Salinity tolerance of larval and juvenile broad whitefish (Coregonus nasus)

1989 ◽  
Vol 67 (10) ◽  
pp. 2392-2397 ◽  
Author(s):  
B. G. E. de March
Keyword(s):  
Salinity Tolerance ◽  
Species Distribution ◽  
Laboratory Experiments ◽  
Larval Fish ◽  
The Arctic ◽  
Distribution Data ◽  
Migratory Fish ◽  
Limited Information ◽  
Time To Death ◽  
Arctic Coast

In the absence of distribution data for juvenile broad whitefish, Coregonus nasus, laboratory experiments were designed to elucidate the salinity ranges that the species will tolerate. Larval fish (12–18 mm) died within 120 h at salinities of 12.5‰ and higher at both 5 and 10 °C, though more slowly at 5 °C. Salinities of 12.5 and 15‰, but no higher, were tolerated for 120 h at 15 °C. Larvae fed readily at 15 °C but not at 5 or 10 °C. Slightly larger and more-developed larvae (15–19 mm) were tolerant of 12.5‰ but died within 120 h at 15‰ at the same three temperatures. These fish fed more readily than the younger ones. Larger fish (33–68 mm) were generally tolerant of 15–20‰ but not of higher salinities in 120-h tolerance tests. Larger field-collected fish (27–200 mm) reacted similarly but were more tolerant of salinities between 20 and 27‰ in 96-h tests. Analysis of both experiments with larger fish suggests that time to death was inversely related to size as well as to salinity. Coregonus nasus does not seem to be more tolerant of saline conditions than other freshwater or migratory fish species. Experimental results combined with limited information about the species' distribution suggest that man-made constructions on the arctic coast might seriously affect dispersal or annual migrations.

The Last Interglaciation in Northeast Siberia

1995 ◽  
Vol 43 (2) ◽  
pp. 147-158 ◽  
Author(s):  
Anatoly V. Lozhkin ◽  
Patricia M. Anderson
Keyword(s):  
General Circulation ◽  
General Circulation Models ◽  
The Arctic ◽  
The North ◽  
River Terraces ◽  
Atmospheric General Circulation ◽  
Winter Temperatures ◽  
Atmospheric General Circulation Models ◽  
Arctic Coast ◽  
Organic Deposits

AbstractAlluvial, fluvial, and organic deposits of the last interglaciation are exposed along numerous river terraces in northeast Siberia. Although chronological control is often poor, the paleobotanical data suggest range extensions of up to 1000 km for the primary tree species. These data also indicate that boreal communities of the last interglaciation were similar to modern ones in composition, but their distributions were displaced significantly to the north-northwest. Inferences about climate of this period suggest that mean July temperatures were warmer by 4 to 8°C, and seasonal precipitation was slightly greater. Mean January temperatures may have been severely cooler than today (up to 12°C) along the Arctic coast, but similar or slightly warmer than present in other areas. The direction and magnitude of change in July temperatures agree with Atmospheric General Circulation Models, but the 126,000-year-B.P. model results also suggest trends opposite to the paleobotanical data, with simulated cooler winter temperatures and drier conditions than present during the climatic optimum.

scholarly journals Application Natura 2000 Data For The Invasive Plants Spread Prediction

2015 ◽  
Vol 46 (4) ◽  
pp. 159-166 ◽  
Author(s):  
J. Pěknicová ◽  
D. Petrus ◽  
K. Berchová-Bímová
Keyword(s):  
Environmental Factors ◽  
Invasive Plants ◽  
Species Distribution ◽  
Natura 2000 ◽  
Distribution Model ◽  
Distribution Data ◽  
Habitat Types ◽  
Distribution Models ◽  
Occurrence Data ◽  
Heracleum Mantegazzianum

AbstractThe distribution of invasive plants depends on several environmental factors, e.g. on the distance from the vector of spreading, invaded community composition, land-use, etc. The species distribution models, a research tool for invasive plants spread prediction, involve the combination of environmental factors, occurrence data, and statistical approach. For the construction of the presented distribution model, the occurrence data on invasive plants (Solidagosp.,Fallopiasp.,Robinia pseudoaccacia,andHeracleum mantegazzianum) and Natura 2000 habitat types from the Protected Landscape Area Kokořínsko have been intersected in ArcGIS and statistically analyzed. The data analysis was focused on (1) verification of the accuracy of the Natura 2000 habitat map layer, and the accordance with the habitats occupied by invasive species and (2) identification of a suitable scale of intersection between the habitat and species distribution. Data suitability was evaluated for the construction of the model on local scale. Based on the data, the invaded habitat types were described and the optimal scale grid was evaluated. The results show the suitability of Natura 2000 habitat types for modelling, however more input data (e.g. on soil types, elevation) are needed.

