Hidden in plain sight: The importance of cryptic interactions in marine plankton

Here, we present a range of interactions, which we term “cryptic interactions.” These are interactions that occur throughout the marine planktonic foodweb but are currently largely overlooked by established methods, which mean large‐scale data collection for these interactions is limited. Despite this, current evidence suggests some of these interactions may have perceptible impacts on foodweb dynamics and model results. Incorporation of cryptic interactions into models is especially important for those interactions involving the transport of nutrients or energy. Our aim is to highlight a range of cryptic interactions across the plankton foodweb, where they exist, and models that have taken steps to incorporate these interactions. Additionally, it is discussed where additional research and effort is required to continue advancing our understanding of these cryptic interactions. We call for more collaboration between ecologists and modelers in order to incorporate cryptic interactions into biogeochemical and foodweb models

Combining marine ecology and economy to roadmap the integrated coastal management: A systematic literature review

Integrated coastal management (ICM) relies on the inclusion of economic issues within marine ecology. To assess the progress of this integration, we applied topic modelling and network analysis to explore the pertinent literature (583 Isi-WoS, and 5459 Scopus papers). We classified the topics of interest (i.e., concepts, approaches, and sectors) that combined ecological and economic issues within marine science, we aggregated these topics in fields pertinent to ICM, and tracked the knowledge-exchange between these fields by using an information-flow network. Main findings were: (i) the high trans-disciplinary fashion of studies about marine protection and of those about commercial fisheries, (ii) the weak interaction between studies focusing on potential biohazards and those about environmental management, (iii) the isolation, in the overall information-flow, of studies about ecotourism and aquaculture. We included in a roadmap all the integration routes we detected within ICM, based on the combination of ecological and economic issues. We conclude that, to improve integration, ICM should: (i) Exploit marine protection as a bridge between ecological and economic concepts and approaches, and between maritime economy sectors, (ii) employ systems ecology to pursue trans-disciplinary investigations, (iii) complement systems ecology with citizen science by means of inclusive economic initiatives, such as ecotourism

Intersecting Ecosystem Services Across the Aquatic Continuum: From Global Change Impacts to Local, and Biologically Driven, Synergies and Trade-Offs

The study of ecosystem services requires the integration of different observational points. This is particularly true in Water, as this element continuously cycles, increasing chances of interaction among services originating in different ecosystems. However, aquatic scientists historically approached the study of inland/freshwater and open/marine waters in different ways and this cultural division potentially hampers integrative approaches. Herein, we explored the literature pertaining to ecosystem services across the last 23 years, analysing 4,590 aquatic papers. By aggregating and intersecting topics included in this papers’ collection using text-mining and topical network approaches, we saw that the study of local environmental conditions (e.g., river estuary management) and synergies and trade-offs between services (e.g., carbon sequestration and water purification) can display several potential conceptual links between freshwater and marine sciences. Our analyses suggest that to intersect ecosystem services across the aquatic continuum, the conceptual integration between marine and freshwater science must be reinforced, especially at the interface between different “salinity realms.” Such integration should adopt a “system thinking” perspective, in which the focus is on multiple socio-ecological processes giving rise to interactions that are (i) biologically mediated, (ii) potentially conflicting, and (iii) entangled within networks

Thermal Conversion of Guanylurea Dicyanamide into Graphitic Carbon Nitride via Prototype CNx Precursors

Guanylurea dicyanamide, [(H2N)C(-O)NHC(NH2)2][N(CN)2], has been synthesized by ion exchange reaction in aqueous solution and structurally characterized by single-crystal X-ray diffraction (C2/c, a = 2249.0(5) pm, b = 483.9(1) pm, c = 1382.4(3) pm, β = 99.49(3)°, V = 1483.8(5) × 106 pm3, T = 130 K). The thermal behavior of the molecular salt has been studied by thermal analysis, temperature-programmed X-ray powder diffraction, FTIR spectroscopy, and mass spectrometry between room temperature and 823 K. The results were interpreted on a molecular level in terms of a sequence of thermally induced addition, cyclization, and elimination reactions. As a consequence, melamine (2,4,6-triamino-1,3,5-triazine) is formed with concomitant loss of HNCO. Further condensation of melamine yields the prototypic CNx precursor melem (2,6,10-triamino-s-heptazine, C6N7(NH2)3), which alongside varying amounts of directly formed CNxHy material transforms into layered CNxHy phases without significant integration of oxygen into the core framework owing to the evaporation of HNCO. Thus, further evidence can be added to melamine and its condensation product melem acting as “key intermediates” in the synthetic pathway toward graphitic CNxHy materials, whose exact constitution is still a point at issue. Due to the characteristic formation process and hydrogen content a close relationship with the polymer melon is evident. In particular, the thermal transformation of guanylurea dicyanamide clearly demonstrates that the formation of volatile compounds such as HNCO during thermal decomposition may render a large variety of previously not considered molecular compounds suitable CNx precursors despite the presence of oxygen in the starting material

