scholarly journals Life history and ecology of harbour porpoises (Phocoena phocoena) from West Greenland

2003 ◽  
Vol 5 ◽  
pp. 177 ◽  
Author(s):  
C Lockyer ◽  
M P Heide-Jørgensen ◽  
J Jensen ◽  
M J Walton

During 1988, 1989 and 1995, 187 harbour porpoises (Phocoena phocoena) were sampled from the catches off West Greenland. The samples were taken in 3 areas between 62° N and 70° N: northerly (n=134, Maniitsoq and locations Kangaamiut, Qeqertarsuaq and Qasigiannguit further north), southerly (n=30, Nuuk) and southernmost (n=23, Paamiut). A suite of biological measurements and data were collected from these samples. Comparison of age and length distributions between years and areas indicated that while there were no statistical differences between the Maniitsoq and northerly samples in different years, the southerly Nuuk and Paamiut samples were biased to younger age classes. Application of the Gompertz growth model to length and weight at age data indicated an asymptotic length of 154 cm in females and 143 cm in males with weights of 64 kg and 52 kg respectively. A number of correlations were observed between length, midgirth(G3), body and blubber weights and blubber thickness. Indicators of body condition showed that overall pregnant females were fattest but that blubber thickness was greatest in juveniles. The blubber lipid content was generally 92-95% wet weight of tissue. Stomach content analysis for 92 animals indicated regional differences, although capelin (Mallotus villosus) was predominant in all samples. The presence of fish, squid and crustaceans indicated opportunistic feeding. Females ovulated from age 3-4 years at a length of about 140 cm; combined testis weights >200 g indicated maturation in males from age 2 years upwards at a length >125 cm. Several small embryos were found, consistent with a mating season in late summer. Testis hypertrophy in August also supported a late summer breeding. Analysis of ovarian corpora indicated annual ovulation. Certain biological parameters, including body condition indicators, indicate differences between WestGreenland and eastern North Atlantic populations that agree with published genetic findings.

1993 ◽  
Vol 71 (2) ◽  
pp. 264-272 ◽  
Author(s):  
Knud Falk ◽  
Jan Durinck

The diet of thick-billed murres (Uria lomvia) wintering in coastal western Greenland was studied by analyzing the stomach contents of 202 birds supplied by local hunters in four regions, from October 1988 to March 1989. Fish and crustaceans were present in 68 and 71% (frequency of occurrence), respectively, of all stomachs containing prey remains (n = 195). Fish made up 81% wet weight, and crustaceans most of the remaining 19%, except for < 1% squid (Gonatus sp.) and polychaetes (Nereis sp.). Capelin (Mallotus villosus) was the dominant prey species (61% wet weight), followed by Thysanoessa spp. (17%), Parathemisto spp. (1%), and Meganyctiphanes norvegica (1%). Euphausiids were the most abundant crustaceans (95% wet weight of all crustaceans), except in October, when hyperid amphipods were dominant (89%). Crustaceans were important in the murres' diet only in the northern part of the survey area; birds in the southern part preyed almost exclusively upon capelin. Most birds were in good body condition (based on the amount of body fat), but murres from the southern area had a slightly higher mean fat index than those from the northern area (7.19 vs. 5.35). We suggest that differences in body condition may be related to the higher proportion of fish, which is of higher caloric value, in the diet of murres in the southern area.


2003 ◽  
Vol 5 ◽  
pp. 211
Author(s):  
S F Richardson ◽  
G B Stenson ◽  
C Hood

