Movement Patterns of Sub-Adult Coho in Puget Sound
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Jessica Rohde 1, Tom Quinn 1 , Fred Goetz 1, Kurt Fresh 2 , Anna Kagley 2 Movement Patterns of Sub-Adult Coho Salmon in Puget Sound 1 School of Aquatic and Fishery Sciences, University of Washington 2 Northwest Fisheries Science Center, NOAA
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Migration is a central mechanism affecting the distribution of mobile populations, and intra-specific variation in migration patterns can affect many aspects of their ecology and conservation. Most sub-adult Chinook and coho salmon rear over the continental shelf or offshore waters of the North Pacific Ocean, but some Puget Sound salmon exhibit an alternative migratory pattern, spending all or part of their marine lives within Puget Sound. This “resident” behavior has been linked to decreased growth and increased contaminant accumulation. However, little is known about the movements of individual salmon and duration of their residency in Puget Sound. Accordingly, we tagged 45 sub-adult coho salmon in central Puget Sound with acoustic transmitters and tracked their movements using the array of moored receivers throughout the Salish Sea. Our initial results indicated that most individuals remained in Puget Sound, though several individuals were detected leaving through the Strait of Juan de Fuca and the San Juan Islands. Additionally, between basin movement was minimal; no individuals were detected entering Hood Canal or southern Puget Sound, but there was some movement into the Whidbey Basin. Overall, these results indicate that coho salmon found within Puget Sound in winter-spring are largely separated from those rearing off the coast. Thus resident and migratory individuals seem to be distinct categories, though the factors determining these two pathways are unclear.
Transcript of Movement Patterns of Sub-Adult Coho in Puget Sound
Jessica Rohde1, Tom Quinn1, Fred Goetz1, Kurt Fresh2, Anna Kagley2
Movement Patterns of Sub-Adult Coho Salmon
in Puget Sound
1School of Aquatic and Fishery Sciences, University of Washington
2Northwest Fisheries Science Center, NOAA
Puget Sound Coho Life-Histories
Figure provided by Fred Goetz
?
• Contaminant accumulation• decreased growth
• Are there semi-residents?
ObjectivesCharacterize the movements of
individual sub-adult coho
Spatial scales:I. Do they leave Puget Sound? II. Within Puget Sound, do they move between
basins?III. Within basins, what habitats do they use?IV. What is their vertical distribution?
Temporal scales:V. Does movement vary with season?VI. Are there diel patterns?
Methods• Coho tagged with acoustic transmitters
in central basin• Targeted residents by tagging between
November and June• Population unknown• Detected by moored hydrophonic
receivers
Methods• POST line of receivers in the Strait of
Juan de Fuca• Data from receivers in Puget Sound
shared through Hydra Database
• Gray bars indicate when a fish could be detected• Black x indicates detection• Red x indicates detection outside of Puget Sound
I. Do they leave Puget Sound?
• 2 exits• Deception Pass• Admiralty Inlet
• Strait of Juan de Fuca (JDF) line • deployed throughout
study
• 8 individuals total left Puget Sound• 7 at JDF line • 2 at Willipa Bay• 1 in San Juan
Islands
Coho DetectedNo Coho DetectedTagging Sites
Is there a date threshold after which
sub-adult coho do not leave Puget Sound?
• Coho enter Puget Sound around May 1.
• Spend 18 months in marine waters.
• We tagged coho in Central Puget Sound that had been in marine waters for 1-10 months.
• No pattern in the date of exit.
Time in marine waters prior to tagging
#
Ind
ivid
uals
< 6 months> 6 months
Left Puget SoundDid not leave
II. Do they move between basins?
Coho DetectedTagging Sites
• Limited between basin movement• 1 South Puget Sound• 1 Hood Canal• 9 Whidbey
• Admiralty Inlet• Sub-basin• Curtain April - July
2008• 10 fish detected• 5 of those returned to
central within 5 days• Semi-resident unlikely
III.Within basin distribution
Mean Residence Time (hours)
0 - 23 - 56 - 1011 - 14
# Fish Detected
< 11 - 33 - 1024
Tag Site
30100200295
Depth (m)
IV. Vertical distributionD
ep
th
(m)
Hour of Day
Spring Summer
V. Diel and VI. Seasonal patterns
Summary
I. Some assumed residents leave Puget Sound Coho tagged in Puget Sound in late marine phase less likely to
leave
II. Limited movement between basins Some use of Whidbey basin and Admiralty Inlet
III. Within basins, activity differs between sites May reside longer in shallower habitats
IV. Clear vertical movement Diel: deep at night, shallow during day
Seasonal: pattern stronger in spring than summer
Conclusions
Resident and migratory individuals seem to be distinct categories.
Future work will further investigate the behavioral differences between these two groups.
http://www.emeraldwateranglers.com
Tom QuinnKurt FreshAnna KagleyFred GoetzKelly AndrewsDawn Spilsbury Pucci
Rachel HovelJosh ChamberlinChloe BracisHalley NelsonMegan StachuraCurry Cunningham
Acknowledgements
Miles LogsdonJulian OldenLoveday ConquestNeala KendallMorgan BondThomas Buehrens
