Saving Killer Whales By Increasing Salmon Production

In a January 18, 2019 post, I related the state of Washington’s plan to increase the state’s hatchery salmon production to recover salmon populations and help the endangered southern population of killer whales.  In response to an executive order by the governor of Washington, the Washington Department of Fish and Wildlife’s proposed broad measures to increase the numbers of hatchery-raised salmon smolts released into killer whale migration areas that have minimal numbers of wild salmon.  The program would also enhance commercial and sport fisheries for salmon.  Much of the hatchery program would remain committed to recovery of threatened and endangered wild salmon stocks, which would also get a boost in essential habitat restoration.

The proposal in Washington state calls for an additional 30 million smolts for the Puget Sound estuaries (near Seattle) and an additional 20 million for the Columbia River estuaries, 50 and 20 percent increases, respectively.  The proposal recognizes:

 [H]atchery practices can pose serious genetic and ecological risks to wild populations if not managed carefully with full consideration of all that has been learned over the history of salmonid hatchery programs in the Pacific Northwest. However, the design of this proposal strives to minimize such negative impacts and to afford protection to the existing wild chinook populations to the greatest extent possible.

Elements of the program would include releasing hatchery smolts in lower river and estuary areas.  The program is designed to minimize effects on wild salmon by keeping these releases outside of the normal rearing and migration routes of wild salmon.  In some cases, hatchery salmon fry would be transported to net pens in lower rivers and estuaries for rearing and eventual release of smolts near the ocean, thereby further increasing smolt survival.  Returning adult salmon would home in on such sites, creating opportunities for terminal fisheries for hatchery salmon while retaining upriver spawning grounds for wild salmon.

A similar program is being planned and tested in California in the San Francisco Bay Estuary of the Sacramento and San Joaquin rivers.  Central Valley hatchery salmon smolts are already being trucked to the Bay and nearby coastal estuaries.  A new program element under consideration is the trucking of fry to local Bay estuary net pens for rearing.  If successful, this would create new terminal sport and commercial fisheries, while enhancing coastal fisheries and prey for the California Killer Whale populations.

One goal of the program in California would also be to shift hatchery salmon fisheries away from rearing areas and migration routes of wild salmon.  Rearing fry and releasing smolts in areas not frequented by wild salmon should reduce the effects of the hatchery program on wild salmon.  Similarly, terminal fisheries would focus harvest away from migration routes of wild salmon and reduce competition with wild salmon in spawning areas in upper rivers.  Commercial and sport fisheries would be enhanced along the coast.  New terminal fisheries would be created at estuary and coastal release sites that attract adults originally released at the sites as smolts.

If all goes well, such programs will benefit killer whales, sport and commercial fisheries, and wild salmon population (through reduced competition and better harvest management).

For more detail on Oregon and Washington Select Area Fisheries Enhancement programs see https://www.dfw.state.or.us/fish/OSCRP/CRM/reports/16_reports/2016%20_SAFE%20_Annual.pdf.

 

 

 

Delta Smelt – Spring 2019 Status

Late April and early May 20-mm Surveys provide an excellent picture of the status of Delta smelt population in the estuary. Since 2017, some surveys collected no Delta smelt (Figures 1-3) in the San Francisco Bay-Delta estuary. The 2018 and 2019 survey catches (Figures 1 and 2) are a new low for Delta smelt, lower even than the 2017 survey catch (Figure 3), and the lowest in the 1995-2019 survey period.

The outlook for the Delta smelt population remains grim after these lows. Despite good conditions in spring 2018 and 2019, the severely depressed number of adult spawners indicates a continuing weak potential for recovery.

Figure 1. Catch and lengths of Delta collected in the 20-mm Survey in spring 2019. None were collected in survey 3.

Figure 2. Catch and lengths of Delta collected in the 20-mm Survey in spring 2018. None were collected in surveys 4 and 5.

Figure 3. Catch and lengths of Delta smelt collected in the 20-mm Survey in spring 2017.