Although the stock relationships among harbour porpoise (Phocoena phocoena) in the Northwest Atlantic are unknown, it has been postulated that there are 4 local populations: Bay of Fundy/Gulf of Maine, Gulf of St. Lawrence, Newfoundland, and west Greenland. Data on the Newfoundland population are extremely limited. To determine growth rates and examine if these animals can be differentiated from other sub-populations on the basis of growth characteristics, 94 porpoises caught incidentally in fishing gear along the southeast coast of Newfoundland during the summers of 1990 and 1991 were examined. Most porpoises (56%) were ≤ 4 years of age. Maximum age was 9 for females and 12 for males. Growth rates were similar for both sexes until one year of age, after which females grew longer and weighed more than males of similar ages. Using the Gompertz growth model, asymptotic values for body length were 156.3 cm for females and 142.9 cm for males. Asymptotic weights were 61.6 kg and 49.1 kg for females and males respectively. With the exception of West Greenland porpoise that were shorter and females from Norway that were lighter, Newfoundland porpoises could not be differentiated from animals collected in other areas based on growth data. However, differences in dental deposition patterns were noted suggesting that Newfoundland porpoise may belong to a separate population.


2020 ◽  
Vol 643 ◽  
pp. 197-217 ◽  
Author(s):  
SME Fortune ◽  
SH Ferguson ◽  
AW Trites ◽  
B LeBlanc ◽  
V LeMay ◽  
...  

Climate change may affect the foraging success of bowhead whales Balaena mysticetus by altering the diversity and abundance of zooplankton species available as food. However, assessing climate-induced impacts first requires documenting feeding conditions under current environmental conditions. We collected seasonal movement and dive-behaviour data from 25 Eastern Canada-West Greenland bowheads instrumented with time-depth telemetry tags and used state-space models to examine whale movements and dive behaviours. Zooplankton samples were also collected in Cumberland Sound (CS) to determine species composition and biomass. We found that CS was used seasonally by 14 of the 25 tagged whales. Area-restricted movement was the dominant behaviour in CS, suggesting that the tagged whales allocated considerable time to feeding. Prey sampling data suggested that bowheads were exploiting energy-rich Arctic copepods such as Calanus glacialis and C. hyperboreus during summer. Dive behaviour changed seasonally in CS. Most notably, probable feeding dives were substantially shallower during spring and summer compared to fall and winter. These seasonal changes in dive depths likely reflect changes in the vertical distribution of calanoid copepods, which are known to suspend development and overwinter at depth during fall and winter when availability of their phytoplankton prey is presumed to be lower. Overall, CS appears to be an important year-round foraging habitat for bowheads, but is particularly important during the late summer and fall. Whether CS will remain a reliable feeding area for bowhead whales under climate change is not yet known.


Author(s):  
Flemming G. Christiansen ◽  
Anders Boesen ◽  
Finn Dalhoff ◽  
Asger K. Pedersen ◽  
Gunver K. Pedersen ◽  
...  

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Christiansen, F. G., Boesen, A., Dalhoff, F., Pedersen, A. K., Pedersen, G. K., Riisager, P., & Zinck-Jørgensen, K. (1997). Petroleum geological activities onshore West Greenland in 1996, and drilling of a deep exploration well. Geology of Greenland Survey Bulletin, 176, 17-23. https://doi.org/10.34194/ggub.v176.5055 _______________ The 1996 summer season saw continued petroleum geological activities in the Disko–Nuussuaq area, onshore West Greenland. These took the form of a geological field project led by the Geological Survey of Denmark and Greenland (GEUS), and continued commercial exploration by grønArctic Energy Inc. (grønArctic). In the second year of their licence, grønArctic carried out an airborne geophysical programme early in 1996 and drilled a c. 3 km deep exploration well on Nuussuaq, GRO#3, in the late summer (Fig. 1). Although the detailed results from grønArctic’s exploration are confidential (apart from the information made available at conferences and in press releases), it is evident that knowledge of the Nuussuaq Basin has greatly increased in recent years and that the basin has considerable exploration potential of its own (see Christiansen et al., 1995b, 1996a). The activities by GEUS and the exploration by grønArctic will significantly improve the understanding of the petroleum system of the basin; available data from the 1996 activities have shed light on the types and distribution of oils, source rocks and potential reservoir units.


2022 ◽  
Vol 247 ◽  
pp. 106172
Author(s):  
Peter Fink-Jensen ◽  
Karin Hüssy ◽  
Tonny Bernt Thomsen ◽  
Simon Hansen Serre ◽  
Jens Søndergaard ◽  
...  

