Hawaii Ocean Time-series (HOT)
in the School of Ocean and Earth Science and Technology at the University of Hawai'i



To assist in the interpretation of the data, it can be displayed using the Hawaii Ocean Time-series Data Organization & Graphical System (HOT-DOGS©).

Analytical Method

Unlike the HPLC pigments which are oil soluable, phycoerythrin is a water soluable pigment which can be used as a marker for cyanobacteria such as Trichodesmium spp. Samples were size fractionated through 10µm & 5µm nylon membrane filters, 1L of the filtrate collected, then poured through a 0.4µm poly-carbonate filter. Samples were analyzed using a Turner Designs TD-700 with 544 nm (Ex) and 577 nm (Em) wavelength filters, and the fluorescence obtained. Phycoerythrin was then calculated via the formula:

PE = (fluor - B) / M

where M & B are the slope and intercept respectively of the regression curve obtained by using our pure phycoerythrin stock.


Contour plots of the 0.4µm, 5µm and 10µm fractions of phycoerythrin from 0 to 200 meters are shown in Figure 52. While the > 0.4 µm and > 5 µm fractions do not appear to show any type of seasonality or gradation in the upper ocean, the > 10 µm fraction appears to show a late fall bloom of either Trichodesmium or aggregates containing cyanobacteria.