Keywords: chlorophyll, groundwater seepage, habitat, Hawaii, nutrients, turbidity, water pollution, water quality, suspended solids, nutrient concentrations, coastal waters
Coastal water quality in the Kihei and Lahaina districts of the island of Maui, Hawaiian Islands. Impacts from physical habitat and groundwater seepage: implications for water quality standards
Water quality in terms of nutrient concentrations, turbidity, suspended solids, and chlorophyll a, was studied during 2000–2001 at a total of 27 beaches in the Kihei and West Maui–Lahaina districts of Maui, Hawaiian Islands. Nitrate concentrations varied widely and averaged as much as 15–20 µM at some beaches. Most turbidities fell in the range 1–10 nephelometric turbidity units. Resuspension of bottom sediments on shallow reef flats appeared to be a cause of some of the highest turbidity. Onshore-offshore transect studies showed that turbidity and concentrations of nitrate and chlorophyll a declined dramatically with distance from the shoreline. The dramatic gradients in water quality within the first 100 m from the shoreline and the fact that some violations of water quality criteria within that zone appear to be the result of natural phenomena, underscore the difficulty of assessing the quality of coastal waters based on traditional parameters.