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Understanding species-specific trait responses under future global change scenarios is of importance for conservation efforts and to make informed decisions within management projects. The combined and single effects of seawater acidification and warmer average temperature were investigated by means of the trait responses of Cymodocea serrulata, a tropical seagrass, under experimental conditions. After a 35 d exposure period, biochemical, morphological, and photo-physiological trait responses were measured. Overall, biochemical traits mildly responded under the individual exposure to high temperature and increasing pCO2 values. The response of C. serrulata was limited to a decrease in %C and an increase in the sucrose content in the rhizome under the high temperature treatment, 32 °C. This suggests that this temperature was lower than the maximum tolerance limit for this species. Increasing pCO2 levels increased %C in the rhizome, and also showed a significant increase in leaf δ13C values. The effects of all treatments were sublethal; however, small changes in their traits could affect the ecosystem services they provide. In particular, changes in tissue carbon concentrations may affect carbon storage capacity, one key ecosystem service. The simultaneous study of different types of trait responses contributes to establish a holistic framework of seagrass ecosystem health under climate change.

The loss of biodiversity by the replacement of invasive species could lead to the loss of functional traits that maintain certain ecosystem services (ES). The ES method provides a conceptual framework to value changes of functional traits related to this loss of biodiversity. The Caribbean Sea offers a multifaceted seascape to evaluate this approach as native seagrass species (Thalassia testudinum, Syringodium filiforme or Halodule wrightii) cohabit this region together with the invasive seagrass Halophila stipulacea, native to the Indian Ocean. The functional traits of native seagrass species in the Caribbean are compared to different traits of H. stipulacea observed worldwide with the aim of evaluating the dimensions of this change in terms of the ES that seagrass meadows provide in the Caribbean. Under a changing seascape due to climate change and anthropogenic pressures that have driven the disappearance of most seagrass meadows in the Caribbean, we explore how this invasive seagrass could play a role in restoration attempts as a pioneer species where native species have been lost. The potential unintended consequences of the presence of H. stipulacea to replace services of native species are also noted.

Sewage outfalls are one of the main anthropogenic impacts to coastal systems. Linking the chemical analysis in sediment, and changes in the ecological responses is one of the main tasks in ecosystem assessment for the protection of the marine environment. A three-tiered approach to evaluate the impact of the sewage of a recently built and obsolete Urban Waste Water Treatment Plants (UWWTPs) was performed. The sewage from each UWWTP differentially affected surrounding sediments. Macrobenthic community changes were influenced by the chemical composition in the sediments but also by grain size and organic matter. Abundance of the different families of the macrobenthic communities were correlated with most of the chemicals analyzed. On the contrary, toxicity bioassays were correlated with Zn and PCB concentrations but not with environmental variables. The toxicity tests linked the effect of chemical contamination on macrobenthic communities. A joint assessment of both chemical concentrations and their ecological effects is recommended.

Foliar stable isotopic signatures of nitrogen, carbon, and sulfur in mangrove vegetation from the Pacific coast of Panama were insensitive to inputs from watersheds with different area of forest land cover, and to seasonal, inter-annual, and global-scale-driven contrasts in rainfall and upwelling. N, C, and S content of mangrove vegetation were not affected by inputs from watersheds with different degrees of deforestation, but showed some influence of down-estuary transformations. While there was substantial variation that remained un-explained, isotopic signatures and nutrient contents were largely determined by species-specific features, and showed substantial small-scale variation reflecting local differences, within-estuary plant-sediment links. The ability of mangrove estuaries to erase effects of deforestation points out that conservation of these wetland ecosystems is important, because, at least in the sites we studied, transformations within mangrove estuaries were strong enough to protect water quality in receiving coastal waters.

Tropical marine seagrasses live in environments with low nutrient concentrations. However, as land development intensifies along tropical coastlines, the marine environment in which these organisms grow is becoming more nutrient-rich. Nitrogen (N) uptake, assimilation, translocation and storage under a diversity of N sources in enriched conditions were investigated in two tropical seagrass species, Cymodocea serrulata and Thalassia hemprichii, from an oligotrophic marine environment. Both seagrasses were able to take up different inorganic and organic N sources through their above- and belowground tissues when enriched with high N concentrations. The uptake rates of T. hemprichii were generally higher than C. serrulata in leaves and rhizome, whereas root uptake was systematically higher in C. serrulata. Acropetal and basipetal translocation was observed in both species. Reduction and assimilation of N, measured in terms of their nitrate reductase and glutamine synthetase activity, were correlated with nitrate and ammonium uptake rates, respectively. Cymodocea serrulata showed a tendency to immediately use the available N, whereas T. hemprichii allocated more N in assimilation and storage investment. The responses of these seagrasses to N-enrichment demonstrate their ability to adapt to over-enrichment by varying N sources in the first step of the eutrophication process.

