OCEANOGRAPHIC INFORMATION 2
DIVERSITY body of water sheltered from Snapshots of oceanographic the wind, with little current processes in the southern and relatively low levels of Strait of Georgia reveal a fresh water input, level of diversity that is is an area of exceptionally uncommon for such a small high stratification. If the geographic area. Due in part waters could be removed to the freshwater discharge and looked at in profile, from the Fraser River, the there would be clearly upwelling from Haro Strait, defined layers each with and the varied seabed below, different characteristics. there is a wide range of In contrast, because of the temperatures, salinity levels, large volume of water that currents and stratification. must squeeze through a tiny, twisting channel, Active Pass EXTREMES has waters that are so highly The southern Strait of mixed and churned that the Georgia is more than diverse; phenomenon is visible from it is a zone of extremes. For ferry decks above! instance, Saanich Inlet, a deep
INTERESTING The water in the Strait of Georgia is not much colder than the waters of northern California. INFO
Surface waters move much faster than deeper waters. To travel from the southern Strait of Georgia to the Juan de Fuca Strait, a log at the surface takes only 24 hours; a waterlogged piece of wood 50 metres below takes a full year!
The Fraser River accounts for roughly 80% of the freshwater entering the Strait of Georgia.
11 • PROPOSED SOUTHERN STRAIT OF GEORGIA NATIONAL MARINE CONSERVATION AREA RESERVE ATLAS – CHAPTER 2 •
Supplemental Information
Article References
• Dr. Cliff Robinson, Marine Ecosystem Scientist, Parks Canada • http://en.wikipedia.org/wiki/Strait_of_Georgia • http://www.vancouverisland.com/recreation/?id=161
Map Metadata
SUMMER SURFACE TEMPERATURE, WINTER SURFACE TEMPERATURE, SUMMER SURFACE SALINITY, WINTER SURFACE SALINITY
Fisheries and Oceans Canada, Institute of Ocean Sciences. Base data enhanced with data from: archives of the Marine Environmental Data Service, Ottawa; Institute of Ocean Sciences, Sidney, BC; National Ocean Data Service, Washington, DC; and Project Argo. Observations from seasons
PHOTO CREDITS impacted by severe El Niño and La Niña events were excluded Page 11 - Parks Canada, 2009; from the analysis. Page 12: top left - M. Hiebert; top right - Parks Canada / T. Tomascik; bottom left - M. Hiebert; TIDAL CURRENT VELOCITIES bottom right - Parks Canada / T. Tomascik Fisheries and Oceans Canada, Institute of Ocean Sciences. Based on Mike Foreman’s finite element model for eastern Juan de Fuca Strait and southern Strait of Georgia. 11,697 data points were exported from the current model that averages horizontal velocities over the depth of the water column cal- culating a horizontal root mean square velocity at each point. The model is further described in the Journal of Geophysical Research, 1995.
VERTICAL STRATIFICATION
Calculated using the Simpson and Hunter 1974 model. Based on bottom friction and may not be entirely applicable to the deeper portions of the region. Model works on the following
3 equation: S=log10(H/CdU ) where H is the water depth in (cm),
Cd is the bottom drag taken to be 0.0025 and U is the mean speed of tidal current (cm/s) taken from tidal current velocity data. The stratification parameter is interpreted as: S<1 mixed, 1
12 Proposed Southern Strait of GeorgiaVancouver National Marine Conservation Area Reserve Summer Surface Temperature
Richmond
Gabriola
FALSE NARROWS Island
DODD NARROWS GABRIOLA PASSAGE METRO PYLADES CHANNEL VANCOUVER ¥
Tsawwassen Valdes Island
STRAIT OF GEORGIA
S S A P R E I Point Roberts L Thetis R
O Island P (U.S.A.) Ladysmith ! STUART CHANNEL
Kuper Island Canada - U.S.A. Border Galiano Island TRINCOMALI CHANNEL Chemainus !!!