Ecological assessment of anthropogenic impact in marine ecosystems: The case of Bagnoli Bay

none13noPollutants alter marine systems, interfering with provisioning of ecosystem services; understanding their interaction with ecological communities is therefore critical to inform environmental management. Here we propose a joint compositional- and interaction-based analysis for ecological status assessment and apply it on the benthic communities of the Bagnoli Bay. We found that contamination differentially affects the communities’ composition in the bay, with prokaryotes influenced only by depth, and benthos not following the environmental gradient at all. This result is confirmed by analyses of the community structure, whose network structure suggest fast carbon flow and cycling, especially promoted by nematodes and polychaetes; the benthic prey/predator biomass ratio, adjusted for competition, successfully synthesise the status of predator taxa. We found demersal fish communities to separate into a deep, pelagic-like community, and two shallow communities where a shift from exclusive predators to omnivores occurs, moving from the most polluted to the least polluted sampling units. Finally, our study indicate that indices based on interspecific interactions are better indicators of environmental gradients than those defined based on species composition exclusively.embargoed_20220311Hay Mele B.; Russo L.; Crocetta F.; Gambi C.; Dell'Anno A.; Danovaro R.; Guglielmo R.; Musco L.; Patti F.P.; Riginella E.; Tangherlini M.; Ribera d'Alcala M.; D'Alelio D.Hay Mele, B.; Russo, L.; Crocetta, F.; Gambi, C.; Dell'Anno, A.; Danovaro, R.; Guglielmo, R.; Musco, L.; Patti, F. P.; Riginella, E.; Tangherlini, M.; Ribera d'Alcala, M.; D'Alelio, D

Intra-Genomic Ribosomal RNA Polymorphism and Morphological Variation in Elphidium macellum Suggests Inter-Specific Hybridization in Foraminifera

Elphidium macellum is a benthic foraminifer commonly found in the Patagonian fjords. To test whether its highly variable morphotypes are ecophenotypes or different genotypes, we analysed 70 sequences of the SSU rRNA gene from 25 specimens. Unexpectedly, we identified 11 distinct ribotypes, with up to 5 ribotypes co-occurring within the same specimen. The ribotypes differ by varying blocks of sequence located at the end of stem-loop motifs in the three expansion segments specific to foraminifera. These changes, distinct from typical SNPs and indels, directly affect the structure of the expansion segments. Their mosaic distribution suggests that ribotypes originated by recombination of two or more clusters of ribosomal genes. We propose that this expansion segment polymorphism (ESP) could originate from hybridization of morphologically different populations of Patagonian Elphidium. We speculate that the complex geological history of Patagonia enhanced divergence of coastal foraminiferal species and contributed to increasing genetic and morphological variation

Small, libertine and fit: did recombination and sex promote the evolutionary success of microalgae, from the origin of life to present days?

Microalgae are among the more ancient organisms on Earth. This group of photosynthetic unicells includes pro- and eukaryotes. The first “invented” photosynthesis, the second compartmentalized this metabolic process into plastids, derived from the intracellular domestication of cyanobacteria (endosymbiosis). Microalgae form large populations in all aquatic environments, play a key role in biogeochemical cycles and include several taxa capable to proliferate at extreme, quasi-primordial conditions. The large size and consequent fitness of microalgal populations are explained by their dominant clonal reproduction and the frequent genetic mutations during DNA duplications. Nonetheless, genetic and genomic observations suggest that genetic recombination frequently occurs in both prokaryotic and eukaryotic lineages. Moreover, many eukaryotic microalgae have life cycles including a sexual phase that can provide a regular genetic reassortment. In this contribute, we review studies on natural populations of aquatic and extremophilic microalgal taxa, both pro- and eukaryotes, whose evolutionary origins span 2-0.2  Billions years ago, namely the genera Planktothrix (freshwater cyanobacteria), Galdieria (extremophilic unicellular rhodophytes) and Pseudo-nitzschia (marine diatoms). The data gained so far suggest that genetic recombination and sex appear to play an important role in driving microevolution and promoting population fitness in each of the abovementioned microbial organisms. In a study focused on natural populations of Planktothrix spp. sampled in the subalpine lake district in North Italy, recombination signals were observed by analysing four molecular loci interspersed in the genome. Computational analyses suggest that recombination introduced genetic diversity at a rate more than double than mutations. Recombination provides natural populations of Planktothrix spp. wit h a background genetic diversity from which successful genotypes can eventually emerge and conquer new ecological niches, mimicking population developments typical of pathogenic (epidemic) bacteria. A study on Icelandic strains of Galdieria sulphuraria showed signals of recombination at the level of plastidial genome (i.e., the gene rbcL) in this putatively asexual microalga. A wide post-recombination diversification was inferred in G. sulphuraria populations, suggesting the occurrence of an intense spreading and a high fitness of recombinant lineages. Such recombinations without proper sex (i.e., nuclear recombination), could have been maintained even after primary endosymbiosis. The usefulness of this processes is that it probably promotes RuBisCo stability at extreme temperatures, as already demonstrated in other photosynthetic extremophiles (i.e., the cyanobacterium Synechococcus). Finally, molecular investigations on the diatom Pseudo -nitzschia multistriata reported signals of intra-specific recombination in natural populations (ribosomal ITS). This species showed a highly synchronized and strictly periodic sexual phase in nature, which makes it an obligate sexual organism, since geographically isolated populations would go eventually extinct in absence of sex. Nonetheless, species in the genus Pseudo-nitzschia also showed signals of recombination in the rbcL gene at both intra- and inter-specific level, suggesting that a putatively cyanobacteria-derived plastidial recombination could have been maintained in the course of the evolution of photosynthetic lineages, besides the emergence of proper sex. In presenting and discussing these cases, we aim to develop a conceptual scenario on the origin and benefit of recombination and sex in microlgae, an ecologically and evolutionary relevant group of organisms at global scale