scholarly journals The persistence in time of distributional patterns in marine megafauna impacts zonal conservation strategies

2019 ◽  
Author(s):  
C. Lambert ◽  
G. Dorémus ◽  
V. Ridoux
Keyword(s):  
Species Distribution ◽  
Habitat Model ◽  
Spatial Extent ◽  
Conservation Strategies ◽  
Distribution Data ◽  
Bay Of Biscay ◽  
Mobile Species ◽  
Distributional Patterns ◽  
Marine Megafauna ◽  
Mpa Network

AbstractThe main type of zonal conservation approach corresponds to Marine Protected Areas (MPAs), which are spatially defined and generally static entities aiming at the protection of some target populations by the implementation of a management plan. For highly mobile species the relevance of an MPA over time might be hampered by temporal variations in distributions or home ranges. In the present work, we used habitat model-based predicted distributions of cetaceans and seabirds within the Bay of Biscay from 2004 to 2017 to characterise the aggregation and persistence of mobile species distributional patterns and the relevance of the existing MPA network. We explored the relationship between population abundance and spatial extent of distribution to assess the aggregation level of species distribution. We used the smallest spatial extent including 75% of the population present in the Bay of Biscay to define specific core areas of distributions, and calculated their persistence over the 14 studied years. We inspected the relevance of the MPA network with respect to aggregation and persistence. We found that aggregation and persistence are two independent features of marine megafauna distributions. Indeed, strong persistence was shown in both aggregated (bottlenose dolphins, auks) and loosely distributed species (northern gannets), while some species with aggregated distributions also showed limited year-to-year persistence in their patterns (black-legged kittiwakes). We thus have demonstrated that both aggregation and persistence have potential impact on the amount of spatio-temporal distributional variability encompassed within static MPAs. Our results exemplified the need to have access to a minimal temporal depth in the species distribution data when aiming to designate new site boundaries for the conservation of mobile species.

scholarly journals A Photographic Record of the Upper Headwater Tributaries, Basins and Riparia of the Snake River

2011 ◽  
Vol 33 ◽  
pp. 107-113
Author(s):  
Susan Green ◽  
Dr. Michael Krop
Keyword(s):  
Global Warming ◽  
World War Ii ◽  
The Arctic ◽  
Snake River ◽  
Glacier Bay ◽  
Tundra Vegetation ◽  
The Us ◽  
Arctic Coast ◽  
Vantage Points ◽  
Bear Management

Photographic surveys have been used since the early 1940’s to document coastlines, fuel supplies and river courses. The US Navy, post world war II, flew over the Arctic coast to document possible locations for oil extraction. These very same photos are now being utilized to compare changes in tundra vegetation at the same locations today. John Muirs’ photos of Glacier Bay are a startling testament to the melted glaciers no longer visible from the same vantage point in present times. Taking photographs to monitor change may not tell the entire story behind a change in landscape. However, photos taken over a number of years from the same vantage points, can help monitor landscape changes due to habitat fragmentation, global warming, forest fire, cattle grazing and other land management issues. Photo monitoring is inexpensive, simple and can portray change to many different groups. Of course, photos taken to reveal change must start with documenting current or normal conditions. This is sometimes called baseline monitoring. The park ranger in Glacier National Park did not realize when he took his picture of the Grinnell glacier in 1911 that his photo would become an alarming baseline photo for evidence of global warming. The purpose of this project was to document the Snake River headwater basin and its riparian zones as a document in time for future reference. The original documentation included 48 images of two main headwater areas; the Shoshone and Lewis Lake areas and the Fox Park-Two Ocean Bear Management Areas near the Yellowstone Park border. Since the Shoshone-Lewis lakes are easily assessable and photo space here is limited, I have chosen to only use photos from the more remote areas.

scholarly journals Decline of unique Pontocaspian biodiversity in the Black Sea Basin: a review

2021 ◽  
Author(s):  
Aleksandre Gogaladze ◽  
Mikhail Son ◽  
Matteo Lattuada ◽  
Vitaliy Anistratenko ◽  
Vitaly Syomin ◽  
...  
Keyword(s):  
Black Sea ◽  
Species Distribution ◽  
The Black Sea ◽  
Distribution Data ◽  
Past Century ◽  
Detailed Knowledge ◽  
The Past ◽  
Mollusc Species ◽  
Anthropogenic Threats ◽  
Effective Conservation

