Thorsten BH Reusch

• Professor
• Head of Department at GEOMAR Helmholtz Centre for Ocean Research Kiel

Ctenophora are basal marine metazoans, the sister group of all other animals. Mnemiopsis leidyi is one of the most successful invasive species worldwide with intense ecological and evolutionary research interest. Here, we generated a chromosome-level genome assembly of M. leidyi with a focus on its immune gene repertoire. The genome was 247.97 Mb,...

Climate change and biodiversity loss are global challenges that need to be addressed through a combination of measures. However, political and societal action has not yet kept pace with the urgency of these challenges. Marine carbon sequestering habitats ("Blue Carbon habitats") are globally recognized for their role in climate change mitigation an...

With the amendment to the German Climate Change Act in 2021, the Federal Government of Germany has set the target to become greenhouse gas neutral by 2045. Reaching this ambitious target requires multisectoral efforts, which in turn calls for interdisciplinary collaboration: the Net-Zero-2050 project of the Helmholtz Climate Initiative serves as an...

Community trait variability can arise from the species, genotypic, or individual plastic level. Trait changes on these levels can occur simultaneously, interact, and potentially translate to community functioning. Thus, they are crucial to realistically predict community functional changes. Using a phytoplankton model community comprising a diatom...

Duplicated genes provide the opportunity for evolutionary novelty and adaptive divergence. In many cases, having more gene copies increases gene expression, which might facilitate adaptation to stressful or novel environments. Conversely, overexpression or misexpression of duplicated genes can be detrimental and subject to negative selection. In th...

Humans have become one of the greatest evolutionary forces, and their perturbations are expected to elicit strong evolutionary responses. Accordingly, during (size) selective overharvesting of wild populations, marked phenotypic changes have been documented, while the evolutionary basis is often unresolved. Time-series collections combined with gen...

Plant cells harbor two membrane-bound organelles containing their own genetic material –plastids and mitochondria. Although the two organelles co-exist and co-evolve within the same plant cells, they differ in genome copy number, intracellular organization, and mode of segregation. How these attributes affect the time to fixation, or conversely, lo...

Age and longevity are key parameters for demography and life-history evolution of organisms. In clonal species, a widespread life history among animals, plants, macroalgae and fungi, the sexually produced offspring (genet) grows indeterminately by producing iterative modules, or ramets, and so obscure their age. Here we present a novel molecular cl...

Due to climate change the pathogenic bacterium Vibrio vulnificus proliferates along brackish coastlines, posing risks to public health, tourism, and aquaculture. Here we investigated previously suggested regulation measures to reduce the prevalence of V. vulnificus, locally through seagrass and regionally through the reduction of eutrophication and...

To reach their net‐zero targets, countries will have to compensate hard‐to‐abate CO2 emissions through carbon dioxide removal (CDR). Yet, current assessments rarely include socio‐cultural or institutional aspects or fail to contextualize CDR options for implementation. Here we present a context‐specific feasibility assessment of CDR options for the...

The simulation of deep‐sea conditions in laboratories is technically challenging but necessary for experiments that aim at a deeper understanding of physiological mechanisms or host‐symbiont interactions of deep‐sea organisms. In a proof‐of‐concept study, we designed a recirculating system for long‐term culture (>2 yr) of deep‐sea mussels Gigantida...

Metaorganism research contributes substantially to our understanding of the interaction between microbes and their hosts, as well as their co-evolution. Most research is currently focused on the bacterial community, while archaea often remain at the sidelines of metaorganism-related research. Here, we describe the archaeome of a total of eleven cla...

We present chromosome-level genome assemblies from representative species of three independently evolved seagrass lineages: Posidonia oceanica, Cymodocea nodosa, Thalassia testudinum and Zostera marina. We also include a draft genome of Potamogeton acutifolius, belonging to a freshwater sister lineage to Zosteraceae. All seagrass species share an a...

Ctenophora are basal marine metazoans, the sister group of all other animals. Mnemiopsis leidyi is one of the most successful invasive species worldwide with intense ecological and evolutionary research interest. Here, we generated a chromosome-level genome assembly of M. leidyi with a focus on its immune gene repertoire. The genome was 247.97 Mb,...