1987 ◽  
Vol 135 ◽  
pp. 95-99
Author(s):  
R.J Braithwaite

As part of the GGU programme of hydropower investigations in West Greenland, glaciological and climatological measurements were continued at Qamanarssiip serrnia in 1986. The station was first established in the late summer of 1979 so that records for seven complete summers 1980-1986 are now available. Brief reports on the work have been given by Olesen (1981), Olesen & Braithwaite (1982), Braithwaite (1983a, 1984, 1985a, 1986a). More detailed analyses and presentations of data are given in Braithwaite & Olesen (1982) and Braithwaite (1983b, 1985b). According to present plans, the Qamanarssup serrnia station will not be manned again for a full summer as it has been for the last seven years. However, a reduced programme of measurements will be continued in future years. A brief discussion of future plans is given at the end of this report.


1990 ◽  
Vol 47 (11) ◽  
pp. 2158-2163 ◽  
Author(s):  
Andrew j. Read ◽  
David E. Gaskin

Changes in the growth and reproduction of harbour porpoises from the Bay of Fundy are described by comparing samples collected in 1969–73 and 1985–88. The most pronounced change was an increase in the length of calves, from 92.1 cm (SE 1.6) in 1969–73 to 108 cm (SE 1.3) in 1985–88. Females in 1985–88 attained sexual maturity at a significantly younger age (3.44 yr) and shorter length (143 cm) than females from the older sample (3.97 yr and 147 cm). These changes may be attributable to an increase in prey availability to individual porpoises. This presumed increase in prey availability may have resulted from a decrease in porpoise density caused by incidental mortality in commercial fisheries, a simultaneous increase in prey abundance, or a combination of these factors.


1994 ◽  
Vol 28 (1-2) ◽  
pp. 13-28 ◽  
Author(s):  
Thijs Kuiken ◽  
Peter M. Bennett ◽  
Colin R. Allchin ◽  
James K. Kirkwood ◽  
John R. Baker ◽  
...  

2015 ◽  
Vol 72 (7) ◽  
pp. 2139-2148 ◽  
Author(s):  
Vanessa Minke-Martin ◽  
J. Brian Dempson ◽  
Timothy F. Sheehan ◽  
Michael Power

Abstract Otolith-derived estimates of mean marine temperatures used by West Greenland 1SW Atlantic salmon (Salmo salar) of North American origin were determined for fish collected in 2009 and 2010. Otolith material corresponding to the second summer at sea was subsampled, via micro-milling, and analysed by mass spectrometry to produce stable oxygen isotope (δ18O) values from which temperature use estimates were obtained from a salmonid-based fractionation equation. Mean temperature estimates did not differ significantly by period (early vs. late summer), or capture year. The mean and variation estimates were also consistent with temperature use values previously published in the literature or derived from the limited number of data storage tags that have been retrieved for Atlantic salmon, with 80% of all individuals occupying temperatures in the 3.9–9.7°C range. Among-individual differences in temperature use did not correlate with measured otolith growth zone widths. Given the temporal, spatial and methodological variation associated with the derivation of marine temperature use estimates for Atlantic salmon, the data were interpreted to define a range of preferred temperatures within which among-individual differences in growth were driven by the interaction of feeding and temperature use, possibly as a result of the opportunistic feeding behaviour known to predominate among Atlantic salmon.


1973 ◽  
Vol 30 (8) ◽  
pp. 1111-1130 ◽  
Author(s):  
M. C. Mercer

This paper comprises sight records for nine species and morphometries, color descriptions, and miscellaneous notes on the food and parasites of seven species of small odontocetes observed from West Greenland to Florida 1967–72. Of interest are the first western Atlantic extralimital record of Monodon monoceros, first Newfoundland records of Stenella coeruleoalba, and extralimital records of Delphinapterus leucas from Newfoundland. Intraspecific variability is described in the pigmentation patterns of Phocoena phocoena.


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