Miriam Weber

HYDRA Marine Sciences GmbH

Biodegradable polymers are an important part of the solution toolbox to achieve circularity in the plastic economy and overcome negative impacts of a linear plastic economy. Biodegradable polymers need to excel not only on a mechanical performance level in the application to fulfill their function during the use phase but also on a biodegradation p...

Ongoing efforts focus on quantifying plastic pollution and describing and estimating the related magnitude of exposure and impacts on human and environmental health. Data gathered during such work usually follows a receptor perspective. However, Life Cycle Assessment (LCA) represents an emitter perspective. This study examines existing data gatheri...

Significance Seagrass meadows colonize shallow coastlines around the world and represent sites of intense carbon cycling. Due to their capacity to produce methane, seagrass ecosystems constitute net sources of methane to the atmosphere. Here, we identify key processes and microorganisms responsible for methane formation in seagrass-covered sediment...

Symbiotic N2-fixing microorganisms have a crucial role in the assimilation of nitrogen by eukaryotes in nitrogen-limited environments1–3. Particularly among land plants, N2-fixing symbionts occur in a variety of distantly related plant lineages and often involve an intimate association between host and symbiont2,4. Descriptions of such intimate sym...

The seafloor is considered the major sink for plastic debris in the world's oceans. Biodegradable polymers are available on the market as a substitute for conventional plastic and could potentially end up in the same environment. To gain more insight into the effects of different sediments on the degradation rate of biodegradable plastic we perform...

Plastic particles in the ocean are typically covered with microbial biofilms, but it remains unclear whether distinct microbial communities colonize different polymer types. In this study, we analyzed microbial communities forming biofilms on floating microplastics in a bay of the island of Elba in the Mediterranean Sea. Raman spectroscopy revealed...

The performance of the biodegradable plastic materials polyhydroxyalkanoate (PHA), polybutylene sebacate (PBSe) and polybutylene sebacate co-terephthalate (PBSeT), and of polyethylene (LDPE) was assessed under marine environmental conditions in a three-tier approach. Biodegradation lab tests (20 °C) were complemented by mesocosm tests (20 °C) with...

Submarine methane emissions in the Tuscan Archipelago have been studied since the 1960s, both for economic and research purposes. Offshore gas seepage is mainly concentrated southward and westward of Elba island, along N-S faults related to recent extensional activity in the Tuscan shelf and N-S trending positive magnetic anomalies, which have been...

The pollution of the natural environment, especially the world’s oceans, with conventional plastic is of major concern. Biodegradable plastics are an emerging market bringing along potential chances and risks. The fate of these materials in the environment and their possible effects on organisms and ecosystems has rarely been studied systematically...

We report primary production and respiration of Posidonia oceanica meadows determined with the non-invasive aquatic eddy covariance technique. Oxygen fluxes were measured in late spring at an open-water meadow (300 m from shore), at a nearshore meadow (60 m from shore), and at an adjacent sand bed. Despite the oligotrophic environment, the meadows...

The pollution of the natural environment, especially the world's oceans, with conventional plastic is of major concern. Biodegradable plastics are an emerging market bringing along potential chances and risks. The fate of these materials in the environment and their possible effects on organisms and ecosystems has rarely been studied systematically...

We performed first experiments to evaluate the potential of photoluminescence spectroscopy to detect microplastics using a 405 nm laser diode for sample excitation. A set of nine bulk plastic samples and nine samples of natural materials typically found in the marine environment were examined and compared. The plastic and non-plastic materials coul...

In many seagrass sediments, lucinid bivalves and their sulfur-oxidizing symbionts are thought to underpin key ecosystem functions, but little is known about their role in nutrient cycles, particularly nitrogen. We used natural stable isotopes, elemental analyses, and stable isotope probing to study the ecological stoichiometry of a lucinid symbiosi...

In many seagrass sediments, lucinid bivalves and their sulfur-oxidizing symbionts are thought to underpin key ecosystem functions, but little is known about their role in nutrient cycles, particularly nitrogen. We used natural stable isotopes, elemental analyses, and stable isotope probing to study the ecological stoichiometry of a lucinid symbiosi...

