In 2001, a small miracle occurred in a stream south of the city of Arcata:
the salmon came back. Lots of them. The stream, called Morrison Gulch, flows
into Jacoby Creek, which empties into Humboldt Bay. Biologists knew it had
once been spawning ground for salmon, because for several years they had
counted hundreds trying to make their way upstream to mate--600 in one
winter alone. But an old culvert under Quarry Road blocked the way; not one
fish could make the jump into it from the pool below. Faced with such a
barrier, some fish will try to find other places to spawn; others will die
of exhaustion from their futile attempt to reach historic spawning grounds.
Then, in August 2001, the County replaced the Quarry Road culvert with a
wider one and regraded the stream above and below to raise the channel,
allowing the fish to move freely through the new culvert. With the barrier
gone, the salmon moved right back into the stream. That winter, biologists
counted 70 coho returning to spawn, and the following winter they observed
238 adults and 116 redds (spawning nests).
What happened in the Jacoby Creek watershed is happening, or beginning to
happen, in many watersheds along the coast from Del Norte County to
Monterey. In the past ten years, through collaborative efforts by counties,
state and federal agencies, private landowners, and nonprofit organizations,
almost 300 miles of streams have been reopened to salmon and restored to
conditions favorable to the fishes’ survival. At a time when everything else
seems to be going wrong for West Coast salmon, this achievement is a ray of
sunshine.
Locked Out
Culverts and other small stream barriers may seem trivial compared to the
large and intractable difficulties salmon face--drought, water diversions,
hydropower dams, changes in ocean productivity--but there are so many of
them that they have effectively locked fish out of huge areas of spawning
habitat. A 2004 report by the Coastal Conservancy identified more than
19,000 barriers in California’s coastal watersheds, at least 1,400 of them
severe or impassable.
Even obstacles that are not completely impassable to adult salmon can
exhaust the fish before they reach spawning grounds, or keep juveniles,
which can’t jump as high as adults, from reaching tributaries that serve as
safe havens during floods. “It’s a huge problem,” said Tom Weseloh, North
Coast manager for California Trout. “If you’ve got a barrier at the mouth of
a watershed, the whole watershed is impaired.”
Long before people knew about the life cycles of anadromous fish, they
understood that salmon needed to be able to move freely up- and downstream.
In his 2003 book King of Fish: The Thousand-Year Run of Salmon, geologist David R. Montgomery wrote of a 12th-century English statute
requiring that English rivers “be kept free of obstructions so that a
well-fed three-year-old pig could stand sideways in the stream without
touching either side.” Pigs were not at issue; the purpose was to protect
salmon.
Despite many such laws and restrictions over the centuries, the needs of
fish have rarely been considered when roads and other structures were built,
until recently. In California’s early days, many coastal roads were cut
right next to creeks for the logging industry, and streams were constricted
and blocked by pipes and culverts. In 1935, federal fisheries biologists
surveying streams in the Klamath and Shasta National Forests reported that
culverts were cutting off salmon from the Klamath River and other main
streams, and recommended that small bridges be used instead. They were
ignored.
Those roads, usually built quickly and cheaply, have eroded over the years,
spilling sediment into the creeks and causing creekbanks to fail. During
heavy rains, the old culverts block water and sediment flow, causing floods.
But quick fixes cost less up front than bringing back a more natural
streamflow, and because there are so many barriers, removing any one of them
seemed a waste of time and money--until 1996 and 1997, when coho salmon on
the North and Central Coasts were listed as threatened or endangered under
the Endangered Species Act (ESA).
|