Myriam Rodríguez

A domain independent natural language interface to databases capable of processing complex queries

We present a method for creating natural language interfaces to databases (NLIDB) that allow for translating natural language queries into SQL. The method is domain independent, i.e., it avoids the tedious process of configuring the NLIDB for a given domain. We automatically generate the domain dictionary for query translation using semantic metadata of the database. Our semantic representation of a query is a graph including information from database metadata. The query is translated taking into account the parts of speech of its words (obtained with some linguistic processing). Specifically, unlike most existing NLIDBs, we take seriously auxiliary words (prepositions and conjunctions) as set theory operators, which allows for processing more complex queries. Experimental results (conducted on two Spanish databases from different domains) show that treatment of auxiliary words improves correctness of translation by 12.1%. With the developed NLIDB 82of queries were correctly translated (and thus answered). Reconfiguring the NLIDB from one domain to the other took only ten minutes.

Biotic indexes reveal the impact of harbour enlargement on benthic fauna

Environmental effects of enlargement works in Puerto Calero (Lanzarote, Canary Islands) were analysed in the sediments using abiotic variables (total hydrocarbons, polyaromatic hydrocarbons, organic matter and granulometry) and three biotic indexes (AMBI, M-AMBI and BENTIX). A before–after/control–impact (BACI) design was developed with four sampling campaigns, before (November 2004), during (March and July 2005) and after (July 2006) works. Inner stations were characterised by high concentrations of pollutants (total hydrocarbons and polyaromatic hydrocarbons). A temporal trend (2004–2006) was observed in macrofaunal assemblage structure, and thus in AMBI, M-AMBI and BENTIX indexes. Macrobenthic assemblages also mirrored the pollution gradient, with bioindicator species in inner stations (the polychaete Pseudopolydora paucibranchiata and the mollusc Abra alba), sensitive species (the sipunculid Aspidosiphon muelleri, the crustacean Pariambus typicus and the polychaete Aponuphis bilineata) in outer stations and ubiquitous species (the polychaetes Aricidea assimilis and Armandia polyophthalma) in both stations (inner and outer).

Six-year study of meiofaunal dynamics in fish farms in Tenerife (Canary Islands, NE Atlantic Ocean)

In our six-year study, we investigated the dynamics of the meiofaunal community directly under the influence of a fish farm, in adjacent areas and in control areas outside the fish farm influence. Our data showed spatial, seasonal and annual variation in the meiofaunal community under the influence of the fish farm; however, no clear trend is discernible. Copepods are positively associated with mud and very fine sands, which seem to increase with time under the fish farm and adjacent areas, particularly in summer. As shown throughout the study period, copepods could soon take over other components of the community, resulting in a community shift. Our approach to investigate the dynamics of a community with a quick response to environmental changes proves useful to detect early-stage deviations from non-affected areas, which could be critical to distinguish environmental impacts before they cause major shifts in the environment.

Macrofaunal communities of threatened subtidal maërl seabeds on Tenerife (Canary Islands, north-east Atlantic Ocean) in summer

This study contributes with the first data on physical and taxonomical structure of macrofaunal assemblages of maërl beds from the Canary Islands. Maërl beds and Cymodocea nodosa meadows of the Canary Islands are considered biodiversity hot-spots in terms of taxonomic and functional biodiversity with a broad geographical and depth ranges. The authors have studied the structure of the macrofaunal assemblages on different habitat types (Cymodocea, Caulerpa, sabellid field, garden eel and maërl beds). Samples were taken at a range of depths between 14 and 46 m. Correlations were performed among abiotic variables (granulometry, organic matter, nitrogen and phosphates) and the most abundant taxa. Similarity analysis was performed to explore the patchiness of seabeds at a local scale. Significant differences were found in macrofaunal assemblages among seabed types, with highest abundances and lowest biodiversity in sabellid fields, where the sabellid Bispira viola dominated. The polychaetes Aponuphis bilineata and Chone filicauda and the mollusc Turritella brochii were the most abundant taxa on maërl beds. The mosaic of granulometric conditions would explain the associated macroinfaunal community structure and contribute to the creation of diversity on these relatively well preserved seabeds at a local scale.

Effects of proximity to offshore fish farms over soft-bottom macrofauna

Sea-cage fish farms impact the seabed within their immediate vicinity, potentially affecting recipient communities. We assessed whether proximity to three sea-cage fish farms at the Canary Islands altered patterns in the abundance, assemblage structure and richness of soft-bottom macrofauna. We related among-farm variability in dissimilarities in macrofaunal assemblage structure between seabeds beneath cages and controls to differences in hydrodynamics, production and seabed topography. Contrasting patterns of species abundances with varying proximity to fish farms were observed: some species decreased while other species increased their abundances with increasing distance at some farms. Although faunal assemblages at 0 m (i.e. beneath the cages) were different, in terms of assemblage structure, from those found at controls, pairwise differences in assemblage structure among distances away varied among the studied fish farms. Species richness showed inconsistent patterns with proximity to cages among fish farms. In summary, inconsistent patterns of macrofaunal assemblages with varying proximity to aquaculture facilities preclude confident predictions on the way offshore aquaculture alters macrofauna in the study region.

Are assemblages of the fireworm Hermodice carunculata enhanced in sediments beneath offshore fish cages

Abundances of the fireworm Hermodice carunculata were counted through a monitoring assessment study of fish cages in Barranco Hondo (NE Tenerife). Seven campaigns were conducted from November 2007 to June 2010 and temporal variations were found, as well as differences among sampling stations. The polychaete H. carunculata obtained its highest abundance in sediments beneath fish cages throughout the study period. Thus, the assemblages of this omnivorous species were favoured by the presence of fish cages.

Effects of organic enrichment on macrofauna community structure: an experimental approach

The determination of the resilience of benthic assemblages is a capital issue for the off-shore aquaculture industry in its attempts to minimize environmental disturbances. Experimental studies are an important tool for the establishment of thresholds for macrofaunal assemblages inhabiting sandy seabeds. An experiment was conducted with three treatments (Control, 1x and 3x),in which organic load (fish pellets) was added (1x (10 g of fish pellets) and 3x (30 g)). A reduction in abundance of individuals and species richness was found as between the control and organic-enriched treatments. Significant changes in assemblage structure were also found, mainly due to the decrease of the sensitive tanaid Apseudes talpa in organically-enriched treatments. AMBI and M-AMBI indices were calculated and a decrease of ecological status was observed in treatment 3x.

Confounding response of macrofauna from a confluence of impacts: brine and sewage pollution

Throughout the shores of the world, a confluence of different sources of pollution is common, e.g., through outlets releasing brine, industrial, and domestic sewage. In this study, we assessed whether a combined disposal of domestic sewage and brine altered the patterns of abundance and assemblage structure of subtidal macrofauna inhabiting sandy sea beds on the south coast of Gran Canaria (Canary Islands, NE Atlantic Ocean). Samples were collected in two surveys (May 2008 and January 2009) at three distances (0, 15, and 30 m) away from the discharge point. Macrofaunal abundances showed different patterns with varying proximity from the disposal point in the two surveys. In May 2008, lower abundances were observed at 0 m (53.89±46.82 ind.) than at 15 m (120±91.7 ind.) and 30 m (283.89±189.33 ind.) away from the disposal point. In January 2009, however, higher abundances were observed at 0 m (131.33±58.69 ind.) than at 30 m (100±24.44 ind.) and 15 m (84.78±58.39 ind.) away from the disposal point. Significant differences in macrofaunal assemblage structure were found with varying proximity from the discharge point in both surveys. The effect of proximity from the disposal point was confounded by changes in sedimentary composition between surveys, which contributed to explain differences in macrofaunal abundances and assemblage structure with varying proximity from the discharge point. As a result, confounding drivers of macrofaunal assemblage structure, here, changes in sediment composition, accounted for changes in macrofaunal abundances and assemblage structure with varying proximity from a combined disposal point of brine and sewage.