Assessing Octopus vulgaris distribution using Maximum Entropy model.
1, Valavanis V2, Rocha F1 & Quesada H3
1 Depto. Ecología y Biología Animal, Facultad de Ciencias del Mar, Universidad de Vigo. Spain.
2 Marine Geographic Information Systems, Hellenic Center for Marine Research, Crete, Greece
3 Depto. Bioquímica, Genética e Inmunología, Facultad de Biología, Universidad de Vigo
The common octopus (Octopus vulgaris), the most important commercially harvested octopus species, is distributed in temperate and tropical waters of Mediterranean Sea, eastern and western Atlantic and some areas in the north western Pacific. Its populations are typically unstable and respond rapidly to changes in environmental conditions and paralarval and juvenile mortalities. In this study a new approach is proposed to study and model Octopus vulgaris distribution, the so called Maximum Entropy Model (maxent). This model predicts which areas satisfy the requirements of the Octopus and evaluates which variables have more importance for its distribution. The model was implemented recovering geographical information from more than 250 presence data collected from surveys data and bibliographical records. For every presence data the following set of environmental data was gathered: sea surface temperature (SST in ºC), salinity (‰), chlorophyll-α (CHLA in mg/m³), precipitation, sediment type, wind speed, wind direction and euphotic depth (m). The results of the analysis showed that SST is the main variable involved in Octopus vulgaris distribution. These results were contrasted with the available literature.