Effects of a fluctuation in Fraser River discharge of primary production in the central Strait of Georgia, British Columbia, Canada

1997 ◽  
Vol 54 (5) ◽  
pp. 1015-1024 ◽  
Author(s):  
K Yin ◽  
P J Harrison ◽  
R J Beamish
Keyword(s):  
British Columbia ◽  
Primary Production ◽  
River Discharge ◽  
Euphotic Zone ◽  
Early Summer ◽  
Phytoplankton Production ◽  
Fraser River ◽  
Strait Of Georgia ◽  
Chl A ◽  
First Time

High-resolution vertical profiles of salinity, temperature, fluorescence, and nutrients (NO3 and SiO4) were taken along a transect in the central Strait of Georgia, British Columbia. The Fraser River discharge increased rapidly over 4 days and then decreased over the following 3 days (June 16-19, 1991). The thickness and extent of the estuarine plume increased as a response to the increased river discharge. As the estuarine plume flowed seaward, the nutricline (NO3) became shallower and broader, resulting in an increase in NO3 in the euphotic zone. Entrainment of NO3 may explain the increase in NO3 in the surface layer, and the amount of NO3 entrained was estimated to be 5-10 times higher than river-borne NO3. The utilization of entrained nutrients increased Chl a concentrations and primary production to levels comparable with spring bloom values. Our results clearly demonstrated for the first time that entrainment of nutrients and phytoplankton production in the central Strait of Georgia are closely coupled to fluctuations in the Fraser River discharge as the estuarine plume moves seaward. The timing and magnitude of the May-June freshet could control the entrainment of nutrients and thus maintain high primary productivity in late spring - early summer.

Bedforms, bed material, and bedload transport in a salt-wedge estuary: Fraser River, British Columbia

1989 ◽  
Vol 26 (7) ◽  
pp. 1440-1452 ◽  
Author(s):  
R. A. Kostaschuk ◽  
M. A. Church ◽  
J. L. Luternauer
Keyword(s):  
British Columbia ◽  
River Discharge ◽  
Bedload Transport ◽  
Fraser River ◽  
Seasonal Fluctuations ◽  
Salt Wedge ◽  
Migration Rates ◽  
Material Load ◽  
Bed Material

The lower main channel of the Fraser River, British Columbia, is a sand-bed, salt-wedge estuary in which variations in velocity, discharge, and bedform characteristics are contolled by river discharge and the tides. Bed-material composition remains consistent over the discharge season and in the long term. Changes in bedform height and length follow but lag behind seasonal fluctuations in river discharge. Migration rates of bedforms respond more directly to river discharge and tidal fall than do height and length. Bedform characteristics were utilized to estimate bedload transport in the estuary, and a strong, direct, but very sensitive relationship was found between bed load and river discharge. Annual bedload transport in the estuary is estimated to be of the order of 0.35 Mt in 1986. Bedload transport in the estuary appears to be higher than in reaches upstream, possibly because of an increase in sediment movement along the bed to compensate for a reduction in suspended bed-material load produced by tidal slack water and the salt wedge.

Primary Production and Phytoplankton in the Experimental Lakes Area, Northwestern Ontario, and other Low-Carbonate Waters, and a Liquid Scintillation Method for Determining 14C Activity in Photosynthesis

1971 ◽  
Vol 28 (2) ◽  
pp. 189-201 ◽  
Author(s):  
D. W. Schindler ◽  
S. K. Holmgren
Keyword(s):  
Primary Production ◽  
Liquid Scintillation ◽  
Species Abundance ◽  
Euphotic Zone ◽  
Phytoplankton Production ◽  
Phytoplankton Species ◽  
Experimental Lakes Area ◽  
Phytoplankton Species Composition ◽  
Northwestern Ontario ◽  
Filtration Error

A modified 14C method is described for measuring phytoplankton production in low-carbonate waters. The procedure includes the use of the Arthur and Rigler (Limnol. Oceanogr. 12: 121–124, 1967) technique for determining filtration error, liquid scintillation counting for determining the radioactivity of membrane filters and stock 14C solutions, and gas chromatography for measuring total CO2.Primary production, chlorophyll a, and total CO2 were measured for two dates in midsummer from each of several lakes in the Experimental Lakes Area (ELA), ranging from 1 to 1000 ha in area and from 2 to 117 m in maximum depth. Phytoplankton species abundance and biomass were determined for the same dates. Production ranged from 0.02 to 2.12 gC/m3∙day and from 0.179 to 1.103 g C/m2∙day. Chlorophyll ranged from 0.4 to 44 mg/m3 and from 5 to 98 mg/m2 in the euphotic zone. The corresponding ranges for live phytoplankton biomass were 120–5400 mg/m3 and 2100–13,400 mg/m2. Chrysophyceae dominated the phytoplankton of most of the lakes.A system for classifying the lakes in terms of phytoplankton species composition and production–depth curves is developed.

