Net community production and dark community respiration in a Karenia 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 by Karenia 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 O2 L−1 day−1 with highest rates in bloom waters where abundances exceeded 105 cells L−1. Community dark respiration (R) rates in dark bottles ranged from <10 to 70 µmole O2 L−1 day−1 over 24 h. Gross primary production derived from the sum of NCP and R varied from ca. 20 to 120 µmole O2 L−1 day−1. The proportion of GPP attributed to NCP varied with the magnitude of R during day and night periods. Most surface communities exhibited net autotrophic production (NCP > R) over 24 h, although heterotrophy (NCP < R) characterized the densest sample where K. brevis cell densities exceed 106 cells L−1.

Drivers and effects of Karenia mikimotoi blooms in the western English Channel

“…Importantly, such blooms carry significant effects over larger scales, most notably their (temporal/spatial) contribution to ecosystem productivity. While blooms may occur during a short period of a few weeks, the substantial increase in biomass and primary productivity can heavily dominate the overall season, as has been observed for Karenia brevis in West Florida waters (Bendis et al, 2004;Hitchcock et al, 2010).…”

Suffocating Phytoplankton, Suffocating Waters—Red Tides and Anoxia

“…Red tide forming dinoflagellate blooms of similar magnitude have also been reported for other eastern boundary upwelling systems (e.g., Blasco, 1975) and reported assimilation indices of 4.3 mg C [mg Chl-a] −1 h −1 for a bloom of Gonyaulax polyedra in the Californian upwelling system and of 5.0 mg C [mg Chl-a] −1 h −1 for a bloom of Gymnodinium splendens in the Peruvian upwelling system (Blasco, 1975) are similar to the assimilation indices recorded in the present study, which ranged from 1.83 to 7.23 mg C [mg Chl-a] −1 h −1 . These measures of red tide productivity in eastern boundary upwelling systems are all considerably higher than the estimates of net community production made for Karenia-dominated blooms in coastal waters of West Florida (USA; Hitchcock et al, 2010). 3 | Date of surface water collection, DO concentrations prior to incubation, hourly estimates of net community production (hourly-NCP), including estimates expressed in terms of carbon and normalized to Chl-a, hourly estimates of community respiration (hourly-R n ) as determined in the light carboy, hourly estimates of community respiration as determined in the dark carboy (hourly-R d ), cell, and Chl-a specific values of hourly-R n , daily estimates of net community production (daily-NCP) as determined from the increment in DO concentration in the light bottle over 24 h, daily estimates of respiration (daily-R = hourly-R n × 24; respiration during the day was assumed to be equal to respiration during the night), daily estimates of gross community production (daily-GCP = daily-NCP + daily-R), and the ratio of daily-R: daily-GCP.…”

Productivity evaluation of lotic and lentic water body in Himachal Pradesh, India

“…74 The decrease of oxygen in the dark bottles helps in determination of respiration rate which is given as their carbon equivalents. [75][76][77] Water quality water is affected by the wastes from the homes, agricultural runoff and the drains carrying municipal sewage of the cities. According to the Central Pollution Control Board, untreated sewage is responsible for 70% of the pollution in rivers which results in low DO and high BOD.…”