We developed a point-and-click acoustic data viewer (FishViewer) for exploratory comparison of up to three acoustic survey transects (or three frequencies) at a time and other environmental and biological data (e.g., surface temperature and seabird abundance). FishViewer also contains image-processing tools (e.g., morphological and threshold filters) for distinguishing between fish shoals and plankton patches and for patch identification. These tools and methods are illustrated using survey data collected at three frequencies (38, 120, and 200 kHz) near the Pribilof Islands, Bering Sea, during September 1995. Data were also visualized by converting the patches identified in the acoustic images to polygons, showing the boundaries of each patch using a connected component algorithm. Proximity between these fish shoal and plankton patch polygons was examined statistically using an interval-based nonparametric regression model (generalized additive models) and a distance-based proximity measure. The methods presented for data refinement, visualization, and the establishment of fish-plankton patch proximity serve as a paradigm for scale-robust hypothesis formulation and testing of spatial patterns of fish and plankton.
SubRank: Subgraph Embeddings via a Subgraph Proximity Measure
