Pacific Ocean Perch - Mapping (cont.)
Hard substrates (such as boulders) were almost always covered with invertebrates such as corals or sponges.
Invertebrates sampled at study sites included Paragorgia species (above), champagne flute hydroids (top right) and deepwater sponges (bottom right)
Using a GIS, data were extracted from the multibeam maps included average local slope, rugosity (the variance of the depth), height of each data point relative to the surrounding area. Data extracted from the sidescan sonar maps were average reflectivity and complexity (the variance of the reflectivity).
Using a classification tree analysis (figure above) we developed a “bottom-up” method for integrating the extracted acoustic data and video. The results of the modeling agreed very well with the observed habitat delineations (image below). The error rate for classification of acoustic data was <25%.
In the future, these methods will be used to classify the habitats in the two remaining study sites. The presence of juvenile Pacific ocean perch (POP) within the different habitats observed here will also be examined (see POP: Abundance).
« back
|
