The nucleotide sequence of the mitochondrial DNA molecule of the grey seal, Halichoerus grypus, and a comparison with mitochondrial sequences of other true seals

1993 ◽  
Vol 37 (4) ◽  
Author(s):  
�lfur �rnason ◽  
Anette Gullberg ◽  
Ellinor Johnsson ◽  
Christina Ledje
Keyword(s):  
Mitochondrial Dna ◽  
Nucleotide Sequence ◽  
Halichoerus Grypus ◽  
Grey Seal ◽  
Dna Molecule ◽  
Mitochondrial Sequences

Utilizing next-generation sequencing to identify prey DNA in western North Atlantic grey seal Halichoerus grypus diet

2020 ◽  
Vol 655 ◽  
pp. 227-240
Author(s):  
KR Flanders ◽  
ZH Olson ◽  
KA Ono
Keyword(s):  
Next Generation Sequencing ◽  
Feeding Habits ◽  
Atlantic Menhaden ◽  
Halichoerus Grypus ◽  
Frequency Of Occurrence ◽  
Grey Seal ◽  
Next Generation ◽  
Significant Difference ◽  
Generation Sequencing ◽  
Seal Diet

Increasing grey seal Halichoerus grypus abundance in coastal New England is leading to social, political, economic, and ecological controversies. Central to these issues is the foraging ecology and diet composition of the seals. We studied grey seal feeding habits through next-generation sequencing of prey DNA using 16S amplicons from seal scat (n = 74) collected from a breeding colony on Monomoy Island in Massachusetts, USA, and report frequency of occurrence and relative read abundance. We also assigned seal sex to scat samples using a revised PCR assay. In contrast to current understanding of grey seal diet from hard parts and fatty acid analysis, we found no significant difference between male and female diet measured by alpha and beta diversity. Overall, we detected 24 prey groups, 18 of which resolved to species. Sand lance Ammodytes spp. were the most frequently consumed prey group, with a frequency of occurrence (FO) of 97.3%, consistent with previous studies, but Atlantic menhaden Brevoortia tyrannus, the second most frequently consumed species (FO = 60.8%), has not previously been documented in US grey seal diet. Our results suggest that a metabarcoding approach to seal food habits can yield important new ecological insights, but that traditional hard parts analysis does not underestimate consumption of Atlantic cod Gadus morhua (FO = 6.7%, Gadidae spp.) and salmon Salmo salar (FO = 0%), 2 particularly valuable species of concern.

scholarly journals Complete nucleotide sequence of the mitochondrial DNA from

2005 ◽  
Vol 5 (4-5) ◽  
pp. 315-322 ◽  
Author(s):  
Y ZIVANOVIC ◽  
P WINCKER ◽  
B VACHERIE ◽  
M BOLOTINFUKUHARA ◽  
H FUKUHARA
Keyword(s):  
Mitochondrial Dna ◽  
Nucleotide Sequence ◽  
Complete Nucleotide Sequence

scholarly journals Complete nucleotide sequence of the A+T-rich region of Drosophila mauritiana mitochondrial DNA

2006 ◽  
Vol 81 (1) ◽  
pp. 21-28 ◽  
Author(s):  
Kanako Sugihara ◽  
Ryoko Yui ◽  
Yoko Ibaragi ◽  
Etsuko T. Matsuura
Keyword(s):  
Mitochondrial Dna ◽  
Nucleotide Sequence ◽  
Complete Nucleotide Sequence ◽  
Rich Region ◽  
Drosophila Mauritiana

Predation by Sharks on the Grey Seal (Halichoerus grypus) in Eastern Canada

1983 ◽  
Vol 40 (3) ◽  
pp. 267-271 ◽  
Author(s):  
Paul Brodie ◽  
Brian Beck
Keyword(s):  
Key Words ◽  
Population Size ◽  
Halichoerus Grypus ◽  
Longline Fishery ◽  
Grey Seal ◽  
Eastern Canada ◽  
The Past ◽  
Harbour Seals ◽  
Commercially Important ◽  
Important Fish

The increase in population size of the grey seal (Halichoerus grypus) off eastern Canada over the past 20 yr may be attributed to a decrease in shark stocks, their supposed predators. Reduction of the shark population is presumed to have resulted from a directed longline fishery and, of greater significance, from a change in the fishery for swordfish (Xiphias gladius) from selective harpooning to pelagic longlining, which has produced a large bycatch of sharks. The resulting enhanced survival of grey seals is reflected in greater infestation of commercially important fish species by the codworm (Phocanema decipiens).Key words: grey seals, harbour seals, sharks, swordfish, codworm, predation, fisheries

Nucleotide sequence analysis of the hypervariable region III of mitochondrial DNA in Thais

2016 ◽  
Vol 41 ◽  
pp. 10-14 ◽  
Author(s):  
Punlop Thongngam ◽  
Worraanong Leewattanapasuk ◽  
Tanin Bhoopat ◽  
Padchanee Sangthong
Keyword(s):  
Mitochondrial Dna ◽  
Sequence Analysis ◽  
Nucleotide Sequence ◽  
Hypervariable Region ◽  
Nucleotide Sequence Analysis

scholarly journals Does predation by grey seals (Halichoerus grypus) affect Bothnian Sea herring stock estimates?

2012 ◽  
Vol 69 (8) ◽  
pp. 1448-1456 ◽  
Author(s):  
Anna Gårdmark ◽  
Örjan Östman ◽  
Anders Nielsen ◽  
Karl Lundström ◽  
Olle Karlsson ◽  
...  
Keyword(s):  
Marine Mammals ◽  
Halichoerus Grypus ◽  
Grey Seal ◽  
Older Individuals ◽  
Standard Assessment ◽  
Abundance Estimates ◽  
Stock Biomass ◽  
Key Species ◽  
Spawning Stock ◽  
Bothnian Sea

Abstract Gårdmark, A., Östman, Ö., Nielsen, A., Lundström K., Karlsson O., Pönni, J., and Aho, T. 2012. Does predation by grey seals (Halichoerus grypus) affect Bothnian Sea herring stock estimates? – ICES Journal of Marine Science, 69: . Mortality of small pelagic fish due to marine mammals is generally considered to be low compared with other sources of mortality. With recent recoveries of marine mammal predators worldwide, this may no longer hold. The grey seal (Halichoerus grypus) population in the Bothnian Sea has increased fivefold since 1985. Its main prey, herring (Clupea harrengus), is a key species for fisheries in the region. Yet, current stock assessments assume constant natural mortality, leading to a risk of biased stock estimates with increasing predation and misleading analyses of herring population dynamics. We estimated grey seal predation from diet data and reanalysed herring spawning stock biomass (SSB) during 1973–2009. Accounting for predation increased the herring SSB 16% (maximum 19%), but this was within the confidence intervals when ignoring predation. Although mortality in older individuals was inflated when accounting for seal predation, this did not change the conclusions about drivers of herring dynamics. Accounting for grey seal predation is important for abundance estimates of old herring, but currently not for SSB estimates, given the great uncertainties in the standard assessment. The grey seal impact on Bothnian Sea herring will need to be reassessed if stock age composition, grey seal feeding preferences, or total stock development change.

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