Macroinvertebrate colonization of the marginal zone of a small impoundment in Eastern Canada

1969 ◽  
Vol 47 (6) ◽  
pp. 1229-1238 ◽  
Author(s):  
C. G. Paterson ◽  
C. H. Fernando
Keyword(s):  
Water Temperature ◽  
Environmental Conditions ◽  
Marginal Zone ◽  
Active Process ◽  
Summer Period ◽  
Eastern Canada ◽  
Lotic Environment ◽  
Reservoir Basin ◽  
Laurel Creek ◽  
Macroinvertebrate Fauna

Colonization of the marginal macroinvertebrate fauna of Laurel Creek Reservoir was followed from the time of first filling in the spring of 1967 until the reservoir was drained in mid-October of the same year. Of the 55 taxa found during this period 34 (61.8%) were facultative species which had maintained populations in the lotic environment before impoundment. Colonization was an active process which accelerated as the water temperature increased. Passive colonization by species swept into the reservoir by flooding of the creek and the resultant rapid filling of the reservoir was negligible. For the first 3 months after subsequent filling in the spring of 1968 the marginal fauna was very similar to that of the previous year although colonization was more rapid as a result of overwintering of many limnophilic species in various refugia in the reservoir basin. Colonization of the marginal zone appeared to approach completion, with respect to the prevailing environmental conditions, during the first summer period of the reservoir's existence.

scholarly journals Lagged recovery of fish spatial distributions following a cold-water perturbation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
M. D. Robertson ◽  
J. Gao ◽  
P. M. Regular ◽  
M. J. Morgan ◽  
F. Zhang
Keyword(s):  
Water Temperature ◽  
Species Distribution ◽  
Environmental Conditions ◽  
Cold Water ◽  
Heat Waves ◽  
Rapid Change ◽  
Nonlinear Effects ◽  
Spatial Distributions ◽  
Spatiotemporal Model ◽  
Yellowtail Flounder

AbstractAnomalous local temperature and extreme events (e.g. heat-waves) can cause rapid change and gradual recovery of local environmental conditions. However, few studies have tested whether species distribution can recover following returning environmental conditions. Here, we tested for change and recovery of the spatial distributions of two flatfish populations, American plaice (Hippoglossoides platessoides) and yellowtail flounder (Limanda ferruginea), in response to consecutive decreasing and increasing water temperature on the Grand Bank off Newfoundland, Canada from 1985 to 2018. Using a Vector Autoregressive Spatiotemporal model, we found the distributions of both species shifted southwards following a period when anomalous cold water covered the northern sections of the Grand Bank. After accounting for density-dependent effects, we observed that yellowtail flounder re-distributed northwards when water temperature returned and exceeded levels recorded before the cold period, while the spatial distribution of American plaice has not recovered. Our study demonstrates nonlinear effects of an environmental factor on species distribution, implying the possibility of irreversible (or hard-to-reverse) changes of species distribution following a rapid change and gradual recovery of environmental conditions.

Annual variations in body-size spectra of planktonic ciliate communities and their relationships to environmental conditions: a case study in Jiaozhou Bay, northern China

2012 ◽  
Vol 93 (1) ◽  
pp. 47-55 ◽  
Author(s):  
Henglong Xu ◽  
Yong Jiang ◽  
Wei Zhang ◽  
Mingzhuang Zhu ◽  
Khaled A. S. Al-Rasheid ◽  
...  
Keyword(s):  
Body Size ◽  
Water Temperature ◽  
Environmental Conditions ◽  
Jiaozhou Bay ◽  
Northern China ◽  
The Body ◽  
The Yellow Sea ◽  
Size Spectra ◽  
Annual Variations ◽  
Planktonic Ciliate

The annual variations in body-size spectra of planktonic ciliate communities and their relationships to environmental conditions were studied based on a 12-month dataset (June 2007 to May 2008) from Jiaozhou Bay on the Yellow Sea coast of northern China. Based on the dataset, the body sizes of the ciliates, expressed as equivalent spherical diameters, included five ranks: S1 (5–35 μm); S2 (35–55 μm); S3 (55–75 μm); S4 (75–100 μm); and S5 (100–350 μm). These body-size ranks showed a clear temporal succession of dominance in the order of S2 (January–April) → S1 (May–July) → S4 (August–September) → S3 (October–December). Multivariate analyses showed that the temporal variations in their body-size patterns were significantly correlated with changes in environmental conditions, especially water temperature, salinity, dissolved oxygen concentration (DO) and nutrients. In terms of abundance, rank S2 was significantly correlated with water temperature, DO and nutrients, whereas ranks S4 and S5 were correlated with the salinity and nutrients respectively (P < 0.05). These results suggest that the body-size patterns of planktonic ciliate communities showed a clear temporal pattern during an annual cycle and significantly associated with environmental conditions in marine ecosystems.

