FN Archimer Export Format
PT J
TI Free-living and particle-associated prokaryote metabolism in giant kelp forests: Implications for carbon flux in a sub-Antarctic coastal area
BT 
AF SCHAPIRA, MATHILDE
   MCQUAID, Christopher D.
   FRONEMAN, Pierre W.
AS 1:1,2;2:1;3:1;
FF 1:PDG-ODE-LER-LERN;2:;3:;
C1 Rhodes Univ, Dept Zool & Entomol, So Ocean Grp, ZA-6140 Grahamstown, South Africa.
   IFREMER, Lab Environm & Ressource Normandie, Ave Gen Gaulle, F-14520 Port En Bessin, France
C2 RHODES UNIV, SOUTH AFRICA
   IFREMER, FRANCE
SI PORT-EN-BESSIN
SE PDG-ODE-LER-LERN
IN WOS Ifremer jusqu'en 2018
   copubli-int-hors-europe
   copubli-sud
IF 2.32
TC 6
UR https://archimer.ifremer.fr/doc/00088/19939/17760.pdf
LA English
DT Article
DE ;prokaryotes;free-living;particle-associated;growth efficiency;kelp;sub-Antarctic island
AB Extensive beds of large subtidal kelps are characteristic of many temperate and subpolar coastlines. They provide habitats for a wide range of other species and are sites of high primary production that generate large quantities of water-borne particles and dissolved organic compounds that support distinctive communities of prokaryotes. We measured prokaryotic metabolism along transects from the shore to the outside of three giant kelp forests (Macrocystis pyrifera) located in the shelf waters of the Prince Edward Islands (Southern Ocean). Abundance, heterotrophic production (PHP), respiration rates (R-ETS) and growth efficiencies (PGE) were investigated within the particle-associated (PA) and the free-living (FL) communities. Temperature, salinity and inorganic nutrient concentrations indicated distinct hydrological differences among the kelp forests that were related to different levels of freshwater input through island run-off. In contrast, detritus and particulate organic matter concentrations showed a common pattern, decreasing from the near-shore to offshore at all sampling sites, suggesting the retention of organically enriched water masses inshore of the kelp forests. While FL and PA abundances did not differ significantly along transects, FL and PA-PHP and PGE all varied significantly across the kelp forests, following the same pattern across each forest. PA-PGE was significantly higher than FL-PGE in the near-shore waters and farther offshore, while FL-PGE was higher or equal to PA-PGE inside the kelp. This shift can be interpreted in terms of gradients in both the age and origins of organic material across the kelp forests. Higher PA-PGE implies that a larger fraction of organic carbon on colonized particles is converted into prokaryotic biomass and so becomes available to higher trophic levels inshore and offshore of M. pyrifera forests than inside the kelp bed. In contrast, low PA-PGE suggests that a large quantity of carbon passes through the PA-community and is mainly respired within the kelp forest. These results suggest the retention of particles within giant kelp forests. In controlling the metabolic activity of PA and FL prokaryotes, this retention will influence overall carbon flux around the archipelago. In particular, the observation of a common pattern across different M. pyrifera forests has important implications for the role of this species as an autogenic ecological engineer in coastal environments. (C) 2012 Elsevier Ltd. All rights reserved.
PY 2012
PD JUL
SO Estuarine Coastal And Shelf Science
SN 0272-7714
PU Academic Press Ltd- Elsevier Science Ltd
VL 106
UT 000305862800007
BP 69
EP 79
DI 10.1016/j.ecss.2012.04.031
ID 19939
ER

EF