Historic and current distribution patterns, and minimum abundance of killer whales (Orcinus orca) in the north-west Atlantic

2013 ◽  
Vol 94 (6) ◽  
pp. 1253-1265 ◽  
Author(s):  
Jack W. Lawson ◽  
Tara S. Stevens
Keyword(s):  
Distribution Patterns ◽  
Orcinus Orca ◽  
Killer Whales ◽  
North West ◽  
The North ◽  
North Eastern ◽  
Comprehensive Examination ◽  
Coastal Shelf ◽  
Eastern Usa ◽  
Image Collection

This study represents the first comprehensive examination of the distribution and abundance of killer whales (Orcinus orca) in the north-west Atlantic. Based on a collation of sightings data and a multi-year photographic catalogue of killer whales, 836 sighting events have been recorded between 1758 and 2012, with most occurring in the last ten years. Killer whales were most commonly observed during June–September in Newfoundland/Labrador, Canada. Most sightings were made close to shore, although many occurred beyond coastal shelf areas and in water depths in excess of 3000 m. Relatively fewer sightings were recorded on the Scotian Shelf, in the Gulf of St Lawrence or the north-eastern USA, despite appreciable aerial and vessel-based cetacean survey effort. In the north-west Atlantic, killer whales have been sighted both alone and in groups, with group sizes ranging from 2 to 30 whales (rarely more than 15, although an aggregation of 100 was reported 43 years ago). Groups usually comprised 2–6 individuals. Based on photographic records, there are at least 67 identified killer whales in the northwest Atlantic; this is an underestimate, since a large portion of our image collection was not of sufficient quality to be considered in the analysis, and many of the whales do not have easily discernible markings. The discovery curve of newly-identified whales has not plateaued, suggesting that there are more whales to identify. These data allow us to better understand the ecology of these killer whales, and provide a baseline against which population changes and distribution patterns can be assessed.

scholarly journals Passive acoustic monitoring of killer whales (Orcinus orca) reveals year-round distribution and residency patterns in the Gulf of Alaska

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hannah J. Myers ◽  
Daniel W. Olsen ◽  
Craig O. Matkin ◽  
Lara A. Horstmann ◽  
Brenda Konar
Keyword(s):  
Killer Whale ◽  
Marine Ecosystem ◽  
Distribution Patterns ◽  
Gulf Of Alaska ◽  
Acoustic Monitoring ◽  
Orcinus Orca ◽  
Killer Whales ◽  
Passive Acoustic Monitoring ◽  
The North ◽  
Passive Acoustic

AbstractKiller whales (Orcinus orca) are top predators throughout the world’s oceans. In the North Pacific, the species is divided into three ecotypes—resident (fish-eating), transient (mammal-eating), and offshore (largely shark-eating)—that are genetically and acoustically distinct and have unique roles in the marine ecosystem. In this study, we examined the year-round distribution of killer whales in the northern Gulf of Alaska from 2016 to 2020 using passive acoustic monitoring. We further described the daily acoustic residency patterns of three killer whale populations (southern Alaska residents, Gulf of Alaska transients, and AT1 transients) for one year of these data. Highest year-round acoustic presence occurred in Montague Strait, with strong seasonal patterns in Hinchinbrook Entrance and Resurrection Bay. Daily acoustic residency times for the southern Alaska residents paralleled seasonal distribution patterns. The majority of Gulf of Alaska transient detections occurred in Hinchinbrook Entrance in spring. The depleted AT1 transient killer whale population was most often identified in Montague Strait. Passive acoustic monitoring revealed that both resident and transient killer whales used these areas much more extensively than previously known and provided novel insights into high use locations and times for each population. These results may be driven by seasonal foraging opportunities and social factors and have management implications for this species.

Stanowiska reliktowego gatunku Betula humilis (Betulaceae) w Dolinie Górnego Nurca na Nizinie Północnopodlaskiej

2019 ◽  
pp. 161-168
Author(s):  
Aleksander Kołos
Keyword(s):  
Drainage Ditches ◽  
North West ◽  
Hay Meadows ◽  
The North ◽  
South West ◽  
North Eastern ◽  
New Localities ◽  
Western Border ◽  
Betula Humilis ◽  
Trees And Shrubs

Betula humilis Schrank (shrubby birch) is among the most endangered shrub species in Poland. All localities are in the eastern and northern parts of the country, where the species reaches the western border of its geographical range in Europe. Betula humilis is disappearing in Poland due to wetland melioration and shrub succession. Over 80% of the localities described in Poland have not been confirmed in the last 20 years. Five new localities of B. humilis in the North Podlasie Lowland were recorded from 2008 to 2019 in the Upper Nurzec Valley (Fig. 1): 1–1.5 km south-west of Pawlinowo village (in the ATPOL GC7146 plot) and 1.5–2 km north-west of Żuki village (ATPOL GC7155, GC156 and GC166). The population near Pawlinowo (locality 1) is currently composed of ~80 individuals (101 individuals were noted in 2010) and is one of the largest populations in north-eastern Poland. Betula humilis grows there within patches dominated by Salix rosmarinifolia and megaforbs. The population at locality 5 is composed of 18 individuals. At the remaining localities, only 1–4 individuals were found, scattered along drainage ditches surrounded by hay meadows. At some of these localities the species is threatened with extinction. It is suggested to remove competitive trees and shrubs (mainly Populus tremula, Betula pubescens and Salix cinerea) in order to maintain the local populations.

