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11 pages, 5 figures, 2 tables, supplementary information https://doi.org/10.1038/s42003-021-02165-3.-- Data availability: The authors declare that the data supporting the findings of this study are available within the paper and its Supplementary Data files, The last hundred years have seen the introduction of many sources of artificial noise in the sea environment which have shown to negatively affect marine organisms. Little attention has been devoted to how much this noise could affect sessile organisms. Here, we report morphological and ultrastructural changes in seagrass, after exposure to sounds in a controlled environment. These results are new to aquatic plants pathology. Low-frequency sounds produced alterations in Posidonia oceanica root and rhizome statocysts, which sense gravity and process sound vibration. Nutritional processes of the plant were affected as well: we observed a decrease in the number of rhizome starch grains, which have a vital role in energy storage, as well as a degradation in the specific fungal symbionts of P. oceanica roots. This sensitivity to artificial sounds revealed how sound can potentially affect the health status of P. oceanica. Moreover, these findings address the question of how much the increase of ocean noise pollution may contribute in the future to the depletion of seagrass populations and to biodiversity loss, With the funding support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S), of the Spanish Research Agency (AEI)

13 pages, 9 figures, supplementary data https://doi.org/10.1016/j.envpol.2022.119853.-- Data availability: Data will be made available on request, The installation of marine renewable energy devices (MREDs, wind turbines and converters of wave, tidal and ocean thermal energy) has increased quickly in the last decade. There is a lack of knowledge concerning the effects of MREDs on benthic invertebrates that live in contact with the seabed. The European common cuttlefish (Sepia officinalis) is the most abundant cephalopod in the Northeast Atlantic and one of the three most valuable resources for English Channel fisheries. A project to build an offshore wind farm in the French bay of Saint-Brieuc, near the English Channel, raised concern about the possible acoustic impact on local cuttlefish communities. In this study, consisting of six exposure experiments, three types of noise were considered: 3 levels of pile-driving and 3 levels of drilling. The objectives were to assess possible associated changes in hatching and larva survival, and behavioural and ultrastructural effects on sensory organs of all life stages of S. officinalis populations. After exposure, damage was observed in the statocyst sensory epithelia (hair cell extrusion) in adults compared to controls, and no anti-predator reaction was observed. The exposed larvae showed a decreased survival rate with an increasing received sound level when they were exposed to maximum pile-driving and drilling sound levels (170 dB re 1 μPa2 and 167 dB re 1 μPa2, respectively). However, sound pressure levels's lower than 163 dB re 1 μPa2 were not found to elicit severe damage. Simulating a scenario of immobile organisms, eggs were exposed to a combination of both pile driving and drilling as they would be exposed to all operations without a chance to escape. In this scenario a decrease of hatching success was observed with increasing received sound levels, We acknowledges the institutional support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX 2019-000928-S). Funding for this project was provided by Ailes Marines SAS (Iberdrola Group). Project: Noise influence for cuttlefish invertebrate - St Brieuc Wind Farm Site (Ref. CPCS – 771596). France

Special issue Ocean Noise: From Science to Management.-- 15 pages, 8 figures, Global change is the origin of increased occurrence of disturbance events in natural communities, with biological invasions constituting a major threat to ecosystem integrity and functioning. The apple snail (Pomacea maculata) is a freshwater gastropod mollusk from South America. Considered one of the 100 most harmful invasive species in the world, due to its voracity, resistance, and high reproductive rate, it has become a global problem for wetland crops. In Catalonia, it has affected the rice fields of the Ebre Delta since 2010 with significant negative impact on the local economy. As a gastropod mollusc it possesses statocysts consisting of a pair of sacs, one located on each side of the foot, that contain multiple calcium carbonate statoconia. This study shows the first ultrastructural images of pathological changes in the sensory epithelium of the statocyst of apple snail adults with an increase in the severity of the lesions over time after exposure to low frequency sounds. Sound-induced damage to the statocyst could likely result in an inhibition of its vital functions resulting in a potential reduction in the survival ability of the apple snail and lead to an effective mitigation method for reducing damage to rice fields, With the institutional support of the ‘Severo OchoaCentre of Excellence’ accreditation (CEX2019-000928-S)

