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Title: OTEC environmental benchmark survey Kahe Point, Oahu, May 1980-May 1981. Final report

Technical Report ·
DOI:https://doi.org/10.2172/5069774· OSTI ID:5069774

Six biological/chemical cruises at two stations off Kahe Point, Oahu, Hawaii which took place between May 1980 and May 1981 are detailed. The objective was to evaluate the variability of physical, chemical, and biological variables within a potential OTEC siting area over a yearly cycle. The minimum ..delta..T observed between surface waters and 700 m was about 19/sup 0/C. Nutrient concentrations showed typical profiles with the largest variability occurring at depth. Strong positive correlations exist between nitrate and both phosphate and silicate. Both dissolved organic nitrogen and phosphorus are highest in the surface mixed layer, decline through the nutricline, and become relatively constant near 900 m. Nutrient concentrations also showed significant variation with time of year and between stations in both near surface and deep water. The vertical distribution of chlorophyll a showed a maximum between 55 m and 120 m. The euphotic zone extended to about 130 m. Total biomass concentrations were uniform in the upper 80 m declining with depth. Primary productivity was uniform with depth down to 90 m and then declined. Phytoplankton measurements varied mainly with depth and time of year. Zooplankton biomass and number were higher in surface waters and decreased with depth. As with nutrient and phytoplankton data, zooplankton variability was greatest with depth. However, zooplankton measurements showed significant differences between day and night. Additionally, small but significant variations due to time of year and station-to-station were observed. Zooplankton taxonomic analyses from these two sites were consistent with analyses from other tropical sites.

Research Organization:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Noda (E.K.) and Associates, Honolulu, HI (USA); Oceanic Inst., Waimanalo, HI (USA); Hawaii Univ., Kaneohe (USA). Hawaii Inst. of Marine Biology
DOE Contract Number:
W-7405-ENG-48
OSTI ID:
5069774
Report Number(s):
DOE/NBM-2016055; ON: DE82016055
Resource Relation:
Other Information: Portions of document are illegible
Country of Publication:
United States
Language:
English