Seasonal and vertical distribution of picoplankton in Llyn Padarn, Gwynedd

Kennaway, Gabrielle; Edwards, Gerald E.

doi:10.1080/00071618900650391

Cited by 14 publications

(20 citation statements)

References 37 publications

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“…1985;PROBYN and PAINTING 1985). There was a poor correspondence between average epilimnetic temperature and average population abundance in our study lakes, contrary to observations from marine (MURPHY and HAUGEN 1985) and freshwater (KENNAWAY and EDWARDS 1989) systems, where picoplankton abundance was positively correlated with temperature. Temperature does not appear to have a major effect on picoplankton abundance and vertical distribution in our study lakes; rather it is likely that in temperate and subarctic lakes nutrients and to a lesser extent light determine the upper limits of population density.…”

Section: Discussioncontrasting

confidence: 85%

Autotrophic Picoplankton: Community Composition, Abundance and Distribution across a Gradient of Oligotrophic British Columbia and Yukon Territory Lakes

Stockner

Shortreed

1991

Intl Review of Hydrobiology

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Autotrophic picoplankton communities were examined in eleven oligotrophic lakes from a broad geographic region of western Canada, representing a variety of physico-chemical and biological conditions. During our study, several of the lakes were treated with additions of inorganic nitrogen and phosphorus fertilizers. Picoplankton communities in most lakes were dominated (> 70 %) by unicellular or colonial coccoid cyanobacteria, provisionally identified by morphological and autofluorescence properties as Synechocuccus. Also common in some lakes were red-fluorescing cyanobacteria and Chlorellu-like eucaryotes. Autotrophic picoplankters contributed from 36-63 % to total chlorophyll, from c 2-26 % to total phytoplankton carbon, and from 29-53 % to total photosynthesis. Average populations ranged from < 5-10,OOO cells. ml-* in winter and early spring to 65-75,ooO cells.ml-1 in summer and fall. Peak densities in most lakes occurred in AugustSeptember and most populations were within the epilimnion or metalimnionhypolimnion boundary. Subsurface peaks were prevalent only in untreated, strongly stratified lakes. Eucaryotic picoplankters became dominant in acidic (pH < 6.2), humic lakes. ColoniaI picoplankters were more common in more productive interior lakes in August, and though present, were uncommon in coastal systems. Picoplankton populations exhibited large increases under ice in a Yukon lake, and their abundance and seasonal distribution showed little relation to temperature or to light. Fertilization of lakes resulted in picoplankton population increases (> 2 x) and the elimination of subsurface peaks. Nutrients were considered to be one of the major factors controlling population abundance in these oligotrophic lakes with average pH > 6.5.

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Section: Discussioncontrasting

confidence: 85%

Autotrophic Picoplankton: Community Composition, Abundance and Distribution across a Gradient of Oligotrophic British Columbia and Yukon Territory Lakes

Stockner

Shortreed

1991

Intl Review of Hydrobiology

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“…In Llyn Padarn, during 1986-87. Kennaway & Edwards (1989) found that 38-54% of the chlorophyll a biomass was attributable to picopiankton with a maximum of 75% total chlorophyll in May 1987 at a water depth of 9 m. In the present study of Padarn picopiankton, the contribution to biomass was lowest, between 4 and 15%, during the spring and autumn maxima in total algal biomass resulting from diatom growth (Fig. 8).…”

Section: Discussioncontrasting

confidence: 44%

“…Previous studies in this lake have shown the presence of moderate populations of small-celled green algae, corresponding to the nanoplankton size category 2-20 |im. together with larger-celled diatoms (Priddle & Happey-Wood, 1983) and recently Kennaway & Edwards (1989) have described autotrophic picoplankton in this lake. The present investigation describes in more detail the population biology and distribution of the picophytoplankton in Llyn Padarn and assesses the contribution of picoplankton.…”

Section: Introductionmentioning

confidence: 98%

Temporal and spatial patterns in the distribution and abundance of pico, nano and microphytoplankton in an upland lake

Happey‐Wood

1991

Freshwater Biology

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SUMMARY. 1. An investigation of the seasonal and depth distribution of populations of autotrophic picoplankton (0.2–2 μm), nanophytoplankton (>2<20 μm) and larger microalgal plankton (>20μm) was carried out over 21/2 years, 1988–90, in Llyn Padarn, a mesotrophic upland lake in North Wales. 2. Cell numbers of picophytoplankton ranged from <102 to >106 cells cm−3. Maximum numbers of nanoplankton were c. 104 cells cm−3 and the greatest abundance of microalgal plankton, diatoms, reached 12 × 103 cells cm−3. 3. Three types of picoalgae were distinguished: coccoid to oval Synechococcus—Synechocystis, the rod‐shaped Synchecococcus capitatus Bailey‐Watts & Komárek and Chlorella minutissima Fott & Nováková, with maximum numbers of 1.2 × 106, 37.8 × 103 and 44.1 × 103 cells cm−3, respectively. 4. Picophytoplankton exhibited periods of exponential growth: the first in spring, and the second in August—September with an intervening population minimum in early to midsummer. Specific rates of population increase for picophytoplankton were low, with minimum apparent generation times of 3.8 days in summer 1989. 5. Nanophytoplankton included seven species of phytoflagellates and two non‐motile species. These algae were present for about 10 months in each year exhibiting a fluctuation in population density of 102−‐103 cells cm−3. 6. There were spring and autumn maxima in chlorophyll a concentrations in the lake water corresponding to the growth of planktonic diatoms. Maximum total biomass concentration was 35 mg m−3 chlorophyll a, whereas pico, nano and microphytoplankton had individual maxima of 7.7, 8.4 and 31.0 mg m−3 chlorophyll a, respectively. Picophytoplankton often contributed > 60% of the total algal chlorophyll a in the epilimnion. 7. The growth patterns and seasonal periodicities of the three size‐categories of planktonic algae in Llyn Padarn were distinct. Picophytoplankton persist throughout much of the year with periods of very low abundance, < 100 cells cm−3, occurring in winter and midsummer. Thus for much of the year, there was a large inoculum of these cells in the lake to initiate growth leading to the population maxima in spring and late summer. Nanoplankton populations, a diverse assemblage, fluctuated in numbers over the period February–November; no population decline in midsummer comparable to picophytoplankton was observed. The larger microphyloplankton exhibited classical seasonal periodicity, namely diatom growth in spring and late summer–autumn with growth of large‐celled chlorophytes in the intervening summer period.

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“…Size fractionation of chlorophyll in the present and some previous studies (Craig 1986, Kennaway & Edwards 1989, Riemann et al 1990, Sondergaard 1991 showed, however, high and probably unrealistic APP chlorophyll concentrations compared with calculated chlorophyll values. Furthermore, there was no relationship between measured APP chlorophyll concentrations and biovolumes, a rather common but often unnoticed feature in the literature.…”

Section: Picoalgal Abundance and Biomassmentioning

confidence: 55%

Picoalgae in Danish coastal waters during summer stratification

Søndergaard¹,

Jensen²,

Ærtebjerg³

1991

Mar. Ecol. Prog. Ser.

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The abundance and relative importance of picoalgae (autotrophic picoplankton, APP) were surveyed in Danish marine waters during summer stratification to test the hypothesis of high APP importance under oligotrophy. A picoalgal community dominated by Synechococcus was found at 28 of 29 stations visited. Abundance in the mixed surface layers ranged from 6 X lo6 cells 1-I in the eutrophic German Bight to 4.5 X lo8 cells l 1 in the Baltic. Differences in cell sizes among different areas were also found. Total APP biovolumes and < 2 pm fractionated chlorophyll concentrations showed no relationship; consequently the APP biomass as indicated by chlorophyll was calculated from the biovolume estimates. High relative APP importance was negatively related to total chlorophyll, A power function with an exponent close to -1 showed the best model of the relative importance. However, an analysis of the APP chlorophyll values in the mixed surface waters showed a constant biomass of 0.5 to 0.6 pg chl 1 1 , although with a trend for higher values in the Baltic and lower values in the German Bight. Thus, picoalgal biomass could be considered constant over the entire range of total chlorophyll, and increases in total autotrophic biomass were mainly due to increases in the nanoplankton

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Seasonal and vertical distribution of picoplankton in Llyn Padarn, Gwynedd

Cited by 14 publications

References 37 publications

Autotrophic Picoplankton: Community Composition, Abundance and Distribution across a Gradient of Oligotrophic British Columbia and Yukon Territory Lakes

Autotrophic Picoplankton: Community Composition, Abundance and Distribution across a Gradient of Oligotrophic British Columbia and Yukon Territory Lakes

Temporal and spatial patterns in the distribution and abundance of pico, nano and microphytoplankton in an upland lake

Picoalgae in Danish coastal waters during summer stratification

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