distribution and abundance of their prey, to how whales, seabirds and prey interact.

Why are we monitoring?

Killer whale and calf

RESIDENT ECOTYPE (AB POD) AND TRANSIENT ECOTYPE (AT1 POPULATION) KILLER WHALES DIED FOLLOWING THE EXXON VALDEZ OIL SPILL IN 1989. THE AB POD IS RECOVERING AFTER 22 YEARS BUT HAS STILL NOT REACHED PRE-SPILL NUMBERS. THE AT1 POPULATION IS NOT RECOVERING AND MAY BE HEADED TOWARD EXTINCTION

These data, when combined with those from the Environmental Drivers component and the EVOS Trustee Council’s Herring Long-term Monitoring Program, are key for addressing questions about food web dynamics, including:

  • What are the population trends of key open ocean species  (killer whales, seabirds, humpback whales, forage fish) in PWS?
  • How can forage fish (fish that are prey for other species of fish, birds or mammals) population trends in PWS be effectively monitored?
  • Are variations in seabird abundance and distribution associated with zooplankton stocks and/or oceanographic conditions?
  • Is the success of herring and forage fish surviving the winter tied to spring and summer productivity (the amount of marine plants that photosynthesize in the ocean) and seasonal or year-to-year differences in the zooplankton community?
  • Is the success of herring and forage fish surviving the winter associated with winter conditions on the Gulf of Alaska Shelf or in PWS?

DOWNLOAD 2015 PELAGIC ECOSYSTEMS COMPONENT OVERVIEW