scholarly journals Infrasound and the Avian Navigational Map

2001 ◽  
Vol 54 (3) ◽  
pp. 377-391 ◽  
Author(s):  
Jonathan T. Hagstrum
Keyword(s):  
Shock Waves ◽  
Magnetic Compass ◽  
Experimental Results ◽  
Supersonic Transport ◽  
Atmospheric Processes ◽  
Topographic Features ◽  
Navigational Map ◽  
The North ◽  
North Eastern ◽  
Eastern Usa

Birds can accurately navigate over hundreds to thousands of kilometres, and use celestial and magnetic compass senses to orient their flight. How birds determine their location in order to select the correct homeward bearing (map sense) remains controversial, and has been attributed to their olfactory or magnetic senses. Pigeons can hear infrasound down to 0·05 Hz, and an acoustic avian map is proposed consisting of infrasonic cues radiated from steep-sided topographic features. The source of these infrasonic signals is microseisms continuously generated by interfering oceanic waves. Atmospheric processes affecting the infrasonic map cues can explain perplexing experimental results from pigeon releases. Moreover, four recent disrupted pigeon races in Europe and the north-eastern USA intersected infrasonic shock waves from the Concorde supersonic transport. Having an acoustic map might also allow clock-shifted birds to test their homeward progress and select between their magnetic and solar compasses.

scholarly journals Evaluation of Soil Moisture Variability in Poland from SMOS Satellite Observations

2019 ◽  
Vol 11 (11) ◽  
pp. 1280 ◽  
Author(s):  
Bogusław Usowicz ◽  
Jerzy Lipiec ◽  
Mateusz Lukowski
Keyword(s):  
Soil Moisture ◽  
North West ◽  
Moisture Contents ◽  
North East ◽  
The North ◽  
Linear Distance ◽  
Classical Statistics ◽  
Ocean Salinity ◽  
North Eastern ◽  
Smos Satellite

Soil moisture (SM) data play an important role in agriculture, hydrology, and climate sciences. In this study, we examined the spatial-temporal variability of soil moisture using Soil Moisture Ocean Salinity (SMOS) satellite measurements for Poland from a five-year period (2010–2014). SMOS L2 v. 551 datasets (latitudinal rectangle 1600 × 840 km, centered in Poland) averaged for quarterly (three months corresponding to winter, spring, summer, and autumn) and yearly values were used. The results were analysed with the use of classical statistics and geostatistics (using semivariograms) to acquire information about the nature of anisotropy and the lengths and directions of spatial dependences. The minimum (close to zero) and maximum soil moisture values covered the 0.5 m3 m−3 range. In particular quarters, average soil moisture did not exceed 0.2 m3 m−3 and did not drop below 0.12 m3 m−3; the corresponding values in the study years were 0.171 m3 m−3 and 0.128 m3 m−3. The highest variability of SM occurred generally in winter (coefficient of variation, CV, up to 40%) and the lowest value was recorded in spring (around 23%). The average CV for all years was 32%. The quarterly maximum (max) soil moisture contents were well positively correlated with the average soil moisture contents (R2 = 0.63). Most of the soil moisture distributions (histograms) were close to normal distribution and asymmetric data were transformed with the square root to facilitate geostatistical analysis. Isotropic and anisotropic empirical semivariograms were constructed and the theoretical exponential models were well fitted (R2 > 0.9). In general, the structural dependence of the semivariance was strong and moderate. The nugget (C0) values slightly deceased with increasing soil moisture while the sills (C0 + C) increased. The effective ranges of spatial dependence (A) were between 1° and 4° (110–440 km of linear distance). Generally, the ranges were greater for drier than moist soils. Anisotropy of the SM distribution exhibited different orientation with predominance from north-west to south-east in winter and spring and changed for from north-east to south-west or from north to south in the other seasons. The fractal dimension values showed that the distribution of the soil moisture pattern was less diverse (smoother) in the winter and spring, compared to that in the summer and autumn. The soil moisture maps showed occurrence of wet areas (soil moisture > 0.25 m3 m−3) in the north-eastern, south-eastern and western parts and dry areas (soil moisture < 0.05 m3 m−3) mainly in the central part (oriented towards the south) of Poland. The spatial distribution of SM was attributed to soil texture patterns and associated with water holding capacity and permeability. The results will help undertake appropriate steps to minimize susceptibility to drought and flooding in different regions of Poland.

