Plankton food web structure and productivity under ocean alkalinity enhancement.

Ocean alkalinity enhancement (OAE) is a nature-based technology for CO removal and storage, but little is known about its environmental safety. We tested a CO-equilibrated OAE deployment in a close-to-natural community using in situ mesocosms in the oligotrophic subtropical North Atlantic and assessed metazoan zooplankton to inform about food web stability, structure, and production. In addition, a literature review complemented experimental results by summarizing physiological responses of marine animals to decreasing proton concentrations, or increased pH.

Biodiversity and distribution of gelatinous macrozooplankton in the North Sea and adjacent waters - dataset from winter 2022.

The diversity and distribution of gelatinous macrozooplankton is described by presenting qualitative and quantitative data of the jellyfish and comb jelly community encountered in the North Sea and Skagerrak/Kattegat during January/February 2022. Data were generated as part of the North Sea Midwater Ring Net (MIK) survey [1], an ichthyoplankton survey conducted at night-time during the quarter 1 (Q1) International Bottom Trawl Survey (IBTS), aboard the Danish R/V DANA (DTU Aqua) and the Swedish R/V Svea (SLU). A total of 100 stations were investigated using a 13 m long Midwater Ring Net (MIK net) with an opening diameter of 2 m and a mesh size of 1.

Hybridization and adaptive introgression in a marine invasive species in native habitats.

Hybridization of distinct populations or species is an important evolutionary driving force. For invasive species, hybridization can enhance their competitive advantage as a source of adaptive novelty by introgression of selectively favored alleles. Using single-nucleotide polymorphism (SNP) microarrays we assess genetic diversity and population structure in the invasive ctenophore in native habitats.

Gelatinous larvacean zooplankton can enhance trophic transfer and carbon sequestration.

Larvaceans are gelatinous zooplankton abundant throughout the ocean. Larvaceans have been overlooked in research because they are difficult to collect and are perceived as being unimportant in biogeochemical cycles and food-webs. We synthesise evidence that their unique biology enables larvaceans to transfer more carbon to higher trophic levels and deeper into the ocean than is commonly appreciated.

Gelatinous macrozooplankton diversity and distribution dataset for the North Sea and Skagerrak/Kattegat during January-February 2021.

This data article includes a qualitative and quantitative description of the gelatinous macrozooplankton community of the North Sea during January-February 2021. Sampling was conducted during the 1 quarter International Bottom Trawl Survey (IBTS) on board the Danish R/V DANA (DTU Aqua Denmark) and the Swedish R/V Svea (SLU Sweden), as part of the ichthyoplankton investigation during night-time. A total of 147 stations were investigated in the western, central and eastern North Sea as well as the Skagerrak and Kattegat.

Distribution and biomass of gelatinous zooplankton in relation to an oxygen minimum zone and a shallow seamount in the Eastern Tropical North Atlantic Ocean.

Physical and topographic characteristics can structure pelagic habitats and affect the plankton community composition. For example, oxygen minimum zones (OMZs) are expected to lead to a habitat compression for species with a high oxygen demand, while upwelling of nutrient-rich deep water at seamounts can locally increase productivity, especially in oligotrophic oceanic waters. Here we investigate the response of the gelatinous zooplankton (GZ) assemblage and biomass to differing oxygen conditions and to a seamount in the Eastern Tropical North Atlantic (ETNA) around the Cape Verde archipelago.

Invasion genomics uncover contrasting scenarios of genetic diversity in a widespread marine invader.

Invasion rates have increased in the past 100 y irrespective of international conventions. What characterizes a successful invasion event? And how does genetic diversity translate into invasion success? Employing a whole-genome perspective using one of the most successful marine invasive species world-wide as a model, we resolve temporal invasion dynamics during independent invasion events in Eurasia. We reveal complex regionally independent invasion histories including cases of recurrent translocations, time-limited translocations, and stepping-stone range expansions with severe bottlenecks within the same species.

Cultivable microbiota associated with Aurelia aurita and Mnemiopsis leidyi.

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 dynamics of the associated microbial community. Aiming to address interspecies competition of cultivable microbes associated with emerging model species of the basal animal phyla Cnidaria (Aurelia aurita) and Ctenophora (Mnemiopsis leidyi), we performed a classical isolation approach.

Differences in the microbiota of native and non-indigenous gelatinous zooplankton organisms in a low saline environment.

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 translocation of bacteria as part of their microbiomes.

Biodiversity of gelatinous macrozooplankton: Quantitative assessment of data and distribution patterns in the southern and central North Sea during August 2018.

This article describes the biodiversity of gelatinous macrozooplankton and presents quantitative field data on their community composition and distribution pattern in the North Sea during August 2018. The data set consists of jellyfish and comb jelly species abundance estimates which are based on sampling at 62 stations in the central and southern North Sea covering Danish waters, the German Bight, waters off the Dutch coast as well as the western North Sea off the UK coast and the central North Sea. The sampling gear was a 13 m long MIK-net (modified Methot Isaac Kidd net; Ø 2 m, mesh size 1 mm, mesh size cod end 500 μm) deployed in double oblique hauls from the surface to 5 m above the sea floor.