Release of abiotic methane from marine seeps into the atmosphere is a major source of this potent greenhouse gas. Methanotrophic microorganisms in methane seeps use methane as carbon and energy source, thus significantly mitigating global methane emissions. Here we investigated microbial methane oxidation at the sediment‐water interface of a shallo...

In many seagrass sediments, lucinid bivalves and their sulfur-oxidizing symbionts are thought to underpin key ecosystem functions, but little is known about their role in nutrient cycles, particularly nitrogen. We used natural stable isotopes, elemental analyses, and stable isotope probing to study the ecological stoichiometry of a lucinid symbiosi...

Seepage of methane (CH4) on land and in the sea may significantly affect Earth’s biogeochemical cycles. However processes of CH4 generation and consumption, both abiotic and microbial, are not always clear. We provide new geochemical and isotope data to evaluate if a recently discovered CH4 seepage from the shallow seafloor close to the Island of E...

Porewater chemistry and isotope compositions (δ13CDIC and δ18OH2O) at gas emission and reference spots 1–3 (locations indicated on map; Fig 1). Samples were taken in 2011. (XLSX)

Additional sulphide and DIC concentrations and δ13CDIC-values of porewater samples taken in 2009 and measured in 2010. (XLSX)

In this Article, the completeness and number of contigs for draft genomes from two individuals of Laxus oneistus are incorrect in the main text, although the correct information is included in Table 1. The original and corrected versions of the relevant sentence are shown in the correction notice.

We investigated light, water velocity, and CO2 as drivers of primary production in Mediterranean seagrass (Posidonia oceanica) meadows and neighboring bare sands using the aquatic eddy covariance technique. Study locations included an open-water meadow and a nearshore meadow, the nearshore meadow being exposed to greater hydrodynamic exchange. A th...

Subseabed CO2 storage is considered a future climate change mitigation technology. We investigated the ecological consequences of CO2 leakage for a marine benthic ecosystem. For the first time with a multidisciplinary integrated study, we tested hypotheses derived from a meta-analysis of previous experimental and in situ high-CO2 impact studies. Fo...

The increasing amount of plastic littered into the sea may provide a new substratum for benthic organisms. These marine fouling communities on plastic have not received much scientific attention. We present, to our knowledge, the first comprehensive analysis of their macroscopic community composition, their primary production and the polymer degrad...

The unprecedented rate of CO2 increase in our atmosphere and subsequent ocean acidification (OA) threatens coastal ecosystems. To forecast the functioning of coastal seagrass ecosystems in acidified oceans, more knowledge on the long-term adaptive capacities of seagrass species and their epibionts is needed. Therefore we studied morphological chara...

pH profiles in close vicinity of the Posidonia oceanica leaves (originating from CO2-R) when subjected to seawater acidification. pHT profiles (averages ± s.d.) were measured on the convex side of P. oceanica leaves at seawater pH 7.6 (triangle), 6.6 (square) and 5.5 (circle). Measurements started from the leaf surface (distance = 0 μm), and were p...

Community structures of P. oceanica epibionts. Non-metric multidimensional scaling (NMDS) ordination plots representing the community compositions of sessile epibiont taxa (A, 2D stress: 0.21), meiofauna at higer taxon level (B, 2D stress: 0.06), copepod species (C, 2D stress: 0.09) and nematode species (D, 2D stress: 0.12). The numbers provided to...

Relative abundance of meiofauna, copepod, nematode and sessile epibiont taxa on the Posidonia oceanica rhizomes and leaves and in the vent site and reference site. Meiofauna, copepod and nematode data are based on abundances, sessile epibiont data are based on presence/absence data. (DOCX)

Oxygenic and anoxygenic photosynthesis were studied with microsensors in microbial mats found at 9-10 m depth in anoxic and sulfidic water in Little Salt Spring (Florida, USA). The lake sediments were covered with a 1-2 mm thick red mat dominated by filamentous Cyanobacteria, below which Green Sulfur Bacteria (GSB, Chlorobiaceae) were highly abunda...

Open-Bio was a research project funded by the European Commission within the 7th Framework Programme for Research and Technological Development FP7. The goal was to investigate how bio-based products can be integrated into the market using standardisation, labelling and procurement. One part of the project (WP5: In-situ biodegradation) was focussed...

