Pico- and nanoplankton biomass and production in the two largest atoll lagoons of French Polynesia

Abstract

Pico-and nanoplankton concentrations were measured in the lagoonal waters of the 2 largest atolls of French Polynesia (Fakarava and Rangiroa). Growth, production and grazing rates were estimated using diffusion chambers near the reef flat spillways and near the main channels of the atolls. The overall microbial biomass was dominated by picoplankton, with very high abundances of bacteria and cyanobacteria, these 2 groups representing each 20 to 50% of the total carbon. Nanoplankton (auto-and heterotrophic flagellates) constituted only 10 to 15% of the total biomass. Microbial concentrations were 1.5 to 3-fold lower near the reef flat spillways than near the channels. This suggests an important biomass production inside the lagoon. At Rangiroa, growth rates varied from 0.02 to 0.06 h-1 for bacteria and from 0.01 to 0.04 h-1 for the other groups (cyanobacteria, autoand heterotrophic flagellates). At Fakarava, growth rates were in the same range except for the heterotrophic flagellates (0.05 to 0.17 h-1). Growth rates were significantly higher near the reef flat spillways than near the channels. More than 50% of both bacterial and cyanobacterial production was grazed by the higher trophic levels in both atolls. Bacterial production was enhanced by a nitrogen enrichment whereas production of cyanobacteria and flagellates was enhanced by both a nitrogen and a phosphorus enrichment.

Long-Term Presence of the Island Mass Effect at Rangiroa Atoll, French Polynesia

“…These results agree with past studies that found increased phytoplankton biomass around islands and atolls in the Tuamotu Archipelago despite the surrounding oligotrophic waters of the South Pacific Subtropical Gyre (Ferrier-Pagès and Furla, 2001). Studies found enhanced biomass inside atoll lagoons with particulate organic matter to be 2-5 times higher inside the atolls compared to the open ocean (Charpy et al, 1997;Ferrier-Pagès and Furla, 2001). The Island Mass Effect was first described over 70 years ago (Doty and Oguri, 1956), since then, IME has been documented for numerous island-reef ecosystems (e.g., Signorini et al, 1999;Palacios, 2002;Andrade et al, 2014;Gove et al, 2016).…”

“…The magnitude and frequency of enhanced chlorophyll-a concentration clearly indicate presence of the Island Mass Effect (IME) in coastal waters offshore of Tiputa Channel. These results agree with past studies that found increased phytoplankton biomass around islands and atolls in the Tuamotu Archipelago despite the surrounding oligotrophic waters of the South Pacific Subtropical Gyre (Ferrier-Pagès and Furla, 2001). Studies found enhanced biomass inside atoll lagoons with particulate organic matter to be 2-5 times higher inside the atolls compared to the open ocean (Charpy et al, 1997;Ferrier-Pagès and Furla, 2001).…”

Long-Term Presence of the Island Mass Effect at Rangiroa Atoll, French Polynesia

“…These results agree with past studies that found increased phytoplankton biomass around islands and atolls in the Tuamotu Archipelago despite the surrounding oligotrophic waters of the South Pacific Subtropical Gyre (Ferrier-Pagès and Furla, 2001). Studies found enhanced biomass inside atoll lagoons with particulate organic matter to be 2-5 times higher inside the atolls compared to the open ocean (Charpy et al, 1997;Ferrier-Pagès and Furla, 2001). The Island Mass Effect was first described over 70 years ago (Doty and Oguri, 1956), since then, IME has been documented for numerous island-reef ecosystems (e.g., Signorini et al, 1999;Palacios, 2002;Andrade et al, 2014;Gove et al, 2016).…”

“…The magnitude and frequency of enhanced chlorophyll-a concentration clearly indicate presence of the Island Mass Effect (IME) in coastal waters offshore of Tiputa Channel. These results agree with past studies that found increased phytoplankton biomass around islands and atolls in the Tuamotu Archipelago despite the surrounding oligotrophic waters of the South Pacific Subtropical Gyre (Ferrier-Pagès and Furla, 2001). Studies found enhanced biomass inside atoll lagoons with particulate organic matter to be 2-5 times higher inside the atolls compared to the open ocean (Charpy et al, 1997;Ferrier-Pagès and Furla, 2001).…”

Re‐Evaluation of the EUK516 Probe for the Domain Eukarya Results in a Suitable Probe for the Detection of Kinetoplastids, an Important Group of Parasitic and Free‐Living Flagellates

“…In absolute numbers, the abundance of eukaryotic microbes in our field samples was similar to those in other studies of tropical lagoon water (i.e. 1,000–3,000 eukaryotic cells/ml) (Ferrier‐Pagès and Furla 2001; González et al 1998). Cell numbers were much higher in the sediments with 1.0–2.5 × 10 5 cells/ml (sand+pore water volume), which was simply a reflection of the large bacterial numbers available as prey to heterotrophic flagellates.…”

Spatial and temporal variability of the pico- and nanophytoplankton and bacterioplankton in a deep Polynesian atoll lagoon

“…The phytoplankton composition reported in this study, with 83% of chl a extracted from picoplankton communities being dominated in terms of abundance by Synechococcus and Prochlorococcus, was in the range of previous surveys in tropical lagoons (Charpy et al 1992, Ferrier-Pagès & Furla 2001. However, picophytoplankton abundances appeared to be higher than mean levels generally found on Polynesian atolls, the mean Prochl, Syn and Peuk abundances observed in Ahe being 1.7-, 1.3-and 3.2-fold higher, respectively, than mean values found in the 11 atoll lagoons investigated by Charpy & Blanchot (1998).…”

