Lonborg C.,University of Swansea |
Lonborg C.,CSIC - Institute of Marine Research |
Alvarez-Salgado X.A.,CSIC - Institute of Marine Research
Global Biogeochemical Cycles | Year: 2012
At least 15% of the 2 Pg y-1 of dissolved organic carbon (DOC) that accumulates in the surface layer of the open ocean has been exported from the ocean margins. The C: N: P stoichiometry of the production and microbial degradation of dissolved organic matter (DOM) in the coastal ocean conditions the quality of the exported substrates. In this work, DOC, dissolved organic nitrogen (DON) and phosphorus (DOP) bioavailability measurements from published bottle incubation experiments have been compiled and reanalyzed to examine the role of bioavailable DOM (BDOM) in the coastal ocean. DOM bioavailability decreased significantly (p < 0.001) in the sequence DOP > DON > DOC, with bioavailable DOC (BDOC) representing 22 ± 12% (mean ± SD) of the total DOC, bioavailable DON (BDON) 35 ± 13% of the total DON and bioavailable DOP (BDOP) 70 ± 18% of the total DOP. This suggests that the role of DOM on the recycled and export production of the coastal ocean is more relevant for the P than for the N and for the N than for the C biogeochemical cycles. First-order microbial degradation rate constants (k) of BDOM (normalized to 15°C) increased significantly (p < 0.05) in the same sequence, with kC being 0.066 ± 0.065 day-1, kN 0.111 ± 0.096 and kP 0.154 ± 0.137 day-1. Significant (p < 0.001) power relationships were found among kC, kN and k P (R2 = 0.84-0.87). The C: N: P molar ratio of the DOM that resists microbial degradation was extremely depleted in N and P, 2835 (±3383): 159 (±187): 1, compared with the BDOM fraction, 197 (±111): 25 (±16): 1. The flushing time (t) of the coastal ocean in relation to the turnover time of BDOM (1/k), i.e., t. k, dictates the fate-degradation versus accumulation-of the large scale export of BDOM, which could fuel parts of the oceanic new production and influence the N/P limitation of the open ocean. © 2012. American Geophysical Union. All Rights Reserved.
Figueras A.,CSIC - Institute of Marine Research
Advances in Experimental Medicine and Biology | Year: 2012
The zebrafish (Danio rerio) has been extensively used in biomedical research as a model to study vertebrate development and hematopoiesis and recently, it has been adopted into varied fields including immunology. After fertilization, larvae survive with only the innate immune responses because adaptive immune system is morphologically and functionally mature only after 4-6 weeks postfertilization. This temporal separation provides a suitable system to study the vertebrate innate immune response in vivo, independently from the adaptive immune response. The transparency of early life stages allows a useful real-time visualization. Adult zebrafish which have complete (innate and adaptative) immune systems offer also advantages over other vertebrate infection models: small size, relatively rapid life cycle, ease of breeding, and a growing list of molecular tools for the study of infectious diseases. In this review, we have tried to give some examples of the potential of zebrafish as a valuable model in innate immunity and inflammation studies.
Alonso-Fernandez A.,CSIC - Institute of Marine Research |
Saborido-Rey F.,CSIC - Institute of Marine Research
Journal of Experimental Marine Biology and Ecology | Year: 2012
Proximate composition and energy content in Trisopterus luscus have been studied to address energy allocation strategy. Energy reserves in pouting females are mainly associated with lipids stored in the liver. Water content appeared to be a useful index in order to obtain very accurate predictions of energy density, particularly for ovaries and liver. Condition indices, HSI and K, are suitable to analyze nutritional status of fish, since they reflect changes in energy content and proximate composition in the different tissues studied. The seasonality of energy reserves was detected and is closely related to the sexual cycle, indicating that females pouting display a period of energy storage, mainly through lipid deposition in the liver. Therefore, T. luscus should be considered a capital rather than an income breeder, as the energy for reproduction comes essentially from stored energy. © 2012 Elsevier B.V.