Chemosynthetic symbioses are partnerships between invertebrate animals and chemosynthetic bacteria. The latter are the primary producers, providing most of the organic carbon needed for the animal host's nutrition. We sequenced genomes of the chemosynthetic symbionts from the lucinid bivalve Loripes lucinalis and the stilbonematid nematode Laxus on...

Seagrass meadows of Posidonia oceanica represent hotspots of productivity in the oligotrophic Mediterranean Sea. The lack of dissolved inorganic nitrogen in the seawater has led to the suggestion that the N-demand of these meadows might be in part supported by microbial dinitrogen (N2) fixation. However, currently there are no direct N2 fixation me...

The anaerobic oxidation of methane (AOM) is a key biogeochemical process regulating methane emission from marine sediments into the hydrosphere. AOM is largely mediated by consortia of anaerobic methanotrophic archaea (ANME) and sulfate-reducing bacteria (SRB), and has mainly been investigated in deep-sea sediments. Here we studied methane seepage...

The anaerobic oxidation of methane (AOM) is a key biogeochemical process regulating methane emission from marine sediments into the hydrosphere. AOM is largely mediated by consortia of anaerobic methanotrophic archaea (ANME) and sulfate-reducing bacteria (SRB), and has mainly been investigated in deep-sea sediments. Here we studied methane seepage...

The Open-Bio project and background of this deliverable: Open-Bio was a research project funded by the European Commission within FP7. The goal was to investigate how bio-based products can be integrated into the market, using standardisation, labelling and procurement. One part of the project was research on the biodegradability of bio-based poly...

The production of biodegradable plastic is increasing. Given the augmented littering of these products an increasing input into the sea is expected. Previous laboratory experiments have shown that degradation of plastic starts within days to weeks. Little is known about the early composition and activity of biofilms found on biodegradable and conve...

Benthic cyanobacterial mats (BCMs) are impacting coral reefs worldwide. However, the factors and mechanisms driving their proliferation are unclear. We conducted a multi-year survey around the Caribbean island of Curaçao, which revealed highest BCM abundance on sheltered reefs close to urbanised areas. Reefs with high BCM abundance were also charac...

Benthic cyanobacterial mats (BCMs) are impacting coral reefs worldwide. However, the factors and mechanisms driving their proliferation are unclear. We conducted a multi-year survey around the Caribbean island of Curaçao, which revealed highest BCM abundance on sheltered reefs close to urbanised areas. Reefs with high BCM abundance were also charac...

Abundant microbial mats, recently discovered in underwater freshwater springs in the hypersaline Dead Sea, are mostly dominated by sulfur oxidizing bacteria. We investigated the source of sulfide and the activity of these communities. Isotopic analysis of sulfide and sulfate in the spring water showed a fractionation of 39-50 ‰ indicative of active...

Cyanobacteria and diatom mats are ubiquitous in hypersaline environments but have never been observed in the Dead Sea, one of the most hypersaline lakes on Earth. Here we report the discovery of phototrophic microbial mats at underwater freshwater seeps in the Dead Sea. These mats are either dominated by diatoms or unicellular cyanobacteria and are...

Geophys Res Abs 16, #9431

Vestimentiferan tubeworms colonize hydrothermal vents and cold seeps worldwide. They lack a digestive system and gain nutrition from endosymbiotic sulfur-oxidizing bacteria. It is currently assumed that vestimentiferan tubeworms harbor only a single endosymbiont type. A few studies found indications for additional symbionts but conclusive evidence...

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##MIMARKS:3.0-Data-START## investigation_type :: mimarks-survey assembly :: Sequencher 4.6 chimera_check :: Bellerophon; 2004 collection_date :: 2009-07-13 depth :: 545 m biome :: marine biome feature :: hydrothermal vent material :: ocean water geo_loc_name :: Italy; Mediterranean Sea; Southern Tyrrhenian Sea lat_lon :: 39.29694 N 14.38583 E lib_c...

##MIMARKS:3.0-Data-START## investigation_type :: mimarks-survey chimera_check :: Bellerophon; 2004 collection_date :: 2009-07-13 depth :: 545 m biome :: marine biome feature :: hydrothermal vent material :: ocean water geo_loc_name :: Italy; Mediterranean Sea; Southern Tyrrhenian Sea lat_lon :: 39.29694 N 14.38583 E lib_const_meth :: vector lib_rea...

