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A pesar del gran interés ecológico y económico que tiene el mero (Epinephelus marginatus), y el importante esfuerzo investigador realizado desde los años 90, no se han definido las condiciones para su óptimo engorde en cautividad. En general, las mejores condiciones de cultivo son las que proporcionan un ambiente similar al existente en el medio natural, y en el mero, estas condiciones estarían relacionadas con sus hábitos sedentarios, que al ocupar cuevas en el fondo, le permitiría destinar gran parte de la energía adquirida a crecimiento. Las diferentes condiciones de cultivo ensayadas en este estudio muestran que la presencia de refugios (CR) no mejoró el engorde respecto al cultivo sin refugios (SR), mientras que el grupo cultivado en jaula (JAU) mostró el menor peso medio a lo largo del estudio, con 123,1±67,5 g a los 645 días de edad (DDE), frente a SR y CR, que fueron similares, pero con una mayor dispersión en los peces CR (151,6±42,3 g y 164,7±84,6 g, respectivamente). El aumento del diámetro del refugio (225 DDE) y la retirada de la jaula (400 DDE) mejoraron los parámetros de engorde, aumentando el peso un 62% frente al 29% del periodo previo, y un 47% a 530 DDE respecto al 12% del periodo previo, respectivamente, pero no disminuyó la dispersión. La falta de refugios no perjudicó el engorde respecto a su presencia, mientras que el cultivo en jaula requiere un suministro de alimento mejorado.

El cultivo de Seriola dumerili constituye una opción a la diversificación y crecimiento de la producción de peces marinos, que aprovecharía, además, los sistemas de producción e instalaciones en el mar comúnmente usadas para especies como Sparus aurata. Sin embargo, este crecimiento podría estar amenazado por las patologías especificas e inespecíficas de ambas especies, principalmente las causadas por ectoparásitos. Este estudio muestra, en grupos de dorada (GD), seriola (GS) y dorada y seriola juntas (GDS-GSD), una evolución estable del número de huevos de Zeuxapta seriolae (GS: 35±10, y GDS-GSD: 67±24) y de Sparicotyle chrysophrii (GD: 59±10, y GDS-GSD: 22±4), mientras que los huevos de Neobebedenia melleni colectados en GS (2483±364) y GDS-GSD (3168±474) fueron entre un 15 y 20% más altos que en GD (508±100). No se encontraron diferencias en el hematocrito, glucosa, proteína, colesterol y triglicéridos de cada especie cultivada sola o de forma conjunta durante el estudio, pero los niveles de glucosa plasmática en seriola fueron un 50% más altos, y el colesterol un 30% más bajo que en la dorada. NewSpec

We combine consistently dated benthic carbon isotopic records distributed over the entire Atlantic Ocean with numerical simulations performed by a glacial configuration of the Norwegian Earth System Model with active ocean biogeochemistry, in order to interpret the observed Cibicides δ13C changes at the stadial-interstadial transition corresponding to the end of Heinrich Stadial 4 (HS4) in terms of ocean circulation and remineralization changes. We show that the marked increase in Cibicides δ13C observed at the end of HS4 between ~2000 and 4200 m in the Atlantic can be explained by changes in nutrient concentrations as simulated by the model in response to the halting of freshwater input in the high latitude glacial North Atlantic. Our model results show that this Cibicides δ13C signal is associated with changes in the ratio of southern-sourced (SSW) versus northern-sourced (NSW) water masses at the core sites, whereby SSW is replaced by NSW as a consequence of the resumption of deep water formation in the northern North Atlantic and Nordic Seas after the freshwater input is halted. Our results further suggest that the contribution of ocean circulation changes to this signal increases from ~40 % at 2000 m to ~80 % at 4000 m. Below ~4200 m, the model shows little ocean circulation change but an increase in remineralization across the transition marking the end of HS4. The simulated lower remineralization during stadials than interstadials is particularly pronounced in deep subantarctic sites, in agreement with the decrease in the export production of carbon to the deep Southern Ocean during stadials found in previous studies.