Crofton ! E PA IV SS T
C C
A A
! P T
Ganges A Mayne
I S N
A
N P Island S Prevost A
U S
M S S A
Island W G
N PLUMPER SOUND A
A E N
R S Maple R Saltspring O O
! N W North Tumbo Island Bay S Island C H Pender A
N N Island E L Saturna Island ! Duncan Fulford Harbour ! South
COWICHAN BAY Russell Island Pender Island P
! R E
V
O
Cowichan Bay S T Moresby L P E A N S N A Portland S Island CH A BOUNDARY PASS TE G LLI E SATE Island
S A A N I C H I N L E T Rum Island Sidney! Mill Bay !
S ID N C E O Y C R H D A Sidney O N V N A E L Island C H A N N E L ! Brentwood D'Arcy Bay Island San Juan Island HARO STRAIT (U.S.A.)
< 10 °C 13.0 - 13.5 °C
10.0 - 10.5 °C 13.5 - 14.0 °C
10.5 - 11.0 °C 14.0 - 14.5 °C
11.0 - 11.5 °C 14.5 - 15.0 °C
11.5 - 12.0 °C 15.0 - 15.5 °C VICTORIA
12.0 - 12.5 °C 15.5 - 16.0 °C
12.5 - 13.0 °C
Not for navigation. Produced in the Western and Northern Service Centre, Parks Canada. Data Source: Fisheries and Oceans Canada, 0 5 10 15 Institute of Ocean Sciences. Median summer km surface temperature of ocean. °C denotes degrees Projection: BC Environment Albers Celsius. Horizontal Datum: NAD 83
JUAN DE FUCA STRAIT
13 Proposed Southern Strait of GeorgiaVancouver National Marine Conservation Area Reserve Winter Surface Temperature
Richmond
Gabriola
FALSE NARROWS Island
DODD NARROWS GABRIOLA PASSAGE METRO PYLADES CHANNEL VANCOUVER ¥
Tsawwassen Valdes Island
STRAIT OF GEORGIA
S S A P R E I Point Roberts L Thetis R
O Island P (U.S.A.) Ladysmith ! STUART CHANNEL
Kuper Island Canada - U.S.A. Border Galiano Island TRINCOMALI CHANNEL Chemainus !!!
Crofton ! E PA IV SS T
C C
A A
! P T
Ganges A Mayne
I S N
A
N P Island S Prevost A
U S
M S S A
Island W G
N PLUMPER SOUND A
A E N
R S Maple R Saltspring O O
! N W North Tumbo Island Bay S Island C H Pender A
N N Island E L Saturna Island ! Duncan Fulford Harbour ! South
COWICHAN BAY Russell Island Pender Island P
! R E
V
O
Cowichan Bay S T Moresby L P E A N S N A Portland S Island CH A BOUNDARY PASS TE G LLI E SATE Island
S A A N I C H I N L E T Rum Island Sidney! Mill Bay !
S ID N C E O Y C R H D A Sidney O N V N A E L Island C H A N N E L ! Brentwood D'Arcy Bay Island San Juan Island HARO STRAIT (U.S.A.)
< 7 °C VICTORIA
7.0 - 7.5 °C
7.5 - 8.0 °C
Not for navigation. Data Source: Fisheries and Oceans Canada, Produced in the Western and Northern Service Centre, Parks Canada. Institute of Ocean Sciences. Median winter 0 5 10 15 surface temperature of ocean. °C denotes degrees km Celsius. Projection: BC Environment Albers Horizontal Datum: NAD 83
JUAN DE FUCA STRAIT
14 Proposed Southern Strait of GeorgiaVancouver National Marine Conservation Area Reserve Summer Surface Salinity
Richmond
Gabriola
FALSE NARROWS Island
DODD NARROWS GABRIOLA PASSAGE METRO PYLADES CHANNEL VANCOUVER ¥
Tsawwassen Valdes Island
STRAIT OF GEORGIA
S S A P R E I Point Roberts L Thetis R
O Island P (U.S.A.) Ladysmith ! STUART CHANNEL
Kuper Island Canada - U.S.A. Border Galiano Island TRINCOMALI CHANNEL Chemainus !!!
