Hawai'i Fishing Predictor

This app is a tool for determining where and when one might have the best success for fishing around the Hawaiian Islands. The technology is based on predicting the upwelling of deeper waters which are rich in nutrients. Nutrient-rich water means a greater abundance of phytoplankton and zooplankton. And these attract fish.

The upwelling of deeper, colder water around Hawai’i is a result of tidal action, occurring every 12-13 hours, but not coinciding with tidal sea level variations. Since the temperature-salinity structure of the water column changes from month to month, the magnitudes and locations of the greatest cold-water upwelling will vary. To predict this tidal action, we use water temperature at 90m (50 fathoms) to determine a water nutrient parameter. This allows us to specify variations in location from day-to-day and month-to-month. The water temperature variations around Hawaii are predicted using high-resolution, dynamic, numerical ocean models. The models are a version of the Princeton Ocean Model (see http://www.ccpo.odu.edu/POMWEB/) and cover Kauai/Niihau, Oahu, and Hawai’i Island. POM solves primitive, partial differential equations based on the conservation of energy, momentum, mass, heat, salt, and turbulence.

The initial three-dimensional temperature and salinity (T-S) fields for the POM come from the U.S. Navy's Pacific NCOM model. We use the NCOM dynamic climatology which represents the actual T-S structure for a given day for a given month. The models are calibrated and verified for tidal forcing. Our approach results in ocean temperature variations that are physically consistent and dynamically-balanced. The models utilize appropriate tidal forcing for the three major semi-diurnal tidal constituents (S2, M2, and N2 tides) and the three major diurnal tidal constituents (K1, P1, and O1 tides). Each model simulation produces a field of amplitudes and phases for a given constituent. From these fields, we can produce accurate predictions of a water nutrient predictor for a given location and time.

A graphic is used to show the spatial variations of the magnitudes of nutrient upwelling. The user uses the graphic to select a location for which he wants a prediction of the times of maximum nutrient upwelling. After selecting a start time for the prediction, the app uses the appropriate tidal amplitudes and phases and the mean longitudes of the sun, moon, and lunar perigee to generate a 6 day prediction. In addition to the times of maximum nutrient content in the water column, the phase of the moon for each time is provided.