Growth and survival of two populations of Fucus vesiculosus were studied at its southern limit of distribution on the eastern Atlantic coast. Experimentally denuded areas at an estuarine and a semi-exposed site in an upwelling area (NW Spain) were followed for 17 months. Three different cohorts were detected during the sampling period. Differences among the three cohorts in terms of growth, reproduction and survival were detected. These differences may be due to the different time of appearance of the different cohorts or the presence of the previously established individuals when the second and third cohorts were recruited. Although growth of the cohorts recruiting in autumn was faster than for the cohorts recruiting in spring and summer, individual growth was represented in all cases by a logistic function, as the fastest rates of increase in length occurred during the first 6 months of life, and maximum length was attained after the thallus reached 1 year in age. In the same way, production was...

Stable isotope composition of brown macroalgae has been widely used to monitor N loading during the last decades but some of the required assumptions when using them to detect anthropogenic inputs remain untested. In this study several experiments were run with two key species, A. nodosum and F. vesiculosus , to determine internal nitrogen isotope dynamics. First, the equilibration of the isotopic values of the different parts of the thallus of these species was tested by growing them under different water sources. Then, nitrate uptake capacity and N transport along the frond were tested by 15 N enrichment experiments. The results indicate that although the growing tips had the highest uptake rates, older parts of the frond of both species have the capacity to incorporate N at low rates. No evidence of N transport along the thallus, from the tip to the basal segment of the frond or the converse was found. These results show that the growing tips of these macroalgae can be used to monitor N loadings at time scales from weeks ( F. vesiculosus ) to months ( A. nodosum ). The use of non-growing parts of the thallus to do retrospective studies cannot be recommended because of their measurable exchange of N with the surrounding water.

While it is generally agreed that δ15N of brown macroalgae can discriminate between anthropogenic and natural sources of nitrogen, this study provides new insights on net fractionation processes occurring in some of these species. The contribution of continental and marine sources of nitrogen to benthic macroalgae in the estuaryria system of A Coruña (NW Spain) was investigated by analyzing the temporal (at a monthly and annual basis) and spatial (up to 10 km) variability of δ15N in the macroalgae Ascophyllum nodosum and three species of the genus Fucus (F. serratus, F. spiralis and F. vesiculosus). Total nitrate and ammonium concentrations and δ15N-DIN, along with salinity and temperature in seawater were also studied to address the sources of such variability. Macroalgal δ15Nand nutrient concentrations decreased fromestuarine to marinewaters, suggesting larger dominance of anthropogenic nitrogen sources in the estuary. However, δ15N values of macroalgae were generally higher than those of ambient nitrogen at all temporal and spatial scales considered. This suggests that the isotopic composition of thesemacroalgae is strongly affected by fractionation during uptake, assimilation or release of nitrogen. The absence of correlation between macroalgal and water samples suggests that the δ15N of the species considered cannot be used for monitoring short-term changes. But their long lifespan and slow turnover rates make them suitable to determine the impact of the different nitrogen sources integrated over long-time periods., ANILE (CTM2009-08396 and CTM2010-08804-E) of the Plan Nacional de I+D+i (Spain), and RADIALES of the Instituto Español de Oceanografía., 3,2580

