Phytoplankton Ecology of Vancouver Harbor

1979 ◽  
Vol 36 (1) ◽  
pp. 1-10 ◽  
Author(s):  
John G. Stockner ◽  
David D. Cliff

Phytoplankton production and distribution were examined over a 2-yr period in the Burrard Inlet system, which includes a true fiord (Indian Arm), a shallow blind inlet (Port Moody Arm), and a turbulent narrows region that is contiguous to the Port of Vancouver. Greatest annual production occurred in Port Moody Arm with a mean of 532 g C∙m−2∙yr−1 while the lowest values were in Indian Arm and the Narrows region, averaging about 260 g C∙m−2∙yr−1. Nitrate and zooplankton grazing were the main factors limiting phytoplankton production in Indian Arm, while flushing and poor light conditions influenced phytoplankton growth in the Narrows and outer Burrard Inlet. Most of the discharges of domestic and industrial wastes have been diverted to the Fraser River, and Vancouver Harbor can be considered relatively clean and pollution-free because of strong tidal mixing and seaward flushing. The only sign of eutrophication in the inlet is in Port Moody Arm where sufficient nutrients from sewage discharges and a relatively stable mixed-layer depth create near optimal conditions for phytoplankton growth. Daily production here is among the highest recorded in the literature for Pacific coastal marine waters. Key words: Phytoplankton, primary production, coastal marine embayment, fiord, phytoplankton succession and distribution, chlorophyll a

1979 ◽  
Vol 36 (6) ◽  
pp. 657-666 ◽  
Author(s):  
J. G. Stockner ◽  
D. D. Cliff ◽  
K. R. S. Shortreed

Observations of phytoplankton production, abundance, and distribution were made at 16 stations in the Strait of Georgia from 1975 to 1977. The discharge of turbid Fraser River water exerts a strong influence on phytoplankton production and distribution in surface waters by rapid light attenuation and horizontal advection. At plume boundaries and back eddies where light conditions improve, very high production occurs (> 4–5 g C∙m−2∙d−1), because of rapidly replenished nutrients supplied by the Fraser River. Advection, turbulence, zooplankton grazing, and summer nitrate depletion collectively impart a heterogeneous distribution pattern to phytoplankton in the surface waters of the Strait of Georgia. Mean annual production varies from lows of 150 g C∙m−2 in Fraser River plume to highs of over 500 g C∙m−2 in sheltered boundary waters of inlets. Recent increases in ammonia and nitrate from land drainage and domestic sewage, mainly through the Fraser River, are related to increases in phytoplankton standing stocks in the Strait. Key words: phytoplankton, primary production, eutrophication, coastal marine, phytoplankton distribution and succession, chlorophyll a, pelagic


Author(s):  
James G. Parker ◽  
R. S. Rosell ◽  
K. C. MacOscar

Spring and autumn phytoplankton blooms are characteristic of those temperate marine waters where thermal stratification occurs during the summer months (e.g. Raymont, 1976). However, in well-mixed coastal waters the phytoplankton production cycle may consist of a single peak of growth during the summer (Boalch, Harbour & Butler, 1978; Wafar, Le Carre & Birrien, 1983). In a recent paper, Brander & Dickson (1984) considered evidence from the Irish Sea continuous plankton recorder which reflects the phytoplankton growth cycle largely in the well-mixed areas of the sea. These data suggested a single late peak of production, in contrast to the bimodal blooms which are known to develop in the stratified areas of the Irish Sea (Burrows & Sharpies, 1973; Slinn, 1974). The purpose of the present work was to establish the production cycle for Belfast Lough, which lies adjacent to the North Channel, an area of strong tidal mixing which forms the northerly exit for water from the Irish Sea (Lee & Ramster, 1981; Howarth, 1984). There have been no previous measurements of primary production in Belfast Lough. There was considerable interest in this topic in the early years of this century when the Royal Commission on Sewage Treatment (1908) heard evidence that nutrient inputs from sewers into the lough resulted in excessive growth of the green alga Ulva, which caused a nuisance as it decayed around the shores. Although there have been no recent reports of this phenomenon, several sewage works continue to discharge partially treated effluent to the lough. An aim of this work was therefore to assess the role of anthropogenic nutrient inputs upon phytoplankton growth.


PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9430
Author(s):  
Francoise Morison ◽  
James Joseph Pierson ◽  
Andreas Oikonomou ◽  
Susanne Menden-Deuer

The impacts of grazing by meso- and microzooplankton on phytoplankton primary production (PP) was investigated in the surface layer of the western North Atlantic during spring. Shipboard experiments were performed on a latitudinal transect at three stations that differed in mixed layer depth, temperature, and mesozooplankton taxonomic composition. The mesozooplankton community was numerically dominated by Calanus finmarchicus at the northern and central station, with Calanus hyperboreus also present at the northern station. The southern station was >10 °C warmer than the other stations and had the most diverse mesozooplankton assemblage, dominated by small copepods including Paracalanus spp. Microzooplankton grazing was detected only at the northern station, where it removed 97% of PP. Estimated clearance rates by C. hyperboreus and C. finmarchicus suggested that at in-situ abundance these mesozooplankton were not likely to have a major impact on phytoplankton abundance, unless locally aggregated. Although mesozooplankton grazing impact on total phytoplankton was minimal, these grazers completely removed the numerically scarce > 10 µm particles, altering the particle-size spectrum. At the southern station, grazing by the whole mesozooplankton assemblage resulted in a removal of 14% of PP, and its effect on net phytoplankton growth rate was similar irrespective of ambient light. In contrast, reduction in light availability had an approximately 3-fold greater impact on net phytoplankton growth rate than mesozooplankton grazing pressure. The low mesozooplankton grazing impact across stations suggests limited mesozooplankton-mediated vertical export of phytoplankton production. The constraints provided here on trophic transfer, as well as quantitative estimates of the relative contribution of light and grazer controls of PP and of grazer-induced shifts in particle size spectra, illuminate food web dynamics and aid in parameterizing modeling-frameworks assessing global elemental fluxes and carbon export.


2015 ◽  
Vol 72 (6) ◽  
pp. 1926-1941 ◽  
Author(s):  
Rica Mae Enriquez ◽  
John R. Taylor

Abstract About 60 years ago, Sverdrup formalized the critical depth hypothesis to explain the timing of the spring phytoplankton bloom in terms of the depth of the surface mixed layer. In recent years, a number of refinements and alternatives to the critical depth hypothesis have been proposed, including the critical turbulence hypothesis which states that a bloom can occur when turbulent mixing is sufficiently weak, irrespective of the mixed layer depth. Here, we examine the relative influence of wind-driven mixing and net surface heating on phytoplankton growth. Of particular interest is whether wind-driven mixing can delay the spring bloom after winter convection gives way to net surface warming. We address these questions using high-resolution large-eddy simulations (LES) coupled with a simple phytoplankton model. We also describe an analytical phytoplankton model with a formulation for the turbulent mixing based on the LES results. For a constant, prescribed surface heat flux, net phytoplankton growth is seen when the windstress is smaller than a critical value. Similarly, for a constant windstress, a critical heat flux separates cases with growing and decaying phytoplankton populations. Using the LES results, we characterize the critical windstress and critical heat flux in terms of other physical and biological parameters and propose a simple expression for each based on the analysis of the analytical model. Phytoplankton growth begins when the mixing depth shoals above the critical depth, consistent with the critical depth hypothesis. Our results provide a framework to interpret blooms in other conditions where both the depth and the intensity of turbulent mixing might be crucial factors in influencing phytoplankton growth.


1989 ◽  
Vol 46 (S1) ◽  
pp. s183-s199 ◽  
Author(s):  
R. Ian Perry ◽  
Peter C. F. Hurley ◽  
Peter C. Smith ◽  
J. Anthony Koslow ◽  
Robert O. Fournier

Chlorophyll and nitrate data from monthly surveys off southwest Nova Scotia indicate the spring phytoplankton bloom began near the end of March of each year, occurring early (late) in 1984 (1983). The highest chlorophyll biomass(all months) was found in 1985. Using survey data, the Sverdrup hypothesis for the initiation of the bloom was tested by comparing the critical depth, Zcr, for net phytoplankton production to the observed mixed-layer depth, Zmix. Survey median Zcr/Zmix were consistently less than 1 until May, suggesting that observed blooms were initiated by events outside the specific survey periods. Results of a mixed-layer model incorporating surface heating, differential advection and turbulent dissipation by wind and tide showed reasonable agreement with observed mixed depths, and patterns of the mean (modelled) mixed-layer light intensity are significantly correlated with observed chlorophyll biomass. In 1983 and 1984, mean light intensities first exceeded the critical value for a bloom to occur in late March. In 1985, transient periods of stratification in mid-February and early March produced intensities greater than the critical value. These events, together with higher nitrate concentrations and lower Zooplankton biomass, appear to be responsible for the high chlorophyll biomass observed in 1985.


