scholarly journals Harbour porpoises (Phocoena phocoena) in the North Atlantic: Biological parameters

2003 ◽  
Vol 5 ◽  
pp. 71 ◽  
Author(s):  
Christina Lockyer
Keyword(s):  
North Atlantic ◽  
Growth Parameters ◽  
Growth Models ◽  
Maximum Size ◽  
Biological Information ◽  
Biological Parameters ◽  
Structure Information ◽  
The North ◽  
Age Related ◽  
The North Atlantic

Biological parameters for harbour porpoises are reviewed throughout their range in the North Atlantic. Most information is based on studies of a combination of directed catches, bycatches and strandings. All these sources are valuable for providing biological information, but each carries some bias when it comes to interpretation of parameters, especially those involving age structure. Information on age-related parameters, reproduction and growth is presented and assessed by region and/or population, of which there may be 14 throughout the North Atlantic. Among age related parameters, maximum longevity recorded is 24 years; maximal rate of population growth is probably 9.4% but in the range 5-10%; mortality is highest in year 1, and <5% of the population live beyond 12 years; an estimate of 0.867 with a maximum age of 23 years has been given for survival. Among reproductive parameters, age at sexual maturation falls between 3-4 years for both sexes; age at first parturition is probably 4-5 years; age at first ovulation is >3 years; ovulation rates fall in the range 0.64 - 0.988 corpus per year, and reproductive interval is 1.01-1.57 years; pregnancy rates are generally in the range 0.74 - 0.986 per year, meaning that not all females produce a calf every year; there is seasonal breeding/mating in the period June–August; gestation lasts 10-11 months; parturition generally occurs between mid-May to mid-July; duration of lactation is uncertain, but is probably at least 8 months; size at birth is usually in the range 65-75 cm with a maximum size of about 80 cm. Sex ratio is biased to males throughout life: 1.1-1.2 males : 1.0 females in the foetal stage, and 1.1-1.7 males : 1.0 females post-natal. Growth parameters indicate an asymptotic length and weight that varies with population, but usually falls in the range 153-163 cm and 55-65 kg for females and 141-149 cm and 46-51 kg for males. Growth models used for length and weight are typically based on von Bertalanffy and Gompertz models. Length at sexual maturity also varies with population, but is usually in the range 138-147 cm for females and 127-135 cm for males. There is no information based on vertebral epiphyseal fusion to indicate age at physical maturity. Foetal growth appears normal, but there is uncertainty about the existence of embryonic diapause. Size/age at weaning are uncertain, but size may be <115 cm and at an age >8 months; however, entirely independent feeding may not occur until about 10 months.

Size at Maturity, Fecundity, and Embryonic Growth of the Spiny Dogfish (Squalus acanthias) in British Columbia Waters

1972 ◽  
Vol 29 (12) ◽  
pp. 1717-1723 ◽  
Author(s):  
K. S. Ketchen
Keyword(s):  
British Columbia ◽  
North Atlantic ◽  
North Pacific ◽  
Average Length ◽  
Maximum Size ◽  
The Sea Of Japan ◽  
The North ◽  
The North Atlantic ◽  
Time Of Year ◽  
The North Pacific

Information on the biology of dogfish in British Columbia waters, none of it previously reported, is compared with similar information from other areas of the North Pacific as well as the North Atlantic.Males and females on both sides of the Pacific have an approximate maximum size of 100 and 130 cm, respectively, or at least 10 cm greater than in the North Atlantic. Females in the North Pacific mature at an average length of 92–100 cm depending on region, as compared to 77–82 cm in the North Atlantic. Males likewise mature at a larger size in the North Pacific.Observations in Canadian west coast waters show a weak correlation between number of embryos and length of the mother (r = 0.57).Female dogfish produce 2–17 young with an average of 6–7 in the North Pacific off the British Columbia coast; 3–25, averaging 12 in the Sea of Japan; 1–9, averaging 4 in the northwest Atlantic; and 1–10, averaging 3–5 in the northeast Atlantic. Size at birth is about the same throughout the northern hemisphere being between 23 and 30 cm with an average of 25–27 cm.Intrauterine growth rate is essentially the same in all regions, but at any given time of year differences is size are substantial and are determined largely by differences in time of conception.

scholarly journals Genetic structure of the lumpfish Cyclopterus lumpus across the North Atlantic

