scholarly journals Water temperature drives variability in salmonfly abundance, emergence timing, and body size

2019 ◽  
Vol 35 (7) ◽  
pp. 1013-1022 ◽  
Author(s):  
Heidi E. Anderson ◽  
Lindsey K. Albertson ◽  
David M. Walters
Keyword(s):  
Author(s):  
Henglong Xu ◽  
Yong Jiang ◽  
Wei Zhang ◽  
Mingzhuang Zhu ◽  
Khaled A. S. Al-Rasheid ◽  
...  

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.


Author(s):  
P. R. Walne

The rate of water filtration by bivalves has long excited interest, but it has in practice proved difficult to measure in conditions where the animal is relatively free from constraint. Its estimation is important from a number of aspects: feeding studies; as an indicator of the animal's reaction to its environment; and for predicting the flow of water required for the culture of economically important species. The work reported in this paper started as part of the general programme on shellfish culture in progress at this laboratory. During the development of a suitable method for studying the water requirements it became clear that one factor, water current, had a more important influence than has been generally recognized.


2019 ◽  
Vol 49 (1) ◽  
pp. 230-237
Author(s):  
S M Starr ◽  
N E McIntyre

Abstract Current climate projections for the Great Plains of North America indicate markedly increased air temperatures by the end of the current century. Because the Great Plains contains &gt;80,000 intermittent wetlands that serve as irreplaceable wildlife habitat, this projected warming may have profound effects throughout a continental-scale trophic network. However, little research has been done to determine how projected warming may affect the growth, development, or survival of even common species in this region. We conducted laboratory warming experiments, using an abundant amphibious predatory insect, Enallagma civile (Hagen, 1861), as a model organism, to determine whether projected warming may affect development or survival. Eggs were collected and reared under four water temperature regimes representing current (26°C) and projected future conditions (32, 38, and 41°C). Nymph body size after each molt, development rate, and deaths were recorded. Elevated water temperatures were found to significantly affect the survivorship of E. civile eggs and nymphs as well as adult body size at emergence: an increase in temperature incurred a decrease in survival and size. Nymphs in the two hotter treatments were smaller and had low survivorship whereas individuals in the cooler temperatures generally survived to adulthood and were larger. Nymphs reared at 32°C experienced accelerated ontogenetic development compared with the other temperatures, going from egg to adult in 26 d. Projected elevated temperatures may, thus, be both advantageous and detrimental, causing concern for aquatic invertebrates in this region in the future.


1986 ◽  
Vol 64 (1) ◽  
pp. 8-11
Author(s):  
Louise Vallières ◽  
Antoine Aubin

Copepod populations of three temporary freshwater pools (Alnus unit, Carex unit, and Molinia unit) were studied using a standard approach (species versus abiotic factors) and a holistic one (body size and feeding ecology). Multiple regression analyses of data indicate that the physical and chemical features of water (temperature, pH, dissolved oxygen, mineral content, and depth) explain 62 to 98% of the variability of carnivorous copepods, while the abundance of their prey accounts for much less. No size class of prey seems to be preferred. The abundance of decaying organic matter, typical of such pools, would result in an overabundance of prey. Predators would then be under the control of nonalimentary factors.


2012 ◽  
Vol 69 (5) ◽  
pp. 821-832 ◽  
Author(s):  
Irene Parra ◽  
Ana Almodóvar ◽  
Daniel Ayllón ◽  
Graciela G. Nicola ◽  
Benigno Elvira

This study looks at the relative influence of water temperature and density dependence on the spatial variation in body size of 126 brown trout ( Salmo trutta ) cohorts from 12 Iberian rivers over a 12-year period. Mean cohort mass and length of age groups 0+ to 2+ varied significantly among sampling sites because of the concurrent effect of water temperature and density dependence. Density in suitable habitat had a limiting role that influenced potential maximum growth of cohorts, and water temperature differentiated these cohorts in two groups of sites with high and low potential maximum growth. Water temperature had a positive cumulative effect on body size of all age classes. However, body size of age-0 trout was nonlinearly influenced by short-term exposure to extreme water temperature. Thus, extremely high temperatures became a limiting factor and had deleterious effects on growth. There were intracohort and intercohort effects of density dependence throughout the life span, which were mainly due to the density in the available suitable habitat of trout of the same age or older. The present study supports the hypothesis that both density-dependent and density-independent processes are crucial for the understanding of population dynamics and that their relative importance varies across scales of space and time.


2004 ◽  
Vol 61 (6) ◽  
pp. 857-869 ◽  
Author(s):  
Brett Albanese ◽  
Paul L Angermeier ◽  
Sundar Dorai-Raj

Identifying factors that influence fish movement is a key step in predicting how populations respond to environmental change. Using mark–recapture (four species) and trap capture (eight species) data, we examined relationships between three attributes of movement and 15 ecological variables. The probability of emigrating from a reach was positively related to intermittency (one species) and body size (one species) and negatively related to distance from the mainstem creek (two species) and habitat complexity (one species). The number of fish moving upstream through traps was positively related to increases in flow (five species), day length (three species), and water temperature (two species); the number moving through downstream traps was positively associated with increases in flow (three species). Distance moved was greater for fish moving through unsuitable reaches (one species). Floods have a pervasive effect on fish movement, and human activities that affect flows will have widespread implications. The importance of other factors varies interspecifically, which may translate into variation in persistence and colonization rates. For example, species that exhibit reach fidelity in complex habitats may increase movement if habitats are homogenized. These species may suffer population declines because of the cost of increased movement and may ultimately be replaced by ecological generalists.


1991 ◽  
Vol 48 (10) ◽  
pp. 1838-1845 ◽  
Author(s):  
Bror Jonsson ◽  
Jan Henning L'Abée-Lund ◽  
Tor G. Heggberget ◽  
Arne J. Jensen ◽  
Bjørn O. Johnsen ◽  
...  

Longevity in 25 populations of anadromous brown trout (Salmo trutta) showed a significant trend with increasing life span at latitudes of 58–70°N in Norway, with the largest change from 58 to 60°N. Moreover, longevity was negatively correlated with temperature and growth rate in freshwater and at sea. Body size was negatively correlated with water temperature and growth rate in freshwater, but not with latitude or water temperature and growth rate at sea. Thus, conditions influencing development and metabolic rates in fresh water seem more important than conditions in the sea in determining variation in longevity and body size of anadromous brown trout. Our results support the hypothesis that interpopulation variation in longevity and body size is influenced by rate of metabolism, chiefly influenced by ambient water temperature.


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