Red List Category

Red List Criteria

Version

2008

Kovacs, K. (IUCN SSC Pinniped Specialist Group)

Kovacs, K. & Lowry, L. (Pinniped Red List Authority)

Hooded Seals in the northwest Atlantic breeding areas are currently either stable or increasing modestly. However, the northeast Atlantic stock has declined by 85-90 % over the last 40-60 years. The cause of the decline is unknown, but very recent data suggests that it is on-going (30% within 8 years), despite the protective measures that have been taken in the last few years. Although the Hooded Seal is thought to be panmictic, the precipitous decline in the eastern stock (from over half a million to 70 000) over a period of a few decades warrants that the hooded seal be classified as Vulnerable.

IUCN Evaluation of the Hooded Seal, Cystophora cristata
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.

Generation time in Hooded Seals is approximately 10 years. Hooded Seals have experienced a dramatic decline over the last three generations (30 years) in the northeast Atlantic stock but the causes are not clearly reversible, nor understood (global decline is, however, not > 50%).

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.

Hooded Seals in the northeast Atlantic have experienced a dramatic decline over the past 40-60 years (the precise time-frame is not known). This stock has been reduced by 85-90% since World War II. It is currently in decline, the causes of which are unknown (the decline may not be reversible). The northwest Atlantic stock of hooded seals is stable or increasing moderately in recent decades. Overall, the global population has declined by approximately 35-40% and thus this species should be considered Vulnerable.

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

There is concern that Hooded Seal will be negatively impacted by climate-change induced alternations to sea ice extent and character, as well as potential changes in the ecosystem that will affect its food supply. The relatively restricted distribution and some degree of overlap in diet with commercial fisheries add to the risk factor for this species.

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.

It is suspected that a population reduction will occur in the next 100 years for Hooded Seals due to climate-change induced alterations to the physical and biological resources upon which this species depends. A marked reduction has already been observed in the northeast Atlantic for unknown reasons. The decline has not ceased and may not be reversible.

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 Hooded Seals is >20,000 km².

B2. Area of occupancy (AOO): CR
The AOO of Hooded Seals is > 2,000 km².

AND at least 2 of the following:
(a) Severely fragmented, OR number of locations: CR = 1; EN
(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.

(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.

C. Small population size and decline
Number of mature individuals: CR
Both segments of the hooded seal population exceed 10,000 mature individuals.

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)

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%

(b) Extreme fluctuations in the number of mature individuals.

D. Very small or restricted population
Number of mature individuals: CR AND/OR restricted area of occupancy typically: AOO
Both segments of the hooded seal population exceed 1,000 mature individuals.

E. Quantitative analysis
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

There has been no population viability analysis conducted on hooded seals.

Listing recommendation — The relatively restricted distribution of Hooded Seals, their dependence on sea ice for breeding, moulting and resting and the observed, significant, declines for unknown reasons in the northeast Atlantic stock suggest that upgrading of this species to Vulnerable is warranted under criterion A2b. The observation of increased numbers of vagrant Hooded Seals well beyond their normal range, on both sides of the North Atlantic, suggests that the global population of Hooded Seals is experiencing change throughout the species range, despite the contrasting population trends in the west and east.