scholarly journals Spatio-temporal patterns of the oceanic conditions and nearshore marine community in the Mid-Atlantic Bight (New Jersey, USA)

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7927 ◽  
Author(s):  
Juan C. Levesque
Keyword(s):  
New Jersey ◽  
Dissolved Oxygen ◽  
Water Temperature ◽  
Environmental Conditions ◽  
Clupea Harengus ◽  
Sediment Type ◽  
Temperature Preference ◽  
Marine Fauna ◽  
The World ◽  
Marine Community

Oceanic environmental conditions influence, shape, and control the geographical range, spatial distribution, abundance, and size composition of marine fauna. Water temperature, salinity, dissolved oxygen, depth, and sediment type influence select fish life-history characteristics and community structure. Marine communities are vulnerable to major changes in environmental conditions, but the response and severity depends on various biological or ecological factors, such as resilience to stress or adaptation. Researchers around the world have predicted and documented numerous alterations in fish communities caused by ongoing significant physicochemical shifts associated with natural and potentially unnatural sources, but published studies describing the historical conditions are lacking for most regions around the world, including the coastal waters off New Jersey. Given the need to understand these processes, a multifaceted investigation was undertaken to describe, evaluate, and compare the oceanic conditions and nearshore marine fauna community off New Jersey during 1988 through 2015. Findings showed the oceanic conditions varied over time and space. Mean surface water temperature increased significantly about 0.6 °C per decade, mean salinity decreased about 1.3 psu per decade, and dissolved oxygen increased 0.09 mg/l per decade. Over 20.4 million fish and invertebrates (1,338.3 mt) representing 214 (water temperature preference classified) species (not including unidentified species) were collected within 15 strata (areas: 12−26) off the coast of New Jersey from 1988 to 2015. Three marine fauna water temperature preference groups (coldwater-adapted, warmwater-adapted, and subtropic-adapted) were identified in the study area. The main coldwater-adapted species collected were longfin squid (Loligo pealei) (n = 2, 225, 975), Atlantic herring (Clupea harengus) (n = 544, 032), and little skate (Leucoraja erinacea) (n = 316, 356), while Atlantic butterfish (Peprilus triacanthus) (n = 2, 873, 138), scup (Stenotomus chrysops) (n = 1, 318, 569), and northern searobin (Prionotus carolinus) (n = 503, 230) represented the warmwater-adapted group. Bay anchovy (Anchoa mitchilli) (n = 9, 227, 960), striped anchovy (Anchoa hepsetus) (n = 245, 214), and Atlantic moonfish (Vomer setapinnis) (n = 38, 691) denoted the subtropic-adapted group. Subtropic-adapted species were the most abundant and coldwater-adapted were the least abundant water temperature preference group. The estimated abundance of coldwater-adapted species declined, warmwater-adapted species slightly increased, and subtropic-adapted species decreased with time, which suggest the environmental conditions are influencing and thereby shifting the marine community.

The ecology of terricolous lichens of the Northern Conifer – Hardwood forests of central Eastern Canada

1968 ◽  
Vol 46 (8) ◽  
pp. 1043-1078 ◽  
Author(s):  
J. D. H. Lambert ◽  
P. F. Maycock
Keyword(s):  
Environmental Conditions ◽  
Ground Level ◽  
Hardwood Forests ◽  
Deciduous Tree ◽  
Eastern Canada ◽  
Central Canada ◽  
Terricolous Lichens ◽  
Moisture Conditions ◽  
Tree Composition ◽  
Lichen Growth

A quantitative analysis of the terricolous (ground) lichens in the Northern Conifer – Hardwood forests of central Canada is presented. Seventy-one forest stands were sampled to determine the composition of the tree and lichen strata. Tree composition was expressed in terms of a series of importance values determined from measures of frequency, density, and dominance on a relative basis, with the importance values for all trees in a stand totalling 300. A statistical analysis of lichen distribution showed that while lichens reacted in a similar manner to moisture conditions as the trees they were more commonly found in stands on dry sites. An ordination of stands indicated that optimum environmental conditions for lichen growth were found in dry young conifer stands of low absolute dominance with fairly open canopies, with slowly decomposing ground litter of decidedly acidic reaction.The increase of deciduous tree species in the mesic segments of the moisture gradient produced environmental conditions unsuitable for most of the lichen species recorded. The reduced occurrence of lichens in such sites was interpreted as being related to the lack of suitable substrates, reduction in light intensity at ground level, increased litter, and a more rapid turnover of organic matter.

