Event Abstract

Back to Event

Habitats characterization of circalittoral rocky bottoms of the Avilés Canyon System (Cantabrian Sea)

Francisco S. Delgado1*, Augusto R. Basalo1, Maria G. Ballesteros1, Elena Prado1*, Teodoro Patrocinio1, Pilar Ríos1, Antonio Punzon1, Jose Rueda1 and Javier Cristobo1
  • 1 Instituto Español de Oceanografía (IEO), Spain

The area of the Cantabrian sea continental shelf located in the headwaters of the Avilés Canyon System (ACS) is characterized by rocky outcrops (Gómez-Ballesteros et al., 2014). This is mainly due to the sedimentary transport mechanisms associated with the ACS oceanographic dynamics. This area is currently declared as Site of Community Importance (SCI) in the context of the Natura 2000 network, mainly due to the existence of coral reefs (Sánchez et al., 2014). In this area operates some artisanal fisheries so that it is compulsory to know the vulnerable habitats spatial distribution in order to identify potential conflicts of use (Punzón et al., 2016). The LIFE+ INTEMARES project (www.intemares.com) has as main objective to ensure the effective management of Spanish Marine Protected Areas (MPA) net. For the elaboration, update and approval of Management Plans of ACS it is necessary to identify the conflict of uses between the conservation of vulnerable habitats and the fisheries. The INDEMARES, SponGES, ECOMARG and INTEMARES projects took place a series of multidisciplinary surveys in the area using different samplers for both sedimentary and rocky grounds (Fig.1). In this study, we have identified, characterized and mapped the different habitats and the communities that occupy the hard bottoms, using three analytic strategies: 1) Abiotic surrogate (unsupervised classification of environmental scenarios); 2) Assemble and predict together (multivariate analysis) and 3) Predict first, assemble later (supervised classification, habitat suitability modeling), following the same criterions explained in Sánchez et al., 2017. The study of the main environmental variables that explain the settlement of sessile organisms was performed using the ISOCLUSTER tool, implemented in GIS software, and using depth and derivative variables from the bathymetry (slope, Bathymetric Position Index-BPI) together with the seabed characterization (facies). It is based on the Iterative Minimum Distance (IMD), which is the result of minimizing the variance within clusters as a way of optimizing partitioning efficiency. The results provide the estimated distribution of seabed areas that differ with respect to topography and substratum type for areas adjacent to earlier mapping sites. Six main habitat classes are identified from these abiotic data (Figure 2). The main explanatory variables for the hard bottoms habitat classification have been the BPI and the slope (Table 1). For the study of the communities of these rocky habitats we have been completed visual transects using a photogrammetric sled and stations accomplished with a rocky dredge which has allowed the estimation of the spatial distribution and density of the different species, following the same methodology explained in Sánchez et al., 2017. The most frequent species are of the following taxonomic groups: Porifera (21 species), Briozoa (13), Echinodermata (10), Polychaeta (8), Mollusca (7), Cnidaria (7) and others (8). With respect to the density of individuals the most abundant species have been: Ophiothrix fragilis (6.884 ind. by ha), Leptometra celtica (3.453), Phakellia ventilabrum (1.579), Dendrophyllia cornigera (0.379) and Gracilechinus acutus (0.084). The cup sponge (Ph. ventilabrum) and the yellow coral (D. cornigera) are the most representative structural species of the vulnerable habitat 1170 Reefs on the studied area, preferably dwells in very rough bottoms with high positive BPI fine scale. Habitat suitability models using environmental layers from acoustic methods are appropriate for the meso-habitats (10 mt to 1 km) or macro-habitat (1 to 10 mt) mapping. Taking into account the structural complexity of these rocky habitats, and to be able to characterize the micro-habitat (< 1 mt) and the behaviour of some typical species it is necessary a higher spatial resolution. We are testing the application of suitability models using environmental layers obtained from image analysis. From this methodology it`s possible to obtain environmental variables equivalent to those of the acoustic methods (slope, rugosity, BPI, aspect, etc.) but with a few millimeter of resolution which will allow us to apply suitability models for microhabitats mapping. As an example, Figure 3 shows that small rocky ridges, identified in red by its positive BPI, constitute the preferred micro-habitat for filter-feeders species, in this case the brittlestar Ophiotrix fragilis. Figure captions: Figure 1. Study area and samples carried out to characterize the habitats and species distribution from INDEMARES, SponGES and INTEMARES surveys. Figure 2. Predicted spatial distribution of the six main habitat classes obtained from ISOCLUSTER analysis using bathymetry, slope, fine scale BPI and seabed characterization as environmental variables. Figure 3. Methodology process to obtain preferred micro-habitat of the brittlestar Ophiotrix fragilis.3D model reconstruction from videotransects using photogrammetric analysis.