Knowledge gaps pertaining to the remediation of freshwater lakes impacted by oil spills have persisted despite recent record highs for oil production and transportation across vulnerable regions in North America. The multiyear Freshwater Oil Spill Remediation Study (FOReSt), conducted at the IISD-Experimental Lakes Area in Canada, is focusing on the efficacy of minimally invasive methods for remediating oil spills in freshwater boreal lakes. In this thesis, the impacts and remediation of diluted bitumen (dilbit) and conventional heavy crude oil (CHV) spills were investigated (year 1), as were a variety of different remediation methods for spills of dilbit on different shoreline substrates (year 2). Two common small-bodied fish, fathead minnows (Promephales promelas) and finescale dace (Chrosomus neogaeus), were used to assess exposure to petrogenic polycyclic aromatic compounds (PACs) in model enclosed shoreline ecosystems impacted by spills and remediated using minimally invasive techniques. Short-term exposure to PACs, the most toxicologically relevant compounds in oil, was assessed in fish using biliary metabolite concentrations. In year one, finescale dace and fathead minnows residing in oil treated enclosures each had biliary pyrene metabolite concentrations that were positively correlated with pyrene concentrations in the water of the enclosures. Three months after the initial spills, fish in the enclosure receiving dilbit were significantly more exposed to PACs than fish in reference enclosures that did not receive oil. In year two, both finescale dace and fathead minnows residing in oil-treated exposures, regardless of shoreline substrate, showed increased exposure to PACs compared to fish in reference enclosures and the pristine lake environment two and a half months after the spills. No significant differences in exposure were observed among the remediation treatments. Biliary PAC metabolite concentrations were positively predicted by parent PAC concentrations in periphyton. PACs in periphyton two and a half months after oil introduction were positively correlated with PACs in the enclosures one week after spills, suggesting fish also had increased exposure to periphyton-bound alkyl-PACs. This thesis validates the use of small-bodied fish in assessing PAC exposure following freshwater oil spills and demonstrates the difficulties in estimating exposure using environmental concentrations in natural systems.

The environment during early life history strongly impacts phenotypic development in all organisms, which further influences developmental trajectory and ecological fitness later in life. Depending on the developmental stage and magnitude of change in the environment, phenotypes may become irreversible and thus have a long-lasting effect later in life. This thesis was designed to better understand how changes in the environment may influence plasticity and variation of metabolic phenotypes of Lake Sturgeon (Acipenser fulvescens) within the first year of life. Broadly speaking, the thesis tested two hypotheses that 1) all measured phenotypes would be plastic; and 2) durations of environmental effects on phenotypic development would be correlated with distinct developmental windows. Studies were developed to examine 1) short-term effects of temperature or diet on metabolic phenotypes such as metabolic rate, energy density, fatty acid profiles, and growth (Chapters 2 and 3) and 2) longer-term effects of temperature or diet during early life on these metabolic phenotypes (Chapters 4, 5 and 6). The first experimental chapter (Chapter 2) examined ontogenetic development of metabolic rate and demonstrated that dietary shifts between Artemia to bloodworm resulted in cessation of growth with elevated routine metabolic rate. Chapter 3 examined how fatty acid profiles and plasma cortisol concentration were influenced by environmental temperature and showed that decreasing temperature led to increases in mono- and polyunsaturated fatty acids in both phospholipids and triglycerides, and food deprivation resulted in lack of difference between baseline and peak cortisol concentrations. Chapter 4 examined how temperature during early life influenced plasticity of growth and showed that temperature post-dietary transition resulted in a transient effect on growth and energy metabolism without long-term effects post-winter. Chapter 5 examined how temperature during early life could influence growth and fatty acid metabolism when fish were exposed to colder temperatures later in life and demonstrated that elevated temperatures resulted in a longer-term effect on growth but lack of transcriptional responses of desaturating fatty acids when exposed to a cold temperature (3.5°C) later in life. The final experimental chapter, Chapter 6 examined longer-term effects of diet at the onset of exogenous feeding on metabolism and growth and demonstrated that an enriched diet resulted in prolonged effects on growth, digestive enzyme activity and survival prior to a simulated overwintering. This doctoral thesis research revealed that all measured metabolic phenotypes were plastic, but subtle changes in temperature and diet during early life history resulted in transient or prolonged effects on growth and metabolism in age-0 lake sturgeon. Results will aid our understanding of cohort and population dynamics as well as contribute to the development of conservation strategies for lake sturgeon, a species at risk or endangered across its natural range.

