Conservation genetics a tool for species survival

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2 Conservation genetics a tool for species survival 1. Conservation Genetics in biodiversity policy 2. Genetic resources What is genetic diversity? High and low diversity 3. For effective species survival Practical applications and studies

3 Conservation Genetics in conservation policy

4 Genetic diversity politically important Genetic diversity is recognised as a key component of biodiversity Biological diversity is comprised of genetic differences within species, the diversity of species and the variety of ecosystems (The Convention on Biological Diversity, CBD) Tree levels of biodiversity: Genetic diversity: between individuals and populations Species diversity Ecosystem diversity

5 Genetics: neglected in biodiversity management In Europe, genetics is currently inadequately represented in biodiversity policy The Habitats Directive, the corner stone of Europe s nature conservation policy, does not directly refer to genetic differences within species Stark contrast to US and Canada

6 Conservation genetics Offers highly applicable tools for Assessing favourable conservation status provided by the Habitats Directive Achieving goals of Convention on Biological Diversity (CBD) Measures genetic diversity Uses the results to manage and conserve natural populations

7 Genetic resources What is genetic diversity?

8 What is genetic diversity? The genome contains the genetic code of an individual DNA in most species An individual s blueprint is encoded in genes. The gene information is encoded by building blocks : A, C, G, T The code of a gene varies slightly between individuals this is genetic diversity Lynx family in Heinburg, Germany. Photos: Joachim S. Müller

9 Differences create diversity There are often small differences in the code of a gene, even between individuals of the same population These genetic differences contribute to individual differences in e.g. height, fur colour, temperature tolerance More differences = more genetic diversity in individuals, populations and species

10 Genetic diversity is everywhere Genetic diversity exists Between individuals Between populations Between species

11 Genetic resources High and low diversity

12 High genetic diversity helps populations survive Low genetic diversity can lead to inbreeding depression Genetically similar individuals have a higher risk of producing offspring that have hereditary diseases

13 Endangered species suffer from low genetic diversity Human induced changes have led to smaller population sizes Habitat fragmentation caused by urbanisation, forestry, agriculture, fishing etc. Lower genetic diversity and higher risk of inbreeding 80 % of endangered species have lowered genetic diversity (Spielman et al. 2004, PNAS) Clearcut in southern Finland. Photo: Marjatta Sihvonen

14 Genetic diversity can reflect adaptation Populations that have adapted to their local environment are expected to have distinct genetic patterns It is important to detect and maintain these differences Otters. Photo: Cyril Blazy

15 Future in genes Climate change is forcing species to adapt to new conditions or move away High genetic diversity means there are more genetic variants that might be suited to the new conditions Possessing higher genetic diversity provides a population with more tickets in the lottery Dryas octopetala in the Alps, Germany. Photo: Steve Smith

16 For effective species survival Studies and applications

17 What can conservation genetics do to help preserve diversity? Where do individuals come from and what population or species they belong to? Do populations mix in nature? How to detect hybrid individuals? Are populations genetically healthy? How to identify distinct populations and relevant conservation units? How to predict the genetic outcome of management or harvesting decisions? Are populations diverse enough for the future?

18 Where do individuals come from and what population or species they belong to???

19 Genetics for forensics saving endangered tuna species Example The genus Thunnus comprised of eight species known as tunas Several species widely traded including the Atlantic bluefin tuna (Thunnus thynnus) One of the most endangered trade fish in the world Traded as commercial commodities, the identification of endangered species is difficult Viñas et al., 2009, PLoS One

20 DNA cannot be hidden in tuna salad Example DNA based methodologies provide very precise tools, that can identify all the different life stages of marine species Common forensic DNA tools were not able to distinguish all tuna species Using the combination of two genetic markers, all eight tuna species can be distinguished from any kind of processed tissue Viñas et al., 2009, PLoS One

21 Do populations mix in nature? If populations are genetically different, most likely they do not mix = no gene flow Check whether populations are connected

22 Detecting hybrid individuals Example Individuals that have genetic characteristics of two species Lesser white fronted goose (Anser erythropus) is considered vulnerable in the IUCN Red List Has suffered a rapid population reduction in key breeding population in Russia, decline predicted to continue The Fennoscandian population has undergone a severe historical decline, and has not yet recovered Lesser white fronted goose that escaped from captivity in Espoo, Finland. Photo: Matti Rekilä

23 Captive population unsuitable for the wild Example Genetic signals of hybridisation with two other goose species in captive population Unsuitable for wild stock supplementation Supplementation with other individuals from other wild populations recommended instead Ruokonen et al. 2007, Conservation Genetics

24 Are populations genetically healthy? Measure genetic diversity Compare past and present levels Estimate population size See whether population is changing Plan breeding programs to avoid inbreeding or species mixing Ruokonen et al. 2007, Conservation Genetics

25 Genetic rescue Example A population of Swedish adders suffered from inbreeding depression Stillborn offspring, low genetic variability Researchers released 20 males from another population breeding succes and population size increased Correspond to increase in genetic diversity Madsen et al. 1999, Nature Adder in the spring mood. Photo: Marjatta Sihvonen