Crofton ! E PA IV SS T
C C
A A
! P T
Ganges A Mayne
I S N
A
N P Island S Prevost A
U S
M S S A
Island W G
N PLUMPER SOUND A
A E N
R S Maple R Saltspring O O
! N W North Tumbo Island Bay S Island C H Pender A
N N Island E L Saturna Island ! Duncan Fulford Harbour ! South
COWICHAN BAY Russell Island Pender Island P
! R E
V
O
Cowichan Bay S T Moresby L P E A N S N A Portland S Island CH A BOUNDARY PASS TE G LLI E SATE Island
S A A N I C H I N L E T Rum Island Sidney! Mill Bay !
S ID N C E O Y C R H D A Sidney O N V N A E L Island C H A N N E < 19.5 psu 24.50 - 25.0 psu L ! 19.0 - 20.0 psu 25.0 - 25.5 psu Brentwood D'Arcy Bay Island 20.0 - 20.5 psu 25.5 - 26.0 psu San Juan Island HARO STRAIT (U.S.A.) 20.5 - 21.0 psu 26.0 - 26.5 psu
21.0 - 21.5 psu 26.5 - 27.0 psu
21.5 - 22.0 psu 27.0 - 27.5 psu
22.0 - 22.5 psu 27.5 - 28.0 psu
22.5 - 23.0 psu 28.0 - 28.5 psu
23.0 - 23.5 psu 28.5 - 29.0 psu VICTORIA
23.5 - 24.0 psu 29.0 - 29.5 psu
24.0 - 24.5 psu 29.5 - 30.0 psu
Not for navigation. Data Source: Fisheries and Oceans Canada, Produced in the Western and Northern Service Centre, Parks Canada. Institute of Ocean Sciences. Median summer 0 5 10 15 surface salinity of ocean. psu denotes practical km salinity units. Projection: BC Environment Albers Horizontal Datum: NAD 83
JUAN DE FUCA STRAIT
15 Proposed Southern Strait of GeorgiaVancouver National Marine Conservation Area Reserve Winter Surface Salinity
Richmond
Gabriola
FALSE NARROWS Island
DODD NARROWS GABRIOLA PASSAGE METRO PYLADES CHANNEL VANCOUVER ¥
Tsawwassen Valdes Island
STRAIT OF GEORGIA
S S A P R E I Point Roberts L Thetis R
O Island P (U.S.A.) Ladysmith ! STUART CHANNEL
Kuper Island Canada - U.S.A. Border Galiano Island TRINCOMALI CHANNEL Chemainus !!!
Crofton ! E PA IV SS T
C C
A A
! P T
Ganges A Mayne
I S N
A
N P Island S Prevost A
U S
M S S A
Island W G
N PLUMPER SOUND A
A E N
R S Maple R Saltspring O O
! N W North Tumbo Island Bay S Island C H Pender A
N N Island E L Saturna Island ! Duncan Fulford Harbour ! South
COWICHAN BAY Russell Island Pender Island P
! R E
V
O
Cowichan Bay S T Moresby L P E A N S N A Portland S Island CH A BOUNDARY PASS TE G LLI E SATE Island
S A A N I C H I N L E T Rum Island Sidney! Mill Bay !
S ID N C E O Y C R H D A Sidney O N V N A E L Island C H A N N E L ! Brentwood D'Arcy Bay Island San Juan Island HARO STRAIT (U.S.A.) < 26.5 psu
26.5 - 27.0 psu
27.0 - 27.5 psu
27.5 - 28.0 psu
28.0 - 28.5 psu
28.5 - 29.0 psu VICTORIA
29.0 - 29.5 psu
29.5 - 30.0 psu
Not for navigation. Data Source: Fisheries and Oceans Canada, Produced in the Western and Northern Service Centre, Parks Canada. Institute of Ocean Sciences. Median winter 0 5 10 15 surface salinity of ocean. psu denotes practical km salinity units. Projection: BC Environment Albers Horizontal Datum: NAD 83
JUAN DE FUCA STRAIT
16 Proposed Southern Strait of GeorgiaVancouver National Marine Conservation Area Reserve Tidal Current Velocities
Richmond
Gabriola
FALSE NARROWS Island
DODD NARROWS GABRIOLA PASSAGE METRO PYLADES CHANNEL VANCOUVER ¥
Tsawwassen Valdes Island
STRAIT OF GEORGIA
S S A P R E I Point Roberts L Thetis R
O Island P (U.S.A.) Ladysmith ! STUART CHANNEL
Kuper Island Canada - U.S.A. Border Galiano Island TRINCOMALI CHANNEL Chemainus !!!
