Salmon Ocean Ecology

The SWFSC initiated a Central California salmon survey in 1995. The NWFSC commenced a broad ecosystem survey in 1998. A full coast-wide survey began in 2010 as a Cooperative Research Program between NWFSC and SWFSC with ties to similar programs in Canada and Alaska forming a coast-wide survey of the pelagic ecosystem. These surveys collect data on salmonid stock distribution, abundance and condition along with ecosystem conditions and are the longest regular time series of biological and oceanographic data off an approximately 1000 mile section of the California Current spanning from Central California to the Canadian border. The surveys are designed to enhance stock assessment and increase our understanding of the marine ecosystem. While NOAA and other agencies have spent vast sums to restore and enhance freshwater anadromous salmonid habitat, the success of restoration efforts can only be assessed if marine conditions are considered. Current assessment methods for salmon are based on sibling regressions (jack and older cohort returns). Over the past decade there have been severe forecasting errors for every major river system from the Fraser to the Sacramento. Further, these forecasts provide no early warning with sibling data being analyzed only months before harvest goals are set. This lack of an early warning system for fisheries collapse has resulted in severe economic consequences to the NOAA and the public, as demonstrated by the Sacramento Chinook fishery shut down during the previous decade (note the California salmon survey was suspended in 2005 due to ship time limitations removing early warning potential). Alternative assessment methods being developed from the surveys incorporate multiple ecosystem variables to provide new methods for predicting adult salmon run sizes that are often more accurate than sibling regressions with the potential for early warning forecasts of critical stock failures.

Salmon surveys are filling critical data gaps in both temporal and spatial sampling limitations of other surveys. Specifically, many NMFS coastal pelagic surveys making use of the new NOAA FSV class vessels are inhibited by operational restrictions that prevent sampling inshore of 1 nm and the 40m isobaths. The small coastal trawlers chartered for the salmon surveys enable targeted sampling in this critical piece of habitat. Further the salmon surveys repeated temporal sampling between spring/summer and fall provides ecosystem and stock data to other research and assessment programs whose ship time allocations can only sample one time of year. The survey addresses PFMC Research and Data needs (2008) evaluation identified several critical data gaps in section 4.2.2 High Priority Research Issues Pg 21- “Stock Migration and Distribution Research is needed to improve our ability to estimate contributions of natural stocks in ocean fisheries and escapement. Potential research areas include 1) association studies to determine the degree to which hatchery stocks can be used to represent the distribution and migration patterns of natural stocks; 2) GSI, DNA, otolith marking, and scale studies; 3) improved statistical methods and models; and 4) basic research on stock distribution and migration patterns.” Pg 22-“New Forecast and Harvest Models. Develop forecast and harvest models for numerous west coast salmon stocks including Klamath River spring Chinook, California coastal Chinook, Oregon coastal Chinook, and Central California coastal coho. This information could then be used to establish or reevaluate appropriate conservation objectives.” Under Section 4.4 Interaction of Hatchery and Wild salmon pg 24: Early Ocean Life-history information . Points of comparison between hatchery and wild stocks could include: ocean distribution, migration paths and timing, size and growth, food habits, and survival rates. Currently the only data on pre-fishery stock migration and distribution comes from the salmon surveys and applying GSI techniques to the collected samples on relative density and distribution of many California and Pacific Northwest salmon stocks and critical juvenile recruitment stages. Many publications and reports have been produced regarding salmon migration, size, growth, disease, parasites, feeding habits, overall health, the importance of top down and bottom up processes, survival relative to changes in ocean conditions, etc. (MacFarlane 2010; Jacobson et al. 2012, Trudel et al. 2002, Keister et al. 2011, Orsi et al 2007.). This strongly links climate change with changes in California Primary and Secondary Productivity. Related to this was the observation that ocean conditions is often the cause of the collapse of west coast salmon runs, not freshwater conditions (Lindley 2009). Central Valley salmon enter a unique ocean environment, the Gulf of the Farallones, and respond differently to ocean conditions than do salmon farther north (MacFarlane et al., 2005; Williams, 2007). Broad coastal surveys at various times helps capture these variations in ocean utilization and survival. Further, new methods have been developed for early warning indicators of early marine recruitment failure (Woodson et al 2013). All of this is available to contribute to IEA ecosystem components.