'Good genes' and population management
In general, any captive or supportive breeding should minimize the variance in reproductive success that is not linked to viability traits. However, minimizing reproductive skew might not be the best conservation strategy if potential mates differ in their heritable viabilty. If a reproductive skew can be positively linked to heritable viability, there might be a way to optimize this skew with respect to the long-term survival prospects of a population. We are working on the optimal compromise between promoting genetic variation versus promoting heritable viability in small populations.
Examples: Wedekind (Conserv Biol 2002); Wedekind et al. (Proc R Soc B 2008); Jacob et al. (Anim Behav 2009); Jacob et al. (Mol Ecol 2010); Clark et al. (PLoS ONE 2013)
Life-history and population management
Life-history theory predicts that parents weigh their investment in each individual offspring according to the fitness return of the offspring. Parents may therefore alter their investment in particular breeding attempts according to the likelihood of its success and to the perceived attractiveness of their mates. This kind of trade-off calculations may not always work for small populations in their changed (and possibly protected) environment. We study plasticity of life-history traits that could be taken into account in population management.
Examples: Wedekind et al. (Biol Conserv 2007); Rudolfsen et al. (Behav Ecol Sociobiol 2008); Burger et al. (in prep.)
Evolutionary consequences of fishing and fish stocking
By fishing and by supplementing natural fish populations with hatchery-produced larvae and juveniles, humans are likely to select against certain traits and promote others. We study the evolutionary consequence of fishing and stocking in the context of current habitat changes.
Examples: Nusslé et al. (Evol Appl 2009; Evol Ecol 2011); Stelkens et al. (Mol Ecol 2012); Escher et al. (Volkswirtschaftsdirektion des Kantons Bern 2013, 186 pp.)
Sex ratio management
Manipulating population sex ratio is often possible, either through non-invasive methods like changing sex-determining ecological or social factors, or through more invasive methods such as hormone treatment of embryos. There are a number of scenarios in which manipulations of sex ratios may be an option to promote population growth, at least over a certain time span. The most obvious ones are:
(i) Very small or rapidly declining population sizes call for emergency actions like, for example, captive breeding programs. The increase of population size to above critical levels is one of the first aims of these programs. When population growth is restricted by the availability of oocytes, manipulating sex ratio towards more females might be desirable under some circumstances.
(ii) The sex ratio in small populations is sometimes skewed for a variety of reasons. Manipulating the sex ratio of the coming generations towards less skewed ratios or towards different types of skews might be one of the aims of conservation efforts, especially if the present skew is male biased.
Examples: Wedekind (Anim Conserv 2002); Cotton & Wedekind (Conserv Biol 2009); Stelkens & Wedekind (Mol Ecol 2010); Pompini et al. (J Fish Biol 2013); Wedekind et al. (Conserv Biol 2013)
Organic pollution and pathogens in the aquatic environment
Organic pollution, especially the increased availability of nutrients to microbial symbionts, enhances the mortality of many water-living organisms. We experimentally study various pathways that may link organic pollution, pathogen growth, and the viability of fish.
Examples: Wedekind et al. (Ecology 2010); Jacob et al. (Mol Ecol 2010); Clark, Wilkins & Wedekind (Mol Ecol 2013); Clark et al. (Funct Ecol 2014)
Chemical substances that could become exotoxicologically relevant have to pass a number of tests before being marketed. In Switzerland and many other countries, these tests are largely following the OECD guidelines (www.oecd.org). We have listed problems with some of these guidelines, and we are testing alternative methods that have the potential to solve some of these problems and even reduce the evaluation costs for the producer and importer of the substances. We are also testing the evolutionary potential of natural populations to adapt to common pollutants.
Examples: Wedekind, von Siebenthal & Gingold (Environ Pollut 2007); Wedekind (BMC Biol 2014); Brazzola et al. (submitted); Luca et al. (in prep.)
Alleviating the tragedy of the commons
Game theory can to a large extent explain how cooperation evolves in conflict situations. Many conservation problems are the consequence of conflicts, e.g. of cooperation problems between different stakeholders. We use modelling and experimental games to better understand cooperative solutions to social conflicts.
Examples: Wedekind & Milinski (Science 2000); Wedekind & Braithwaite (Curr Biol 2002); dos Santos, Rankin & Wedekind (Proc R Soc B 2011; Evolution 2013)