Special issue Ocean Noise: From Science to Management.-- 20 pages, 22 figures, 1 table, supplementary materials www.mdpi.com/article/10.3390/jmse9101114/s1, The use of bioacoustic methods to address sea lice infestation in salmonid farming is a promising innovative method but implies an exposure to sound that could affect the fish. An assessment of the effects of these techniques related to the salmon’s welfare is presented here. The fish were repeatedly exposed to 350 Hz and 500 Hz tones in three- to four-hour exposure sessions, reaching received sound pressure levels of 140 to 150 dB re 1 µPa2, with the goal of reaching total sound exposure levels above 190 dB re 1 µPa2 s. Gross pathology and histopathological analysis performed on exposed salmons’ organs did not reveal any lesions that could be associated to sound exposure. The analysis of their otoliths through electron microscopy imaging confirmed that the sound dose that was used to impair the lice had no effects on the fish auditory organs, Funding for this project was provided by SEASEL SOLUTIONS AS. Project: An acoustic and Bioacoustic solution to sea lice infestation on salmon- P.O.BOX 93 N-6282 BRATTVÅG. Norway, With the institutional support of the ‘Severo OchoaCentre of Excellence’ accreditation (CEX2019-000928-S)

18 pages, 50 figures, 1 table, supplementary information http://dx.doi.org/10.1080/09670262.2021.1914861.-- Related Research Data: Detection of the widespread presence of the genus Ansanella along the Catalan coast (NW Mediterranean Sea) and the description of Ansanella catalana sp. nov. (Dinophyceae). Source: Taylor & Francis, Many dinoflagellate groups have been overlooked because of their small size compared with their larger counterparts; consequently, little is known about their diversity, distribution, and contribution to the planktonic community. Ansanella is a recently described genus of small marine planktonic dinoflagellates belonging to the order Suessiales. In this study, morphological observations together with molecular SSU and LSU rDNA analyses of clonal strains from the Catalan coast (NW Mediterranean Sea) allowed the identification of A. cf. natalensis and a newly reported species, Ansanella catalana. The cells of A. catalana are oval and 9.6–15.5 μm long; the cell surface is covered with amphiesmal vesicles arranged in 10–13 latitudinal rows; the episome has an apical furrow complex with a single elongated apical vesicle; a type E eyespot is also present. This newly identified species can be distinguished from congeneric species by morphological details of the cell surface, the presence of mucocysts and an extrusome type not previously reported in dinoflagellates. The characterization of this structure could provide insights into extrusome evolution in dinoflagellates. Metabarcoding analysis of plankton and sediment samples from the Catalan coast revealed a wide distribution of Ansanella and the remarkable contribution of this genus to the dinoflagellate communities from three different coastal habitats, Financial support was provided by COPAs project (CTM2017-86121-R). J. Matos was also supported by a grant from Brazil (PE 88881.146191/2017-01). This work acknowledges the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S)

24 pages, 21 figures, 4 tables, The salmon louse Lepeophtheirus salmonis is a major disease problem in salmonids farming and there are indications that it also plays a role in the decline of wild salmon stocks. This study shows the first ultrastructural images of pathological changes in the sensory setae of the first antenna and in inner tissues in different stages of L. salmonis development after sound exposure in laboratory and sea conditions. Given the current ineffectiveness of traditional methods to eradicate this plague, and the strong impact on the environment these treatments often provoke, the described response to sounds and the associated injuries in the lice sensory organs could represent an interesting basis for developing a bioacoustics method to prevent lice infection and to treat affected, Funding for this project was provided by SEASEL SOLUTIONS AS. Project: An acoustic and Bioacoustic solution to sea lice infestation on salmon P.O. BOX 93 N-6282 BRATTVÅG. Norway.-- With funding from the Spanish government through the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S)

Minidiscus comicus is a marine centric diatom that has cells with diameters as small as 1.9 μm, which brings it close to the lower limit of diatom cell size and also near to the lower limit of photosynthetic eukaryote cells. One of the questions that this raises is whether the cycle of size decline and size restoration used by most diatoms to time their life cycle can operate in such small cells. In samples collected from the western Mediterranean during 2009, M. comicus cells were found with diameters ranging from 1.9 to 6.0 μm. The larger cells were initial cells after size restoration, and these still had the valves of their parent cells attached, making it possible to determine the diameter of the threshold below which size restoration could be induced (3.1 μm). During size decline, M. comicus cell shape changed from discoid to spherical. This adaptation helped to reduce and even halt the rate of cell volume decrease, allowing cells to continue to use diameter decline as a clocking mechanism. The results show how adaptable the diatom cell wall can be, in spite of its rigid appearance.

