Methods of physiological energetics were applied to compare growth rates of mussels Mytilus galloprovincialis Lmk from 2 habitats: intertidal and raft cultures. Scope for growth was determined after l and 15 d under standard laboratory conditions Both groups of mussels improved their growth potential during maintenance in the laboratory due to a combination of increased ingestion rate and decreased metabol~c rate. Cultivated mussels presented h~g h e r weight-specific clearance rates, higher absorption efficiency and higher rates of ammonia excretion, w h~c h resulted in increased scope for growth with respect to ~ntertldal mussels. This finding is related to the differential characteristics of these 2 habitats in terms of cycles of food availability and air exposure. Differences between the groups of mussels persisted after 15 d of experimental treatment and were mainly accounted for by absorption efficiency.KEY WORDS: Mussel . Physiological energetics Clearance rate -Metabolic rate Absorption efficiency . A m m o n~a excretion rate . Scope for growth (SFG) . Net growth efficiency (K,)

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8The effect of spawning events of the mussel Mytilus galloprovincialis on both quantitative and 9 qualitative values of byssus secretion and its associated attachment force was investigated. 10Byssogenesis rates and absorption efficiency values were significantly reduced after spawning 11 of individuals. However, the maintenance of individuals under sub-optimal conditions (lack of 12 microalgae in the diet) for a week caused no effect on thread's number. Surprisingly, 13 attachment force varied within a narrow range of values (1.7-1.9 N) with the exception of a 14 significant drop in the experimental group spawned and kept unfed (1.0 N; P<0.001) most 15 likely due to a similar pattern of the thread's thickness variability. 16Qualitative analysis concerned to the amino acid composition of the byssus highlighted a 17 higher presence of the basic residues histidine and lysine in threads secreted by spawned 18 individuals. The presence of both histidine and lysine residues in the byssal collagen is 19 associated to the formation of cross-links and specifically histidine has a functionality with a 20 pronounced effect on metal chelation to stabilise the integrity of the byssus. Results reported 21here evidence the necessity to integrate all components that eventually determine the 22 attachment strength of the mussels to get more insight the plasticity of such secretion. 23Morphology of the byssus (thickness) secreted under different endogenous conditions of 24 2 mussels was the major parameter to explain variability in attachment force. Moreover, 1 aminoacidic composition as quality term of the byssus secreted may also contribute to 2 understand plasticity of this secretion and needs to be extended in further surveys. 3 4

The rapid, global spread of COVID-19, and the measures intended to limit or slow its propagation, are having major impacts on diverse sectors of society. Notably, these impacts are occurring in the context of other anthropogenic-driven threats including global climate change. Both anthropogenic stressors and the COVID-19 pandemic represent significant economic challenges to aquaculture systems across the globe, threatening the supply chain of one of the most important sources of animal protein, with potential disproportionate impacts on vulnerable communities. A web survey was conducted in 47 countries in the midst of the COVID-19 pandemic to assess how aquaculture activities have been affected by the pandemic, and to explore how these impacts compare to those from climate change. A positive correlation between the effects of the two categories of drivers was detected, but analysis suggests that the pandemic and the anthropogenic stressors affect different parts of the supply chain. The immediate measurable reported losses varied with aquaculture typology (land vs. marine, and intensive vs. extensive). A comparably lower impact on farmers reporting the use of integrated multitrophic aquaculture (IMTA) methods suggests that IMTA might enhance resilience to multiple stressors by providing different market options under the COVID-19 pandemic. Results emphasize the importance of assessing detrimental effects of COVID-19 under a multiple stressor lens, focusing on areas that have already locally experienced economic loss due to anthropogenic stressors in the last decade. Holistic policies that simultaneously address other ongoing anthropogenic stressors, rather than focusing solely on the acute impacts of COVID-19, are needed to maximize the long-term resilience of the aquaculture sector.

‘Onium’ compounds, including ammonium and phosphonium salts, have been employed as antiseptics and disinfectants. These cationic biocides have been incorporated into multiple materials, principally to avoid bacterial attachment. In this work, we selected 20 alkyl-triphenylphosphonium salts, differing mainly in the length and functionalization of their alkyl chains, in fulfilment of two main objectives: 1) to provide a comprehensive evaluation of the antifouling profile of these molecules with relevant marine fouling organisms; and 2) to shed new light on their potential applications, beyond their classic use as broad-spectrum biocides. In this regard, we demonstrate for the first time that these compounds are also able to act as non-toxic quorum sensing disruptors in two different bacterial models (Chromobacterium violaceum and Vibrio harveyi) as well as repellents in the mussel Mytilus galloprovincialis. In addition, their inhibitory activity on a fouling-relevant enzymatic model (tyrosinase) is characterized. An analysis of the structure-activity relationships of these compounds for antifouling purposes is provided, which may result useful in the design of targeted antifouling solutions with these molecules. Altogether, the findings reported herein provide a different perspective on the biological activities of phosphonium compounds that is particularly focused on, but, as the reader will realize, is not limited to their use as antifouling agents.