26 Identifying distinct populations Genetically distinct populations can be valuable to protect units for conservation or management Look for distinct genetic patterns Identify priority populations for conservation Management unit 1 MU 2

27 Discovering distinct genetic patterns Example Teno river salmon in northern Finland and Norway Previously considered as one management unit Conservation genetics researchers showed there were many distinct genetic units within the river Vähä et al. 2007, Molecular Ecology Vähä et al. 2008, Evolutionary Applications

28 What do the differences mean? Example Changes in management strategies are being made to recognise and protect the distinct population units within the river E.g when deciting catch limits Suggests that individuals may be adapted to the specific conditions of each river section Ecological information also suggests this Teno salmons. Photo: Panu Orell Vähä et al. 2007, Molecular Ecology Vähä et al. 2008, Evolutionary Applications

29 Prioritizing populations for conservation Example Borderea pyrenaica is an endemic plant of the Pyrenees Classified as vulnerable in the IUCN Red List Only 12 populations in France Borderea pyrenaica in the French Pyrenees Photo: Marc Leclercq Segarra Moragues, J. G. and Catala n, P. 2010, Genetica

30 Problem of the vulnerable species Example The high relative abundance of vulnerable species often precludes management of all populations and individuals Vulnerable species require a cost effective management plan In France, genetic information was used to identify Relevant Genetic Conservation Units in order to make a succesful management plan for B. pyrenaica Segarra Moragues, J. G. and Catala n, P. 2010, Genetica

31 Relevant Genetic Units of B. pyrenaica Example With limited human and economical resources, all 12 populations of B. pyrenaica in France cannot be protected Genetic analyses support differentiation of the B. pyrenaica populations into different management units Five populations would allow preservation of % of the genetic variation of B. pyrenaica This approach could potentially be applied to other low extinction risk category species Segarra Moragues, J. G. and Catala n, P. 2010, Genetica

32 Predicting the genetic outcome of management or harvesting decisions? Which individuals/ populations should be used for stocking? Which individuals/ populations should be hunted? Hunting OK No stocking

33 Golden eagles in the British Isles one or two populations? Example Golden eagle (Aquila chrysaetos) Once widely distributed in the British Isles Now extinct in Ireland, largely confined to the highlands of Scotland Golden eagle at the bird of prey centre in Hagley. Photo: Alex Hay Bourke et al. 2010, Conservation Genetics

34 Past and present diversity compared by genetic methods Example Genetic diversity of the contemporary British population was compared to British and Irish museum specimen Only slight evidence for a loss of genetic variation The population persisted despite ancient bottleneck No evidence for population genetic structure Therefore, all eagles belong to the same population Bourke et al. 2010, Conservation Genetics

35 Safeguarding one population and habitat Example The golden eagles of the British Isles should be considered a single population unit the extinct Irish population was not differentiated from the British one Individuals from the British population are suitable for the Irish reintroduction effort The main objective of conservation measures: Increasing population sizes by safeguarding of individuals Habitat management Bourke et al. 2010, Conservation Genetics

36 Are populations diverse enough to survive in the future?

37 Seagrasses: genetic diversity and survival in the changing world? Example Seagrasses are an ecologically successful polyphyletic group of marine angiosperms Seagrasses provide habitat for fishes and invertebrates and play an important role in nutrient cycling and sediment stabilization Zostera marina is the key species of seagrass meadows worldwide Segrass medow in the Baltic Sea. Photo: Metsähallitus 2008 Reusch et al. 2005, PNAS, Procaccini et al. 2007, Journal of Experimental Marine Biology and Ecology

38 Promoting ecosystem resiliance Example In 2003, an extreme heat wave hit the southwestern Baltic Seagrass communities with higher genetic diversity recovered faster from the heat wave The benthic fauna also prefers genetically diverse seagrass meadows More genetic diversity in seagrass more individuals of bivalves, snails and isopods Reusch et al. 2005, PNAS, Procaccini et al. 2007, Journal of Experimental Marine Biology and Ecology

39 Biodiversity in genes preparing for the future Example Genetic diversity of key species can replace the role of species diversity in a species poor coastal ecosystem High genetic diversity can provide a buffer against extreme climatic events Genetic diversity is important for maintaining both genetic and species diversity in order to enhance ecosystem resilience Reusch et al. 2005, PNAS, Procaccini et al. 2007, Journal of Experimental Marine Biology and Ecology

40 Practical considerations DNA for genetic analysis easy to obtain Single hair, feather of hair Costs: 10 to 50 per individual 500 to per study The overall price depends on methods and numbers of populations Genetic work can be outsourced Choosing the right tools is important Contact conservation genetics researchers when planning the project Advice about samples and analyses needed to answer the questions you are interested in Reusch et al. 2005, PNAS, Procaccini et al. 2007, Journal of Experimental Marine Biology and Ecology

41 Use genetics in conservation!!!

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