PHOTOSYNTHETIC RESPONSE OF NATURAL ASSEMBLAGES OF MARINE BENTHIC MICROALGAE TO SHORT‐AND LONG‐TERM VARIATIONS OF INCIDENT IRRADIANCE IN BAFFIN BAY, TEXAS 1

• Published in: Journal of Phycology
• Main Authors: Blanchard, Gérard F., Montagna, Paul A.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 1992
• Subjects: Baffin Bay
• Online Access: http://dx.doi.org/10.1111/j.0022-3646.1992.00007.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.0022-3646.1992.00007.x; https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.0022-3646.1992.00007.x

ABSTRACT This study was designed to understand the high variability characterizing primary production rates of microphytobenthos. The photosynthetic efficiency (α B ) and photosynthetic capacity (P B max ) of the microphytobenthos were measured at different times of the day on two different dates (8 May and 7 July 1990). In July, unusually low light conditions were caused by the development of a brown tide (chrysophytes). Both light‐limited and light‐saturated photosynthesis changed at hourly and monthly scales. There was a linear relationship between α B and P B max , suggesting a common response to environmental factors [α B = 0.0075(±0.00063)·P B max + 0.00097(±0.0071), R 2 = 0.94]. Incident irradiance at the sediment‐water interface was the primary physical factor that explained variability of both α B (84%) and P B max (92%). Temperature had a negative but minor effect that explained an extra 8% and 2% of the variance, respectively. There was no diel rhythm of α B and P B max and incident irradiance was regulated by wind‐induced currents. Therefore, microphytobenthos photosynthesis seemed to be primarily controlled by wind events in Baffin Bay.