Quantum yield of the marine benthic microflora of near-shore coastal Penang, Malaysia

2005 ◽  
Vol 56 (7) ◽  
pp. 1047 ◽  
Author(s):  
A. McMinn ◽  
S. Sellah ◽  
W. A. Wan Ab. Llah ◽  
M. Mohammad ◽  
F. Md. Sidik Merican ◽  
...  
Keyword(s):  
Primary Production ◽  
Suspended Solids ◽  
Euphotic Zone ◽  
Water Clarity ◽  
Quantum Yields ◽  
Chl A ◽  
Near Shore ◽  
High Concentrations ◽  
A Minor ◽  
Reduced Water

Benthic microalgal communities often contribute more than 30% of the primary production of shallow coastal and estuarine areas. At Muka Head Penang (Pulau Pinang) and the Songsong Islands (Pulau Songsong), Kedah, Malaysia, high concentrations of suspended solids and phytoplankton biomass (10.6 mg Chl a m−3) has reduced water clarity such that the euphotic zone of these areas is less than 2 m and 3 m deep respectively. The benthic microalgal communities, which were composed of the diatom genera Cocconeis, Fragilaria, Paralia and Pleurosigma, had a low biomass, had low maximum quantum yields (0.325 ± 0.129), were poorly adapted to their light environment and were constantly light limited. These characteristics suggest that the benthic microalgal communities were likely to have made only a minor contribution to the total primary production of the area.

New and regenerated primary production in a productive reservoir ecosystem

2010 ◽  
Vol 67 (2) ◽  
pp. 278-287 ◽  
Author(s):  
Leah M. Domine ◽  
Michael J. Vanni ◽  
William H. Renwick
Keyword(s):  
Primary Production ◽  
Euphotic Zone ◽  
Gizzard Shad ◽  
Phytoplankton Production ◽  
Total Production ◽  
Relative Importance ◽  
Dorosoma Cepedianum ◽  
New Production ◽  
Total Primary Production ◽  
The Difference

The concept of new and regenerated production has been used extensively in marine ecosystems but rarely in freshwaters. We assessed the relative importance of new and regenerated phosphorus (P) in sustaining phytoplankton production in Acton Lake, a eutrophic reservoir located in southwestern Ohio, USA. Sources of nutrients to the euphotic zone, including watershed loading, fluxes from sediments, and excretion by sediment-feeding fish (gizzard shad, Dorosoma cepedianum ), were considered sources of new P input that support new primary production and were quantified over the course of a growing season. Regenerated production was estimated by the difference between new and total primary production. New production represented 32%–53% of total primary production, whereas regenerated production represented 47%–68% of total primary production. P excretion by gizzard shad supplied 45%–74% of new P and 24% of P required for total production. In summary, fluxes of P from the watershed and those from sediment-feeding fish need to be considered in strategies to reduce eutrophication in reservoir ecosystems.

Variation in Body Morphology Among British Columbia Populations of Coho Salmon, Oncorhynchus kisutch

1985 ◽  
Vol 42 (12) ◽  
pp. 2020-2028 ◽  
Author(s):  
Eric B. Taylor ◽  
J. D. McPhail
Keyword(s):  
British Columbia ◽  
Coho Salmon ◽  
Function Analysis ◽  
Oncorhynchus Kisutch ◽  
Fraser River ◽  
Strait Of Georgia ◽  
Coastal Streams ◽  
Morphological Differences ◽  
Median Fins ◽  
Coastal British Columbia

