Evaluating Potential Occurrence of Sound

NOAA provides the guidance below to assess potential for listed ESA marine mammal occurrences in project areas. There are 8 marine mammal species on the West Coast of the United States.  Southern Resident killer whales occur predictably in Washington and Oregon water, but their range includes California up to the Queen Charlotte Islands.  Other Endangered Species Act-listed marine mammals and turtles can occur in Washington and Oregon waters, but are generally less likely to occur in nearshore areas. More information about these species is available in stock assessment reports and status reviews.

Southern Resident killer whales spend considerable time in the Georgia Basin from late spring to early autumn, with concentrated activity in the inland waters of the state of Washington around the San Juan Islands, and then move south into Puget Sound in early autumn. While these are seasonal patterns, Southern Resident killer whales have the potential to occur throughout their range, from central California north to the Queen Charlotte Islands, at any time of the year.

The Whale Museum manages a long-term database of Southern Resident killer whale sightings and geospatial locations in inland waters of Washington State. While these data are predominately opportunistic sightings from a variety of sources (public reports, commercial whale watching, Soundwatch, Lime Kiln State Park land-based observations, and independent research reports), these orcas are highly visible in inland waters, and widely followed by the interested public and research community. The dataset does not account for level of observation effort by season or location; however, it is the most comprehensive long-term dataset available to evaluate broad-scale habitat use by Southern Resident killer whales in inland waters. For these reasons, NOAA Fisheries relies on the number of past sightings to assess the likelihood of Southern Resident killer whale presence in a project area when work would occur. The Whale Museum developed a set of maps that reports the number of unique Southern Resident killer whale sighting days 5.1MB in inland waters per quadrate 94.5MB and month over a near 20-year timeframe.