Babarro J.M.F.,CSIC - Institute of Marine Research |
Abad M.J.,Grupo de Polimeros CIT
Marine Ecology Progress Series | Year: 2013
The co-existence patterns of 2 mytilid species were studied in order to evaluate the performance of the alien mussel Xenostrobus securis and the indigenous Mytilus galloprovincialis through monospecific and mixed co-habiting experiments in the Ría de Vigo (northwest Spain). Mytilus galloprovincialis was found to be the best performer in all tests. Shell growth was ∼4-fold greater for the indigenous mussel when deployed without interspecific competition and regardless of density. Differences in shell growth were found to be similar within mixed populations wherein M. galloprovincialis showed greater ability for upward migratory movements on the mixed beds and distanced itself from the mud influenced layer. The alien X. securis, however, was found to inhabit underneath the M. galloprovincialis layer, which resulted in higher mortality rates. Species-specific features such as byssus filaments and lifestyle may account for such different behaviour. M. galloprovincialis secreted thicker and stronger shells and byssus regardless of their density in both monospecific and mixed experiments. This might indicate that the indigenous mussel performs better when confronted with abiotic stress or biotic pressure. The alien X. securis is currently found to establish high-density patches of individuals at the confluence of main rivers that flow into the estuary (highly heterogeneous scenario). Such behaviour favours its settlement far from the native mussel influence area. X. securis also colonises hard substrates that are notfully occupied by other invertebrates, but its range was found to be limited by the presence of the indigenous mussel. Copyright © 2013 Inter-Research.
Wyatt T.,CSIC - Institute of Marine Research
Deep-Sea Research Part II: Topical Studies in Oceanography | Year: 2014
Margalef's mandala maps phytoplankton species into a phase space defined by turbulence (A) and nutrient concentrations (Ni); these are the hard axes. The permutations of high and low A and high and low Ni divide the space into four domains. Soft axes indicate some ecological dynamics. A main sequence shows the normal course of phytoplankton succession; the r-K axis of MacArthur and Wilson runs parallel to it. An alternative successional sequence leads to the low A-high Ni domain into which many red tide species are mapped. Astronomical and biological time are implicit. A mathematical transformation of the mandala (rotation) links it to the classical bloom models of Sverdrup (time) and Kierstead and Slobodkin (space).Both rarity and the propensity to form red tides are considered to be species characters, meaning that maximum population abundance can be a target of natural selection. Equally, both the unpredictable appearance of bloom species and their short-lived appearances may be species characters. There may be a correlation too between these features and long-lived dormant stages in the life-cycle;s then the vegetative planktonic phase is the 'weak link' in the life-cycle. Red tides are thus due to species which have evolved suites of traits which result in specific demographic strategies. © 2012 Elsevier Ltd.
Filgueira R.,CSIC - Institute of Marine Research |
Castro B.G.,University of Vigo
Continental Shelf Research | Year: 2011
Based on the stable isotope composition in 15N and 13C of different potential sources of organic matter and consumers of an intertidal Zostera marina meadow located in San Simón Bay (Ría de Vigo, NW of Spain), a simplified food web of this community was reconstructed. For this purpose, some alternatives in different steps of the most used methodology of stable isotope dietary analysis were developed that cope with some of the limitations associated to the interpretation of isotopic signals for food web analysis, those of uncertainty on the fractionation value, mathematical model to use for the diet resolution and shortage of the isotope number for discriminating many food sources. The application of this protocol to the studied community reported similar results to those from other studies based on similar trophic webs, emphasizing the importance of local primary producers, especially microphytobenthos, which could be available for several primary consumers through resuspension forced by tidal hydrodynamic. The good agreement with previous results suggests that the proposed protocol is a feasible alternative to elucidate the most plausible trophic relationships in complex trophic webs using stable isotopes analysis. © 2010 Elsevier Ltd.
Investigation of production method, geographical origin and species authentication in commercially relevant shrimps using stable isotope ratio and/or multi-element analyses combined with chemometrics: An exploratory analysis
Ortea I.,CSIC - Institute of Marine Research |
Gallardo J.M.,CSIC - Institute of Marine Research
Food Chemistry | Year: 2015
Three factors defining the traceability of a food product are production method (wild or farmed), geographical origin and biological species, which have to be checked and guaranteed, not only in order to avoid mislabelling and commercial fraud, but also to address food safety issues and to comply with legal regulations. The aim of this study was to determine whether these three factors could be differentiated in shrimps using stable isotope ratio analysis of carbon and nitrogen and/or multi-element composition. Different multivariate statistics methods were applied to different data subsets in order to evaluate their performance in terms of classification or predictive ability. Although the success rates varied depending on the dataset used, the combination of both techniques allowed the correct classification of 100% of the samples according to their actual origin and method of production, and 93.5% according to biological species. Even though further studies including a larger number of samples in each group are needed in order to validate these findings, we can conclude that these methodologies should be considered for studies regarding seafood product authenticity. © 2014 Elsevier Ltd. All rights reserved.
