scholarly journals Thermal tolerance depends on season, age and body condition in imperilled redside dace Clinostomus elongatus

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Andy J Turko ◽  
Colby B Nolan ◽  
Sigal Balshine ◽  
Graham R Scott ◽  
Trevor E Pitcher
Keyword(s):  
Water Temperature ◽  
Body Condition ◽  
Thermal Tolerance ◽  
Habitat Restoration ◽  
Stream Temperature ◽  
Causal Link ◽  
Safety Margins ◽  
Summer Temperatures ◽  
Chrosomus Erythrogaster ◽  
Autumn And Winter

Abstract Urbanization tends to increase water temperatures in streams and rivers and is hypothesized to be contributing to declines of many freshwater fishes. However, factors that influence individual variation in thermal tolerance, and how these may change seasonally, are not well understood. To address this knowledge gap, we studied redside dace Clinostomus elongatus, an imperilled stream fish native to rapidly urbanizing areas of eastern North America. In wild redside dace from rural Ohio, USA, acute upper thermal tolerance (i.e. critical thermal maximum, CTmax) ranged between ~34°C in summer (stream temperature ~22°C) and 27°C in winter (stream temperature ~2°C). Juveniles had higher CTmax than adults in spring and summer, but in winter, CTmax was higher in adults. Thermal safety margins (CTmax − ambient water temperature; ~11°C) were less than the increases in peak water temperature predicted for many redside dace streams due to the combined effects of climate change and urbanization. Furthermore, behavioural agitation occurred 5–6°C below CTmax. Safety margins were larger (>20°C) in autumn and winter. In addition, redside dace were more sensitive (2.5°C lower CTmax) than southern redbelly dace Chrosomus erythrogaster, a non-imperilled sympatric cyprinid. Body condition (Fulton’s K) of adult redside dace was positively correlated with CTmax, but in juveniles, this relationship was significant only in one of two summers of experiments. Next, we measured CTmax of captive redside dace fed experimentally manipulated diets. In adults, but not juveniles, CTmax was higher in fish fed a high- vs. low-ration diet, indicating a causal link between nutrition and thermal tolerance. We conclude that redside dace will be challenged by predicted future summer temperatures, especially in urbanized habitats. Thus, habitat restoration that mitigates temperature increases is likely to benefit redside dace. We also suggest habitat restoration that improves food availability may increase thermal tolerance, and thus population resilience.

Conservation, Ecology, and Management of Catfish: The Second International Symposium

2011 ◽  
Keyword(s):  
International Symposium ◽  
Body Condition ◽  
Relative Abundance ◽  
Habitat Restoration ◽  
Missouri River ◽  
Natural State ◽  
Pylodictis Olivaris ◽  
Conservation Ecology ◽  
Flathead Catfish ◽  
Growth Increments

<em>Abstract</em>.—An assessment of the flathead catfish <em>Pylodictis olivaris</em> population in the Missouri River bordering Nebraska was conducted between 1997 through 2008. The Missouri River was divided into four sections based on physical and geomorphologic uniqueness (upper unchannelized, lower unchannelized, upper channelized, and lower channelized). Two sections were sampled annually, and each section was sampled on alternate years. Boat electrofishing collected 12,846 fish in 83.5 h from 701 sampling stations. Most flathead catfish sampled (98%) were less than 510 mm total length (quality length), with significantly more fish captured in channelized than unchannelized reach. Fish from channelized sections also had higher mean total lengths and larger growth increments but were in poorer body condition than those from unchannelized sections. Low relative abundance of flathead catfish in the upper unchannelized section and scarcity of large individuals were attributed to poor habitat conditions. Habitat restoration along with restoring natural riverine processes would return the river to a more natural state and would not only benefit flathead catfish, but other native Missouri River fishes as well.

scholarly journals Assessing the impacts of hydrologic and land use alterations on water temperature in the Farmington River basin in Connecticut