Crofton ! E PA IV SS T
C C
A A
! P T
Ganges A Mayne
I S N
A
N P Island S Prevost A
U S
M S S A
Island W G
N PLUMPER SOUND A
A E N
R S Maple R Saltspring O O
! N W North Tumbo Island Bay S Island C H Pender A
N N Island E L Saturna Island ! Duncan Fulford Harbour ! South
COWICHAN BAY Russell Island Pender Island P
! R E
V
O
Cowichan Bay S T Moresby L P E A N S N A Portland S Island CH A BOUNDARY PASS TE G LLI E SATE Island
S A A N I C H I N L E T Rum Island Sidney! Mill Bay !
S ID N C E O Y C R H D A Sidney O N V N A E 0 - 0.1 m/s L Island C H A N N E 0.1 - 0.2 m/s L ! Brentwood 0.2 - 0.3 m/s D'Arcy Bay Island San Juan 0.3 - 0.4 m/s Island HARO STRAIT (U.S.A.) 0.4 - 0.5 m/s
0.5 - 0.6 m/s
0.6 - 0.8 m/s
0.8 - 1.0 m/s
1.0 - 1.5 m/s VICTORIA 1.5 - 2.3 m/s
Data Source: Fisheries and Oceans Canada, Institute of Ocean Sciences. Tidal Current Velocities obtained from Mike Foreman's finite
element model for eastern Juan de Fuca Strait and Not for navigation. southern Strait of Georgia. Horizontal velocities Produced in the Western and Northern Service Centre, Parks Canada.
averaged over the depth of the water column 0 5 10 15 to calculate a horizontal Root Mean Square velocity km at each point. m/s denotes metres/second. Projection: BC Environment Albers Horizontal Datum: NAD 83
JUAN DE FUCA STRAIT
17 Proposed Southern Strait of GeorgiaVancouver National Marine Conservation Area Reserve Vertical Stratification
Richmond
Gabriola
FALSE NARROWS Island
DODD NARROWS GABRIOLA PASSAGE METRO PYLADES CHANNEL VANCOUVER ¥
Tsawwassen Valdes Island
STRAIT OF GEORGIA
S S A P R E I Point Roberts L Thetis R
O Island P (U.S.A.) Ladysmith ! STUART CHANNEL
Kuper Island Canada - U.S.A. Border Galiano Island TRINCOMALI CHANNEL Chemainus !!!
Crofton ! E PA IV SS T
C C
A A
! P T
Ganges A Mayne
I S N
A
N P Island S Prevost A
U S
M S S A
Island W G
N PLUMPER SOUND A
A E N
R S Maple R Saltspring O O
! N W North Tumbo Island Bay S Island C H Pender A
N N Island E L Saturna Island ! Duncan Fulford Harbour ! South
COWICHAN BAY Russell Island Pender Island P
! R E
V
O
Cowichan Bay S T Moresby L P E A N S N A Portland S Island CH A BOUNDARY PASS TE G LLI E SATE Island
S A A N I C H I N L E T Rum Island Sidney! Mill Bay !
S ID N C E O Y C R H D A Sidney O N V N A E L Island C H A N N E L ! Brentwood D'Arcy Bay Island San Juan Island HARO STRAIT (U.S.A.)
-2 - 0 mixed region
0 - 1 mixed region
1 - 2 frontal region
2 - 4 stratified region
4 - 8 stratified region VICTORIA 8 - 16 stratified region
Data Source: Fisheries and Oceans Canada. Tidal current velocities from Mike Foreman's finite Not for navigation. element model were used to calculate vertical Produced in the Western and Northern Service Centre, Parks Canada. stratification using Simpson and Hunter 1974 0 5 10 15 model based on bottom friction. Values are shown km as a dimensionless mixing parameter. Projection: BC Environment Albers Horizontal Datum: NAD 83
JUAN DE FUCA STRAIT
18