Eukaryotic and cyanobacterial communities associated with marine snow particles in the oligotrophic Sargasso Sea.

Marine snow aggregates represent heterogeneous agglomerates of dead and living organic matter. Composition is decisive for their sinking rates, and thereby for carbon flux to the deep sea. For oligotrophic oceans, information on aggregate composition is particularly sparse.

Resolving structure and function of metaorganisms through a holistic framework combining reductionist and integrative approaches.

Current research highlights the importance of associated microbes in contributing to the functioning, health, and even adaptation of their animal, plant, and fungal hosts. As such, we are witnessing a shift in research that moves away from focusing on the eukaryotic host sensu stricto to research into the complex conglomerate of the host and its associated microorganisms (i.e.

Functions of the Microbiota for the Physiology of Animal Metaorganisms.

Animals are usually regarded as independent entities within their respective environments. However, within an organism, eukaryotes and prokaryotes interact dynamically to form the so-called metaorganism or holobiont, where each partner fulfils its versatile and crucial role. This review focuses on the interplay between microorganisms and multicellular eukaryotes in the context of host physiology, in particular aging and mucus-associated crosstalk.

Use of intraoperative intracavitary (direct-contact) ultrasound for resection control in transsphenoidal surgery for pituitary tumors: evaluation of a microsurgical series.

Background: Perisellar infiltration may be responsible for incomplete removal of pituitary tumors. Since intraoperative visualization of parasellar structures is difficult during transsphenoidal surgery, we are describing the use of intraoperative direct contact ultrasound (IOUS).

Methods: Within 5 years, in 113 transsphenoidal operations (58 male, 55 female, age 14-81 years, 110 pituitary adenomas (mean diameter 26.

Gelatinous plankton is important in the diet of European eel (Anguilla anguilla) larvae in the Sargasso Sea.

Limited insight into eel larvae feeding and diet prevents a holistic overview of the life-cycle of catadromous eels and an understanding of the ecological position of their early stages in marine waters. The present study evaluated the diet of larval European eel, Anguilla anguilla - a critically endangered species. Next-generation 18S rRNA gene sequencing data of Sargasso Sea eel larvae gut contents and marine snow aggregates was compared with a reference plankton database to assess the trophic relations of eel larvae.

Food availability drives plastic self-repair response in a basal metazoan- case study on the ctenophore Mnemiopsis leidyi A. Agassiz 1865.

Many marine invertebrates including ctenophores are capable of extensive body regeneration when injured. However, as for the invasive ctenophore Mnemiopsis leidyi, there is a constant subportion of individuals not undergoing whole body regeneration but forming functionally stable half-animals instead. Yet, the driving factors of this phenomenon have not been addressed so far.

Selection for life-history traits to maximize population growth in an invasive marine species.

Species establishing outside their natural range, negatively impacting local ecosystems, are of increasing global concern. They often display life-history features characteristic for r-selected populations with fast growth and high reproduction rates to achieve positive population growth rates (r) in invaded habitats. Here, we demonstrate substantially earlier maturation at a 2 orders of magnitude lower body mass at first reproduction in invasive compared to native populations of the comb jelly Mnemiopsis leidyi.

Ectopic Adrenocorticotropic Hormone-Secreting Pituitary Adenomas: An Underestimated Entity.

Background: The diagnosis of Cushing disease is based on endocrinological pa-rameters, with no single test being specific. In some patients, dynamic thin-slice sellar magnetic resonance imaging fails to detect a pituitary tumor.

Objective: The purpose of this study is to investigate the role of ectopic pituitary adenoma in this situation.

Production of a high level of laccase by submerged fermentation at 120-L scale of Cerrena unicolor C-139 grown on wheat bran.

Submerged fermentation in a stirred bioreactor of the white rot fungus Cerrena unicolor C-139 was done at a 120-L scale in the presence of wheat bran as a cheap lignocellulosic substrate for fungus growth and laccase production. Enzyme monitoring showed that laccase production started after 2 days of cultivation, attaining a maximum activity of 416.4 U·mL(-1) at day 12 of fermentation.

Immobilized laccase of Cerrena unicolor for elimination of endocrine disruptor micropollutants.

The white-rot fungus Cerrena unicolor C-139 produced 450 000 U l(-1) of laccase when cultivated in submerged (50 ml) fermentation of wheat bran. Laccase (benzenediol: oxygen oxidoreductase, EC 1.10.

Ctenophore population recruits entirely through larval reproduction in the central Baltic Sea.

The comb jelly Mertensia ovum, widely distributed in Arctic regions, has recently been discovered in the northern Baltic Sea. We show that M. ovum also exists in the central Baltic but that the population consists solely of small-sized larvae (less than 1.

Multi-decadal changes in tundra environments and ecosystems: synthesis of the International Polar Year-Back to the Future project (IPY-BTF).

Understanding the responses of tundra systems to global change has global implications. Most tundra regions lack sustained environmental monitoring and one of the only ways to document multi-decadal change is to resample historic research sites. The International Polar Year (IPY) provided a unique opportunity for such research through the Back to the Future (BTF) project (IPY project #512).