Seagrass meadows have a disproportionally high organic carbon (Corg) storage potential within their sediments and thus can play a role in climate change mitigation via their conservation and restoration. However, high spatial heterogeneity is observed in Corg, with wide differences seen globally, regionally, and even locally (within a seagrass mead...

To reach their net-zero targets, countries will have to compensate hard-to-abate CO emissions through carbon dioxide removal (CDR). Yet, current assessments rarely include socio-cultural or institutional aspects or fail to contextualize CDR options for implementation. Here we present a context-specific feasibility assessment of CDR options for the...

Plant cells harbor two membrane-bound organelles containing their own genetic material – plastids and mitochondria. Although the two organelles co-exist and co-evolve within the same plant cells, they differ in genome copy number, intracellular organization, and mode of inheritance. How these attributes determine the time to fixation, or conversely...

Age and longevity are key parameters for demography and life-history evolution of organisms. In clonal species, a widespread life history among animals, plants, algae and fungi, the sexually produced offspring (the genet) grows indeterminately by producing iterative modules, or ramets. The age of large genets often remains elusive, while estimates...

Over recent years the number of studies on the assisted evolution of corals has increased dramatically, with most able to demonstrate enhanced tolerance of the coral holobiont (that is, the cnidarian host, the photosynthetic symbionts and other microbes), (Drury et al., 2022 and more). Yet significant knowledge gaps exist in our fundamental underst...

Molecular clocks are the basis for dating the divergence between lineages over macroevolutionary timescales (~105 to 108 years). However, classical DNA-based clocks tick too slowly to inform us about the recent past. Here, we demonstrate that stochastic DNA methylation changes at a subset of cytosines in plant genomes display a clocklike behavior....

Mitochondrial genomes (mitogenomes) of flowering plants are composed of multiple chromosomes. Recombination within and between the mitochondrial chromosomes may generate diverse DNA molecules termed isoforms. The isoform copy number and composition can be dynamic within and among individual plants due to uneven replication and homologous recombinat...

Background: The widespread Indo-Pacific coral species Pocillopora acuta Lamarck, 1816 displays varying levels of asexual versus sexual reproduction, with strong repercussions on genetic diversity, connectivity and genetic structuring within and among populations. For many geographic regions, baseline information on genetic diversity is still lacki...

Genome sequencing enables answering fundamental questions about the genetic basis of adaptation, population structure and epigenetic mechanisms. Yet, we usually need a suitable reference genome for mapping population-level resequencing data. In some model systems, multiple reference genomes are available, giving the challenging task of determining...

Currents are unique drivers of oceanic phylogeography and thus determine the distribution of marine coastal species, along with past glaciations and sea-level changes. Here we reconstruct the worldwide colonization history of eelgrass (Zostera marina L.), the most widely distributed marine flowering plant or seagrass from its origin in the Northwes...

Mitochondrial genomes (mitogenomes) of flowering plants are comprised of multiple chromosomes. Their copy number and composition can be dynamic within and among individual plants due to uneven replication of the chromosomes and homologous recombination. Nonetheless, despite their functional importance, the level of mitogenome conservation within sp...

The Arctic Ocean is home to a unique fauna that is disproportionately affected by global warming but that remains under‐studied. Due to their high mobility and responsiveness to global warming, cephalopods and fishes are good indicators of the reshuffling of Arctic communities. Here, we established a nekton biodiversity baseline for the Fram Strait...

Molecular clocks are the basis for dating the divergence between lineages over macro-evolutionary timescales (~10^5-10^8 years). However, classical DNA-based clocks tick too slowly to inform us about the recent past. Here, we demonstrate that stochastic DNA methylation changes at a subset of cytosines in plant genomes possess a clock-like behavior....

Seagrasses comprise the only submerged marine angiosperms, a feat of adaptation from three independent freshwater lineages within the Alismatales. These three parallel lineages offer the unique opportunity to study convergent versus lineage-specific adaptation to a fully marine lifestyle. Here, we present chromosome-level genome assemblies from a r...

Most fish stocks in the European Union (EU) are still being overfished. One recent measure of the EU common fisheries policy to curb overfishing is the introduction of landing obligations that are meant to reduce discards, but the success of landing obligations is controversial, as discards still take place. In the German Western Baltic Sea , disca...

