number of legal-sized white sturgeon (38 to 54 inches in fork length) in the
Columbia River downstream of Bonneville Dam declined in 2018 while the number
of sturgeon large enough to spawn (over 65 inches FL) – adults – remained
steady from 2017 numbers, according to a 2018 report by the Oregon Department
of Fish and Wildlife.
sturgeon – those large enough but not too large to fill a legal slot allowed
for fishing – declined 19 percent from 2017 and was 28 percent lower than the
peak abundance in 2016. In 2018, biologists say there were 162,182 legal-sized
sturgeon (63 percent of the conservation status level) in the river downstream
of Bonneville and 6,108 adult-sized fish (3-year average is 7,493 fish and the
desired abundance is 9,250 fish, while the conservation status threshold
abundance is about 3,900 fish).
sizes of sturgeon, however, have abundances that are “firmly above conservation
status,” the report says (https://www.dfw.state.or.us/agency/commission/minutes/19/02_Feb/Exhibit%20B/Attachement%201_Agenda%20Item%20Summary.pdf),
an abundance that could allow fishing this year.
considered in a broader time scale the trend in sub-adult abundance has been,
and continues to be, positive since 2012,” the report says.
conservation status of white sturgeon was set in 2011 by both Oregon and
Washington Commissions when they adopted the Lower Columbia River and Oregon
Coast White Sturgeon Conservation Plan that sets long-term management goals for
the sturgeon that would constitute healthy and harvestable numbers.
Jones, Ocean/Salmon Columbia River Program Manager for ODFW, is briefing the
Oregon Fish and Wildlife Commission today (Feb. 8) at its meeting in Portland,
on the status of white sturgeon in the lower Columbia River and lower
there could be fishing for white sturgeon in 2019 similar to the last couple of
years’ sport and commercial fishing set by the Commission, “but that’s somewhat
dependent on Commission guidance – which I hope we may get Friday,” Jones said.
there is a “reduced relative abundance of juvenile and sub-legal sized fish, an
extended period of low young-of-year (YOY) recruitment, as measured by catch
per net (CPN), and a leveling out or downturn year-over-year in most metrics,”
the report says. “Taken together these signs point to ongoing low productivity
over the last several years, and indicate that the precautionary approach to
fisheries management we have used over the last several years should continue.”
said he’s not certain why young of year recruitment is down, but one thought is
predation by steller sea lions.
don’t have a causative relationship worked out, but there is growing evidence
that, irrespective of predation, the abundance of steller sea lions appears to
be negatively correlated with successful white sturgeon recruitment, that is to
say, the more stellers are around the lower recruitment we measure,” he said.
the lower Columbia River white sturgeon population cannot be considered truly
healthy, the report says, unless abundance targets are met and it has a
balanced, sustainable stock structure across life history stages. Large
abundance estimates with a stock structure dominated by juveniles indicates
successful recruitment is occurring regularly, assuring replacements for mortality
at older life stages.
desired percentage of juveniles that make up the entire population would be 95
percent, but in 2018 the percentage was about 63 percent. That’s still above
the conservation status in the Plan (60 percent).
reduced relative abundance of juvenile and sub-legal sized fish over time
indicates ongoing productivity issues,” the report says. “We do not anticipate
this trend changing in the immediate future; however, if future recruitment is
more like that witnessed in pre-2009 or 2017, this trend may, with time,
retention fisheries were closed 2009 through 2016, although in the latter year
catch and release was allowed. Retention fishing resumed in 2017 and continued
in 2018, but fishing was allowed in three areas and the slot size was reduced
to 44 to 50 inches to dampen catch rates and lengthen the season, the report
says. Anglers were allowed 2,960 white sturgeon in the estuary, 1,230 in the
mainstem Columbia River upstream of the Wauna power lines at river mile 40 and
740 in the lower Willamette River.
estuary fishery was scheduled for ten days during mid-May through early June in
2018, and was ultimately extended for an eleventh day with an estimated catch
of 2,412 white sturgeon from 18,294 angler trips. The main-stem fishery was
scheduled for two Saturdays during September and produced a catch of 1,049
white sturgeon from 11,031 trips.
with recreational retention, commercial harvest also continued in 2018 with a
guideline of 1,230 44 to 54-inch FL white sturgeon available. In off-channel
and fall mainstem Zone 4/5 commercial fisheries, a combined 826 of the 1,230
commercial guideline was harvested, the report says.
CBB, October 27, 2017, “Sturgeon Fishing Day Added, Mainstem Night Fishing Ban
Lifted, Wild Steelhead Passage Still Very Low,” http://www.cbbulletin.com/439783.aspx
CBB, October 13, 2017, “States Set Two Days For Sturgeon Retention Fishing
Downstream Of Bonneville Dam; Fish Over 66-Inches,” http://www.cbbulletin.com/439717.aspx
June 16, 2017, “With More Fish Caught Than Expected, States Close Lower
Columbia Sturgeon Fishing,” http://www.cbbulletin.com/439103.aspx
February 10, 2017, “Harvest Managers Extend Tribal Sturgeon Gillnetting For One
CBB, Feb. 26, 2016, “Lower Columbia River White Sturgeon Overall Numbers
Continue To Grow, ‘Ongoing Productivity Issues' ” http://www.cbbulletin.com/436114.aspx