Where Have the Southern Residents Been?

July 10, 2019

If the presence (or absence) of the Southern Resident killer whales in what is supposed to be their “core summer habitat” is a measure of how well that habitat (officially designated as Critical Habitat) provides the benefits and protections the whales need, the whales are not giving the area a passing grade.  The Southern Resident killer whales were missing from their “core summer habit” for two months from early May until early July.  Their unprecedented absence at this time of the year has many wondering where the residents have been and whether or not they have been seen.

     Yes, while the whales were conspicuously absent from the “core summer habitat” in recent months, members of the J, K, and L pods, including the elusive L54’s, have been photographed by several different research groups operating under permit in coastal waters.  However, it is important to note that no single research group has a complete compilation of all of the most recent Southern Resident sighting information on a day-to-day basis or in real time.

     The most detailed encounter information at this time of year typically comes from research encounters.  There are at least seven different organizations in the US and Canada operating under permit in coastal waters, some encountering residents while out on coastal surveys or out on the water for a different purpose, and others conducting field research focused on killer whales.

     It is customary for many of the research teams to provide their photos of Southern Resident killer whales to the Center for Whale Research, the research group that has been compiling photographs and documenting sightings for more than 40 years.  However, several sources typically delay sending their photos until the fall and winter months, after their field seasons have concluded and the pace is not so hectic.  Hence much of the photo ID work that is done at the Center for Whale Research for the coastal sightings is a winter project.  

 

     Therefore, as much as people may want to know where the whales are on a daily basis, the simple truth is that the Center for Whale Research will have a better picture of their movements and their distribution, but not until many months from now after all the photos have been received and the ID work is complete. 

     In addition, the research encounter data will be supplemented with coastal sighting reports from other sources.  These have proven to be invaluable over the years because they help fill data gaps.   If you have coastal sighting reports with photos or videos, please consider sharing them with the Center for Whale Research.  If you see Southern Resident sighting information, photos or videos posted on social media, please contact the Center for Whale Research so that we may reach out to the source(s).  For several reasons, the Center for Whale Research and our research colleagues can only use first-hand reports for our data bases; however, we are not permitted to use reports, photos or videos without the consent of the first-hand sources.  

     Here are two maps of confirmed Southern Resident sighting reports compiled from Center for Whale Research encounters, sighting supporters, research colleagues, and reports submitted to Orca Network.  The data span 2017 through July 7, 2019, based on photos received to date (additional 2019 photos are expected for the May-July time period, and for other months of the year as well).  There is one point per day per geographic area (coastal, Salish Sea, core summer habitat, Puget Sound).  For example, if the whales move from the outer coast into the Strait of Juan de Fuca a single day, there will be one point where first sighted on the coast, and one point where first sighted in the Strait of Juan de Fuca.

     The maps do not include sightings which very well could have been Southern Resident killer whales, but there were no photos or videos provided to the Center for Whale Research to confirm.

Figure 1.  Map of Confirmed Southern Resident Killer Whale Sightings in US and BC Waters for 2017 through  July 7, 2019 (Compiled by the Center for Whale Research; based on photos received as of July 7, 2019)

 

Figure 2.  Map of Confirmed Southern Resident Killer Whale Sightings in WA and BC Waters for 2017 through July 7, 2019 (Compiled by the Center for Whale Research; based on photos received as of July 7, 2019)

 

     Another source of sighting information comes from passive acoustic recorders that are being utilized by different research groups.   For example, the Canadian Department of Fisheries and Oceans has been deploying devices called Autonomous Multichannel Acoustic Recorders at a number of different geographic locations.  The recorders are moored well below the surface of the ocean, and include hydrophones as well as data recorders.  Unlike the hydrophone network on the west side of San Juan Island, these devices do not provide information in real time.  Instead, the devices have to be periodically retrieved for analysis of the recorded data.  This kind of instrumentation and data collection have yielded some surprising results, and have been key to expanding the Southern Resident killer whale Critical Habitat in Canadian waters to include Swiftsure Bank and a portion of the southwest side of Vancouver Island, from the western entrance of the Strait of Juan de Fuca northwest to about the Tofino area (Reference 1).  The above sighting maps (Figure 1 and Figure 2) do not reflect any of this acoustic data. 

     The Whale Museum in Friday Harbor also collects sighting data.  This data set has been instrumental in establishing the current Southern Resident Critical Habitat in US waters.  For a recent publication, see Reference 2.

 

 

Chinook Salmon Abundance

     Southern Resident killer whale presence in the “core summer habitat” during the months of April through September has shown a downward trend in the past decade.  Similarly, the abundance of Fraser River Chinook salmon, as measured by the Albion Chinook Test Fishery on the Fraser River, has also shown a decline (Figure 3).  This is especially true for the spring Chinook runs. 