The economics of biodiversity is gaining traction and with it the economic valuation of ecosystem services (ESS). Most current developments neglect microbial diversity, although microbial communities provide ecosystem services of great importance. Here we argue that microbial biodiversity (hereafter microbiodiversity) translates into considerable e...

Genome-level sequencing enables us to ask fundamental questions about the genetic basis of adaptation, population structure, and epigenetic mechanisms, but usually requires a suitable reference genome for mapping population-level re-sequencing data. In some model systems, multiple reference genomes are available, giving researchers the challenging...

Currents are unique drivers of oceanic phylogeography and so determine the distribution of marine coastal species, along with past glaciations and sea level changes. Here, we reconstruct the worldwide colonization history of eelgrass (Zostera marina L.), the most widely distributed marine flowering plant or seagrass from its origin in the Northwest...

Communities and their functioning are jointly shaped by ecological and evolutionary processes that manifest in diversity shifts of their component species and genotypes. How both processes contribute to community functional change over time is rarely studied. We here repeatedly quantified eco‐evolutionary contributions to CO2‐driven total abundance...

Seagrass meadows have a disproportionally high organic carbon (Corg) storage potential within their sediments and thus can play a role in climate change mitigation via their conservation and restoration. However, high spatial heterogeneity is observed in Corg, with wide differences seen globally, regionally, and even locally (within a seagrass mead...

Significance A central goal in invasion genomics is to identify and determine the mechanisms that underlie the successful colonization, establishment, and subsequent range expansion of invasive populations of nonindigenous species. Using a whole-genome approach, we evaluate the importance of genetic diversity for the successful establishment of non...

The deep sea is among the largest, most biologically diverse, yet least-explored ecosystems on Earth. Baseline information on deep-sea biodiversity is crucial for understanding ecosystem functioning and for detecting community changes. Here, we established a baseline of cephalopod community composition and distribution off Cabo Verde, an archipelag...

Balancing selection describes evolutionary processes that maintain genetic diversity. To date, the number of impacted genes and underlying biological functions remain elusive. Using 60 three-spined stickleback genomes (Gasterosteus aculeatus) from five recently diverged lake-river population-pairs, we performed genome-wide scans across two levels o...

Balancing selection describes evolutionary processes that maintain genetic diversity. To date, the number of impacted genes and underlying biological functions remain elusive. Using 60 three-spined stickleback genomes ( Gasterosteus aculeatus ) from five recently diverged lake-river population-pairs, we performed genome-wide scans across two levels...

Shifts in microbial communities and their functioning in response to environmental change result from contemporary interspecific and intraspecific diversity changes. Interspecific changes are driven by ecological shifts in species composition, while intraspecific changes are here assumed to be dominated by evolutionary shifts in genotype frequency....

Seagrasses, a polyphyletic group of about 60 marine angiosperm species, are the foundation of diverse and functionally important marine habitats along sheltered sedimentary coasts. As a novel ecological function with high societal relevance, a role of the seagrass leaf canopy for reducing potentially harmful bacteria has recently been hypothesized...

Somatic genetic variation (SoGV) may play a consequential yet underappreciated role in long-lived, modular species among plants, animals, and fungi. Recent genomic data identified two levels of genetic heterogeneity, between cell lines and between modules, that are subject to multilevel selection. Because SoGV can transfer into gametes when germlin...

Carbon sequestration and storage in mangroves, salt marshes and seagrass meadows is an essential coastal ‘blue carbon’ ecosystem service for climate change mitigation. Here we offer a comprehensive, global and spatially explicit economic assessment of carbon sequestration and storage in three coastal ecosystem types at the global and national level...

Background: Seagrasses (Alismatales) are the only fully marine angiosperms. Zostera marina (eelgrass) plays a crucial role in the functioning of coastal marine ecosystems and global carbon sequestration. It is the most widely studied seagrass and has become a marine model system for exploring adaptation under rapid climate change. The original draf...

