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Ballard
Locks Sockeye Salmon Counts
Lake Washington
sockeye salmon have been counted each year since 1972 as they enter
freshwater at the Ballard Locks. The Washington Department of Fish and
Wildlife (WDFW) counted the sockeye from 1972 through 1992, and currently
Muckleshoot Indian Tribe and WDFW staffs conduct the counts cooperatively.
Although small numbers of sockeye enter the system in May and early
June, the period from the second week of June through the end of July
is the standard counting interval used to determine if there are sufficient
sockeye to open fishing seasons. Sockeye counts begin on June 12th each
year to provide consistent data from year to year. The sockeye are sample
counted daily during set time periods as they pass through both the
locks and the fishway, and the counts are converted into a daily total
number of fish passing upstream. In early July, State and Tribal managers
begin to make weekly projections of the expected total run size based
on the current total counts. When the co-managers believe that the total
run size includes sufficient surplus fish above the escapement goal
of 350,000 sockeye, sport and Tribal fishing seasons will be opened.
2008 Pre-season
Sockeye Forecast
The pre-season forecast for the 2008 sockeye return is about 105,000.
The estimate is based primarily upon fry production from the spawners
in 2003 and 2004. Since lake and marine survival rates are highly variable
from year to year, the actual return to Lake Washington could be higher
or lower than 105,000.
Collecting biological
samples from adult sockeye
In 2008 a comprehensive biological sampling program will continue gathering
critical information for the management of Lake Washington sockeye salmon,
including changes in populations, survival rates, genetic identification,
changes in size, etc.
The goal is to collect
approximately 200 adult sockeye each week as they move from seawater
into the Lake Washington Basin. Biologists from the Muckleshoot Indian
Tribe will lead the sampling effort, with the collaboration of WDFW
staff who will assist in the collection and processing of samples from
the adult sockeye. Seattle Public Utilities provides funding for processing
and analysis of these biological samples.
The types of
information that will be collected are:
- Scales
- Lengths
- Genetic Samples
(DNA)
- Mark Samples
(Otoliths and tags)
- Sex
The following
are examples of three important biological data sets.
Age Composition
- Sockeye salmon age compositions are a necessary step in measuring
survival rates. Insufficient age data have been collected in recent
years because of budget constraints and due to the difficulty of collecting
a representative sample. Scales from the adult fish will be used to
determine ages.
Wild/hatchery
proportions - Artificially produced sockeye salmon will be an
important component of the return in 2008 and coming years. The hatchery
fish are 100% otolith (small bones inside the head) marked for differentiation
from wild-origin sockeye. The accurate estimation of the numbers of
returning hatchery fish is important to evaluate hatchery performance,
and can be used to inform in-season fishery management decisions.
Genetic Diversity
- Because genetic (DNA) analysis has only recently become available
as an assessment tool, consistent genetic sampling programs have not
been a part of the management process. Tissue samples collected from
Lake Washington sockeye stocks will be used to make future comparisons
between populations based on DNA profiles. This may allow the in-season
monitoring of the returns of various wild and hatchery stocks, the
crafting of protective measures in fisheries, and may allow the measurement
of the influence of hatchery fish on wild sockeye.
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Sockeye
Salmon Counts at the Ballard Locks For June-July 2007
| Date |
Daily
Count |
Total
Count |
|
Date |
Daily
Count |
Total
Count |
6/12
|
412
|
412 |
|
7/7
|
2,342
|
39,459 |
6/13
|
480
|
892 |
|
7/8
|
702
|
40,161 |
6/14
|
451
|
1,343 |
|
7/9
|
2,390
|
42,551 |
6/15
|
715
|
2,058 |
|
7/10
|
798
|
43,349 |
6/16
|
849
|
2,907 |
|
7/11
|
579
|
43,928 |
6/17
|
561
|
3,468 |
|
7/12
|
690
|
44,618 |
6/18
|
834
|
4,302 |
|
7/13
|
805
|
45,423 |
6/19
|
2,293
|
6,595 |
|
7/14
|
710
|
46,133 |
6/20
|
1,796
|
8,391 |
|
7/15
|
1,714
|
47,847 |
6/21
|
1,404
|
9,795 |
|
7/16
|
1,475
|
49,322 |
6/22
|
1,254
|
11,049 |
|
7/17
|
1,232
|
50,554 |
6/23
|
1,964
|
13,013 |
|
7/18
|
1,501
|
52,055 |
6/24
|
2,472
|
15,485 |
|
7/19
|
408
|
52,463 |
6/25
|
2,120
|
17,605 |
|
7/20
|
698
|
53,161 |
6/26
|
3,220
|
20,825 |
|
7/21
|
686
|
53,847 |
6/27
|
1,868 |
22,693 |
|
7/22
|
537
|
54,384 |
6/28
|
1,341
|
24,034 |
|
7/23
|
223
|
54,607 |
6/29
|
2,115
|
26,149 |
|
7/24
|
225 |
54,832 |
6/30
|
1,048
|
27,197 |
|
7/25
|
1,233
|
56,065 |
7/1
|
573
|
27,770 |
|
7/26
|
1,538 |
57,603 |
7/2
|
1,411
|
29,181 |
|
7/27
|
881 |
58,484 |
7/3
|
2,335
|
31,516 |
|
7/28
|
684 |
59,168 |
| 7/4
|
1,721
|
33,237 |
|
7/29
|
432 |
59,600 |
7/5
|
1,525
|
34,762 |
|
7/30
|
273
|
59,873 |
7/6
|
2,355 |
37,117 |
|
7/31
|
244
|
60,117 |
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