Description
The project will expand the established cooperation to a field of research very much needed in both institutions and highly demanded by fisheries managers and other stakeholders. The objective is to investigate associations between fish and three-dimensional habitats, with emphasis on the redfish. The donor partner, Marine Research Institute of Iceland MRI will provide the data for the descriptors and prepare the GIS layers that show their spatial distributions and will contribute to the analysis of the data and the writing of the manuscript. The expected results derived from the Icelandic datasets will result in an improved understanding on the habitat preferences of fish and on the underlying drivers that influence these associations, both at individual sites and in a broader context. They will aim to publish two scientific articles based on the work carried out in the project. Expected benefits would be for fisheries and research groups studying sea habitats
Summary of project results
The project was formulated to examine fish and habitat interactions based on data collected within Icelandic waters and initiating habitat mapping incentives within Galician waters. The activity performed included: 1) Habitat and fish interactions in the Lónsdjúp through (SE-Iceland). Beneficiary worked on two manuscripts, to be submitted to Deel Sea Research journal. The first manuscript compares fish communities on and off coral habitats based on long-line catches. The data for analysis originates from two long-line cruises carried out in 2009 and 2010. This paper shows that the fish community was highly influenced by the overall habitat rugosity rather than due to the presence of cold-water corals per se. This conclusion was based on multivariate analysis that separated the effects of coral presence from other habitat predictors. The second paper examines the small-scale habitat associations of redfish on cold-water coral grounds. Various statistical tools were used, both univariate and multivariate, to examine associations between fish and habitats. This study shows that redfish (Sebastes spp.) was highly associated to three-dimensional habitats, especially cold-water corals. Further analysis were carried out to examine the spatial associations of redfish to habitat features. Both studies highlight the importance of applying statistical tools that enable decomposing the variation of the predictor variables. 2) Data analysis on regional differences in fish-habitat associations was in progress at the end of the funded stay. This involved examining fish and habitat interactions at 10 other sites than Lónsdjúp case study area. During preliminary analysis of data it became clear that fish densities were in many cases too low in these sites to enable any formal examination of the fish and habitat interactions. 3) A workshop was held on “Habitat mapping in Galician waters” on April 8, 2015.
Summary of bilateral results
In recent years the Marine Research Institute of Iceland has been involved in mapping seabed habitats within the Icelandic 200 Nm exclusion zone. This includes mapping of seascapes (underwater landscapes) with multibeam sonar and benthic habitats. This institute provided the data for the descriptors and prepare the GIS layers that show their spatial distributions. At the same time, it benefited from the expertise of the Spanish Institute of Marine Research of Vigo in fish population dynamics, life history traits and behaviour. There is a vast experience of Project Promoter researchers on redfish life history for more than 25 years, including Icelandic and adjacent waters redfish. This experience includes life history traits such as reproductive cycle, spawning behaviour, recruitment, growth, maturation, fecundity which determine vertical and horizontal fish movements, and hence habitat use. The workshop “Habitat mapping in Galician waters”, held within the frame of this project, was the first step towards formulating a collaborative project which had the aim to 1) map seabed habitats and 2) identify important fish habitats in Atlantic Islands of Galicia National Park. The future use of the results derived from this project is mainly twofold. Firstly, the scientific output in terms of scientific papers will be of interest to the wider scientific community, especially with respect to studies on fish and habitat interactions. Secondly, the project will facilitate establishment of future projects.