Corrigendum: Evidence of Cnidarians sensitivity to sound after exposure to low frequency underwater sources Scientific Reports 6: 37979 (2016) https://dx.doi.org/10.1038/srep37979.-- 2 pages

Special volume: Planet Ocean. Scientia Marina 80(Suppl.1) 2016.-- 8 pages, 6 figures, [EN] Minidiscus comicus is a marine centric diatom that has cells with diameters as small as 1.9 μm, which brings it close to the lower limit of diatom cell size and also near to the lower limit of photosynthetic eukaryote cells. One of the questions that this raises is whether the cycle of size decline and size restoration used by most diatoms to time their life cycle can operate in such small cells. In samples collected from the western Mediterranean during 2009, M. comicus cells were found with diameters ranging from 1.9 to 6.0 μm. The larger cells were initial cells after size restoration, and these still had the valves of their parent cells attached, making it possible to determine the diameter of the threshold below which size restoration could be induced (3.1 μm). During size decline, M. comicus cell shape changed from discoid to spherical. This adaptation helped to reduce and even halt the rate of cell volume decrease, allowing cells to continue to use diameter decline as a clocking mechanism. The results show how adaptable the diatom cell wall can be, in spite of its rigid appearance, [ES] Minidiscus comicus es una diatomea céntrica marina cuyas células pueden alcanzar diámetros mínimos de tan solo 1.9 μm, lo que las acerca al límite inferior de tamaño de las células de diatomeas y en general de las células eucariotas fotosintéticas. Una de las preguntas que surgen es si el ciclo de disminución y restauración de tamaño usado por la mayoría de las diatomeas para medir los tiempos de su ciclo de vida pueda realizarse en estas pequeñas células. En muestras del Mediterráneo occidental tomadas durante 2009, las células de M. comicus presentaron diámetros de 1.9 a 6.0 μm. Las células mayores eran células iniciales después de la restauración de tamaño y aún tenían pegadas las valvas de las células progenitoras, lo cual hace posible determinar el umbral de diámetro que puede inducir a la restauración (3.1 µm). Se observó que al disminuir el tamaño, la forma de la célula cambiaba de discoidea a esférica. Esta adaptación ayuda a reducir e incluso detiene la tasa de disminución del volumen de la célula, lo que permite a las células continuar usando la disminución del diámetro como un mecanismo cronometrador. Los resultados muestran cuán adaptable puede ser la pared celular de las diatomeas, a pesar de su rígida apariencia, This work was supported by the projects FAMOSO (CTM2008-06261-C03), JSPS Grants-in-Aid for Scientific Research 26291085 and 15K14784 and Open Partnership Joint Projects of JSPS Bilateral Joint Research Projects

26 pages, 7 figures, 4 tables, supporting information https://doi.org/10.1371/journal.pone.0154050.s001 https://doi.org/10.1371/journal.pone.0154050.s002 https://doi.org/10.1371/journal.pone.0154050.s003, Here we present, for the first time, the elemental concentration, including C, N and O, of single phytoplankton cells collected from the sea. Plankton elemental concentration and stoichiometry are key variables in phytoplankton ecophysiology and ocean biogeochemistry, and are used to link cells and ecosystems. However, most field studies rely on bulk techniques that overestimate carbon and nitrogen because the samples include organic matter other than plankton organisms. Here we used X-ray microanalysis (XRMA), a technique that, unlike bulk analyses, gives simultaneous quotas of C, N, O, Mg, Si, P, and S, in single-cell organisms that can be collected directly from the sea. We analysed the elemental composition of dinoflagellates and diatoms (largely Chaetoceros spp.) collected from different sites of the Catalan coast (NW Mediterranean Sea). As expected, a lower C content is found in our cells compared to historical values of cultured cells. Our results indicate that, except for Si and O in diatoms, the mass of all elements is not a constant fraction of cell volume but rather decreases with increasing cell volume. Also, diatoms are significantly less dense in all the measured elements, except Si, compared to dinoflagellates. The N:P ratio of both groups is higher than the Redfield ratio, as it is the N:P nutrient ratio in deep NW Mediterranean Sea waters (N:P = 20–23). The results suggest that the P requirement is highest for bacterioplankton, followed by dinoflagellates, and lowest for diatoms, giving them a clear ecological advantage in P-limited environments like the Mediterranean Sea. Finally, the P concentration of cells of the same genera but growing under different nutrient conditions was the same, suggesting that the P quota of these cells is at a critical level. Our results indicate that XRMA is an accurate technique to determine single cell elemental quotas and derived conversion factors used to understand and model ocean biogeochemical cycles, This work was supported by project PUDEM (REN2003-06637-C02, Spanish Ministry of Science and Technology, now Spanish Ministry of Economy and Competitiveness); and by an I3P fellowship (CSIC, Spanish Ministry of Education and Culture) to M. Segura-Noguera. Both funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript