Browsing by Author "Subida, M. D."

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    Exploring gaps in mapping marine ecosystem services: A benchmark analysis
    (ELSEVIER SCI LTD, 2020) Nahuelhual, L.; Vergara, X.; Bozzeda, F.; Campos, G.; Subida, M. D.; Outeiro, L.; Villasante, S.; Fernandez, M.
    We assessed the gaps between current and "model mapping routines", which represent a benchmark for mapping marine ecosystem services (ESs). Model mapping routines comprised 17 selected variables and their best-rated alternatives depending on the mapping purpose, namely, marine spatial planning, environmental impact assessment, vulnerability and risk analysis, marine protected areas management, payments for ecosystem services, and natural resources management. We conducted a systematic search of articles (n = 64) from which information on the 17 variables and their alternatives was retrieved. We assessed gaps using similarity matrices, according to the co-occurrence index. The largest gaps (as measured by average distances >0.5 between actual and best options) occurred in articles reporting natural resources management as purpose, whereas the smallest were related to marine protected areas management and payments for ecosystem services. The gaps were due to departures in different individual variables. For example, in the case of marine spatial planning the omission of tradeoffs, scenario analysis, multiple scales, and threshold analyses explained the gap, whereas in vulnerability and risk assessment the omission of thresholds, the lack of consistency of the indicators used, and the absence of a definition of ESs explained the gap. We trust that this study will help to recognize that ESs mapping studies should be guided by the purpose of a given intervention rather than by the technical capacities and disciplines of the researchers, if the ESs approach expects to reach a real impact into public policies.
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    Multivariate methods and artificial neural networks in the assessment of the response of infaunal assemblages to sediment metal contamination and organic enrichment
    (2013) Subida, M. D.; Berihuete, A.; Drake, P.; Blasco, J.
    A 4-year annual sediment survey was conducted in an organically enriched tidal channel to compare the performance of univariate community descriptors, traditional multivariate techniques (TM) and artificial neural networks (AANs), in the assessment of infaunal responses to moderate levels of sediment metal contamination. Both TM approaches and the SOM ANN revealed spatiotemporal patterns of environmental and biological variables, suggesting a causal relationship between them and further highlighting subsets of taxa and sediment variables as potential main drivers of those patterns. Namely, high values of non-natural metals and organic content prompted high abundances of opportunists, while high values of natural metals yielded typical tolerant assemblages of organically enriched areas. The two approaches yielded identical final results but ANNs showed the following advantages over TM: ability to generalise results, powerful visualization tools and the ability to account simultaneously for sediment and faunal variables in the same analysis. Therefore, the SOM ANN, combined with the K-means clustering algorithm, is suggested as a promising tool for the assessment of the ecological quality of estuarine infaunal communities, although further work is needed to ensure the accuracy of the method. (c) 2013 Elsevier B.V. All rights reserved.