The temporal, spatial and evolutionary dynamics of populations in coastal ecosystems are strongly influenced by interactions among species. Within the AG Community & Evolutionary Ecology we connect observational, experimental and molecular biological approaches to investigate the effects of these biotic interactions (e.g. predation and parasitism). We aim to identify the causes that lead to changes in population structure and species distributions and reveal general adaptive strategies of organisms confronted with changing environments. We focus on the effects of invasive species establishing new interactions and comparative ecosystem research. By using experimental approaches on various spatial scales much larger than the Wadden Sea we are analysing ecological patterns from the genetic to the community level.
Sedimentary coasts such as the European Wadden Sea are dominated by endobenthic organisms living in the bottom. Only a few species form important habitats on the sediment surface which represent oases of biodiversity and species interactions. We investigate these kind of interactions in seagrass and mussel beds as well as in reefs of introduced oysters and algal forests. The results are used to assess the functional significance of these bioengineering species and biotic habitats.
In many coastal ecosystems of the world an increasing number of introduced non-native species is observed which may strongly alter native habitats, species interactions and ecosytem functioning. We conduct an ongoing rapid assessment program on neobiota at German coasts and investigate the effects of exotic species on ecosystem level as well as their interactions with native organisms.
Currently, global warming especially causes strong effects on Arctic ecosystems. We study the consequences of increasing water temperatures on species interactions in Arctic benthic coastal communities. From these investigations we predict future scenarios for a warmer marine Arctic ecosystem and its species communites.
Parasitism is a strong selective force that can lead to rapid evolutionary dynamics since hosts and parasites engage into an arms race between resistance/tolerance and infectivity/virulence. Invasive species offer an excellent opportunity to study these coevolutionary interactions because invasive hosts often leave their parasites behind when invading a new habitat. There they are often confronted with new parasites, which resets the evolutionary clock. We study adaptations of hosts and parasites on the phenotypic and the geneotypic level using invasive Pacific oysters as a host for opportunistic Vibrio bacteria, which are in turn host to specific viruses (i.e. phages). But also parasites can be introduced and infect indigenous species as novel hosts. The invasive copepod parasites (Mytillicola intestinalis und Mytillicola orientalis) that infect blue mussels as a new host in the Wadden Sea are excellent examples not only for host-parasite interactions, but also for novel adaptations in parasite-parasite interactions. The rapid evolutionary repsonses occuring over <10 generations demonstrate the strength of parasite selection as well as the usefulness to use invasive species to investigate these questions.
Products:
Wendling, C.C., Wegner, K.M. (2015). Adaptation to enemy shifts: rapid resistance evolution to local Vibrio spp. in invasive Pacific oysters. Proc Roy Soc B:Biol Sci 282 (1804) 20142244
Feis, M.E., John, U., Lokmer, A., Luttikhuizen, P.C., and Wegner, K.M. (2018). Dual transcriptomics reveals co-evolutionary mechanisms of intestinal parasite infections in blue mussels Mytilus edulis. Mol Ecol 27(6), 1505-1519
Wegner, K.M., Piel, D., Bruto, M., John, U., Mao, Z., Alunno-Bruscia, M., et al. (2019). Molecular Targets for Coevolutionary Interactions Between Pacific Oyster Larvae and Their Sympatric Vibrios. Frontiers in Microbiology 10, 2067. doi: 10.3389/fmicb.2019.02067.
Feis, M.E., Gottschalck, L., Ruf, L.C., Theising, F., Demann, F., and Wegner, K.M. (2022). Invading the Occupied Niche: How a Parasitic Copepod of Introduced Oysters Can Expel a Congener From Native Mussels. Frontiers in Marine Science 9. doi: 10.3389/fmars.2022.915841
Piel, D., Bruto, M., Labreuche, Y., Blanquart, F., Goudenège, D., Barcia-Cruz, R., et al. (2022). Phage–host coevolution in natural populations. Nature Microbiology. doi: 10.1038/s41564-022-01157-1.
Phenotypic plasticity can buffer the detrimental effects of stressful environments, because the same genotype can produce different phenotypes depending on environmental conditions. This enables a fast repsonse to changing selction regimes. If a correlation between environment of the parents and of the offspring exists, it can be a selective advantage to transfer information about phenotypically plastic traits to the offspring. We investigate the epigenetic mechanisms of transgenerational plasticity (TGP) in the context of ocean warming and performance in a marine population of the threespine stickleback (Gasterosteus aculeatus), and could show that the thermal environment of the mother has a strong influence on the fitness of the offspring in a matching environment. Mechanistically the plastic adaptation is linked to higher efficiency of the mitochondrial energy metabolism that are directly transferred from mother to offspring via the eggs. Effects seen at the physiological and phenotypic level are underlain by changes in gene expression (transcriptomes) inherited from mothers and grandmothers, indicating an epigenetic basis to TGP.
Products:
Shama, L.N.S., Strobel, A., Mark, F.C., Wegner, K.M., 2014. Transgenerational plasticity in marine sticklebacks: maternal effects mediate impacts of a warming ocean. Functional Ecology 28, 1482-1493.
Shama, L.N., Wegner, K.M., 2014. Grandparental effects in marine sticklebacks: transgenerational plasticity across multiple generations. J Evol Biol 27, 2297-2307.
Shama, L.N.S, Mark, F.C., Strobel, A., Lokmer, A., John, U., Wegner, K.M., 2016. Transgenerational effects persist down the maternal line in marine sticklebacks: gene expression matches physiology in a warming ocean. Evolutionary Applications 9, 1096-1111.
Donelson, J.M., Salinas, S., Munday, P.L., Shama, L.N.S., 2018. Transgenerational plasticity and climate change experiments: where do we go from here? Global Change Biology 24, 13-34.
Higher organisms are not only part of ecosystems - they also represent an ecosystem for a diverse assemblage of microbes. These microbiota are important for many physiological processes of the host (e.g. development, digestion, but also defense against parasites and disease). With the help of moder sequecning technology we investigate the role of mircrobiota in various organs of oysters, mussels and fish under changing envrionmental conditions and infection by parasites. We could show that a stable, diverse microbial community in the hemolypmh can protect marine bivalves from infections, but that these communities are also vulnerable to environmental pertubations and climate change linking the envrionment to host fitness via its microbiota.
Products
Lokmer A, Wegner KM (2015) "Hemolymph microbiome of Pacific oysters in response to temperature, temperature stress and infection", ISME Journal 9:670-682
Scanes, E., Parker, L.M., Seymour, J.R., Siboni, N., King, W.L., Danckert, N.P., et al. (2021). Climate change alters the haemolymph microbiome of oysters. Mar Pollut Bull 164, 111991. doi: 10.1016/j.marpolbul.2021.111991.
Paillard, C., Gueguen, Y., Wegner, K.M., Bass, D., Pallavicini, A., Vezzulli, L., et al. (2021). Recent advances in bivalve-microbiota interactions for disease prevention in aquaculture. Curr Opin Biotechnol 73, 225-232. doi: 10.1016/j.copbio.2021.07.026.