Winter Survival and Growth of Chondrus crispus in Onshore Culture Tanks

1986 ◽  
Vol 43 (2) ◽  
pp. 263-268 ◽  
Author(s):  
Peter F. Shacklock ◽  
James S. Craigie
Keyword(s):  
Environmental Conditions ◽  
Stocking Density ◽  
Ice Cover ◽  
Winter Survival ◽  
Chondrus Crispus ◽  
Eastern Canada ◽  
Net Production ◽  
Survival And Growth ◽  
Reliable Methods ◽  
Natural Irradiance

Commercial aquaculture of Chondrus crispus in eastern Canada required the development of reliable methods for ensuring the winter survival of a healthy, vegetative inoculum. Two procedures were investigated. Agitated cultures of C. crispus (stocking density <6 kg∙m−2) in running seawater grew at average rates of 0.21–0.34 kg∙m−2∙wk−1 during two winters under natural irradiance. Cultures maintained in undisturbed, outdoor tanks of seawater over three winters showed little or no net production; however, survival was excellent provided that the stocking density remained below approximately 10 kg∙m−2. The plants were capable of resuming growth when environmental conditions improved. We found no difference in the responses of the several haploid and diploid isolates examined. Large vegetative inocula required for commercial aquaculture can be maintained simply and reliably in tanks of clean seawater if they are undisturbed and an ice cover is allowed to form.

A regional analysis of the impact of dams on water temperature in medium-size rivers in eastern Canada

2016 ◽  
Vol 73 (12) ◽  
pp. 1885-1897 ◽  
Author(s):  
Audrey Maheu ◽  
André St-Hilaire ◽  
Daniel Caissie ◽  
Nassir El-Jabi ◽  
Guillaume Bourque ◽  
...  
Keyword(s):  
Water Temperature ◽  
Thermal Regime ◽  
Regional Scale ◽  
Regional Analysis ◽  
Annual Runoff ◽  
Rate Of Change ◽  
Medium Size ◽  
Regulated Rivers ◽  
Eastern Canada ◽  
The Impact

Various studies have helped gain a better understanding of the thermal impacts of dams on a site-specific basis, but very few studies have compared the thermal impacts of varying types of dams within the same region. In this study, we conducted a regional-scale assessment of the impacts of dams on the thermal regime of 13 medium-size rivers in eastern Canada. The objectives of this study were to identify features of the thermal regime of rivers that are predominantly impacted by dams and to compare the impacts associated with different types of regulation (run-of-river, storage, peaking). The thermal regime of regulated and unregulated rivers was characterized using 15 metrics that described the magnitude, frequency, duration, timing, and rate of change of water temperature. Results indicate that storage and peaking dams impounding at least 10% of the median annual runoff generally (i) reduced the magnitude of water temperature variation at seasonal, daily, and subdaily timescales and (ii) increased the monthly mean water temperature in September. This regional assessment offers important insight regarding a generalized pattern of thermal alteration by dams, and this information could be used to guide biological monitoring efforts in regulated rivers.

scholarly journals Effect of Environmental Conditions and Morphometric Parameters on Surface Water Temperature in Polish Lakes

Water ◽  
2018 ◽  
Vol 10 (5) ◽  
pp. 580 ◽  
Author(s):  
Mariusz Ptak ◽  
Mariusz Sojka ◽  
Adam Choiński ◽  
Bogumił Nowak
Keyword(s):  
Surface Water ◽  
Water Temperature ◽  
Environmental Conditions ◽  
Morphometric Parameters ◽  
Surface Water Temperature

scholarly journals Investigation into Settlement Behaviour of Mussels and the Hydrology of a Selected Area with a View to Farming the Shellfish

2021 ◽  
Author(s):  
◽  
Philip Tortell
Keyword(s):  
Water Temperature ◽  
Mytilus Edulis ◽  
Environmental Conditions ◽  
Catchment Area ◽  
Organic Nitrogen ◽  
Water Movement ◽  
Freshwater Inflow ◽  
Small Catchment ◽  
Perna Canaliculus ◽  
Suitable Substrate