     The Fraser River hosts five aggregate Chinook stocks:  two returning to the river to spawn in the spring, two returning to spawn in the summer, and one, the white-fleshed Harrison salmon, returning to the river in the fall.  The approximate timing of the runs is shown in the upper portion of Figure 3.  Abundant Fraser River Chinook runs could feed the Southern Resident killer whales from about April through September; however, it seems that even the J pod whales have had to start searching elsewhere for food at this time of year.

     The lower portion of Figure 3 shows the cumulative Chinook salmon counts for the Albion Chinook Test fishery on the Fraser River, starting with the year, 1988.  The data for the older years, 1988-2004, are colored in pale shades.  The data for 2005 through 2019 appear in bolder colors.  This color scheme makes it easy to see how poor the runs have been in recent years compared to previous years.  The five worst years have been 2012, 2013, 2016, 2017, and 2018.  It is too soon to know how 2019 will compare, but returns to date have been poor.

     It should be noted that although these data offer a glimpse into the health of the Fraser River Chinook runs, they do not tell the complete story.  Run size estimates would also include harvest and other factors.  In addition, fisheries experts would point out that these Chinook counts by themselves are lacking the precision needed to estimate salmon escapement numbers.  For example, fisheries experts would take the data and account for what is called “effort” (the size of the net, the time spent with the test net in the water actively collecting data, etc.), resulting in better estimates of overall Chinook salmon escapement (number of spawners) from year to year.  Nonetheless, the data in this form are readily available and posted on a daily basis, and do provide some insight that the rest of us can use to get a general sense of how the Fraser River Chinook salmon runs are faring.

 

Figure 3.  Cumulative Chinook Salmon Counts for the Albion Test Fishery on the Fraser River (1988-2019, as of July 8, 2019)

 

     In addition to the Fraser River, another river of special interest is the Columbia River.  Like the Fraser, the Columbia River hosts Chinook runs with spring, summer, and fall timing.  The fall run is typically much larger than either the spring or summer runs. 

     The number of Chinook salmon passing the Columbia River’s Bonneville Dam to spawn in tributaries above the dam are counted on a daily basis.  As with the Albion Test Fishery results, these provide some insight into the size of the run in real-time, but do not reflect total abundance.  The Chinook salmon counts at the Bonneville Dam do not include salmon that left the main stem to spawn in tributaries below the dam, in-river harvest in the area below the dam (quite significant in some years), ocean harvest, or mortality due to predation or other causes.

     The next graph (Figure 4) shows the Chinook salmon counts for the Bonneville Dam with the spring-timed counts in blue and the summer-timed counts in green (the fall-timed counts are not shown).  The time period of interest starts in 1975, about the time the Center for Whale Research began the Southern Resident Orca Survey.  Sadly the spring-timed counts for 2019 are the lowest in about 20 years. The summer run has not yet concluded, but to date is similar to that of 2007, also one of the worst summer runs in recent years.

Figure 4.  Cumulative Chinook Salmon Counts at the Bonneville Dam on the Columbia River for the Spring and Summer Runs (1975-2019, as of July 8, 2019; Fall run not shown)

 

Concluding Remarks

     Although the geographic area in and around the San Juan Islands and the lower Strait of Georgia (about as far north as the Fraser River) has been the “core summer habitat” for many of the Southern Resident killer whales for decades, the past decade has been a period of change.  There is evidence that the changes are tied to the decline of the Fraser River Chinook salmon stocks during that same time period.   Increasing the abundance of the Fraser River Chinook salmon stocks is one of the keys to the recovery of the Southern Resident killer whale population. 

     Are the whales finding what they need off the coast?  Coast-wide, there are fewer rivers hosting spring and summer Chinook salmon runs than fall runs, and the relative abundance of the spring and summer runs is typically considerably smaller than the abundance of fall runs.   Restoration of Columbia River and other Chinook stocks is needed to ensure the whales can find the food they need.

     The whales that are alive today need food tomorrow and well into the future, 12 months a year.  It goes without saying that making more Chinook salmon available to this endangered Southern Resident killer whale population is not a simple process.  Thank you to all the advocates who are working to draw attention to the Chinook salmon situation. 

     On a personal note, in my former engineering life, the toughest challenges were never solved by single individuals nor were they solved by groups of like-minded people; they were solved by teams of people who came to the table with different strengths and weaknesses, different experiences, different perspectives, and who, as a team, could harness a power that was far greater than the sum of the individual parts.

 

- Jane Cogan

 

References:

  1. Ford, J.K.B., Pilkington, J.F., Reira, A., Otsuki, M., Gisborne, B., Abernethy, R.M., Stredulinsky, E.H., Towers, J.R., and Ellis, G.M. 2017. Habitats of Special Importance to Resident Killer Whales (Orcinus orca) off the West Coast of Canada. DFO Can. Sci. Advis. Sec. Res. Doc. 2017/035. viii + 57 p.

  2. Olson, J.K., Wood, J. , Osborne, R.W., Barrett-Lennard, L. Larson, S., Sightings of southern resident killer whales in the Salish Sea 1976−2014: the importance of a long-term opportunistic dataset, Endangered Species Research, Vol. 37: 105–118, 2018

 

 

 

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