Assess nutrient sources, fluxes, and water quality of ponds within the Kaloko-Honokohau National Historical Park : Final report
Bienfang P. 2007. Assess nutrient sources, fluxes, and water quality of ponds within the Kaloko-Honokohau National Historical Park : Final report. Oceanography Department, University of Hawaii-Manoa. Honolulu, Hawaii
The purpose of the project is to assess the prevailing water quality conditions and the extent of natural variability over time, and under the variety of conditions experienced by these aquatic resources. This report summarizes work completed July 2004 - August 2006. The samplings to date regularly included assessments of two residential wells, three test wells within the park boundary, six anchialine pools, seven stations within Kaloko pond and twelve stations within Aimakapa pond. These field assessments collected both hydrographic data and water quality samples from each of the above mentioned environments. Sampling of the wells intended to evaluate the quality of the hydrographic input to the Park’s aquatic systems. The two residential wells were located makai (i.e., down-gradient) of residential housing but mauka (i.e., up-gradient) of existing/proposed industrial developments, and the three test wells were located seaward of existing/proposed industrial developments and Kaahumanu Highway. The hydrographic data, consisting of temperature, pH, salinity, and dissolved oxygen, have been compiled together with the tidal condition prevailing at the time of collection. Water quality data consists of ammonium (NH4,), nitrate + nitrite (NO3+NO2), phosphate (PO4), silicate (SiO2), total dissolved organic nitrogen (DON), total dissolved organic phosphate (DOP), and chlorophyll a. Station locations within the Aimakapa and Kaloko ponds were determined with GPS, and marked with floats throughout the project. The surveys in 2004 were descriptive in nature. Station grids were laid out, GPS coordinates determined, and initial hydrographic and water quality data were taken synoptically from a number of station locations within the various aquatic environments. These data were used to identify prospective station locations, sampling and analytical strategies to be applied going forward that would most likely be most illustrative of general conditions within the park. The majority of the data reported in this analysis were collected from January 2005 to August 2006. All aquatic habitats within the KAHO Park are significantly influenced by groundwater intrusion. The concentrations of the water quality parameters were typical of those found in other aquatic habitats in the Kona area that are similarly influenced by groundwater intrusion. All water quality parameters showed substantial temporal and spatial variability as reflected by the relative standard deviation values that approached 100% within any given water type and/or for any given parameter over the time of monitoring. This degree of variation reflects the sum of variability associated with the combination of proximity to groundwater intrusion, tidal cycles, seasons, biological activity, sampling, processing and analysis are higher in the wells and pools for all parameters than those found in Kaloko or Aimakapa fishponds. In general, the water quality characteristics of all aquatic habitats within the KAHO boundaries appeared to be predominantly influenced by hydrologic forces driving the mixing of low-saline, high-nutrient groundwater and high-saline...
- Type
- Unpublished Report
- Authors
- Bienfang, P
- Date of Issue
- 2007-02
- Publisher
- Oceanography Department, University of Hawaii-Manoa
- Units
- KAHO
- Keywords
- Aquatic Sciences, Dissolved Oxygen, Monitoring, particulate organic matter, Water Quality