Protocolo de calidad de muestreos RIM y OAB Protocolo de calidad para los programas de muestreo a bordo y en tierra (puerto/lonja) de la flota española que faena, tanto en el noroeste (NO) de África en el marco de Acuerdos de Asociación de Pesca Sostenible (AAPS), como en el caladero nacional de Canarias (región ultra periférica).

Predicting fitness in natural populations is a major challenge in biology. It may be possible to leverage fast-accumulating genomic datasets to infer the fitness effects of mutant alleles, allowing evolutionary questions to be addressed in any organism. In this paper, we investigate the utility of one such tool, called PROVEAN. This program compares a query sequence with existing data to provide an alignment-based score for any protein variant, with scores categorized as neutral or deleterious based on a preset threshold. PROVEAN has been used widely in evolutionary studies, e.g., to estimate mutation load in natural populations, but has not been formally tested as a predictor of aggregate mutational effects on fitness. Using three large, published datasets on the genome sequences of laboratory mutation accumulation lines, we assessed how well PROVEAN predicted the actual fitness patterns observed, relative to other metrics. In most cases, we find that a simple count of the total number of mutant proteins is a better predictor of fitness than the number of variants scored as deleterious by PROVEAN. We also find that the sum of all mutant protein scores explains variation in fitness better than the number of mutant proteins in one of the datasets. We discuss the implications of these results for studies of populations in the wild.

The dataset compiles pigment content, absorptance data, photosynthetic parameters and primary production data as proxies for summertime photoacclimation of the temperate intertidal eelgrass Zostera marina after a 25-day exposure to a natural light intensity gradient (6, 36, 74, 133, 355, 503 and 860 µmol photons/m²/s) under laboratory conditions at the Pointe-au-Père research station, East Rimouski, Quebec, Canada. The data bundle contains: 1) photosynthetic and total absorptance data at the end of the experiment, which respectively represent the fraction of incident visible light absorbed by the photosynthetic tissues corrected and not corrected for non-photosynthetic absorption; 2) pigment content at the end of the experiment, which includes chlorophyll a and b and total carotenoids contents; 3) photosynthetic parameters obtained by Rapid Light Curves (RLC) on days 5 and 25, including photosynthetic apparatus efficiency (alpha), capacity (ETRmax) and saturation (Ek); 4) whole shoot primary production at the end of the experiment, which was calculated from oxygen fluxes under light and dark conditions, and normalized by leaf surface.

Oral communication The microbe-dissolved organic matter (DOM) interactions include microbial uptake and DOM reworking and release, affecting the composition of the heterogeneous DOM pool. In turns, this distinct DOM composition can select for microbial assemblages. We investigated the diversity of microbial (both Bacteria and Archaea) communities (combining Illumina tag sequencing of 16S rRNA gen -amplicon sequencing variants, ASVs- and metagenomics) and the chemodiversity of dissolved organic molecules (extracted by solid phase extraction and analyzed by Fourier Transform Ion Cyclotron Resonance Mass Spectrometry, FT-ICR-MS) in the Eastern North Atlantic Ocean off the Galician coast (43oN, 9o-15oW). Sampling ranged from 100 m to 5000 m, thereby encompassing a wide variety of water masses with contrasting origins and different aging. Applying diversity ecological metrics to both organic compounds and ASVs, we found that microbial diversity and richness were negatively correlated with DOM concentration and chemo-diversity. Besides, our results demonstrated the link between this trend and water mass aging, which enhances biosphere taxonomic diversity but reduces molecular variety. DOM diversity, decreasing along the water mass aging gradient, would likely reflect the persistence of the most refractory molecules, generated as by- product of the DOM degradation by microbes. In two PCoAs based on the metagenomic data, combined PCoA axis 1 and PCoA axis 2, explained the 80% and 20% of the microbial gene ́s structural variability among water masses. The oldest water masses, originated at high latitudes, such as NADW and LDW, were associated to higher abundance of genes involved in metabolism of aromatic compound. Intermediate waters such as ENACWst were related to sulphur/iron/phosphorous metabolism-related genes. Surface waters were linked to genes involved in photosynthesis, autotrophy and cell division. Taken together, the observed increase of DOM homogenization along water mass aging was associated to differences in the functional diversity of microbial communities