Aim The unique aquatic Pontocaspian (PC) biota of the Black Sea Basin (BSB) is in decline. Lack of detailed knowledge on the status and trends of species, populations and communities hampers a thorough risk assessment and precludes effective conservation. This paper aims to review PC biodiversity trends using endemic molluscs as a model group. We aim to assess changes in PC habitats, community structure and species distribution over the past century and to identify direct anthropogenic threats. Location Black Sea Basin (Bulgaria, Romania, Moldova, Ukraine and Russia). Methods Presence/absence data of target mollusc species was assembled from literature, reports and personal observations. PC biodiversity trends in the NW BSB coastal regions were established by comparing 20th and 21st century occurrences. Direct drivers of habitat and biodiversity change were identified and documented. Results A very strong decline of PC species and communities during the past century is driven by a) damming of rivers, b) habitat modifications negatively affecting salinity gradients, c) pollution and eutrophication, d) invasive alien species and e) climate change. Four out of 10 studied regions, namely, the Danube Delta – Razim Lake system, Dniester Liman, Dnieper-South Bug Estuary and Taganrog Bay-Don Delta contain the entire spectrum of ecological conditions to support PC communities and still host threatened endemic PC mollusc species. Distribution data is incomplete, but the scale of deterioration of PC species and communities is evident from the assembled data, as are major direct threats. Main conclusions PC biodiversity in the BSB is profoundly affected by human activities. Standardised observation and collection data as well as precise definition of PC biota and habitats are necessary for targeted conservation actions. This study will help to set the research and policy agenda required to improve data collection to accommodate effective conservation of the unique PC biota.

scholarly journals Large-Scale Variation in Growth of Black Brant Goslings Related to Food Availability

The Auk ◽  
2001 ◽  
Vol 118 (4) ◽  
pp. 1088-1095 ◽  
Author(s):  
James S. Sedinger ◽  
Mark P. Herzog ◽  
Brian T. Person ◽  
Morgan T. Kirk ◽  
Tim Obritchkewitch ◽  
...  
Keyword(s):  
Large Scale ◽  
Grazing Pressure ◽  
The Arctic ◽  
First Year ◽  
Principal Mechanism ◽  
Density Dependent ◽  
Brood Rearing ◽  
Branta Bernicla ◽  
Black Brant ◽  
Arctic Coast

AbstractWe examined variation in growth of Black Brant (Branta bernicla nigricans) goslings among two colonies on the Yukon-Kuskokwim Delta in southwestern Alaska and the Colville River Delta on Alaska's Arctic coast. We simultaneously measured abundance and quality of a key food plant, Carex subspathacea, and grazing pressure on that plant at the three colonies. Our goal was to measure variation in gosling growth in relation to variation in grazing pressure and food abundance because growth of goslings is directly linked to first-year survival, and consequently is the principal mechanism for density-dependent population regulation. Goslings grew substantially faster on the arctic coast and were nearly 30% larger than those on the Yukon-Kuskokwim Delta at four to five weeks old. Faster growth on the arctic coast was associated with 2× greater standing crop of C. subspathacea during brood rearing than on the Yukon-Kuskokwim Delta. Dispersal rates are high enough (Lindberg et al. 1998) to rule out local adaptation and genetic variation as explanations for observed variation in growth. Our results are consistent with lower survival of goslings from the Yukon-Kuskokwim Delta during their first fall migration and stronger density-dependent regulation on the Yukon-Kuskokwim Delta than on the Arctic coast.

scholarly journals High resolution snow distribution data from complex Arctic terrain: a tool for model validation

2002 ◽  
Vol 2 (3/4) ◽  
pp. 147-155 ◽  
Author(s):  
Ch. Jaedicke ◽  
A. D. Sandvik
Keyword(s):  
High Resolution ◽  
Snow Cover ◽  
Numerical Models ◽  
The Arctic ◽  
Distribution Data ◽  
Blowing Snow ◽  
Data Set ◽  
Meteorological Model ◽  
Drift Model ◽  
Snow Distribution

Abstract. Blowing snow and snow drifts are common features in the Arctic. Due to sparse vegetation, low temperatures and high wind speeds, the snow is constantly moving. This causes severe problems for transportation and infrastructure in the affected areas. To minimise the effect of drifting snow already in the designing phase of new structures, adequate models have to be developed and tested. In this study, snow distribution in Arctic topography is surveyed in two study areas during the spring of 1999 and 2000. Snow depth is measured by ground penetrating radar and manual methods. The study areas encompass four by four kilometres and are partly glaciated. The results of the surveys show a clear pattern of erosion, accumulation areas and the evolution of the snow cover over time. This high resolution data set is valuable for the validation of numerical models. A simple numerical snow drift model was used to simulate the measured snow distribution in one of the areas for the winter of 1998/1999. The model is a two-level drift model coupled to the wind field, generated by a mesoscale meteorological model. The simulations are based on five wind fields from the dominating wind directions. The model produces a satisfying snow distribution but fails to reproduce the details of the observed snow cover. The results clearly demonstrate the importance of quality field data to detect and analyse errors in numerical simulations.

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