Stable isotopic N, C, and S in food webs of 8 mangrove estuaries on the Pacific coast of Panama were measured to 1) determine whether the degree of deforestation of tropical forests on the contributing watersheds was detectable within the estuarine food web, and 2) define external sources of the food webs within the mangrove estuaries. Even though terrestrial rain forest cover on the contributing watersheds differed between 23 and 92%, the effect of deforestation was not detectable on stable isotopic values in food webs present at the mouth of the receiving estuaries. We used stable isotopic measures to identify producers or organic sources that supported the estuarine food web. N isotopic values of consumers spanned a broad range, from about 2.7 to 12.3‰. Mean δ15N of primary producers and organic matter varied from 3.3 for macroalgae to 4.7‰ for suspended particulate matter and large particulate matter. The δ13C consumer data varied between-26 and-9‰, but isotopic values of the major apparent producers or organic matter sampled could not account for this range variability. The structure of the food web was clarified when we added literature isotopic values of microphytobenthos and coralline algae, suggesting that these, or other producers with similar isotopic signature, may be part of the food webs. Fil: Viana, Inés G.. Centro Oceanográfico de La Coruna; España. Marine Biological Laboratory; Estados Unidos Fil: Valiela, Ivan. Marine Biological Laboratory; Estados Unidos Fil: Martinetto, Paulina Maria del Rosario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina Fil: Monteiro Pierce, Rita. Marine Biological Laboratory; Estados Unidos Fil: Fox, Sophia E.. National Park Service; Estados Unidos

Many chemicals that are currently used in aquaculture have not been evaluated with regard to their specific effects on the aquatic environment. In the present study, the toxic effects of several chemicals associated with land-based marine fish farming activities were assessed using two species of marine microalgae (Phaeodactylum tricornutum and Isochrysis galbana). Mini-scale toxicity tests were performed with six antibiotics (amoxicillin, ampicillin, flumequine, oxytetracycline, streptomycin and sulfadiazine) and two disinfectants (formaldehyde and hypochlorite). Amoxicillin and streptomycin did not exert toxic effects. Sulfadiazine was the most toxic chemical; the EC50 values were 0.11 mg/L and 1.44 mg/L for P. tricornutum and I. galbana respectively. As expected, the disinfectants displayed high toxicity, and P. tricornutum was particularly sensitive to these compounds. Although the differences in microalgal sensitivity depended on the chemical considered, both species were highly sensitive to most of ...

The nitrogen isotope ratio (δ15N) in tissues of native macroalgae was evaluated as a means of indicating the intensity and spatial extent of organic contamination due to disposal of waste from land-based marine fish farms (LBMFFs). Three species of macroalgae from the genus Fucus and the green macroalgae Codium tomentosum were selected for study. The study was carried out at seven flat marine fish farms located in Galicia (NW Spain). Tests were carried out to determine the intra-annual variation in δ15N values and any differences between selected macroalgae. The δ15N values enrichment was observed close to the disposal point, and δ15N values varied more widely throughout the year (±5.57 ‰) at sites affected by the marine fish farm effluent compared to natural conditions (±2 ‰). No significant differences in the isotopic signals were observed in the different species studied (standard major axis). The δ15N values of macroalgae may be an ideal means of detecting the presence of LBMFFs effluents.

The use of stored samples of macroalgae (Fucus ceranoides, Fucus spiralis and Fucus vesiculosus) to monitor contamination of coastal areas was evaluated. The samples, collected from sampling sites (SS) along the entire coast of Galicia (NW Spain) in 5 sampling surveys carried out between 1990 and 2007, were stored in an Environmental Specimen Bank (ESB). The δ15N was measured in the macroalgal tissues as an indicator of eutrophication. A decrease in δ15N (p

Different European Framework Directives have established a series of objectives for conservation of the coast, and monitoring tools must be made available to test compliance with these aims. In the present study the use of macroalgae deposited in an Environmental Specimen Bank was evaluated as a possible environmental tool for monitoring the coastal ecosystem. The concentrations of Al, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, V and Zn in three species of the genus Fucus (Fucus spiralis, Fucus vesiculosus and Fucus ceranoides) were measured at sampling sites distributed along the coast of Galicia (NW Spain). In the period 1990-2001, the concentrations of the metals were higher in 1990 than in 2001, with the exception of: i) Mn in F. ceranoides and Fe in F. spiralis-F. vesiculosus, for which there were no differences between the sampling periods, and ii) Zn in F. vesiculosus and Fe in F. ceranoides, for which the concentrations were higher in 2001 than in 1990. In the period 2001-2007 concentrations of the metals were more stable, especially in F. ceranoides (e.g. Al, Fe, Hg, Ni and V). The concentrations were also more stable vin F. vesiculosus in 2005 (i.e. Al, Cr, Fe, Mn and Zn). The population density distributions are consistent with the results of the statistical tests. The results indicate that macroalgae of the genus Fucus may be useful for applying different European Framework Directives, given that the macroalgae are sufficiently sensitive to changes in concentrations of metals, and may be suitable for long-term monitoring and used for the detection of increased concentrations of metals (real-time monitoring).