Preliminary findings of restriction fragment differences in mitochondrial DNA among killer whales (Orcinus orca)

1989 ◽  
Vol 67 (10) ◽  
pp. 2592-2595 ◽  
Author(s):  
Tracy A. Stevens ◽  
Deborah A. Duffield ◽  
Edward D. Asper ◽  
K. Gilbey Hewlett ◽  
Al Bolz ◽  
...  
Keyword(s):  
Mitochondrial Dna ◽  
North Atlantic ◽  
North Pacific ◽  
Killer Whale ◽  
Vancouver Island ◽  
Restriction Pattern ◽  
Orcinus Orca ◽  
Killer Whales ◽  
The North ◽  
The North Pacific

A preliminary assessment of mitochondrial DNA restriction patterns in the killer whale (Orcinus orca) was conducted using 10 captive North Atlantic killer whales from the southeastern coast of Iceland, a captive-born offspring of one of these whales, and 9 North Pacific killer whales. No restriction pattern variation was seen among these whales, using the enzymes BamH I, Bgl II, Hinf I, Kpn I, or Pvu II. Restriction pattern variation was found using the enzyme Hae III. This restriction endonuclease distinguished the North Atlantic killer whales (type 1) from the North Pacific killer whales. The North Pacific killer whales were further differentiated into two groups: those originating from the "resident" communities of the Vancouver Island region (type 2), and those from the "transient" community of Vancouver Island, as well as those stranded along the Oregon coast (type 3). The observed Hae III restriction pattern differences suggest that mitochondrial DNA analysis will be a valuable technique for investigating regional and local distributions of maternal lineages among killer whale pods, especially in the North Pacific.

Population genetics of two tropical sharks, Carcharhinus tilstoni and C. sorrah, in Northern Australia

1989 ◽  
Vol 40 (5) ◽  
pp. 541 ◽  
Author(s):  
S Lavery ◽  
JB Shaklee
Keyword(s):  
Eastern Coast ◽  
Population Subdivision ◽  
Starch Gel Electrophoresis ◽  
Northern Australia ◽  
Tissue Samples ◽  
North West ◽  
The North ◽  
North Eastern ◽  
Starch Gel ◽  
Sufficient Variation

The genetic structure of the Australian populations of Carcharhinus tilstoni and C. sorrah was investigated by starch gel electrophoresis. Tissue samples were taken from 1580 sharks from throughout the fishery, which extends from the North-West Shelf (off Western Australia) to the north-eastern coast of Queensland. From a total of 47 enzyme loci screened in each species, 13 proved to be polymorphic (P0.99) for at least one species, with only 5 loci for each species showing sufficient variation (P0.95) to be of use in the analysis of population structure. Mean heterozygosity values were relatively low: 0.037 for C. tilstoni and 0.035 for C. sorrah. A low level of population subdivision was found within each species, with FST values of 0.0094 for C. tilstoni and 0.0076 for C. sorrah. There was insufficient evidence to suggest that there is more than one population of either species of shark in Australian waters.

Charge fingerprints of forest organic horizons from north-eastern USA

Soil Research ◽  
1997 ◽  
Vol 35 (3) ◽  
pp. 553 ◽  
Author(s):  
Donald S. Ross ◽  
Richmond J. Bartlett
Keyword(s):  
Close Association ◽  
Choline Chloride ◽  
Base Cation ◽  
Exchange Capacity ◽  
Organic Soils ◽  
Ph Change ◽  
The North ◽  
North Eastern ◽  
Eastern Usa ◽  
Active Research

The charge fingerprint procedure was used to characterise the exchange properties of high- organic forest soils from the north-eastern USA. Twenty-six Oa or A horizon samples were obtained from active research sites to provide samples with a range in carbon from 15·1 to 49·4% and pH (in 1 mM CaCl2) from 2·8 to 4·2. Fingerprints were similar to those developed for other variably charged soils except that significant quantities of exchangeable H+ were found and no appreciable anion exchange capacity was measured. The magnitude of the ‘base’ cation capacity (CECB) varied linearly with pH, averaging >50% change per unit pH change. A good estimate of the CECB was obtained from the sum of cations removed by a single extraction with 1·0 М choline chloride (slope 1·03, r2 = 0·91). Variations in exchangeable Al3+ or H+ with pH were related to the quantity found in untreated samples, probably because of the close association between exchangeable and organically complexed forms. The total CEC was closely related to the sum of cations removed by 0·1 M BaCl2 (slope 1·05, r2 = 0·96). Although low ionic strength may be difficult to maintain in low pH samples, the fingerprint method appears to allow precise interpolation of the organic soils’ exchange capacity at field pH.

scholarly journals A three decade assessment of climate-associated changes in forest composition across the north-eastern USA

2017 ◽  
Vol 54 (6) ◽  
pp. 1592-1604 ◽  
Author(s):  
Arun K. Bose ◽  
Aaron Weiskittel ◽  
Robert G. Wagner
Keyword(s):  
Forest Composition ◽  
The North ◽  
North Eastern ◽  
Eastern Usa
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