[env-trinity] CBB: Study Identifies Ocean Distribution Of Fall Chinook

[Kier Associates]

This Columbia Basin Bulletin article is stunningly uninformative. 

 

Nowhere does it - nor the summary of the Canadian Journal of Fisheries and
Aquatic Sciences it cites - identify how fish from the various river-basin
stocks have been identified 

 

Has the zombie West Coast Salmon Genetic Stock Identification Collaboration
come to life? I assume so if Mr
<https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uac
t=8&ved=0ahUKEwjV-pmw-uLbAhVG-qwKHVMYA4QQFggnMAA&url=https%3A%2F%2Fdigitalco
mmons.csumb.edu%2Fcgi%2Fviewcontent.cgi%3Farticle%3D1026%26context%3Dsns_fac
&usg=AOvVaw3u6KUhmo4_bo2rEcH12OIi> Satterthwaite was part of the project
team

 

But not a word - did you notice? - of how the fish were identified as to
their rivers of origin - just talk of the model/ its results

--

Nat Bingham, then the Pacific Coast Federation of Fishermen's Associations
restoration coordinator, saw with crystal clarity the wisdom of the
then-nascent  genetic stock identification (GSI) science/ how the Human
Genome Project had thrust the rapid DNA analysis tools into our hands, and
he was pushing for a West Coast GSI collaboration with might and main at the
time of his untimely death 20 years ago last month

 

Advancing GSI science will substantially strengthen the management of
mixed-stock Pacific salmon ocean fisheries 

 

So far as I can tell the Columbia Basin Bulletin article does nothing to
spotlight GSI 

 

Did I miss something?

 

Bill Kier

From: env-trinity [mailto:env-trinity-bounces at velocipede.dcn.davis.ca.us] On
Behalf Of Sari Sommarstrom
Sent: Wednesday, June 20, 2018 10:22 AM
To: 'Env-trinity'
Subject: [env-trinity] CBB: Study Identifies Ocean Distribution Of Fall
Chinook

 

Columbia Basin Bulletin

 

Study Identifies Ocean Distribution Of Fall Chinook; Should Help
Target/Avoid Certain Stocks 

Posted on Friday, June 15, 2018 (PST) 

 

A recent study of the general locations of salmon in the Pacific Ocean could
help managers steer heavy fishing away from threatened and endangered
stocks. 

 

The study estimates the distribution in the ocean of a far-ranging number of
fall run chinook stocks, including populations from California's Central
Valley to populations in southern British Columbia.

 

"We show how fall chinook from different river systems have systematically
different ocean distributions and that these ocean distributions can vary
substantively by season," said Andrew Olaf Shelton, a research ecologist in
the Conservation Biology Division of NOAA's Northwest Fisheries Science
Center in Seattle. "We use these new estimates of ocean distribution to make
projections of how many fall chinook salmon from different origin systems
are in different spatial areas."

 

He added that the information from the study should be useful to managers
thinking about how to target, or avoid, particular stocks. Shelton called
these "spatial management options."

 

Historically, commercial and recreational fisheries took a high fraction of
salmon returns, in some cases over 50 percent of the returning fish, Shelton
said. However, fisheries harvest has declined over the past 30 years
coast-wide, including the closure of some fisheries entirely - the Strait of
Georgia commercial troll fishery - or the temporary closure of some areas
like the California and southern Oregon troll closure more recently.

 

As a general guideline, fish were generally distributed in the ocean near to
their origin, the study says. For example, fish that originate between
California and southern Oregon almost always remain in waters south of
British Columbia, while fish originating in the far north, seldom journeyed
south. Nearly all chinook found in the Salish sea originated there and few
strays from other areas are found.

 

Fish from the Columbia River basin showed the broadest spatial distribution
"with significant proportions present in areas from California to Alaska."

 

In addition, there are seasonal distributions occurring with fish from
nearly all regions, according to the study. Fish from a given region in the
ocean tend to be in more northerly areas in summer than in winter or spring,
and because of spawning migrations, chinook tend to be located near their
region of origin in the fall.

 

"Using hierarchical models to estimate stock-specific and seasonal variation
in ocean distribution, survivorship, and aggregate abundance of fall run
Chinook salmon" was published online April 15, 2018, in the Canadian Journal
of Fisheries and Aquatic Sciences
(http://www.nrcresearchpress.com/doi/abs/10.1139/cjfas-2017-0204#.WyLJ_qdKjI
U).

 

Shelton's co-authors are Will Satterthwaite, research ecologist in the
Fisheries Ecology Division at NOAA's Southwest Fisheries Science Center in
Santa Cruz; Eric Ward and Blake Feist, statisticians, in the Conservation
Biology Division at the Northwest Fisheries Science Center; and Brian Burke,
supervisory research fishery biologist, fish ecology division at the
Northwest Fisheries Science Center.

 

"We show that Chinook salmon ocean distribution depends strongly on region
of origin and varies seasonally while survival showed regionally varying
temporal patterns," the study says. "Simulations incorporating juvenile
production data provide proportional stock composition in different ocean
regions and the first coastwide projections of Chinook salmon aggregate
abundance."

 

Although not directly addressing abundance of juveniles in the ocean,
Shelton said, the models developed by these researchers do, among other
things, estimate survival of young chinook salmon from each release group
and assesses how survival changed over the years of the study (releases
between 1978 and 1990). 

 

"In general our results show a mild decline in survivorship for most (but
not all) origin regions over that period, but there is a lot of variability
both within and among regions," Shelton said. "We are interested in trying
to understand both the trend across years and the variability within years
in future work."

 

The general importance of this study is that it provides predictions of
ocean distribution of fall chinook that will help improve management over
both the short and long term. Understanding which stocks are where and when
they are there is important for allowing exploitation on healthy stocks and
avoiding harvest on depleted stocks. 

 

"Our work is not the final say for chinook salmon ocean distribution, but it
is an important step forward," Shelton said. "Our work provides methods for
estimating ocean distribution of salmon species that are general and
extendable."

 

He said the researchers are now working to incorporate data from recent
years to other species and run types (they are currently expanding their
work to spring chinook), and to include information about how ocean
distributions shift with climactic drivers such as ocean temperature.

 

The model also allows individuals to play out management scenarios to
understand the consequences for chinook abundance, Shelton said.

 

One example summarized in the study is a prediction of the consequences of
reducing by half the number of hatchery fish of Puget Sound stocks. In that
case, available fish would decline substantively in Puget Sound, but other
areas would also be notably affected, he said.

 

Other uses for the model could include an investigation of the consequences
of shifting the spatial and seasonal intensity of ocean fisheries for
particular stocks. It can be applied to understand drivers of chinook salmon
biology, such as climate effects on ocean distribution as well as the
management effects of changing juvenile production.

 

"Our work as a tool has broad application for understanding patterns of
spatio-temporal variation among Chinook salmon and other tagged salmonid
populations," the study says. "Additionally, it is a simulation platform for
exploring the consequences of biological variation and management decisions
on an important marine resource."

 

 

 

 

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