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Logotyp för Naturhistoriska riksmuseet

Photo: Markus Ahola

RiSe-Gen: Developing genomic tools for ringed seal population monitoring in the Baltic Sea

Understanding how marine species respond to climate warming and human activities is essential for the management of marine ecosystems. However, this requires cost-effective tools for population monitoring. Here, using genomic data, species distribution modelling and forward simulations we will develop a robust multi-disciplinary monitoring and management framework for the ringed seal, a top predator in the Baltic Sea.

Forskningsområden: Populationsanalys och -övervakning

Forskningsämnen: Bevarande, Evolution, Klimatförändringar, Populationsgenetik

Project period: 2025-2027

Participating Departments from the museum: Department of Nature and Environment Monitoring (NA)

Marine ecosystems are profoundly affected by the rapid rate of climate change. Studying the impacts of climate change through marine biodiversity monitoring is thus of paramount importance to devise effective conservation measures for marine ecosystems. Marine top predators play a crucial role in maintaining ecosystem structure and are important targets for population monitoring. While traditional monitoring tools provide valuable data on population size and trends, they offer limited insight into populations’ biology and represent a large investment in resources.

In contrast, genomic tools are cost-effective complementary approach to species monitoring by allowing to estimate many biological parameters such as population size and trends, number of breeders, reproductive output, dispersal, as well as genetic indices of conservation relevance including inbreeding and adaptive variation.

Here, we propose to develop genomic resources for the monitoring of ringed seal (Pusa hispida botnica), an understudied top predator in the Baltic Sea that is highly vulnerable to climate warming. Using whole-genome sequencing, we will first perform large-scale analyses to estimate population size, infer population structure and dispersal patterns as well as estimate genome-wide diversity in the whole Baltic metapopulation. Secondly, based on these data we will develop ~1000 highly-variable diagnostic markers and genotype ~400 seal samples allowing for the periodic large- and fine-scale estimation of population size, population structure, genome-wide diversity as well as parentage and kinship analyses. Finally, we will use species distribution modelling and forward genome-informed simulations to predict the future distributional, demographic and genomic responses of ringed seals to climate warming and harvesting regimes. This project will allow to develop a robust multi-disciplinary approach for the long-term monitoring, management and for decisions on hunting quotas of Baltic ringed seal.

Project description

Climate warming is severely impacting ecosystems globally and warming seas are already inducing shifts in species diversity and distribution. The decline of species playing a crucial role in the ecosystem will potentially induce irreversible cascading effects and ecosystem restructuring. To understand the effects of warming temperatures on species ranges and population dynamics and develop appropriate conservation measures for marine ecosystems, it is thus critical to develop robust monitoring approaches.

While traditional monitoring (e.g. population counts, satellite telemetry) provides valuable data on wild population census sizes (NC) and trends, behaviour, and habitat use but are labour-intensive and costly. In contrast, genetic monitoring provides a cost-effective and complementary method to population monitoring, allowing to estimate past and current effective population size (Ne), number of breeders (Nb), dispersal patterns, kinshipand genetic indicators of conservation relevance (e.g. inbreeding, adaptive variation).

Predicting the future responses of species to various stressors is also essential for species monitoring and management, especially with the high degree of uncertainty about the effects of climate warming and human pressure (e.g. hunting). Combining empirical genomic data, Species Distribution Models and genomic simulations thus represents the perfect multidisciplinary framework to predict the future ecological, evolutionary and genomic responses of species to climate.

The ringed seal (Pusa hispida botnica) is an important top predator in the Baltic Sea and is highly vulnerable to climate warming as females rely on sea ice for breeding and nursing their pups. However, the high uncertainty on seal numbers and connectivity among subpopulations and the low resolution of traditional genetic markers require the urgent need for the development of a robust genomic monitoring for ringed seal in the Baltic.

Here, we propose to develop a genomic monitoring tool for ringed seals in the Baltic using an extensive collection of tissue samples, state-of-the-art population genomics analyses and simulations. The project has three main goals:

  1. Perform large-scale population genomics analyses for baseline knowledge of ringed seal
  2. Develop genetic markers for large- and fine-scale monitoring of ringed seals
  3. Predict the future distributional, demographic and genomic responses of ringed seals to climate warming, habitat reduction and hunting intensity

Societal relevance

The Baltic ringed seals are monitored under the HELCOM framework as an indicator species for Baltic Sea health, with management divided into two units: the Bothnian Bay and the three southern breeding areas. However, limited understanding of gene flow and demographic trends, especially among southern subpopulations affected by poor ice conditions, necessitates data on population structure and dispersal to refine conservation and management actions.

Standardised monitoring for southern subpopulations is hampered by ice scarcity, making population estimates critical for ICES, which provides evidence-based guidance on marine management. The Working Group for Marine Mammal Ecology (WGMME) will use these findings to enhance management strategies for ringed seals in the Baltic.

This research also informs sustainable hunting strategies by providing data on abundance, breeding numbers, and dispersal, helping to set hunting quotas and geographical limits to protect vulnerable subpopulations. Additionally, insights into population dynamics will aid in addressing resource competition between seals and fisheries, guiding sustainable fishing practices and minimizing conflicts through detailed ecological modeling and projections.

Financial support

Naturvårdsverket (grant number: 2024-00132)

Team

Niclas Gyllenstrand| Curator

mail ikon

08-519 54 284

Martin Sköld| Senior Curator

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martin.skold@nrm.se

Markus Ahola | Senior Curator

Anja Carlsson | Senior Curator

Karl Lundström | SLU

Principal Investigator

Nicolas Dussex

Nicolas Dussex

Researcher

Population Analysis and Monitoring

Epost-ikon nicolas.dussex@nrm.se

Resarch Areas: Population Analysis and Monitoring

Research Subjects: Climate change, Evolution, Population genetics, Conservation

Page manager: Nicolas Dussex