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Este artículo contiene 13 páginas, 6 figuras., The red swamp crayfish (Procambarus clarkii) is the most widely spread freshwater crayfish worldwide. Competing physiological traits can influence invasion success in any given environment by limiting the available scope for aerobically demanding activities. While high flows have been associated with reduced crayfish movement upstream, the effects of flow alteration on their metabolic demands have been largely overlooked. In this study, we estimated routine metabolic rate (RMR) at rest and oxygen consumption rates of crayfish under different current velocities in a flume respirometer, while maximum metabolic rate (MMR) was determined using the exhaustive chase protocol. We also measured some morphometric variables in males and females of crayfish. Oxygen uptake substantially increased with crayfish size and current velocity due to increased energy expenditure to overcome drag and hold a stationary position. Sexual dimorphism in morphological traits did not lead to sexual differences in oxygen uptake. Moreover, we found that individuals operated close to their maximum aerobic capacity at elevated current velocities (≥ 25 cm s− 1). This suggested that the high flow-driven energetic demand may compromise the energy available for reproduction, growth and dispersal, thereby affecting overall fitness. These metabolic constraints could partly explain the failed invasions of invasive crayfish in fast-flowing waters., This work was supported by the Government of Catalonia (ref. 2017 SGR 548). Francesc Rubio-Gracia benefitted from a predoctoral fellowship from the University of Girona (IFUdG17).Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. This research was funded by the Government of Catalonia (ref. 2017 SGR 548) and by the University of Girona (IFUdG17).

Este artículo contiene 11 páginas, 5 figuras, 1 tabla., Ongoing human pressures over recent decades have caused the loss and ensuing impoverishment of the complexity and diversity of Mediterranean habitats dominated by algal species of the order Fucales. Gongolaria barbata, a habitat-forming Fucales species that has disappeared in several places across the Mediterranean, was reintroduced in a cove (Cala Teulera, Maó Bay, Menorca) where it was known to have been locally extinct for more than 40 years. Reintroduction was performed in 2011 using innovative non-destructive techniques. Here we describe the expansion patterns of the population ten years after its reintroduction, and we look at the size-structure distribution of the restored population compared to one of the only natural populations known in Spain (Fornells Bay, Menorca). Newly settled individuals exhibit a progressive dispersal pattern from restoration sites, favouring rocky substrates at the shallowest level parallel to the shore. The area occupied by G. barbata has increased by almost three orders of magnitude in ten years, from approximately 3.6 m2 of the initially restored area to a current restored area of 2093 m2. Recruits and juveniles dominate the restored population but some individuals have reached large size classes, the overall size distribution resembling the reference population. The high-resolution cartography included in our study enables an accurate mid to long-term assessment of the expansion of G. barbata. Incorporating such tools in restored marine forests would facilitate the implementation of efficient management policies that will help reinforce their conservation., Funding was provided by IEO (“Mola-Menorca Dos Project”, financed by the Direcció General de Recerca del Govern de les Illes Balears through the European Regional Development Fund).

In coastal systems, planktonic and benthic silicifiers compete for the pool of dissolved silicon, a nutrient required to make their skeletons. The contribution of planktonic diatoms to the cycling of silicon in coastal systems is often well characterized, while that of benthic silicifiers such as sponges has rarely been quantified. Herein, silicon fluxes and stocks are quantified for the sponge fauna in the benthic communities of the Bay of Brest (France). A total of 45 siliceous sponge species living in the Bay account for a silicon standing stock of 1215 tons, while that of diatoms is only 27 tons. The silicon reservoir accumulated as sponge skeletons in the superficial sediments of the Bay rises to 1775 tons, while that of diatom skeletons is only 248 tons. These comparatively large stocks of sponge silicon were estimated to cycle two orders of magnitude slower than the diatom stocks. Sponge silicon stocks need years to decades to be renewed, while diatom turnover lasts only days. Although the sponge monitoring over the last 6 years indicates no major changes of the sponge stocks, our results do not allow to conclude if the silicon sponge budget of the Bay is at steady state, and potential scenarios are discussed. The findings buttress the idea that sponges and diatoms play contrasting roles in the marine silicon cycle. The budgets of these silicon major users need to be integrated and their connections revealed, if we aim to reach a full understanding of the silicon cycling in coastal ecosystems.

How the morphology of captive-reared fish is affected by structural enrichment in their rearing tanks is not well understood. Some studies have suggested that deficiencies in rearing environments could produce inappropriate body shape in salmonids [...]

13 pages, 3 tables, 3 figures.-- This is an Open Access article distributed under the terms of the Creative Commons Attribution License, The worldwide disruption caused by the beginning of the COVID-19 pandemic has dramatically impacted the activities of marine scientists working towards the goals of the UN Ocean Decade. As in other disciplines, marine early-career researchers (ECRs) are essential contributors to the development of novel and innovative science. Based on a survey of 322 of our peers, we show that the pandemic negatively impacted marine ECRs in ways that further exacerbate existing structural challenges such as social isolation, job insecurity, and short-term contracts, competitive funding, and work pressure. Furthermore, we find that the success and wellbeing of marine ECRs depends heavily on networking opportunities, gaining practical experience, collecting data, and producing publications, all of which were disrupted by the pandemic. Our analysis shows that those in the earliest stages of their careers feel most vulnerable to long-term career disadvantage as a result of the pandemic. This paper contributes to the empirical body of work about the impacts of the pandemic on marine science and offers recommendations on how marine ECRs should be supported to achieve the UN Ocean Decade’s goal of producing “the science we need for the ocean we want”, This work was partly supported by funding received from the wider EuroMarine organization and the financial donation from BNP Paribas as part of their pilot support of EuroMarine and its ECR network, OYSTER. This funding was received for 2019 and 2020. EF is funded by the European Social Fund and Scottish Funding Council. AMW and AS are supported by the MEESO project (www.meeso.org), which has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No. 817669. LCG is supported by the TRIATLAS project, which has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No. 817578. MLA is supported by the Xunta de Galicia postdoctoral programme (grant number: IN606B-2019/002). CG is funded by Fundación Tatiana Pérez de Guzmán el Bueno predoctoral fellowship, Medioambiente 2019. MF was funded by Portuguese national funds from FCT—Foundation for Science and Technology through project UIDB/04 326/2020 and CEECINST/00 114/2018 and by a Juan de La Cierva Formación fellowship (FJC2019-038970-I, Ministerio de Ciencia e Innovación, Spanish Goverment). SP was supported by a post-doctoral grant from the University of Bologna and by the STIMARE project (CUP: J56C18001240001). TTD is supported by the Slovenian Research Agency (research core funding No. P1-0237 and programme for young researchers, in accordance with the agreement on (co) financing research activities). GS received financial support by the projects NAUTILOS (grant agreement No. 101000825) and EUROqCHARM (grant agreement No. 101003805) that received funding from the European Union’s Horizon 2020 research and innovation programme