A Seasonal Analysis of the Armoured Dinoflagellates of Loch Eriboll, North Scotland

1995 ◽  
Vol 75 (1) ◽  
pp. 219-233 ◽  
Author(s):  
John D. Dodge
Keyword(s):  
Seasonal Pattern ◽  
Early Summer ◽  
Fish Farm ◽  
Alexandrium Tamarense ◽  
Diatom Bloom ◽  
Dinophysis Acuminata ◽  
Seasonal Analysis ◽  
A Site

The armoured planktonic dinoflagellates present at a site adjacent to a floating fish-farm in Loch Eriboll, North Scotland, were studied by surface net-sampling, mainly at two-weekly intervals, over a period of four years 1990–1993. A total of 62 species was recorded. Some dinoflagellates were present at all times of the year but they reached their lowest numbers in May, during the spring diatom bloom, and their highest numbers in mid-summer. There was usually a seasonal pattern in which the most abundant dinoflagellate during the early summer was the heterotrophic species Protoperidinium ovatum, and this was followed in the later summer by the autotroph Ceratium fusus. In 1993 the pattern was rather different, with Gonyaulax species abundant in June and, later in the year, both Protoperidinium cerasus and P. excentricum having periods of abundance. Potential toxin-producing dinoflagellates, Alexandrium tamarense (PSP) and Dinophysis acuminata (DSP), were found in small numbers.

Seasonal patterns of fine-root production and mortality in Prunus avium in Scotland

2004 ◽  
Vol 34 (7) ◽  
pp. 1534-1537 ◽  
Author(s):  
John A Baddeley ◽  
Christine A Watson
Keyword(s):  
Prunus Avium ◽  
Fine Root ◽  
Seasonal Pattern ◽  
Early Summer ◽  
Root Production ◽  
Root Dynamics ◽  
Root Numbers ◽  
Short Period ◽  
A Site ◽  
Observation Period

The seasonal pattern of root dynamics in Prunus avium (L.) L. (wild cherry) was determined using mini rhizotron observations of the production and disappearance of individual roots over a 2-year period at a site in northeast Scotland. The largest percentage of observed root appearance and disappearance took place at a depth of 10 cm (34%) compared with approximately 20% at each of three lower depths down to 30 cm. Of the 37 574 roots·m–2 produced in total over the 2-year observation period, some 78% disappeared during the study. Over 90% of new root production occurred between March and October. Root production was highest in June 1998 (2263 roots·m–2) and lowest in January of 1998 and 1999 (31 roots·m–2). Combination of these data with counts of root disappearance showed that there was a net increase in root numbers per tree between March and June. From June onwards, the rate of root disappearance exceeded the rate of production. Thus, any annual increase in the number of roots depended upon a short period of major root production in late spring – early summer.

Anions and Cations in Ice Cores from Dolleman Island and the Palmer Land Plateau, Antarctic Peninsula

1988 ◽  
Vol 10 ◽  
pp. 121-125 ◽  
Author(s):  
Robert Mulvaney ◽  
David A. Peel
Keyword(s):  
Antarctic Peninsula ◽  
Isotope Composition ◽  
Seasonal Pattern ◽  
Austral Summer ◽  
Ice Cores ◽  
Late Summer ◽  
Ionic Species ◽  
Weddell Sea ◽  
Seasonal Maximum ◽  
A Site

High-resolution anion profiles of Cl-, NO3- and SO4 2− are presented for two cores from the Antarctic Peninsula. A 47.2 m core from a site on the Palmer Land plateau (74°01’S, 70°38’W), spans the period 1942–80, and a 10.5 m core from Dolleman Island (70°35.2’S, 60°55.5’W), on the east coast of the peninsula, spans the period 1973–85. The seasonal pattern of deposition of these species has been determined by reference to the oxygen-isotope composition. Averaged over 38 years, the annual cycle of SO4 2− at Gomez shows a seasonal maximum during the austral summer, and minimum during the winter, whereas the Cl- cycle is more complex and may show the influence of equinoctial storms. The Dolleman core is significantly influenced by the proximity of the Weddell Sea, with a mean Cl- concentration five times greater than in the core from the plateau, and it shows a clear seasonal maximum in late-summer snowfall. There is no significant long-term trend in the 38 years’ data from the plateau site, suggesting that global pollution does not contribute significantly to the anion budget. Both anions and the cations Na+, K+ and H+ have been measured for more than a complete year of snowfall and the balance of ionic species is excellent.

The Diets and Dietary Preferences of Rattus-Fuscipes and Rattus-Lutreolus at Walkerville in Victoria

1987 ◽  
Vol 14 (1) ◽  
pp. 35 ◽  
Author(s):  
DC Cheal
Keyword(s):  
Plant Material ◽  
Early Summer ◽  
Fleshy Fruit ◽  
Dietary Overlap ◽  
Dietary Preferences ◽  
Faecal Analysis ◽  
Dietary Component ◽  
Rattus Fuscipes ◽  
A Site ◽  
Short Time

The diets of Rattus fuscipes and R. lutreolus from a site in central southern Victoria were investigated by faecal analysis. R. lutreolus was predominantly herbivorous; in heath it selected the basal stems of certain cyperaceous herbs, and in forest it ate non-sclerophyllous grasses. Fungi were an important dietary component and seed might be eaten in some quantity for a short time in spring and early summer. R. fuscipes showed little dietary overlap with R. lutreolus; in forest it was reliant on fungi and fibrous plant material from particular grasses; in heath it relied on particular cyperaceous species in winter, and ate primarily fleshy fruit, seed and arthropods in summer. Dietary preferences are compared with the relative abundance of diet items in the habitat. Both species are selective, and this selectivity changes with season. The effects of the availability of preferred diet items on the species' distributions are discussed.

scholarly journals Seasonal Affective Disorder: An Overview of Assessment and Treatment Approaches

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Sherri Melrose
Keyword(s):  
Affective Disorder ◽  
Seasonal Affective Disorder ◽  
Seasonal Pattern ◽  
Light Therapy ◽  
Early Summer ◽  
Major Depressive ◽  
Assessment And Treatment ◽  
Typical Treatment ◽  
Recurrent Major Depressive Disorder ◽  
Assessment Questionnaire

Seasonal affective disorder or SAD is a recurrent major depressive disorder with a seasonal pattern usually beginning in fall and continuing into winter months. A subsyndromal type of SAD, or S-SAD, is commonly known as “winter blues.” Less often, SAD causes depression in the spring or early summer. Symptoms center on sad mood and low energy. Those most at risk are female, are younger, live far from the equator, and have family histories of depression, bipolar disorder, or SAD. Screening instruments include the Seasonal Pattern Assessment Questionnaire (SPAQ). Typical treatment includes antidepressant medications, light therapy, Vitamin D, and counselling. This paper provides an overview of SAD.

Seasonal variations of metal concentrations in periphyton and taxonomic composition of the algal community at a Yenisei River littoral site

2010 ◽  
Vol 5 (1) ◽  
pp. 125-134 ◽  
Author(s):  
Olesya Anishchenko ◽  
Michail Gladyshev ◽  
Elena Kravchuk ◽  
Elena Ivanova ◽  
Iliada Gribovskaya ◽  
...  
Keyword(s):  
Seasonal Variations ◽  
Early Spring ◽  
Taxonomic Composition ◽  
Early Summer ◽  
Algal Community ◽  
Yenisei River ◽  
Algal Communities ◽  
Metal Contents ◽  
Middle Stream ◽  
A Site

AbstractThe concentrations of metals K, Na, Ca, Mg, Fe, Mn, Zn, Cu, Ni, Pb, Co and Cr, in the water and periphyton (epilithic algal communities) were studied at a site in the middle stream of the Yenisei River (Siberia, Russia) during three years using monthly sampling frequencies. Despite considerable seasonal variations in aquatic concentrations of some metals, there was no correlation between metal contents in the water and in periphyton. Seasonal concentration variations of some metals in periphyton were related to the species (taxonomic) composition of periphytic microalgae and cyanobacteria. Enhanced levels of Ni and Co in periphyton in late autumn, winter, and early spring were likely caused by the predominance of cyanobacteria in the periphytic community, and annual maximum levels of K in periphyton in late spring and early summer were attributed to the domination of Chlorophyta, primarily Ulothrix zonata.

scholarly journals High-Resolution Spatiotemporal Dynamics of Harmful Algae in the Indian River Lagoon (Florida)—A Case Study of Aureoumbra lagunensis, Pyrodinium bahamense, and Pseudo-nitzschia

2021 ◽  
Vol 8 ◽  
Author(s):  
Cary B. Lopez ◽  
Charles L. Tilney ◽  
Eric Muhlbach ◽  
Josée N. Bouchard ◽  
Maria Célia Villac ◽  
...  
Keyword(s):  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Seasonal Pattern ◽  
Indian River Lagoon ◽  
Early Summer ◽  
Temperature Cycle ◽  
Estuarine Ecosystem ◽  
Indian River ◽  
Pyrodinium Bahamense ◽  
Aureoumbra Lagunensis

The Indian River Lagoon (IRL), located on the east coast of Florida, is a complex estuarine ecosystem that is negatively affected by recurring harmful algal blooms (HABs) from distinct taxonomic/functional groups. Enhanced monitoring was established to facilitate rapid quantification of three recurrent bloom taxa, Aureoumbra lagunensis, Pyrodinium bahamense, and Pseudo-nitzschia spp., and included corroborating techniques to improve the identification of small-celled nanoplankton (<10 μm in diameter). Identification and enumeration of these target taxa were conducted during 2015–2020 using a combination of light microscopy and species-specific approaches, specifically immunofluorescence flow cytometry as well as a newly developed qPCR assay for A. lagunensis presented here for the first time. An annual bloom index (ABI) was established for each taxon based on occurrence and abundance data. Blooms of A. lagunensis (>2 × 108 cells L–1) were observed in all 6 years sampled and across multiple seasons. In contrast, abundance of P. bahamense, largely driven by the annual temperature cycle that moderates life cycle transitions and growth, displayed a strong seasonal pattern with blooms (105–107 cells L–1) generally developing in early summer and subsiding in autumn. However, P. bahamense bloom development was delayed and abundance was significantly lower in years and locations with sustained A. lagunensis blooms. Pseudo-nitzschia spp. were broadly distributed with sporadic bloom concentrations (reaching 107 cells L–1), but with minimal concentrations of the toxin domoic acid detected (<0.02 μg L–1). In summer 2020, multiple monitoring tools characterized a novel nano-cyanobacterium bloom (reaching 109 cells L–1) that coincided with a decline in A. lagunensis and persisted into autumn. Statistical and time-series analyses of this spatiotemporally intensive dataset highlight prominent patterns in variability for some taxa, but also identify challenges of characterizing mechanisms underlying more episodic yet persistent events. Nevertheless, the intersect of temperature and salinity as environmental proxies proved to be informative in delineating niche partitioning, not only in the case of taxa with long-standing data sets but also for seemingly unprecedented blooms of novel nanoplanktonic taxa.

scholarly journals Recent patterns of discharge and sediment output of the Gorner Glacier, Switzerland

2020 ◽  
Author(s):  
Günther Prasicek ◽  
François Mettra ◽  
Stuart Lane ◽  
Frédéric Herman
Keyword(s):  
Organic Carbon ◽  
Water Samples ◽  
Water Pressure ◽  
Seasonal Pattern ◽  
Monitoring Program ◽  
Early Summer ◽  
Organic Carbon Content ◽  
European Alps ◽  
Glacier Terminus ◽  
Recent Climate

<p>Recent climate change is causing rapid retreat of alpine glaciers around the globe. As ice melts and glaciers thin, glacier motion and subglacial processes will change. One of the most relevant aspects for down-valley environments, settlements and infrastructure is the potential change in flow discharge and sediment output.</p><p>Here we present the results of an ongoing monitoring program at the Gorner Glacier, Switzerland, the second-largest glacier system in the European Alps.  During the melt season of 2018 and 2019, stage and turbidity were monitored with a 5 minute frequency along a turbulent section of the glacial river, located approximately 1 km downstream of the glacier terminus. For calibration of the turbidity measurements, daily water samples were obtained with an automated pump sampler, supported by additional intermittent manual sampling. The data is complemented by a discharge time series that also contains information on the flushing of a bedload trap at the hydro power weir located about 2 km downstream of the glacier terminus. The discharge and flushing data have a resolution of 15 minutes.  Turbidity and discharge allow estimation of the output of suspended load, while the flushing data inform about bedload. We further measured total organic carbon content of the water samples to infer the water and sediment source.</p><p>Data suggest a clear seasonal pattern, not only in discharge and sediment output, but also in suspended sediment concentration (SSC). While SSC is high during snow melt and in early summer, it decreases rapidly in July and stays at similar levels until September. This may indicate exhaustion of sediment storage beneath the glacier, but could also result from a change in subglacial regime, e.g. from a decrease in subglacial water pressure due to the progressive opening of subglacial cavities during the melt season. High fractions of organic carbon, presumably due to lateral sediment input from hillslopes, occur during storms throughout the entire season.</p>

scholarly journals Anions and Cations in Ice Cores from Dolleman Island and the Palmer Land Plateau, Antarctic Peninsula

