Technical Report No. 60
Sea Grant program, year 04 Project Principal Investigator L.Stephen Lau
Sea Grant Program No. UNIHI-SEA GRANT-72-01 – September 1972
The nature and results of the first year of experimental and evaluative work of the Coastal Water Quality project of the University of Hawaii’s Sea Grant Program are summarized in this report. The project is a multi-directional, multi-disciplinary study directed to the general objectives of identifying and evaluating the social, political, economic, educational, institutional, and scientific and technological factors which impede or expedite the protection and restoration of coastal water environments in Hawaii, as well as of developing the crucial scientific and rational parameters needed in formulating effective policies institutions and systems. To this end, the attainment of eight specific objectives is assigned to appropriate faculty specialists participating in 14 activities which comprise the Project. These specialists have the additional duty of assisting the Principal Investigator in planning the work and in interpreting its results in terms of the general objective. The project is unique in that it seeks to evaluate water quality in terms of stress or well being of aquatic communities, using the traditional chemical, biological, and bacterial parameters of water quality only to identify the factors and their concentrations which are of ecological significance. in turn the ecological findings are utilized to refine the standards and criteria applicable to traditional parameters. Kahana Bay was selected as a coastal water under the influence of relatively undeveloped land. Data already available on the physiography and hydrology of its drainage area, its estuarine and oceanographic aspects, and the nature and movement of its sediments were supplemented by a program of analysis of water and sediments and its biota. As in all situations especial attention was given to the pesticides, heavy metals, and nutrients in water and sediment and to evidence of stress on aquatic communities. Significant findings, which will, if further substantiated, be of value to regulatory agencies of the State, are that only when diluted heavily with fresh water did the dissolved oxygen content in the estuary meet the class AA standard designated for Kahana waters and the phosphorus content was mostly at class AA level (0.02 mg/l) but this value was exceeded seasonally. Nitrogen, and coliform organisms showed a similar., although more variable pattern. Thus Kahana Bay tended to satisfy the class A standards rather than the class AA standards for which the Bay is classified by the State. DDT and PCB (pesticides) in Kahana Bay waters and sediments appeared at levels which seem to be ubiquitous in nature. Heavy metals, particularly Pb, Cd. Zn, and Cu appeared in the sediments in no identifiable pattern and apparently depend on the parent geologic formations from which the sediments are derived. Sugarcane production and milling wastes were studied on Kauai. Observations of mill waste discharge and coastal water, sediments, and biota were made both before and after the 90-year old Kilauea Sugar Company closed down its operations in north Kauai. Untreated mill wastes were found to be the major contributor of wastes from the industry, carrying coliforms, sediments, trash and bagasse. The effect was largely an extensive visible plume and debris in the waters. Sediments, rather than water, harbored most of the nutrients, heavy metals, and pesticides in the ocean. DDT, although not used by the sugarcane industry, was present in small amounts in all waters and sediments. Herbicides used in sugarcane culture did not appear in coastal water. A striking improvement in the aesthetic aspects of the coastal water quickly followed the cessation of mill waste discharges. Fish and other aquatic biota reappeared rapidly after the cessation of mitt operations. Longer term changes in the biota are yet to be assessed. Studies were begun in south Kauai late in the report period to assess the effect of changed operational practices by the McBryde Sugar Company subsequent to an EPA survey of coastal waters of the area in 1968. Company practices demonstrate that it is possible to operate milling operations without discharge to the ocean, and to prevent irrigation tailwater overflows except flooding due to intense rainfall. At the time of reporting no pesticide residues were found offshore except for the 1 part per trillion DDT which seems to be present everywhere. Studies by others on the Hamakua Coast and elsewhere generally show reduction in abundance of biota within the area (perhaps one mile) where waste sediments from mill discharge blanket the normal bottom. The effects of urban wastewater especially sewage, were studied during the report period largely by cooperating with the City and County of Honolulu and the federal agencies in Hawaii engaged in major investigations and projects such as sewage treatment at Sand Island, Pearl Harbor, Kaneohe Bay, and Mokapu Point. The role of the Coastal Water Quality Project in these major enterprises are described in the report. In less extensive situations at Sandy Beach, Waikiki, Maunalua Bay, and Manoa Stream, the Project is amassing data for the effects on the coastal environment of surface runoff and general human activities in urbanized areas. preliminary findings are included in the report. The overall objective for the identification and evaluation of the separate effects of various land uses on the quality of coastal waters is to interpret them in terms of changes in the institutional, economic., and social systems needed to achieve the environmental objectives of the state. To enable researchers to begin this aspect of the study, statutory changes and the zones of mixing that have been granted since 1967, when the federal-state water quality standards were adopted, have been compiled. By continuing to tabulate such institutional changes, the opportunities to integrate relevant scientific knowledge into social policy will be enhanced.