##MIMARKS:3.0-Data-START## investigation_type :: mimarks-survey chimera_check :: Bellerophon; 2004 collection_date :: 2009-07-13 depth :: 545 m biome :: marine biome feature :: hydrothermal vent material :: ocean water geo_loc_name :: Italy; Mediterranean Sea; Southern Tyrrhenian Sea lat_lon :: 39.29694 N 14.38583 E lib_const_meth :: vector lib_rea...

##MIMARKS:3.0-Data-START## investigation_type :: mimarks-survey chimera_check :: Bellerophon; 2004 collection_date :: 2009-07-13 depth :: 545 m biome :: marine biome feature :: hydrothermal vent material :: ocean water geo_loc_name :: Italy; Mediterranean Sea; Southern Tyrrhenian Sea lat_lon :: 39.29694 N 14.38583 E lib_const_meth :: vector lib_rea...

##MIMARKS:3.0-Data-START## investigation_type :: mimarks-survey chimera_check :: Bellerophon; 2004 collection_date :: 2009-07-13 depth :: 545 m biome :: marine biome feature :: hydrothermal vent material :: ocean water geo_loc_name :: Italy; Mediterranean Sea; Southern Tyrrhenian Sea lat_lon :: 39.29694 N 14.38583 E lib_const_meth :: vector lib_rea...

##MIMARKS:3.0-Data-START## investigation_type :: mimarks-survey collection_date :: 2009-07-13 depth :: 545 m biome :: marine biome feature :: hydrothermal vent material :: ocean water geo_loc_name :: Italy; Mediterranean Sea; Southern Tyrrhenian Sea lat_lon :: 39.29694 N 14.38583 E lib_reads_seqd :: 0 lib_size :: 0 nucl_acid_amp :: PCR nucl_acid_ex...

##MIMARKS:3.0-Data-START## investigation_type :: mimarks-survey collection_date :: 2009-07-13 depth :: 545 m biome :: marine biome feature :: hydrothermal vent material :: ocean water geo_loc_name :: Italy; Mediterranean Sea; Southern Tyrrhenian Sea lat_lon :: 39.29694 N 14.38583 E lib_reads_seqd :: 0 lib_size :: 0 nucl_acid_amp :: PCR nucl_acid_ex...

##MIMARKS:3.0-Data-START## investigation_type :: mimarks-survey chimera_check :: Bellerophon; 2004 collection_date :: 2009-07-13 depth :: 545 m biome :: marine biome feature :: hydrothermal vent material :: ocean water geo_loc_name :: Italy; Mediterranean Sea; Southern Tyrrhenian Sea lat_lon :: 39.29694 N 14.38583 E lib_const_meth :: vector lib_rea...

##MIMARKS:3.0-Data-START## investigation_type :: mimarks-survey assembly :: Sequencher 4.6 chimera_check :: Bellerophon; 2004 collection_date :: 2009-07-13 depth :: 545 m biome :: marine biome feature :: hydrothermal vent material :: ocean water geo_loc_name :: Italy; Mediterranean Sea; Southern Tyrrhenian Sea lat_lon :: 39.29694 N 14.38583 E lib_c...

##MIMARKS:3.0-Data-START## investigation_type :: mimarks-survey assembly :: Sequencher 4.6 chimera_check :: Bellerophon; 2004 collection_date :: 2009-07-13 depth :: 545 m biome :: marine biome feature :: hydrothermal vent material :: ocean water geo_loc_name :: Italy; Mediterranean Sea; Southern Tyrrhenian Sea lat_lon :: 39.29694 N 14.38583 E lib_c...

##MIMARKS:3.0-Data-START## investigation_type :: mimarks-survey assembly :: Sequencher 4.6 chimera_check :: Bellerophon; 2004 collection_date :: 2009-07-13 depth :: 545 m biome :: marine biome feature :: hydrothermal vent material :: ocean water geo_loc_name :: Italy; Mediterranean Sea; Southern Tyrrhenian Sea lat_lon :: 39.29694 N 14.38583 E lib_c...