After Thanksgiving, we returned to the lab in Davis. We had finished up our field sampling in
October, gathered the additional samples helpfully collected for us by the Yurok Tribe, BLM and
ODFW and were ready (as ready as we ever are) to turn the samples into sequence-able DNA.
After the many months we spent last winter trial and erroring our way through the lab protocols,
we were primed for success this year. We had figured a few things out, one of the keys being to
begin all steps with fresh reagents. In doing so, and using the knowledge we had gained last
year, we had a brief and effective time conducting the molecular portion of our project. We have
already gotten our data back from this year’s efforts and are now in the process of analyzing it
and adding it to our growing body of information on regional steelhead and Coastal Cutthroat.
Our results from the past few years have shown us where summer-run genetics exist, (notably
above dams on the Rogue, Klamath, Trinity, Mad and Eel Rivers) and around barriers with
known extant populations of summer-run. They have also shown us where we can find traces of
summer-run genetics, even with just a few individuals observed on some years (such as the
North Fork of the Eel River), and where we cannot find any genetic trace, even when 10-20,
some years more than 30, large O. mykiss are seen every summer (the Mattole River). What
these results mean for the future conservation efforts of summer-run and what is happening in
rivers where we do not find any genetic evidence, is still being considered. We know that
steelhead are a highly adaptable species, with a spectrum of life-history traits that we too often
attempt to put into simple categories. We also know that the summer-run genotype is necessary
to have a summer-run population. And the genotype is not maintained once summer-run
populations are gone. We cannot expect summer-run to re-evolve from winter-run populations,
so we need to protect summer-run populations. We do, however, see above barrier, or dam,
resident-trout populations maintaining summer-run genetics. In a future scenario where more
dams come down, there are reservoirs of summer-run genetics waiting to make their way back
to the sea.
As the Eel River dams continue through the FERC decommissioning process, questions are
arising regarding how best to re-establish anadromous fish runs post-dam removal. What we do
not want to see is preemptive and presumptuous human intervention. No hatchery or trap and
haul can do it better than the fish can on their own. Open access to the historic habitat and allow
anadromous fish time to get to know the place again. Remove the barrier and let the migratorily
inclined resident trout take their isolated genetics to the ocean. The life-history, run-timing and
overall genetic diversity is still there, waiting to be set free.