Ecological mapping and data quality assessment for the needs of ecosystem-based marine spatial management: case study Greek Ionian Sea and the adjacent gulfs

Abstract

Mapping of ecosystem components (natural and socioeconomic) is a prerequisite for ecosystem-based marine spatial management (EB-MSM). To initiate the process of EB-MSM in the Greek Ionian Sea and the adjacent gulfs, the main relevant ecosystem components were mapped based on existing spatial information and expert judgment. The natural components mapped included habitat types and species targeted for conservation, according to national and European legislation and international agreements. Main human activities/pressures related to fisheries, aquaculture, tourism, and industry were also mapped. In order to assess the quality of data used to map ecosystem components and therefore take into consideration the inherent uncertainty, an assessment of 5 semi-quantitative data indicators based on a pedigree matrix was conducted. Through this qualitative approach we gained information related to the sources, acquisition and verification procedures, statistical properties, and temporal & geographical correlation, along with the collection process quality of the ecosystem components under study. A substantial overlapping between ecological features and human activities was identified, confirming the need for a well-planned approach to marine space management, in order to mitigate conflicts for marine resources and conserve marine ecosystems and their associated goods and services.

Assembling Ecological Pieces to Reconstruct the Conservation Puzzle of the Aegean Sea

“…One way to overcome this hurdle is the use of a pedigree matrix which transforms qualitative metadata into semi-quantitative indicators of data quality. This approach was originally proposed by Weidema and Wesnaes (1996) and was later tested by Issaris et al (2012) on data used for ecological mapping. Following the methods employed by the aforementioned studies, a modified pedigree matrix was applied to evaluate the reliability, completeness, spatiotemporal cohesion, and data acquisition methods of the datasets used for the mapping of the distribution of ecological features (Table 3).…”

“…Indicator scores were calculated using the weighted average of all data sources considered. Weidema and Wesnaes (1996) and Issaris et al (2012). …”

Assessing uncertainty associated with the monitoring and evaluation of spatially managed areas

“…The last step ensured that all case studies contributed equally to score descriptors, allowing comparisons among descriptors as well as framework steps. These were visualised by means of radar diagrams [23].…”

“…Respective matrices of similarity were then computed based on the Gower distance [24] and multi-dimensional scaling (MDS) ordinations of case studies were hence obtained for every framework step [23,24]. Subsequently, a matrix of Pearson correlations among those similarity matrices was built, and a MDS plot of the framework steps was obtained.…”

“…Pedigree criteria provide insight into the weaknesses of the knowledge that underpin the results by means of qualitative expert judgment [26]. Recent examples of the application of pedigree matrices can be found in [23,27,28]. Here, the pedigree matrix [25] adapted to account for expert judgment of reliability (assessment) and systematic multi-criteria analysis of the production process [25], was adjusted and used.…”