Populations near the geographic distribution limits of the species are considered to live under suboptimal conditions, and hence slight environmental changes can be critical for their survival. The potential sensitivity to disturbances of the long living macroalga Ascophyllum nodosum was analyzed by the determination of growth, recruitment, mortality, and production of biomass in a population near its southern distribution limit. Recruitment, survival and growth rates of 2 yr old individuals were obtained from individuals in the original population after estimating their age from the number of gas bladders in the thallus. Growth and survival were described as continuous non-linear functions of age applied to the population and were further used to make demography-based production estimates. Recruitment of A. nodosum in denudated substrates required a previous cover of other macroalgae (as Fucus vesiculosus) but subsequent settlement of new recruits was not observed, as only one cohort was detected during the 26 month-period of the study. The low production estimates (2,033 g m-2 for a 10 yr period) and poor recruitment indicates high sensitivity of this population to denudation. However, the large variability observed in the growth curves of different populations along this southern distribution area suggest a large potential for adaptation to local conditions that may overcome environmental changes at regional scales., proyecto ANILE (CTM2009-08396 y CTM2010-09904-E) Plan Nacional de I+D+I (España), 2,0110

While it is generally agreed that δ(15)N of brown macroalgae can discriminate between anthropogenic and natural sources of nitrogen, this study provides new insights on net fractionation processes occurring in some of these species. The contribution of continental and marine sources of nitrogen to benthic macroalgae in the estuary-ria system of A Coruña (NW Spain) was investigated by analyzing the temporal (at a monthly and annual basis) and spatial (up to 10 km) variability of δ(15)N in the macroalgae Ascophyllum nodosum and three species of the genus Fucus (F. serratus, F. spiralis and F. vesiculosus). Total nitrate and ammonium concentrations and δ(15)N-DIN, along with salinity and temperature in seawater were also studied to address the sources of such variability. Macroalgal δ(15)N and nutrient concentrations decreased from estuarine to marine waters, suggesting larger dominance of anthropogenic nitrogen sources in the estuary. However, δ(15)N values of macroalgae were generally higher than those of ambient nitrogen at all temporal and spatial scales considered. This suggests that the isotopic composition of these macroalgae is strongly affected by fractionation during uptake, assimilation or release of nitrogen. The absence of correlation between macroalgal and water samples suggests that the δ(15)N of the species considered cannot be used for monitoring short-term changes. But their long lifespan and slow turnover rates make them suitable to determine the impact of the different nitrogen sources integrated over long-time periods.

proyectos ANILE (CTM2009- 08396 and CTM2010-08804-E) del Plan Nacional de I+D+i y RADIALES del Instituto Español de Oceanografía (IEO). C.M. e I.G.V. disfrutaron de contratos FPI del IEO y del Ministerio de Economía y Competividad respectivamente., In this study the effect of inputs of organic matter and anthropogenic nitrogen at small spatial scales were investigated in the benthos of the Ria of A Coruña (NW Spain) using stable carbon and nitrogen isotopes. This ria is characteristically enriched in nutrients provided either by marine processes (as coastal upwelling) or by urban and agricultural waste. Stable isotope composition in trophic guilds of infaunal benthos revealed spatial differences related to their nutrient inputs. The main difference was the presence of an additional chemoautotrophic food web at the site with a large accumulation of organic matter. The enrichment in heavy nitrogen isotopes observed in most compartments suggests the influence of sewage-derived nitrogen, despite large inputs of marine nitrogen. Macroalgae (Fucus vesiculosus) resulted significantly enriched at the site influenced by estuarine waters. In contrast, no differences were found in mussels (Mytilus galloprovincialis), thus suggesting a major dependence on marine nutrient sources for this species. However, the estimations of anthropogenic influence were largely dependent on assumptions required to model the different contributions of sources. The measurement of stable isotope signatures in various compartments revealed that, despite anthropogenic nutrients are readily incorporated into local food webs, a major influence of natural marine nutrient sources cannot be discarded., IEO, Plan nacional I+D+i, 2,2770