<p>Physical observations in the Beatrix Basin, Marlborough Sounds, New Zealand, revealed four distinct regions: a partially exposed northern region with moderate water currents, low rainfall, small catchment area and scant freshwater inflow; a central highly exposed region with strong currents, moderate rainfall, no land catchment area and no direct freshwater inflow; an eastern region with a high degree of exposure and strong water movement, moderate rainfall, extensive catchment and seasonally high freshwater inflow; a southern sheltered region with sluggish water movement, comparatively high rainfall, extensive catchment and the highest rainfall in the study area. Differences between the four regions in monthly mean temperature and salinity were slight and there was an indication of more mixing in the central region than elsewhere. No thermocline was observed and surface water temperature demonstrated a diurnal rhythm in summer. Mean winter temperature fell to 10 degrees C and rose to 17 degrees C in summer. Mean salinity ranged from 32.8 degrees C in winter to 34.8 degrees C in summer and no halocline was present. Salinity fell occasionally after heavy rain, but tidal currents soon dissipated the freshwater except in the southern region where it persisted for a short time. The reproductive cycles of Perna canaliculus and Mytilus edulis aoteanus, the occurrence of their larvae in plankton samples, their season of settlement and peaks in settlement activity, were monitored. Physical environmental conditions preceeding or accompanying spatfall were recorded. A broad temporal relationship was found between spawning adult mussels, pelagic larvae, environmental conditions, and settlement of Perna canaliculus in Elie Bay. It appears that P. canaliculus spawned in early summer and in autumn when the water temperature was 18 plus-minus 0.5 degrees C. However, it was not possible to predict spatfall since the duration of the pelagic phase was not known and settlement is a function of larval survival and dispersal, as well as the presence of a suitable substrate. Accurate spatfall prediction is required to facilitate timed immersion of spat-collecting ropes while ensuring "seasoning" and avoiding fouling. As it was not possible to predict settlement by relating it to other biological or physical phenomena, this study sought an alternative spat-collecting material not so susceptible to fouling but still attractive to mussels. Carbon black fibrillated polypropylene film proved to be such an alternative. The determination of available food for mussels within the study area was attempted using particulate organic nitrogen as the indicator. The problems encountered are discussed. The concentration of particulate organic nitrogen was 11.78 microgram at N/litre. The larvae of Mytilus edulis aoteanus and Aulacomya maoriana were reared in the laboratory to the late veliger stage. The most likely causes of their failure to metamorphose were a too high larval density, an excess of food organisms and the lack of a suitable substrate for settlement. It was not possible to induce spawning of Perna canaliculus under controlled conditions.</p>

scholarly journals The Autoneige as Workaround: Infrastructural Momentum at the Emergence of the Snowmobile

2020 ◽  
Vol 45 (4) ◽  
Author(s):  
Wendy Pringle
Keyword(s):  
Twentieth Century ◽  
Environmental Conditions ◽  
Cultural Context ◽  
Eastern Canada ◽  
Early Twentieth Century ◽  
Developing Communities ◽  
Social Environmental

Background  Drawing on infrastructure theories of communication, this article considers the snowmobile as an exceptional instance of transport and media circulation in rural Québec and Eastern Canada. In the early twentieth century, the snowmobile provided a temporary fix to the isolation of developing communities. When the snow and cold descended on these regions, both transport and communication came to a standstill for months. Analysis  This article explores how the snowmobile provided a workaround to the environmental conditions that cut parts of the nation off from the evolving mobilities of the era. Conclusions and implications  Transporting people, goods, and messages across social and environmental divides, the snowmobile illustrates how challenging topographies can precipitate invention. This process of mediation is indivisible from its social, environmental, and cultural context. Résumé Contexte Se basant sur les théories infrastructurelles de la communication, ce travail examine le rôle de l’autoneige en tant que forme exceptionnelle du transport et de la circulation des médias dans le contexte rural au Québec et dans l’est du Canada. Au début du XXe siècle, l’autoneige représente un remède temporaire à l’isolation des communautés en développement. À l’arrivée de la neige et des temps froids, les moyens de transport et de communication s’immobilisent pendant des mois. Analyse  L’article explore l’histoire de l’autoneige comme solution « de contournement » (work-around) aux conditions environnementales qui isolent alors des régions du pays par rapport à l’évolution contemporaine de la mobilité. Conclusion et implications  En transportant des personnes, des biens et des messages au-delà des divisions sociales et environnementales, l’autoneige illustre la manière dont les obstacles topographiques catalysent l’imagination. Ce processus médiatique est indissociable de son contexte social, environnemental et culturel.    

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