Premium
THE RELATIVE IMPORTANCE OF WATER MOTION ON NITROGEN UPTAKE BY THE SUBTIDAL MACROALGA ADAMSIELLA CHAUVINII (RHODOPHYTA) IN WINTER AND SUMMER 1
Author(s) -
Kregting Louise T.,
Hurd Catriona L.,
Pilditch Conrad A.,
Stevens Craig L.
Publication year - 2008
Publication title -
journal of phycology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.85
H-Index - 127
eISSN - 1529-8817
pISSN - 0022-3646
DOI - 10.1111/j.1529-8817.2008.00484.x
Subject(s) - biology , thallus , nitrogen , nutrient , seawater , flume , algae , botany , sediment , perennial plant , zoology , ecology , flow (mathematics) , chemistry , paleontology , geometry , mathematics , organic chemistry
The influence of seawater velocity (1.5–12 cm · s −1 ) on inorganic nitrogen (N) uptake by the soft‐sediment perennial macroalga Adamsiella chauvinii (Harv.) L. E. Phillips et W. A. Nelson (Rhodophyta) was determined seasonally by measuring uptake rate in a laboratory flume. Regardless of N tissue content, water velocity had no influence on NO 3 − uptake in either winter or summer, indicating that NO 3 − ‐uptake rate was biologically limited. However, when thalli were N limited, increasing water velocity increased NH 4 + uptake, suggesting that mass‐transfer limitation of NH 4 + is likely during summer for natural populations. Uptake kinetics ( V max , K s ) were similar among three populations of A. chauvinii at sites with different mean flow speeds; however, uptake rates of NO 3 − and NH 4 + were lower in summer (when N status was generally low) than in winter. Our results highlight how N uptake can be affected by seasonal changes in the physiology of a macroalga and that further investigation of N uptake of different macroalgae (red, brown, and green) during different seasons is important in determining the relative influence of water velocity on nutrient uptake.