Coastal oceans are particularly affected by rapid and extreme environmental changes with dramatic consequences for the entire ecosystem. Seagrasses are key ecosystem engineers or foundation species supporting diverse and highly productive ecosystems along the coastline that are particularly susceptible to fast environmental changes. In this context...

Seagrasses, a polyphyletic group of about 60 marine angiosperm species, are the foundation of diverse and functionally important marine habitats along sheltered sedimentary coasts. As a novel ecological function with high societal relevance, a role of the leaf canopy for reducing potentially harmful bacteria has recently been hypothesized. Accordin...

Fundamental insight on predator-prey dynamics in the deep sea is hampered by a lack of combined data on hunting behavior and prey spectra. Deep-sea niche segregation may evolve when predators target specific prey communities, but this hypothesis remains untested. We combined environmental DNA (eDNA) metabarcoding with biologging to assess cephalopo...

Cephalopods are pivotal components of marine food webs, but biodiversity studies are hampered by challenges to sample these agile marine molluscs. Metabarcoding of environmental DNA (eDNA) is a potentially powerful technique to study oceanic cephalopod biodiversity and distribution but has not been applied thus far. We present a novel universal pri...

German report about a three year mapping of Mytilus edulis populations along the coast of Schleswig-Holstein, Germany, on behalf of the State Agency for Agriculture, Environment and rural Areas Schleswig-Holstein (LLUR). Abschlussbericht zum Forschungsprojekt im Auftrag des Landesamtes für Landwirtschaft, Umwelt und ländliche Räume des Landes Sch...

All multicellular organisms are associated with a diverse and specific community of microorganisms; consequently, the microbiome is of fundamental importance for health and fitness of the multicellular host. However, studies on microbiome contribution to host fitness are in their infancy, in particular, for less well-established hosts such as the m...

Seagrass meadows, algal forests and mussel beds are widely regarded as foundation species that support communities providing valuable ecosystem services in many coastal regions; however, quantitative evidence of the relationship is scarce. Using the Baltic Sea as a case study, a region of significant socio-economic importance in the northern hemisp...

The cover image is based on the Original Article Cultivable microbiota associated with Aurelia aurita and Mnemiopsis leidyi by Cornelia Jaspers et al., https://doi.org/10.1002/mbo3.1094.

For many coastal areas including the Baltic Sea, ambitious nutrient abatement goals have been set to curb eutrophication, but benefits of such measures were normally not studied in light of anticipated climate change. To project the likely responses of nutrient abatement on eelgrass (Zostera marina), we coupled a species distribution model with a b...

How ecological and evolutionary processes interact and together determine species and community responses to climate change is poorly understood. We studied long-term dynamics (over approximately 200 asexual generations) in two phytoplankton species, a coccolithophore (Emiliania huxleyi), and a diatom (Chaetoceros affinis), to increased CO 2 growin...

The associated microbiota of marine invertebrates plays an important role to the host in relation to fitness, health, and homeostasis. Cooperative and competitive interactions between bacteria, due to release of, for example, antibacterial substances and quorum sensing (QS)/quorum quenching (QQ) molecules, ultimately affect the establishment and dy...

All multicellular organisms are genetic mosaics owing to somatic mutations. The accumulation of somatic genetic variation in clonal species undergoing asexual (or clonal) reproduction may lead to phenotypic heterogeneity among autonomous modules (termed ramets). However, the abundance and dynamics of somatic genetic variation under clonal reproduct...

Protecting the ocean has become a major goal of international policy as human activities increasingly endanger the integrity of the ocean ecosystem, often summarized as “ocean health.” By and large, efforts to protect the ocean have failed because, among other things, (1) the underlying socio-ecological pathways have not been properly considered, a...

The translocation of non-indigenous species (NIS) around the world, especially in marine systems, is increasingly being recognized as a matter of concern. Species translocations have been shown to lead to wide ranging changes in food web structure and functioning. In addition to the direct effects of NIS, they could facilitate the accumulation or t...

Elevated environmental carbon dioxide (pCO2) levels have been found to cause organ damage in the early life stages of different commercial fish species, including Atlantic cod (Gadus morhua). To illuminate the underlying mechanisms causing pathologies in the intestines, the kidney, the pancreas and the liver in response to elevated pCO2, we examine...