Proyectos ANILE (CTM2009-08396 and CTM2010-08804-E) del Plan Nacional de I+D+i y RADIALES del Instituto Español de Oceanografía (IEO). I.G.V. recibió un contrato FPI del Ministerio de Economía y Competividad, Growing human population add to the natural nitrogen loads to coastal waters. As the excess nitrogen is readily incorporated in new biomass anthropogenic and natural nitrogen sources may be traced by the measurement of stable nitrogen isotopes (δ15N). In this study δ15N was determined in two species of macroalgae (Ascophyllum nodosum and Fucus vesiculosus), and in nitrate and ammonium to determine the relative importance of anthropogenic versus natural sources of nitrogen along the coast of NW Spain. Both algal species and nitrogen sources showed similar isotopic enrichment for a given site, but algal δ15N was not related to either inorganic nitrogen concentrations or δ15N in the water samples. The latter suggests that inorganic nitrogen inputs are variable and do not always leave an isotopic trace in macroalgae. However, a significant linear decrease in macroalgal δ15N along the coast is consistent with the differential effect of upwelling. Besides this geographic variability, the influence of anthropogenic nitrogen sources is evidenced by higher δ15N in macroalgae from rias and estuaries compared to those from open coastal areas and in areas with more than 15x103 inhabitants in the watershed. These results indicate that, in contrast with other studies, macroalgal δ15Nis not simply related to either inorganic nitrogen concentrations or human population size but depends on other factors as the upwelling or the efficiency of local waste treatment systems., Plan nacional I+D+i, IEO, 3,2580

Environmental monitoring plans (EMP) that include chemical analysis of water, a battery of bioassays and the study of local hydrodynamic conditions are required for land-based marine aquaculture. In this study, the following standardized toxicity tests were performed to assess the toxicity of effluents from eight land-base marine fish farms (LBMFFs) located on the northwest coast of Spain: bacterial bioluminescence (with Vibrio fischeri at 15 and 30 min), microalgal growth (with Phaeodactyllum tricornutum and Isochrysis galbana) and sea urchin larval development (with Paracentrotus lividus and Arbacia lixula). These bioassays were evaluated for inclusion in routine fish farm monitoring. Effective concentrations (EC(5), EC(10), EC(20), EC(50)) for each bioassay were calculated from dose-response curves, obtained by fitting the bioassay results to the best parametric model. Moreover, a graphical method of integrating the results from the battery of bioassays and classifying the toxicity was proposed, and the potential ecotoxic effects probe (PEEP) index was calculated. The bacterial bioluminiscence test at 30min, growth of I. galbana and larval development of A. lixula were found to be the most sensitive and useful tests. Graphical integration of these test results enabled definition of the ecotoxicological profiles of the different farms. The PEEP index, considering EC(20), efficiently reflected the toxic loading potential of LBMFF effluents. In conclusion, a battery of bioassays with species from different low trophic levels is recommended as a rapid and cost-effective methodology for assessing LBMFF discharges. The graphical integration method and the PEEP index are proposed for consideration in EMPs for such farms.

In aquaculture, disinfection of facilities, prevention of fish diseases, and stimulation of fish growth are priority goals and the most important sources of toxic substances to the environment, together with excretory products from fish. In the present study, embryos of two species of sea urchin (Paracentrotus lividus and Arbacia lixula) were exposed to serial dilutions of six antibiotics (amoxicillin (AMOX), ampicillin, flumequine (FLU), oxytetracycline (OTC), streptomycin (ST), and sulfadiazine [SFD]) and two disinfectants (sodium hypochlorite (NaClO) and formaldehyde [CH(2)O]). Alterations in larval development were studied, and the effective concentrations (ECs) were calculated to evaluate the toxicity of the substances. Both species showed similar sensitivities to all substances tested. Disinfectants (EC(50) = 1.78 and 1.79 mg/l for CH(2)O; EC(50) = 10.15 and 11.1 mg/l for NaClO) were found to be more toxic than antibiotics. AMOX, OTC, and ST caused20 % of alterations, even at the highest concentrations tested. FLU was the most toxic to P. lividus (EC(50) = 31.0 mg/l) and SFD to A. lixula (EC(50) = 12.7 mg/l). The sea urchin bioassay should be considered within toxicity assessment-monitoring plans because of the sensitivity of larvae to disinfectants.