There is an increasing demand for biodiversity mapping to address new challenges in the management of marine ecosystems. Species distribution models are a key tool in supplying part of this information. However, the use of these models in the marine environment is still developing and the reasons for the underlying use of different methodological approaches are not always clear. In this work, we compared four different statistical techniques: the ecological niche factor analysis (ENFA), the MAXimun ENTropy algorithm (MAXENT), general additive Models (GAMs), and Random Forest. ENFA and MAXENT were applied using presence-only data whereas GAM and Random Forest used presenceabsence data. As a case study, we used four deep sea urchin species: Centrostephanus longispinus, Coelopleurus floridanus, Stylocidaris affinis, and Cidaris cidaris. The distribution of the studied sea urchins showed strong bathymetric segregation. Depth was the most important variable, followed by reflectivity and slope. The correlations between the predictive outputs of the models were similar between GAM, Random Forest and MAXENT, and lower for ENFA. Models using presence/absence data showed the highest scores in the four species, significantly outperforming ENFA in most of the cases, although differences with MAXENT were significant in only one species.

January 2015. The distance between solid vertical lines represents 1 nautical mile (1 852 m). The summit of Erica has a minimum depth of ~880 m

Valdivia Bank is an oceanic plateau in the south Atlantic formed by hot spot volcanism at the mid-Atlantic Ridge (MAR) (Kumar, 1979;O'Connor & Duncan, 1990). It is part of Walvis Ridge, an aseismic volcanic chain that stretches from the Namibian margin of west Africa nearly to the MAR. Although commonly attributed to volcanism from a deep mantle plume (Courtillot et al., 2003;Hoernle et al., 2015), its morphology is more complex than plume trails such as the Hawaiian-Emperor and Louisville seamount chains (e.g., O'Connor & Jokat, 2015b;O'Connor & Le Roex, 1992;Sager et al., 2021). Off Africa, the Walvis Ridge is a linear ridge (Frio Ridge) trending SW-NE. It turns to N-S by nearly a right angle at Valdivia Bank, and upon resuming its SW-NE