Castellanos-Martinez S.,CSIC - Institute of Marine Research |
Gestal C.,CSIC - Institute of Marine Research
Journal of Experimental Marine Biology and Ecology | Year: 2013
Cephalopod mollusks are an important marine resource for fisheries, and have received marked attention for studies on organismal biology; they are also good candidates for aquaculture. Wild and reared cephalopods are affected by a wide variety of pathogens, mainly bacteria, protozoa and metazoan parasites. Cephalopods do not have acquired immunity and immunological memory; therefore vaccination cannot be used to protect them against infectious diseases. Their defense mechanisms rely only on their innate immunity. In this review, we will summarize and update knowledge on the most common pathogens, the diseases they cause, and on symbionts. In addition, we provide a general overview of the cephalopod immune system, response to pathogens with a short discussion on the gene expression involved in the immune response by these animals. © 2013 Elsevier B.V.
Murado M.A.,CSIC - Institute of Marine Research |
Prieto M.A.,CSIC - Institute of Marine Research
Science of the Total Environment | Year: 2013
NOEC and LOEC (no and lowest observed effect concentrations, respectively) are toxicological concepts derived from analysis of variance (ANOVA), a not very sensitive method that produces ambiguous results and does not provide confidence intervals (CI) of its estimates. For a long time, despite the abundant criticism that such concepts have raised, the field of the ecotoxicology is reticent to abandon them (two possible reasons will be discussed), adducing the difficulty of clear alternatives. However, this work proves that a debugged dose-response (DR) modeling, through explicit algebraic equations, enables two simple options to accurately calculate the CI of substantially lower doses than NOEC. Both ANOVA and DR analyses are affected by the experimental error, response profile, number of observations and experimental design. The study of these effects - analytically complex and experimentally unfeasible - was carried out using systematic simulations with realistic data, including different error levels. Results revealed the weakness of NOEC and LOEC notions, confirmed the feasibility of the proposed alternatives and allowed to discuss the - often violated - conditions that minimize the CI of the parametric estimates from DR assays. In addition, a table was developed providing the experimental design that minimizes the parametric CI for a given set of working conditions. This makes possible to reduce the experimental effort and to avoid the inconclusive results that are frequently obtained from intuitive experimental plans. © 2013 Elsevier B.V.
Murado Garcia M.A.,CSIC - Institute of Marine Research |
Prieto Lage M.A.,CSIC - Institute of Marine Research
PLoS ONE | Year: 2013
In systems with several effectors, the results of dose-response (DR) experiments are usually assessed by checking them against two hypotheses: independent action (IA) and concentration addition (CA). Both are useful simplifications, but do not represent the only possible responses, and avoid to a large extent the analysis of the interactions that are possible in the system. In addition, these are often applied in such a way that they produce insufficient descriptions of the problem that raises them, frequent inconclusive cases and doubtful decisions. In this work a generative approach is attempted, starting from some simple mechanisms necessarily underlying the response of an elementary biological entity to an effector agent. A set of simulations is formulated next through an equally simple system of logical rules, and several families of virtual responses are thus generated. These families include typical responses of IA and CA modes of action, other ones not less probable from a physiological point of view, and even other derived from common and expectable forms of interactions. The analysis of these responses enabled, firstly, to relate some phenomenological regularities with some general mechanistic principles, and to detect several causes by which the IA-CA dualism is necessarily ambiguous. Secondly, it allowed identifying different forms of synergy and antagonism that contribute to explain some controversial aspects of these notions. Finally, it led to propose two sets of explicit algebraic equations that describe accurately a wide diversity of possible and realistic responses. © 2013 Murado García, Prieto Lage.