2016 ◽  
Vol 7 (2) ◽  
Author(s):  
Nabil Balbeid ◽  
Agus Saleh Atmadipoera ◽  
Alan Frendy Koropitan

<p class="Paragraf"><em>Madden-Julian Oscillation (MJO) is a large-scale phenomenon that occurs in equatorial area, parti-cularly Indonesia. This research aimed to investigate the MJO propagation process and studied the correlation between MJO and sea surface temperature (SST) and chlorophyll-a. Sea variables (SST and chlorophyll-a) and atmosphere variables (</em><em>outgoing longwave radiation</em><em>/OLR, 1,5 km wind,</em><em> and</em><em> surface wind) were band-pass filtered for 20-100 days period. Spectral density from OLR and 1,5 km wind (2003-2012) shows that the MJO period was dominantly occurred for </em><em>40–50</em><em> days. </em><em>Average </em><em>pro-pagation</em><em> of</em><em> </em><em> MJO</em><em> </em><em>velocity </em><em>resulted from the atmospheric variable analysis by </em><em>Hovmöller</em><em> diagram was 4,7 m/s. Cross correlation between SST and OLR in South Java and Banda Sea result</em><em>s</em><em> a strong corre-lation during MJO active phase, where </em><em>MJO too</em><em>k </em><em> place first and was then followed by</em><em> the </em><em>decreasing </em><em>SST </em><em>along the equatorial region</em><em>.</em><em> Increasing chlorophyll-a concentration occured at some areas du</em><em>-</em><em>ring MJO active phase with relatively short phase delay. </em><em>During the MJO active phase, fluctuation of wind velocity generates variation over mixed layer depth and triggers upwelling /entrainment. Nutri-ent was upwelled to the water surface and hence increase phytoplankton production and chlorophyll-a concentration.</em></p><p><em> </em><strong><em>Keywords</em></strong><em>:</em><em> Madden Julian Oscillation, OLR, </em><em>sea surface temperature, surface chlorophyll-a</em></p>


2021 ◽  
Author(s):  
Francesco Mattei ◽  
Michele Scardi

Phytoplankton primary production is a key oceanographic process. It has intimate relationships with the marine food webs dynamics, the global carbon cycle and the Earth’s climate. The study of phytoplankton production on a global scale relies on indirect approaches due to the difficulties associated with field campaigns. On the other hand, modelling approaches require in situ data for both calibration and validation. In fact, the need for more phytoplankton primary production data was highlighted several times during the last decades.Most of the available primary production datasets are scattered in various repositories, reporting heterogeneous information and missing records. For these reasons we decided to retrieve field measurements of marine phytoplankton primary production from several sources and create a homogeneous and ready to use dataset. We handled missing data and added several variables related to primary production which were not present in the original datasets. Subsequently, we carried out a general analysis of the dataset in which we highlighted the relationships between the variables from a numerical and an ecological perspective.Data paucity is one of the main issues hindering the comprehension of complex natural processes.In this framework, we believe that an updated and improved global dataset, complemented by an analysis of its characteristics, can be of interest to anyone studying marine phytoplankton production and the processes related to it.


Author(s):  
R. D. Pingree ◽  
P. M. Holligan ◽  
G. T. Mardell ◽  
R. N. Head

The Celtic Sea extends from the south of Ireland and the St Georges Channel across the continental shelf, with the Bristol and English Channels as its eastern limits (Fig. 1) (Cooper, 1967). Although various investigations of the physical oceanography (Matthews, 1914; Cooper, 1967) and zooplankton (Russell, 1934, a, b, 1936; Corbin, 1947; and more recently Southward, 1962; Bary, 1963) of this area have been carried out, there is little or no information on seasonal changes in levels of chlorophyll ‘a’ and inorganic nutrients, and on the importance of tidal mixing in determining these distributions. Since the speeds of the tidal streams range from weak (∼ 0.5 knot) in the northern part of the Celtic Sea to strong (∼ 3 knots) around the Scilly Isles and Ushant (Fig. 2), the vertical stability of the water column as well as the duration of the seasonal thermocline (Pingree, 1975) are likely to be important factors in determining spatial and temporal variations of phytoplankton production. In this paper the influence of water-column stability on phytoplankton distributions (in spring, summer and autumn) in the Celtic Sea is described, using data for temperature, salinity, chlorophyll ‘a’ and inorganic nutrients obtained during seven cruises in 1975. An account of the red tide conditions that occurred in late July to the north-west of Ushant has already been published (Pingree, Pugh, HoUigan & Forster, 1975).


1995 ◽  
Vol 52 (5) ◽  
pp. 897-902 ◽  
Author(s):  
Richard D. Robarts ◽  
Michael T. Arts ◽  
David B. Donald

Measurements of phytoplankton primary production in three temporary Alberta ponds indicate a huge potential carbon and energy source for higher trophic levels associated with these systems. The ponds had high levels of NO3-N (maximum 1.6 mg∙L−1) and PO4-P (maximum 3.6 mg∙L−1). Water temperature varied by as much as 15 °C over the diel cycle, while primary production peaked in mid-afternoon. Production rates ranged from 0.6 to 400 mg C∙m−3∙T−1 and were strongly correlated (r = 0.9) with phytoplankton density. Total annual production for the ponds varied from 187 to 3311 kg C. These annual production values are low relative to prairie lakes; however, the number of small temporary ponds is about three orders of magnitude greater than lakes making phytoplankton production of these small water bodies a potentially important source of energy in prairie food webs.


Sign in / Sign up

Export Citation Format

Share Document