IUCN Red List Assessment
Red List Category
Red List Criteria
IUCN Evaluation of the Grey Seal, Halichoerus grypus
Prepared by the Pinniped Specialist Group
A. Population reduction Declines measured over the longer of 10 years or 3 generations
A1 CR > 90%; EN > 70%; VU > 50%
Al. Population reduction observed, estimated, inferred, or suspected in the past where the causes of the reduction are clearly reversible AND understood AND have ceased, based on and specifying any of the following:
(a) direct observation
(b) an index of abundance appropriate to the taxon
(c) a decline in area of occupancy (AOO), extent of occurrence (EOO) and/or habitat quality
(d) actual or potential levels of exploitation
(e) effects of introduced taxa, hybridization, pathogens, pollutants, competitors or parasites.
Age-structure data from Grey Seal populations in the late 1970s indicated a generation time of approximately 14 years. Abundance is well known as all major populations are monitored regularly. Subpopulations in the Gulf of St Lawrence and Iceland have declined over last decade but by less than 50%. However, the three main sub populations globally (East Atlantic, West Atlantic, Baltic) have all increased over the past 30 years.
A2, A3 & A4 CR > 80%; EN > 50%; VU > 30%
A2. Population reduction observed, estimated, inferred, or suspected in the past where the causes of reduction may not have ceased OR may not be understood OR may not be reversible, based on (a) to (e) under Al.
A population reduction of Grey Seals has not been observed, estimated, inferred, or suspected in the past 30 years.
A3. Population reduction projected or suspected to be met in the future (up to a maximum of 100 years) based on (b) to (e) under A1.
At present there are no indications that the Grey Seal population is likely to decline in the future. The continued growth of the Canadian and North Sea populations during periods of intense over fishing of several of their important prey species suggests that the populations are robust. Major regime shifts in the north Atlantic could lead to population declines.
A4. An observed, estimated, inferred, projected or suspected population reduction (up to a maximum of 100 years) where the time period must include both the past and the future, and where the causes of reduction may not have ceased OR may not be understood OR may not be reversible, based on (a) to (e) under A1.
A population reduction of Grey Seals has not been observed, estimated, inferred, or suspected in the past 30 years and there are no indications that a decline is likely.
B. Geographic range in the form of either B1 (extent of occurrence) AND/OR B2 (area of occupancy)
B1. Extent of occurrence (EOO): CR
The EOO of Grey Seals is > 1,500,000 km².
B2. Area of occupancy (AOO): CR
The AOO of Grey Seals is > 1,500,000 km².
AND at least 2 of the following:
(a) Severely fragmented, OR number of locations: CR = 1; EN
The Grey Seal population is not severely fragmented and number of breeding locations >> 10.
(b) Continuing decline in any of: (i) extent of occurrence; (ii) area of occupancy; (iii) area, extent and/or quality of habitat; (iv) number of locations or subpopulations; (v) number of mature individuals.
No recorded declines in (i),(ii),(iii),(iv), overall increase in (v) with local declines in Iceland and possibly in Gulf of St Lawrence.
(c) Extreme fluctuations in any of: (i) extent of occurrence; (ii) area of occupancy; (iii) number of locations or subpopulations; (iv) number of mature individuals.
No extreme fluctuations in any of: (I),(ii), (iii) or (iv)
C. Small population size and decline
Number of mature individuals: CR
Annual pup production is approximately 100,000 indicating an adult female population >100,000.
AND either C1 or C2:
C1. An estimated continuing decline of at least: CR = 25% in 3 years or 1 generation; EN = 20% in 5 years or 2 generations; VU = 10% in 10 years or 3 generations (up to a max. of 100 years in future) — N/A
C2. A continuing decline AND (a) and/or (b):
(a i) Number of mature individuals in each subpopulation: CR or
(a ii) % individuals in one subpopulation: CR = 90–100%; EN = 95–100%; VU = 100% — N/A
(b) Extreme fluctuations in the number of mature individuals. — N/A
D. Very small or restricted population
Number of mature individuals: CR AND/OR restricted area of occupancy typically: AOO
The number of mature individuals is certainly > 100,000. AOO is > 1,500,000 km² and the number of locations is > 50.
E. Quantitative Analysis
Indicating the probability of extinction in the wild to be: Indicating the probability of extinction in the wild to be: CR > 50% in 10 years or 3 generations (100 years max.); EN > 20% in 20 years or 5 generations (100 years max.); VU > 10% in 100 years
Long- term continuing increases in total population and most subpopulations suggest very low likelihood of extinction within 3 generations.
Listing recommendation — Continuing, well documented increases in overall population and most subpopulations, low levels of localized hunting and widespread conservation measures in most range states and current population size based on pup production estimates is >400,000. Continued declines in Icelandic waters give cause for concern, but globally, Grey Seals should be classified as Least Concern.
- 1996Lower Risk/least concern