2019 ◽  
Vol 23 (11) ◽  
pp. 4491-4508 ◽  
Author(s):  
John R. Yearsley ◽  
Ning Sun ◽  
Marisa Baptiste ◽  
Bart Nijssen
Keyword(s):  
Land Use ◽  
Water Temperature ◽  
River Basin ◽  
Land Surface ◽  
Canopy Cover ◽  
River System ◽  
Stream Temperature ◽  
Hydrologic Model ◽  
Riparian Buffers ◽  
Connecticut River

Abstract. Aquatic ecosystems can be significantly altered by the construction of dams and modification of riparian buffers, and the effects are often reflected in spatial and temporal changes to water temperature. To investigate the implications for water temperature of spatially and temporally varying riparian buffers and dam-induced hydrologic alterations, we have implemented a modeling system (DHSVM-RBM) within the framework of the state-space paradigm that couples a spatially distributed land surface hydrologic model, DHSVM, with the distributed stream temperature model, RBM. The basic modeling system has been applied previously to several similar-sized watersheds. However, we have made enhancements to DHSVM-RBM that simulate spatial heterogeneity and temporal variation (i.e., seasonal changes in canopy cover) in riparian vegetation, and we included additional features in DHSVM-RBM that provide the capability for simulating the impacts of reservoirs that may develop thermal stratification. We have tested the modeling system in the Farmington River basin in the Connecticut River system, which includes varying types of watershed development (e.g., deforestation and reservoirs) that can alter the streams' hydrologic regime and thermal energy budget. We evaluated streamflow and stream temperature simulations against all available observations distributed along the Farmington River basin. Results based on metrics recommended for model evaluation compare well to those obtained in similar studies. We demonstrate the way in which the model system can provide decision support for watershed planning by simulating a limited number of scenarios associated with hydrologic and land use alterations.

Factors influencing individual predicted total dry matter intake of dairy cattle on farms

2001 ◽  
Vol 2001 ◽  
pp. 183-183
Author(s):  
H.C.F. Wicks ◽  
J.D. Leaver
Keyword(s):  
Dairy Cattle ◽  
Milk Production ◽  
Body Condition ◽  
Dry Matter ◽  
Dry Matter Intake ◽  
Genetic Merit ◽  
Factors Influencing ◽  
Commercial Farms ◽  
Autumn And Winter ◽  
Body Condition Scores

The aim was to estimate the influence of genetic merit (£PIN95) and level of concentrate feeding (Cgrp) on predicted total dry matter intake (tDMI) of individual cows, using records collected from commercial farms. The method described by Wicks & Leaver (2000) was used to estimate individual daily dry matter intakes from seven farms, totalling 4282 monthly records over a two-year period. The method was based on milk production records supplemented by body condition scores and height at withers, which were used to calculated the ME requirements of individual animals. All the records were collected, from autumn and winter (July to March) calving cows during the housed period (August to March).

scholarly journals Thermal Performance Reflects Evolutionary Legacies of Seaweeds and Seagrasses Across a Regional Climate Gradient

2021 ◽  
Author(s):  
Scott Bennett ◽  
Raquel Vaquer-Sunyer ◽  
Gabriel Jorda ◽  
Marina Forteza ◽  
Guillem Roca ◽  
...  
Keyword(s):  
Thermal Performance ◽  
Thermal Sensitivity ◽  
Regional Climate ◽  
Posidonia Oceanica ◽  
Species Variation ◽  
Thermal Limits ◽  
Cystoseira Compressa ◽  
Safety Margins ◽  
Summer Temperatures ◽  
Edge Populations

Abstract Comparative patterns in thermal performance between populations have fundamental implications for a species thermal sensitivity to warming and extreme events. Despite this, within-species variation in thermal performance is seldom measured. Here we compare within-species variation in thermal performance across the Mediterranean Sea, with between-species variation within communities, for two species of seagrass (Posidonia oceanica and Cymodocea nodosa) and two species of seaweed (Padina pavonica and Cystoseira compressa). Experimental populations from four locations representing approximately 75% of each species global distribution and a 6ºC gradient in summer temperatures were exposed to 10 temperature treatments (15ºC to 36ºC), reflecting median, maximum and future temperatures. Thermal performance displayed the greatest variability between species, with optimal temperatures differing by over 10ºC within the same location. Within-species differences in thermal performance were also important for P. oceanica which displayed large thermal safety margins within cool and warm-edge populations and small safety margins within central populations. Overall, experimental upper thermal limits reflected genus-level realised thermal limits, more than realised species-limits or maximum local temperatures. Our findings suggest patterns of thermal performance in Mediterranean seagrasses and seaweeds retain deep ‘pre-Mediterranean’ evolutionary legacies, resulting in unexpected patterns of vulnerability to warming within benthic marine communities.