Ten populations of juvenile coho salmon, Oncorhynchus kisutch, from streams tributary to the upper Fraser River, the lower Fraser River, and the Strait of Georgia region were morphologically compared. Juveniles from coastal streams (Fraser River below Hell's Gate and the Strait of Georgia) were more robust (deeper bodies and caudal peduncles, shorter heads, and larger median fins) than interior Juveniles. Discriminant function analysis indicated that juvenile coho could be identified as to river of origin with 71% accuracy. Juvenile coho from coastal streams were less successfully classified as to stream of origin; however, juveniles could be successfully identified as either coastal or interior with 93% accuracy. Juvenile coho from north coastal British Columbia, Alaska, and the upper Columbia system also fitted this coastal and interior grouping. This suggests that a coastwide coastal–interior dichotomy in juvenile body form exists. Three populations (one interior and two coastal) were studied in more detail. In these populations the coastal versus interior morphology was consistent over successive years, and was also displayed in individuals reared from eggs in the laboratory. Adult coho salmon also showed some of the coastal–interior morphological differences exhibited by juveniles. We concluded that the morphological differences between coastal and interior coho salmon are at least partially inherited.

Sedimentary environments and postglacial history of the Fraser Delta and lower Fraser Valley, British Columbia

1983 ◽  
Vol 20 (8) ◽  
pp. 1314-1326 ◽  
Author(s):  
John J. Clague ◽  
John L. Luternauer ◽  
Richard J. Hebda
Keyword(s):  
British Columbia ◽  
Lacustrine Sediments ◽  
Fraser River ◽  
Large Area ◽  
Borehole Data ◽  
Strait Of Georgia ◽  
Sea Levels ◽  
The Holocene ◽  
Sedimentary Environments ◽  
Channel Deposits

The Fraser River delta, which is about 1000 km2 in area above low tide level, has been built into the Strait of Georgia in southwestern British Columbia during the Holocene. Present-day sedimentary environments, including foreslope, tidal flat, river channel, floodplain, and bog, also existed earlier during the delta's development. Borehole data reveal a succession of sedimentary environments related to Holocene progradation of the delta south and west of New Westminster. At each site, marine basin and distal foreslope sediments are overlain by proximal foreslope materials, which in turn are overlain by coarser intertidal platform and channel deposits capped by floodplain and bog sediments.Initial growth of the Fraser Delta was preceded both by deglaciation of the region and by the rapid westward extension of the Fraser River floodplain down a partially submerged, glacially scoured trough east of New Westminster. Irregularities on the trough floor were covered by fluvial, deltaic, marine, and lacustrine sediments as the floodplain extended westward. About 10 000 years ago, the Fraser River began to empty directly into the Strait of Georgia through a gap in the Pleistocene uplands at New Westminster. A delta was constructed south and west from this site as the sea dropped below its present level relative to the land. Deltaic progradation continued after sea level stabilized at about −12 m elevation after 8000 years BP. A marine transgression between 7000–7500 and 5000–5500 years ago inundated parts of the Fraser proto-delta and temporarily inhibited its seaward advance. This transgression ended with the sea perhaps 1 or 2 m below its present position, whereupon a large area of the delta became emergent and large bogs began to form. During the remainder of the Holocene, the Fraser Delta grew westward, but apparently not southward, under a regime of relatively stable sea levels.

Salt and Freshwater Exchange on Roberts Bank, British Columbia

1988 ◽  
Vol 23 (1) ◽  
pp. 160-178 ◽  
Author(s):  
P.B. Crean ◽  
T.S. Murty ◽  
J.A. Stronach
Keyword(s):  
Fresh Water ◽  
Seasonal Changes ◽  
River Discharge ◽  
Retaining Wall ◽  
Surface Currents ◽  
Fraser River ◽  
Strait Of Georgia ◽  
Shallow Layer ◽  
Layer Flow ◽  
Incoming Tide

Abstract One of the aspects of the seaward movement of fresh water from the Fraser River is its passage tangential to Roberts Bank and subsequent recirculation onto the bank. A synoptic study of the oceanography of the bank is described, part, of a larger study of surface currents in the Strait of Georgia. Seasonal changes in salinity and temperature over Roberts Bank are presented. The freshwater flows and motions of the salt wedges in the river and on the bank are described. Under the restraints of a retaining wall immediately north of the river, and on the incoming tide, a shallow layer of fresh water briefly forms an eddy, varying in size with river discharge and extending over the bank to the south. The influence of the two-layer flow on sedimentation is also discussed.

Sign in / Sign up

Export Citation Format

Share Document