Spatial and temporal variation in genetic diversity of an endangered freshwater seal

Valtonen, Mia; Palo, Jukka U.; Ruokonen, Minna; Kunnasranta, Mervi; Nyman, Tommi

doi:10.1007/s10592-012-0367-5

Cited by 36 publications

(112 citation statements)

References 73 publications

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“…The nocturnal haulout behaviour of the Saimaa ringed seal is also suggested to be an adaptation to avoid human disturbance (Kunnasranta 2001. The present study supports previous findings, which have shown that Sai maa ringed seals exhibit a high degree of site fidelity (Kunnasranta 2001, Kos kela et al 2002, Valtonen et al 2012. In the present study, the median distance between haulout sites of individual seals was 2.5 km, with the maximum distances ranging from 4 to 23 km.…”

Section: Discussionsupporting

confidence: 92%

Haulout patterns of Saimaa ringed seals and their response to boat traffic during the moulting season

Niemi¹,

Auttila²,

Valtonen³

et al. 2013

Endang. Species. Res.

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Conservation of the Critically Endangered ringed seal Phoca hispida saimensis population in Lake Saimaa in Finland requires broader knowledge of the behavioural ecology of this subspecies. Understanding Saimaa ringed seal haulout patterns and their response to boat traffic is crucial for designing sustainable land use and tourism guidelines. Responses of unidentified seals to small outboard motor boat traffic were studied during the moulting season. The median distance at which the seals responded to an approaching boat was 240 m. GPS-phone tags were used to study both circadian and seasonal haulout behaviour patterns of individual seals (n = 8) during the open-water season. The average post-moulting haulout duration was 6 ± 5 h (SD), with a maximum of over 26 h. The seals spent more time hauled out at night (between 21:00 and 06:00 h) after the moult. The time spent hauled out and the haulout frequency declined from early summer to autumn. An individual seal had an average of 13 haulout sites, which were an average of 2.5 km apart. Approximately half of these haulout sites were located in the core 50% of the individual seals' home ranges. The high level of site fidelity emphasizes the need to identify suitable haulout areas and to develop measures for protecting the main resting sites of this endangered population. Additionally, guidelines for seal watching should be developed in order to mitigate the potential disturbance caused by increasing tourism on Lake Saimaa.

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Section: Discussionsupporting

confidence: 92%

Haulout patterns of Saimaa ringed seals and their response to boat traffic during the moulting season

Niemi¹,

Auttila²,

Valtonen³

et al. 2013

Endang. Species. Res.

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“…stayed within an average distance of 5 km from their natal sites. These observations strongly support the findings of telemetric and genetic studies pointing to a high degree of site fidelity among Saimaa ringed seals (Hyvärinen et al 1995, Kunnasranta 2001, Koskela et al 2002, Kunnasranta et al 2002, Niemi et al 2012, 2013b, Valtonen et al 2012, 2014 and highlight the vulnerability of the population to environmental change. The high re-sighting rates (Table 1) similarly confirm not only the high degree of site fidelity, but may also indicate a small population size.…”

Section: Discussionsupporting

confidence: 84%

Photo-ID as a tool for studying and monitoring the endangered Saimaa ringed seal

Koivuniemi

Auttila²,

Niemi³

et al. 2016

Endang. Species. Res.

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Photo-identification (photo-ID) with camera traps was examined as a non-invasive method for studying and monitoring the endangered Saimaa ringed seal Phoca hispida saimensis. An average of 51 game cameras were set up at shoreline haul-out sites in central Lake Saimaa during the moulting seasons in each of the years from 2010 to 2014. Individuals were identified from their lifelong unique lateral fur patterns. A total of 220 000 digital images of seals were obtained from these game cameras and from digital cameras during this period, allowing 164 individuals to be identified, 43% of which were re-sighted in successive years. In the majority of game camera images, both sides of the seal were shown, and it was possible to determine the sex of the seal. The average distance between sightings of individual seals in different years was 1.6 km, suggesting that Saimaa ringed seals exhibit a high degree of moulting site fidelity. In addition, the results support suggestions of natal site fidelity. We propose that photo-ID sampling based on camera traps, and larger-scale photographic survey of the seals, should be implemented as a population monitoring tool of the Saimaa ringed seal. Further application of the photo-ID technique may facilitate mark-recapture population and survival rate estimates for this threatened seal species and provide significant insights into its life history and social behaviour.

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“…FCA axis loads of the regional groups differed significantly from each other (MRPP test, P < 0.001), and all pairwise comparisons were statistically significant ( P < 0.01 in each case). Microsatellite differentiation was moderate in comparison to estimates based on mitochondrial control-region sequences, which were consistently higher for overall differentiation ( F ST = 0.390, P < 0.001 [17]; D est = 0.256, P = 0.047) as well as for pairwise F ST values (Table 3). A highly significant negative relationship between relatedness and spatial distance between pairs of individuals was found using both microsatellites ( b = -0.039, P < 0.001; Figure 4A) and mtDNA ( b Loiselle = -0.055; b Nij = -0.067; both P < 0.001; Figure 4B).…”

Section: Resultsmentioning

confidence: 94%

“…Genetic diversity indices were also calculated across an alternative temporal division scheme, in which individuals were grouped based on their year of birth: 1965–1979 ( N ms = 14), the 1980s ( N ms = 54), the 1990s ( N ms = 47), and the 2000s ( N ms = 54) (see [17] for details on age determination).…”

Section: Methodsmentioning

confidence: 99%

Causes and consequences of fine-scale population structure in a critically endangered freshwater seal

et al. 2014

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BackgroundSmall, genetically uniform populations may face an elevated risk of extinction due to reduced environmental adaptability and individual fitness. Fragmentation can intensify these genetic adversities and, therefore, dispersal and gene flow among subpopulations within an isolated population is often essential for maintaining its viability. Using microsatellite and mtDNA data, we examined genetic diversity, spatial differentiation, interregional gene flow, and effective population sizes in the critically endangered Saimaa ringed seal (Phoca hispida saimensis), which is endemic to the large but highly fragmented Lake Saimaa in southeastern Finland.ResultsMicrosatellite diversity within the subspecies (HE = 0.36) ranks among the lowest thus far recorded within the order Pinnipedia, with signs of ongoing loss of individual heterozygosity, reflecting very low effective subpopulation sizes. Bayesian assignment analyses of the microsatellite data revealed clear genetic differentiation among the main breeding areas, but interregional structuring was substantially weaker in biparentally inherited microsatellites (FST = 0.107) than in maternally inherited mtDNA (FST = 0.444), indicating a sevenfold difference in the gene flow mediated by males versus females.ConclusionsGenetic structuring in the population appears to arise from the joint effects of multiple factors, including small effective subpopulation sizes, a fragmented lacustrine habitat, and behavioural dispersal limitation. The fine-scale differentiation found in the landlocked Saimaa ringed seal is especially surprising when contrasted with marine ringed seals, which often exhibit near-panmixia among subpopulations separated by hundreds or even thousands of kilometres. Our results demonstrate that population structures of endangered animals cannot be predicted based on data on even closely related species or subspecies.

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Spatial and temporal variation in genetic diversity of an endangered freshwater seal

Cited by 36 publications

References 73 publications

Haulout patterns of Saimaa ringed seals and their response to boat traffic during the moulting season

Haulout patterns of Saimaa ringed seals and their response to boat traffic during the moulting season

Photo-ID as a tool for studying and monitoring the endangered Saimaa ringed seal

Causes and consequences of fine-scale population structure in a critically endangered freshwater seal

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