A fundamental problem for the evolution of pregnancy, the most specialized form of parental investment among vertebrates, is the rejection of the nonself-embryo. Mammals achieve immunological tolerance by down-regulating both major histocompatibility complex pathways (MHC I and II). Although pregnancy has evolved multiple times independently among...

How ecological and evolutionary processes interact and together determine species and community responses to climate change is poorly understood. We studied long-term dynamics (over approximately 200 asexual generations) in two phytoplankton species, a coccolithophore (Emiliania huxleyi) and a diatom (Chaetoceros affinis), to increased CO 2 growing...

Epigenetic inheritance has been proposed to contribute to adaptation and acclimation via two information channels: (i) inducible epigenetic marks that enable transgenerational plasticity and (ii) noninducible epigenetic marks resulting from random epimutations shaped by selection. We studied both postulated channels by sequencing methylomes and gen...

All animals are associated with microorganisms; hence, host-microbe interactions are of fundamental importance for life on earth. However, we know little about the molecular basis of these interactions. Therefore, we studied the deep-sea Riftia pachyptila symbiosis, a model association in which the tubeworm host is associated with only one phylotyp...

Ocean acidification (OA), a direct consequence of increasing atmospheric CO2 concentration dissolving in ocean waters, is impacting many fish species. Little is known about the molecular mechanisms underlying the observed physiological impacts in fish. We used RNAseq to characterize the transcriptome of 3 different larval stages of Atlantic cod (Ga...

Cells in multicellular organisms are genetically heterogeneous owing to somatic mutations. The accumulation of somatic genetic variation in species undergoing asexual (or clonal) reproduction (termed modular species) may lead to phenotypic heterogeneity among modules. However, abundance and dynamics of somatic genetic variation under clonal growth,...

The translocation of non-indigenous species around the world, especially in marine systems, is a matter of concern for biodiversity conservation and ecosystem functioning. While specific physical and ecological traits are often recognized to influence the success in the establishment of non-indigenous species, the impact of the associated microbiot...

Background:The interplay between hosts and their associated microbiome is now recognized as a fundamental basis of the ecology, evolution, and development of both players. These interdependencies inspired a new view of multicellular organisms as “metaorganisms.” The goal of the Collaborative Research Center “Origin and Function of Metaorganisms” is...

Repeated and independent emergence of trait divergence that matches habitat differences is a sign of parallel evolution by natural selection. Yet, the molecular underpinnings that are targeted by adaptive evolution often remain elusive. We investigate this question by combining genome-wide analyses of copy number variants (CNVs), single nucleotide...

Atlantic cod (Gadus morhua) is a species of great ecological and economical importance in the Baltic Sea. Here, two genetically differentiated stocks, the western and the eastern Baltic cod, display substantial mechanical mixing, hampering our understanding of cod ecology and impeding stock assessments and management. Based on whole-genome re-seque...

The deep-sea tubeworm Riftia pachyptila lacks a digestive system, but completely relies on bacterial endosymbionts for nutrition. Although the symbiont has been studied in detail on the molecular level, such analyses were unavailable for the animal host, because sequence information was lacking. To identify host-symbiont interaction mechanisms, we...

Marine infectious diseases can have large-scale impacts when they affect foundation species such as seagrasses and corals. Interactions between host and disease, in turn, may be modulated by multiple perturbations associated with global change. A case in point is the infection of the foundation species Zostera marina (eelgrass) with endophytic net...

Human-induced climate change such as ocean warming and acidification, threatens marine ecosystems and associated fisheries. In the Western Baltic cod stock socio-ecological links are particularly important, with many relying on cod for their livelihoods. A series of recent experiments revealed that cod populations are negatively affected by climate...

The associated microbiota of marine invertebrates plays an important role to the host in relation to fitness, health and homeostasis of the metaorganism. As one key chemically-mediated interaction, Quorum sensing (QS) and interference with QS among colonizing bacteria ultimately affects the establishment and dynamics of the microbial community on t...

The translocation of non-indigenous species around the world, especially in marine systems, is a matter of concern for biodiversity conservation and ecosystem functioning. While specific traits are often recognized to influence establishment success of non-indigenous species, the impact of the associated microbial community for the fitness, perform...