Long-Term Presence of the Island Mass Effect at Rangiroa Atoll, French Polynesia

“…These results agree with past studies that found increased phytoplankton biomass around islands and atolls in the Tuamotu Archipelago despite the surrounding oligotrophic waters of the South Pacific Subtropical Gyre (Ferrier-Pagès and Furla, 2001). Studies found enhanced biomass inside atoll lagoons with particulate organic matter to be 2-5 times higher inside the atolls compared to the open ocean (Charpy et al, 1997;Ferrier-Pagès and Furla, 2001). The Island Mass Effect was first described over 70 years ago (Doty and Oguri, 1956), since then, IME has been documented for numerous island-reef ecosystems (e.g., Signorini et al, 1999;Palacios, 2002;Andrade et al, 2014;Gove et al, 2016).…”

“…The magnitude and frequency of enhanced chlorophyll-a concentration clearly indicate presence of the Island Mass Effect (IME) in coastal waters offshore of Tiputa Channel. These results agree with past studies that found increased phytoplankton biomass around islands and atolls in the Tuamotu Archipelago despite the surrounding oligotrophic waters of the South Pacific Subtropical Gyre (Ferrier-Pagès and Furla, 2001). Studies found enhanced biomass inside atoll lagoons with particulate organic matter to be 2-5 times higher inside the atolls compared to the open ocean (Charpy et al, 1997;Ferrier-Pagès and Furla, 2001).…”

Re‐Evaluation of the EUK516 Probe for the Domain Eukarya Results in a Suitable Probe for the Detection of Kinetoplastids, an Important Group of Parasitic and Free‐Living Flagellates

“…In absolute numbers, the abundance of eukaryotic microbes in our field samples was similar to those in other studies of tropical lagoon water (i.e. 1,000–3,000 eukaryotic cells/ml) (Ferrier‐Pagès and Furla 2001; González et al 1998). Cell numbers were much higher in the sediments with 1.0–2.5 × 10 5 cells/ml (sand+pore water volume), which was simply a reflection of the large bacterial numbers available as prey to heterotrophic flagellates.…”

Spatial and temporal variability of the pico- and nanophytoplankton and bacterioplankton in a deep Polynesian atoll lagoon

“…The phytoplankton composition reported in this study, with 83% of chl a extracted from picoplankton communities being dominated in terms of abundance by Synechococcus and Prochlorococcus, was in the range of previous surveys in tropical lagoons (Charpy et al 1992, Ferrier-Pagès & Furla 2001. However, picophytoplankton abundances appeared to be higher than mean levels generally found on Polynesian atolls, the mean Prochl, Syn and Peuk abundances observed in Ahe being 1.7-, 1.3-and 3.2-fold higher, respectively, than mean values found in the 11 atoll lagoons investigated by Charpy & Blanchot (1998).…”

Long-Term Presence of the Island Mass Effect at Rangiroa Atoll, French Polynesia

“…These results agree with past studies that found increased phytoplankton biomass around islands and atolls in the Tuamotu Archipelago despite the surrounding oligotrophic waters of the South Pacific Subtropical Gyre (Ferrier-Pagès and Furla, 2001). Studies found enhanced biomass inside atoll lagoons with particulate organic matter to be 2-5 times higher inside the atolls compared to the open ocean (Charpy et al, 1997;Ferrier-Pagès and Furla, 2001). The Island Mass Effect was first described over 70 years ago (Doty and Oguri, 1956), since then, IME has been documented for numerous island-reef ecosystems (e.g., Signorini et al, 1999;Palacios, 2002;Andrade et al, 2014;Gove et al, 2016).…”

“…The magnitude and frequency of enhanced chlorophyll-a concentration clearly indicate presence of the Island Mass Effect (IME) in coastal waters offshore of Tiputa Channel. These results agree with past studies that found increased phytoplankton biomass around islands and atolls in the Tuamotu Archipelago despite the surrounding oligotrophic waters of the South Pacific Subtropical Gyre (Ferrier-Pagès and Furla, 2001). Studies found enhanced biomass inside atoll lagoons with particulate organic matter to be 2-5 times higher inside the atolls compared to the open ocean (Charpy et al, 1997;Ferrier-Pagès and Furla, 2001).…”

Re‐Evaluation of the EUK516 Probe for the Domain Eukarya Results in a Suitable Probe for the Detection of Kinetoplastids, an Important Group of Parasitic and Free‐Living Flagellates

“…In absolute numbers, the abundance of eukaryotic microbes in our field samples was similar to those in other studies of tropical lagoon water (i.e. 1,000–3,000 eukaryotic cells/ml) (Ferrier‐Pagès and Furla 2001; González et al 1998). Cell numbers were much higher in the sediments with 1.0–2.5 × 10 5 cells/ml (sand+pore water volume), which was simply a reflection of the large bacterial numbers available as prey to heterotrophic flagellates.…”

Spatial and temporal variability of the pico- and nanophytoplankton and bacterioplankton in a deep Polynesian atoll lagoon

“…The phytoplankton composition reported in this study, with 83% of chl a extracted from picoplankton communities being dominated in terms of abundance by Synechococcus and Prochlorococcus, was in the range of previous surveys in tropical lagoons (Charpy et al 1992, Ferrier-Pagès & Furla 2001. However, picophytoplankton abundances appeared to be higher than mean levels generally found on Polynesian atolls, the mean Prochl, Syn and Peuk abundances observed in Ahe being 1.7-, 1.3-and 3.2-fold higher, respectively, than mean values found in the 11 atoll lagoons investigated by Charpy & Blanchot (1998).…”