Occurrence of Unusual Bodies in a Marine Pennate Diatom

Abstract

DURING an investigation of the marine phytoplankton in a shallow Rhode Island coastal salt pond¹, an abundant benthic diatom flora occurred throughout the water column on May 3, 1961. This community was probably roiled up from the bottom during the vertical mixing characteristic of the water-mass at that time (Table 1) ; a distinct halocline persisted prior to this date. The water-mass was 1.5–2.0° C warmer than in mid-April and while the bottom (6 ft.) salinity decreased by 2.5 parts per thousand, the mean water-column salinity decreased by only 1 part per thousand. Similarly, gross changes were not observed in other environmental factors studied : dissolved oxygen, nitrate, nitrite, silicate and phosphate.