Figure 1
Image
Figure 2
Image
Figure 3
Image

Acknowledgements

The authors would like to thank the crew and scientific team aboard the INDEMARES (LIFE07 NAT/E/000732), SponGES (Horizon 2020, Nº 679849) and INTEMARES (LIFE15 IPE/ES/000012) European projects surveys for their contribution in providing database on the study area. This study is part of the Action A2.1 of the INTEMARES project. The Biodiversity Foundation, of the Ministry of the Environment, was the institution responsible for coordinating this project.

References

Gómez-Ballesteros, M., Druet, M., Muñoz, A., Arrese, B., Rivera, J., Sánchez, F., Cristobo, J., Parra, S., García-Alegre, A., González-Pola, C., Gallastegui, J., Acosta, J., 2014. Geomorphology and sedimentary features of the Avilés Canyon System. Cantabrian Sea (Bay of Biscay). Deep-Sea Res. II, 106(2014) 99-117. Punzón, A., J.C. Arronte, F. Sánchez, A. García-Alegre, 2016. Spatial characterization of the fisheries in the Avilés Canyon System (Cantabrian Sea, Spain). Ciencias Marinas (2016), 42(4): 237–260. Sánchez, F., González-Pola, C., Druet, M., García-Alegre, A., Acosta, J., Cristobo, F.J., Parra, S., Ríos, P., Altuna, A., Gómez-Ballesteros, M., Muñoz-Recio, A., Rivera, J., Díaz del Río, G., 2014. Habitat characterization of deep-water coral reefs in La Gaviera canyon (Avilés Canyon System, Cantabrian Sea). Deep Sea Research II, 106, 118-140. Sánchez, F., Rodríguez-Basalo, A., García-Alegre, A., Gómez-Ballesteros, M., 2017. Hard-bottom bathyal habitats and keystone epibenthic species on Le Danois Bank (Cantabrian Sea). Journal of Sea Research 130 (2017), 134-153.

Keywords: circalittoral habitats, marine protected areas, habitat suitability, Photogrammetry, Aviles Canyon System, biodiveristy and ecosystem functioning

Conference: XX Iberian Symposium on Marine Biology Studies (SIEBM XX) , Braga, Portugal, 9 Sep - 12 Sep, 2019.

Presentation Type: Oral Presentation

Topic: Ecology, Biodiversity and Vulnerable Ecosystems

Citation: Delgado FS, Basalo AR, Ballesteros MG, Prado E, Patrocinio T, Ríos P, Punzon A, Rueda J and Cristobo J (2019). Habitats characterization of circalittoral rocky bottoms of the Avilés Canyon System (Cantabrian Sea). Front. Mar. Sci. Conference Abstract: XX Iberian Symposium on Marine Biology Studies (SIEBM XX) . doi: 10.3389/conf.fmars.2019.08.00174

Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters.

The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated.

Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed.

For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions.

Received: 14 May 2019; Published Online: 27 Sep 2019.

* Correspondence:
Dr. Francisco S Delgado, Instituto Español de Oceanografía (IEO), Madrid, Spain, francisco.sanchez@ieo.es
Ms. Elena Prado, Instituto Español de Oceanografía (IEO), Madrid, Spain, elena.prado@ieo.es