During the month of April in 2008, NAZCA’s dive team performed a biodiversity evaluation of the benthic rocky communities in the Puntilla Santa Elena zone using subtidal censuses in 15 different sites that represented the majority of species diversity in the area. The location of each immersion was recorded using a Global Positioning System (GPS).
During September, 2008, we performed a seafloor mapping analysis in the marine area of the “Faunal Production Reserve Puntilla Santa Elena.” Since this study was done before the formal declaration of the reserve and thus the boundaries were not yet defined, only 79% of the actual area of the marine zone was mapped.
For this project we used single beam sonar (Roxann Groundmaster GD-X) with a Furuno LS4100 echosounder (Roxann control box), a mounted acoustic transductor, a Magellan eXplorist XL global positioning system (GPS), and a “Deep Blue” marine video camera system by Ocean System/Splashcam.
The sampling transects were designed taking into account the following parameters:
- The provisional limits of the marine protected area,
- The 50m depth limit,
- The priority locations determined by biological monitoring,
- The basic ship speed of 6 knots, and
- The daily work schedule (hours worked per day).
Once the equipment was installed on the boat, it was calibrated using the help of the “Deep Blue” video system.
The information was processed using Surfer8 and ArcGis 8.3 geographic information systems. The data that showed a change of +/- 1.5 m in 1-second intervals were eliminated from the dataset. With the resulting information, we created a depth model using the “Kriging” interpolation model and a resulting bathymetries map of the zone.
Marine seafloors were evaluated using the interpolation information and the “Nearest Neighbor” method and by considering the information compiled by the biological monitoring.
Among others, the zone known as Low Radius (Vicioso and Aquapark, Location Mapping of Area and GPS points), that represents groups of small and medium-sized rocks, stood out following the analysis. In the Vicioso site, a large variety of gorgonians, corals, algae, and sessile invertebrates are present, as well as a high abundance of commercial fish species.
This information has served as a baseline dataset for the evaluation of current states of marine habitats and their associated marine organisms. It has also facilitated the production of marine reserve maps (bathymetry and seafloor types) that help in making short, medium, and long-term decisions.
– MAP 1: Location of the proposed Marine Reserve and location of the GPS points (11,7 MB, pdf). Also available in the PUBLICATIONS section.
– MAP 2: Bathymetric map of the covered area (10,5 MB, pdf). Also available in the PUBLICATIONS section.
– MAP 3: Habitats of the rocky-sandy bottom of the covered area (7,5 MB, pdf). Also available in the PUBLICATIONS section.