scholarly journals A hierarchical model of daily stream temperature for regional predictions

2018 ◽  
Author(s):  
Daniel J Hocking ◽  
Kyle O'Neil ◽  
Benjamin H Letcher
Keyword(s):  
Water Temperature ◽  
Air Temperature ◽  
Hierarchical Model ◽  
Mean Squared Error ◽  
Thermal Sensitivity ◽  
Stream Temperature ◽  
Eastern United States ◽  
Validation Data ◽  
Temperature Records ◽  
Use Factors

Stream temperature is an important exogenous factor influencing populations of stream organisms such as fish, amphibians, and invertebrates. Many states regulate stream protections based on temperature. Therefore, stream temperature models are important, particularly for estimating thermal regimes in unsampled space and time. To help meet this need, we developed a hierarchical model of daily stream temperature and applied it across the eastern United States. Our model accommodates many of the key challenges associated with daily stream temperature models including the lagged response of water temperature to changes in air temperature, incomplete and widely-varying observed time series, spatial and temporal autocorrelation, and the inclusion of predictors other than air temperature. We used 248,517 daily stream temperature records from 1,352 streams to fit our model and 100,909 records were withheld for model validation. Our model had a root mean squared error of 0.61 C for the fitted data and 2.03 C for the validation data, indicating excellent fit and good predictive power for understanding regional temperature patterns. We then used our model to predict daily stream temperatures from 1980 - 2015 for all streams <200 km2 from Maine to Virginia. From these, we calculated derived stream metrics including mean July temperature, mean summer temperature, and the thermal sensitivity of each stream reach to changes in air temperature. Although generally water temperature follows similar latitudinal and altitudinal patterns as air temperature, there are considerable differences at the reach scale based on landscape and land-use factors.

scholarly journals What causes cooling water temperature gradients in forested stream reaches?

2014 ◽  
Vol 11 (6) ◽  
pp. 6441-6472 ◽  
Author(s):  
G. Garner ◽  
I. A. Malcolm ◽  
J. P. Sadler ◽  
D. M. Hannah
Keyword(s):  
Water Temperature ◽  
Water Column ◽  
Stream Temperature ◽  
Temperature Gradients ◽  
Daily Maximum ◽  
Net Energy ◽  
Net Radiation ◽  
Maximum Water Temperature ◽  
Maximum Water ◽  
Energy Gains

Abstract. Previous studies have suggested that shading by riparian vegetation may reduce maximum water temperature and provide refugia for temperature sensitive aquatic organisms. Longitudinal cooling gradients have been observed during the daytime for stream reaches shaded by coniferous trees downstream of clear cuts, or deciduous woodland downstream of open moorland. However, little is known about the energy exchange processes that drive such gradients, especially in semi-natural woodland contexts, and in the absence of potentially confounding cool groundwater inflows. To address this gap, this study quantified and modelled variability in stream temperature and heat fluxes along an upland reach of the Girnock Burn (a tributary of the Aberdeenshire Dee, Scotland) where riparian landuse transitions from open moorland to semi-natural forest. Observations were made along a 1050 m reach using a spatially-distributed network of ten water temperature micro-loggers, three automatic weather stations and >200 hemispherical photographs, which were used to estimate incoming solar radiation. These data parameterised a high-resolution energy flux model, incorporating flow-routing, which predicted spatio-temporal variability in stream temperature. Variability in stream temperature was controlled largely by energy fluxes at the water column–atmosphere interface. Predominantly net energy gains occurred along the reach during daylight hours, and heat exchange across the bed-water column interface accounted for <1% of the net energy budget. For periods when daytime net radiation gains were high (under clear skies), differences between water temperature observations decreased in the streamwise direction; a maximum difference of 2.5 °C was observed between the upstream reach boundary and 1050 m downstream. Furthermore, daily maximum water temperature at 1050 m downstream was ≤1°C cooler than at the upstream reach boundary and lagged the occurrence of daily maximum water temperature upstream by >1h. Temperature gradients were not generated by cooling of stream water, but rather by a combination of reduced rates of heating in the woodland reach and advection of cooler (overnight and early morning) water from the upstream moorland catchment. Longitudinal thermal gradients were indistinct at night and on days when net radiation gains were low (under over-cast skies), thus when changes in net energy gains or losses did not vary significantly in space and time, and heat advected into the reach was reasonably consistent. The findings of the study and the modelling approach employed are useful tools for assessing optimal planting strategies for mitigating against ecologically damaging stream temperature maxima.

scholarly journals Assessing the Impacts of Hydrologic and Land Use Alterations on Water Temperature in the Farmington River Basin in Connecticut

2019 ◽  
Author(s):  
John R. Yearsley ◽  
Ning Sun ◽  
Marisa Baptiste ◽  
Bart Nijssen
Keyword(s):  
Land Use ◽  
Water Temperature ◽  
River Basin ◽  
Land Surface ◽  
Canopy Cover ◽  
River System ◽  
Stream Temperature ◽  
Hydrologic Model ◽  
Riparian Buffers ◽  
Connecticut River

Abstract. Aquatic ecosystems can be significantly altered by the construction of dams and modification of riparian buffers and the effects are often reflected in spatial and temporal changes to water temperature. To investigate the implications for water temperature of spatially and temporally varying riparian buffers and dam-induced hydrologic alterations, we have implemented a modeling system (DHSVM-RBM) that couples a spatially distributed land surface hydrologic model, DHSVM, with the distributed stream temperature model, RBM. The basic modeling system has been applied previously to several similar-sized watersheds. However, we have made enhancements to DHSVM-RBM that simulate spatial heterogeneity and temporal variation (i.e. seasonal changes in canopy cover) in riparian vegetation, and we included additional features in DHSVM-RBM that provide the capability for simulating the impacts of reservoirs that may develop thermal stratification. We have tested the modeling system in the Farmington River basin in the Connecticut River system that includes varying types of watershed development (e.g. deforestation and reservoirs) that can alter the streams’ hydrologic regime and thermal energy budget. We evaluated streamflow and stream temperature simulations against all available observations distributed along the Farmington River basin. Results based on metrics recommended for model evaluation compare well to those obtained in similar studies. We demonstrate the way in which the model system can provide decision support for watershed planning by simulating a limited number of scenarios associated with hydrologic and land use alterations.

scholarly journals Seed dormancy and germination in Cardiocrinum giganteum var. yunnanense, a perennial herb in China with post-dispersal embryo growth

2020 ◽  
Vol 48 (2) ◽  
pp. 303-314
Author(s):  
Ye-Fang Li ◽  
Jie Song ◽  
Wen-Ling Guan ◽  
Feng-Rong Li
Keyword(s):  
Seed Germination ◽  
Seed Dormancy ◽  
Practical Knowledge ◽  
Perennial Herb ◽  
Late Winter ◽  
Dormancy Breaking ◽  
Morphophysiological Dormancy ◽  
Summer Temperatures ◽  
Autumn And Winter ◽  
Seed Dormancy And Germination

Seeds of Cardiocrinum giganteum var. yunnanense, which is native to China, has underdeveloped embryos when dispersed from parent plants that did not grow until the second autumn and winter after exposure to summer temperatures. Radicles and cotyledons emerged in late winter and spring. Thus, a 15–16 month period was required from dispersal to seed germination. Under laboratory conditions, this period could be shortened to 5–6 months in a 25°C/15°C (60 days) → 15°C/5°C (60 days) → 5°C (60 days) temperature sequence. Based on dormancy-breaking requirements, the seeds have deep simple morphophysiological dormancy (MPD). This is practical knowledge for propagation of the species from seeds.

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