Sunday, January 2, 2011

California salmon

© 2011 Joshua Stark

Last week, the Fresno Bee had a very interesting article on the Sacramento/San Joaquin chinook salmon runs.  While giving some "good" news, it held out the notion that all still is not well with our Valley Kings.  Even with a couple of small mistakes, (e.g., the commercial fishery isn't the only source of all wild-caught California salmon), the story is worth the read, and the Fresno Bee needs folks to click over and support such appropriate journalism, especially considering the farmwater slant this could have taken.

The reporter brought up some very important points about reestablishing wild salmon populations, pointing out that hatchery fish stray from their home rivers at far, far higher rates than naturally spawned salmon, and giving a clear-eyed description of this year's numbers.

For their size, king salmon (Oncorhynchus tschawytscha) are remarkably short-lived creatures.  The typical fish will live 2-4 years, (hopefully) returning to its birth river to spawn and die.  Yet, these fish are often caught in rivers in the 15-40 lb. range (the record Sacramento line-caught fish was 94 lbs.); the amount of nutrients they bring deep inland from the ocean's depths every year is simply stunning. 

Sadly, equally stunning is the fact that about 90% of their wild spawning habitat has been lost behind the Sierra Nevada foothill dams of California.  Though I'm not a huge proponent of the "keystone species" concept (we usually find out that they are all keystones), the loss of California's biggest native movers of biomass (what a romantic notion, eh?) - large predators and salmonids - must have had a tremendous impact on its biodiversity as well as its total populations of wildlife, plants, fungi, etc.

Imagine:  California has the largest number of climates, biomes, plant species, etc. of all the 50 states.  And the vast majority of these evolved with salmon as a nutrient source, including habitats not directly adjacent to salmon waters, as the creatures that fed upon salmon (from grizzlies and wolves to eagles and crows to bacteria) moved throughout the land. 

As the article points out, the numbers of returning salmon are barely meeting salmon managers' hoped-for numbers, but they are meeting them.  This time the crash was largely due to poor ocean conditions.

I can attest to this reason:  Back in 2006, I worked a stint at a California State Park on the Monterey Bay.  One of my jobs was to collect sick or injured birds that washed ashore on the beach, before they hurt somebody (if you ever get the notion to play hero and save a sea bird, just remember:  cormorants go for the eyes).  That Summer, many, many older and young birds were washing ashore, starving to death: there simply wasn't the food supply that the upwelling from the trench brought every year.  The reason was that there was no upwelling, and so instead of seeing blue whales in the Bay, we saw red tides (microorganisms that thrive in warmer Monterey Bay water and suck the oxygen out of it).  This loss of food obviously hurt salmon populations, helping to decrease their numbers by 95%.


Of course, ocean conditions won't be the only culprit.  Just as botanists point out that when an oak is born, it's already got 10 things wrong with it, and though the 11th thing might kill it, but it would have survived if not for the other 10, so it is with all things.  Poor breeding, poor freshwater habitat, droughts, etc.,  may all have impacted our kings.  For example, the fact that hatchery-spawned salmon are dumber than wild-spawned ones might lead one to wonder:  Could naturally-spawned salmon have survived the poor ocean conditions at higher rates than hatchery fish?

Last year, ocean conditions were great, and the fish are coming back at slightly higher rates.  However, we are still far, far below the numbers we should expect for healthy California rivers.  The article notes that the numbers of fish returning this year are roughly double those of last year.  What is not noted is that this doubling brings the total up to what is probably about 10-15% of what we should expect in a healthy year.

If these numbers don't send a chill down your spine, I reckon little else could.

It isn't a huge leap to imagine some small, beautiful flowering plant in a valley, perhaps a fuzzy little thing with pink and yellow petals, or maybe a tall, showy number with a long stalk, gone now because it needed that extra bit of food, brought by a bear after having had its fill of fish at the stream over the ridge.  Perhaps its seeds still sit in the soil, patiently waiting that little extra help...

1 comment:

Bud said...

Great article, Josh. Thanks for keeping us alert.