1988 ◽  
Vol 10 ◽  
pp. 121-125 ◽  
Author(s):  
Robert Mulvaney ◽  
David A. Peel
Keyword(s):  
Antarctic Peninsula ◽  
Isotope Composition ◽  
Seasonal Pattern ◽  
Austral Summer ◽  
Ice Cores ◽  
Late Summer ◽  
Ionic Species ◽  
Weddell Sea ◽  
Seasonal Maximum ◽  
A Site

High-resolution anion profiles of Cl-, NO3- and SO42− are presented for two cores from the Antarctic Peninsula. A 47.2 m core from a site on the Palmer Land plateau (74°01’S, 70°38’W), spans the period 1942–80, and a 10.5 m core from Dolleman Island (70°35.2’S, 60°55.5’W), on the east coast of the peninsula, spans the period 1973–85. The seasonal pattern of deposition of these species has been determined by reference to the oxygen-isotope composition. Averaged over 38 years, the annual cycle of SO42− at Gomez shows a seasonal maximum during the austral summer, and minimum during the winter, whereas the Cl- cycle is more complex and may show the influence of equinoctial storms. The Dolleman core is significantly influenced by the proximity of the Weddell Sea, with a mean Cl- concentration five times greater than in the core from the plateau, and it shows a clear seasonal maximum in late-summer snowfall. There is no significant long-term trend in the 38 years’ data from the plateau site, suggesting that global pollution does not contribute significantly to the anion budget. Both anions and the cations Na+, K+ and H+ have been measured for more than a complete year of snowfall and the balance of ionic species is excellent.

scholarly journals Minding the Gaps in Fish Welfare: The Untapped Potential of Fish Farm Workers

2021 ◽  
Vol 34 (5) ◽  
Author(s):  
Christian Medaas ◽  
Marianne E. Lien ◽  
Kristine Gismervik ◽  
Tore S. Kristiansen ◽  
Tonje Osmundsen ◽  
...  
Keyword(s):  
Participant Observation ◽  
Fish Farming ◽  
Fish Farm ◽  
Farm Workers ◽  
Farmed Fish ◽  
Fish Welfare ◽  
Daily Work ◽  
General Welfare ◽  
A Site ◽  
Sentient Beings

AbstractThe welfare of farmed fish is often regarded with less concern than the welfare of other husbandry animals, as fish are not universally classified as sentient beings. In Norway, farmed fish and other husbandry animals are legally protected under the same laws. Additionally, the legislature has defined a number of aquaculture-specific amendments, including mandatory welfare courses for fish farmers who have a key role in securing animal welfare, also with regards to noting welfare challenges in the production process. This article uses fish welfare courses as a site from which to inquire about the common-sense understanding of fish welfare in Norwegian fish farming. The focus is specifically on fish farm employees, their experiences of welfare-related issues and contradictions in their daily work, and the struggle to act responsibly in aquaculture settings. Through participant observation at welfare courses, as well as interviews and conversations with fish farm workers, the article details how challenges are experienced ‘on the ground’, and suggests how fish farm workers’ own experiential knowledge might be mobilized to improve the general welfare of farmed fish.

Soil water conservation under cultivated fallows in clay soils of south-western Queensland

1976 ◽  
Vol 16 (81) ◽  
pp. 564 ◽  
Author(s):  
AJ Pressland ◽  
GN Batianoff
Keyword(s):  
Soil Moisture ◽  
Soil Water ◽  
Water Conservation ◽  
Field Experiments ◽  
Crop Yields ◽  
Early Summer ◽  
Forage Crop ◽  
Deep Profile ◽  
A Site ◽  
Summer Fallow

Three field experiments to study the effect of time and method of cultivation during fallow on soil moisture accretion and crop growth were established at a site near Charleville, Queensland. The soil was a grey-brown cracking clay (46 per cent clay) typical of the Mitchell grass (Astrebla spp.) downs. In the first experiment, soil moisture accretion was followed on plots cultivated in November 1966 with either a disc plough or scarifier or not cultivated. Soil moisture was increased in the 90 cm deep profile by cultivation, but remained almost constant for the duration of the summer fallow. There was no difference in soil moisture under the disced and scarified plots. The remaining experiments were designed to study the effect of cultivations during fallow on soil moisture at the time of sowings. One early summer cultivation resulted in soil moisture levels similar to that gained from two or more ploughings. However, crop yields were highest following three cultivations. It is concluded that two or three cultivations during fallow decreases loss of soil water through transpiration of weeds and should increase the number of years a forage crop can be expected in south western Queensland.

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