2014 ◽  
Vol 71 (9) ◽  
pp. 2390-2397 ◽  
Author(s):  
Christophe Pampoulie ◽  
Sigurlaug Skirnisdottir ◽  
Guðbjorg Olafsdottir ◽  
Sarah J. Helyar ◽  
Vilhjálmur Thorsteinsson ◽  
...  
Keyword(s):  
Gene Flow ◽  
Genetic Structure ◽  
North Atlantic ◽  
North Atlantic Ocean ◽  
Economic Value ◽  
Biological Knowledge ◽  
Structure Information ◽  
Cyclopterus Lumpus ◽  
The North ◽  
The North Atlantic

Abstract Lumpfish, or lumpsucker, Cyclopterus lumpus (Linnaeus, 1758) is widely distributed in the North Atlantic Ocean. It has a considerable economic value and substantial fisheries occur in several North Atlantic regions owing to the use of its fully ripe internal egg masses in the ovaries as an alternative to sturgeon caviar. Despite being intensively fished in several locations, biological knowledge is limited and no genetic structure information is available. In this study, the stock structure of C. lumpus was investigated across the North Atlantic using ten microsatellite loci. Out of ten loci, two exhibited higher level of differentiation but their inclusion/exclusion from the analyses did not drastically change the observed genetic pattern. A total of three distinct genetic groups were detected: Maine–Canada–Greenland, Iceland–Norway and Baltic Sea. These results, discussed in terms of origin of differentiation, gene flow, and selection, showed that gene flow was rather limited among the detected groups, and also between Greenland and Maine–Canada.

The Currents of the North Atlantic

1892 ◽  
Vol 34 (872supp) ◽  
pp. 13940-13941
Author(s):  
Richard Beynon
Keyword(s):  
North Atlantic ◽  
The North ◽  
The North Atlantic

NATO adaptation to current challenges and mechanisms of Ukraine’s cooperation with the North Atlantic Treaty Organization

2019 ◽  
pp. 73-81
Author(s):  
Oleh Poshedin
Keyword(s):  
North Atlantic ◽  
Task Force ◽  
Response Force ◽  
Cyber Attack ◽  
Adaptation Measures ◽  
Joint Force ◽  
Security Environment ◽  
The North ◽  
The North Atlantic ◽  
Area Of Influence

The purpose of the article is to describe the changes NATO undergoing in response to the challenges of our time. Today NATO, as a key element of European and Euro-Atlantic security, is adapting to changes in the modern security environment by increasing its readiness and ability to respond to any threat. Adaptation measures include the components required to ensure that the Alliance can fully address the security challenges it might face. Responsiveness NATO Response Force enhanced by developing force packages that are able to move rapidly and respond to potential challenges and threats. As part of it, was established a Very High Readiness Joint Task Force, a new Allied joint force that deploy within a few days to respond to challenges that arise, particularly at the periphery of NATO’s territory. NATO emphasizes, that cyber defence is part of NATO’s core task of collective defence. A decision as to when a cyber attack would lead to the invocation of Article 5 would be taken by the North Atlantic Council on a case-by-case basis. Cooperation with NATO already contributes to the implementation of national security and defense in state policy. At the same time, taking into account that all decision-making in NATO based on consensus, Ukraine’s membership in the Alliance quite vague perspective. In such circumstances, in Ukraine you often can hear the idea of announcement of a neutral status. It is worth reminding that non-aligned status did not save Ukraine from Russian aggression. Neutral status will not accomplish it either. All talks about neutrality and the impossibility of Ukraine joining NATO are nothing but manipulations, as well as recognition of the Ukrainian territory as Russian Federation area of influence (this country seeks to sabotage the Euro-Atlantic movement of Ukraine). Think about it, Moldova’s Neutrality is enshrined in the country’s Constitution since 1994. However, this did not help Moldova to restore its territorial integrity and to force Russia to withdraw its troops and armaments from Transnistria.

Traits structure copepod niches in the North Atlantic and Southern Ocean

2018 ◽  
Vol 601 ◽  
pp. 109-126 ◽  
Author(s):  
N McGinty ◽  
AD Barton ◽  
NR Record ◽  
ZV Finkel ◽  
AJ Irwin
Keyword(s):  
Southern Ocean ◽  
North Atlantic ◽  
The North ◽  
The North Atlantic
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