title: Net community production and dark community respiration in aKarenia brevis(Davis) bloom in West Florida coastal waters, USA.
abstract: Oxygen-based productivity and respiration rates were determined in West Florida coastal waters to evaluate the proportion of community respiration demands met by autotrophic production within a harmful algal bloom dominated byKarenia brevis. The field program was adaptive in that sampling during the 2006 bloom occurred where surveys by the Florida Wildlife Research Institute indicated locations with high cell abundances. Net community production (NCP) rates from light-dark bottle incubations during the bloom ranged from 10 to 42 µmole O2L-1day-1with highest rates in bloom waters where abundances exceeded 105cells L-1. Community dark respiration (R) rates in dark bottles ranged from <10 to 70 µmole O2L-1day-1over 24 h. Gross primary production derived from the sum of NCP andRvaried from ca. 20 to 120 µmole O2L-1day-1. The proportion of GPP attributed to NCP varied with the magnitude ofRduring day and night periods. Most surface communities exhibited net autotrophic production (NCP >R) over 24 h, although heterotrophy (NCP <R) characterized the densest sample whereK. breviscell densities exceed 106cells L-1.
authors.affiliation: Rosenstiel School of Marine and Atmospheric Science, University of Miami, 4600 Rickenbacker Cswy., Miami, FL 33149, United States.
authors.forename: Gary L
authors.initials: GL
authors.lastname: Hitchcock
authors.forename: Gary
authors.initials: G
authors.lastname: Kirkpatrick
authors.forename: Peter
authors.initials: P
authors.lastname: Minnett
authors.forename: Valeriy
authors.initials: V
authors.lastname: Palubok
keywords: Florida; Karenia brevis; Net production; Respiration