Influence of coral and algal exudates on microbially mediated reef metabolism

被引:92
作者
Haas, Andreas F. [1 ,2 ]
Nelson, Craig E. [3 ]
Rohwer, Forest [1 ]
Wegley-Kelly, Linda [1 ]
Quistad, Steven D. [1 ]
Carlson, Craig A. [3 ,4 ]
Leichter, James J. [2 ]
Hatay, Mark [1 ]
Smith, Jennifer E. [2 ]
机构
[1] San Diego State Univ, Dept Biol, San Diego, CA 92182 USA
[2] Univ Calif San Diego, Scripps Inst Oceanog, San Diego, CA 92103 USA
[3] Univ Calif Santa Barbara, Marine Sci Inst, Santa Barbara, CA 93106 USA
[4] Univ Calif Santa Barbara, Dept Ecol Evolut & Marine Biol, Santa Barbara, CA 93106 USA
来源
PEERJ | 2013年 / 1卷
基金
美国国家科学基金会;
关键词
Coral; Algae; Microbe; Organic carbon; Metabolism; Central Pacific;
D O I
10.7717/peerj.108
中图分类号
O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];
学科分类号
07 ; 0710 ; 09 ;
摘要
Benthic primary producers in tropical reef ecosystems can alter biogeochemical cycling and microbial processes in the surrounding seawater. In order to quantify these influences, we measured rates of photosynthesis, respiration, and dissolved organic carbon (DOC) exudate release by the dominant benthic primary producers (calcifying and non-calcifying macroalgae, turf-algae and corals) on reefs of Mo'orea French Polynesia. Subsequently, we examined planktonic and benthic microbial community response to these dissolved exudates by measuring bacterial growth rates and oxygen and DOC fluxes in dark and daylight incubation experiments. All benthic primary producers exuded significant quantities of DOC (roughly 10% of their daily fixed carbon) into the surrounding water over a diurnal cycle. The microbial community responses were dependent upon the source of the exudates and whether the inoculum of microbes included planktonic or planktonic plus benthic communities. The planktonic and benthic microbial communities in the unamended control treatments exhibited opposing influences on DO concentration where respiration dominated in treatments comprised solely of plankton and autotrophy dominated in treatments with benthic plus plankon microbial communities. Coral exudates (and associated inorganic nutrients) caused a shift towards a net autotrophic microbial metabolism by increasing the net production of oxygen by the benthic and decreasing the net consumption of oxygen by the planktonic microbial community. In contrast, the addition of algal exudates decreased the net primary production by the benthic communities and increased the net consumption of oxygen by the planktonic microbial community thereby resulting in a shift towards net heterotrophic community metabolism. When scaled up to the reef habitat, exudate-induced effects on microbial respiration did not outweigh the high oxygen production rates of benthic algae, such that reef areas dominated with benthic primary producers were always estimated to be net autotrophic. However, estimates of microbial consumption of DOC at the reef scale surpassed the DOC exudation rates suggesting net consumption of DOC at the reef-scale. In situ mesocosm experiments using custom-made benthic chambers placed over different types of benthic communities exhibited identical trends to those found in incubation experiments. Here we provide the first comprehensive dataset examining direct primary producer-induced, and indirect microbially mediated alterations of elemental cycling in both benthic and planktonic reef environments over diurnal cycles. Our results highlight the variability of the influence of different benthic primary producers on microbial metabolism in reef ecosystems and the potential implications for energy transfer to higher trophic levels during shifts from coral to algal dominance on reefs.
引用
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页数:28
相关论文
共 71 条
[1]   ZONATION AND SEASONALITY OF BENTHIC PRIMARY PRODUCTION AND COMMUNITY RESPIRATION IN TROPICAL MANGROVE FORESTS [J].
ALONGI, DM .
OECOLOGIA, 1994, 98 (3-4) :320-327
[2]  
[Anonymous], 1996, FUNCTIONAL ROLES BIO
[3]  
[Anonymous], J ANIM ECOL
[4]   THE ECOLOGICAL ROLE OF WATER-COLUMN MICROBES IN THE SEA [J].
AZAM, F ;
FENCHEL, T ;
FIELD, JG ;
GRAY, JS ;
MEYERREIL, LA ;
THINGSTAD, F .
MARINE ECOLOGY PROGRESS SERIES, 1983, 10 (03) :257-263
[5]  
Barott K, 2009, PLOS ONE, V4, DOI [10.1371/journal.pone.0008043, 10.1371/journal.pone.0010950]
[6]  
Berkenbusch K, 2003, NEW ZEAL J ECOL, V27, P67
[7]   Contribution of soft-bottoms to the community metabolism (primary production and calcification) of a barrier reef flat (Moorea, French Polynesia) [J].
Boucher, G ;
Clavier, J ;
Hily, C ;
Gattuso, JP .
JOURNAL OF EXPERIMENTAL MARINE BIOLOGY AND ECOLOGY, 1998, 225 (02) :269-283
[8]   Perspectives on mucus secretion in reef corals [J].
Brown, BE ;
Bythell, JC .
MARINE ECOLOGY PROGRESS SERIES, 2005, 296 :291-309
[9]   RELEASE OF DISSOLVED ORGANIC-MATTER BY SOME MARINE MACROPHYTES [J].
BRYLINSKY, M .
MARINE BIOLOGY, 1977, 39 (03) :213-220
[10]   MICROBIAL NITROGEN TRANSFORMATIONS IN UNCONSOLIDATED CORAL-REEF SEDIMENTS [J].
CAPONE, DG ;
DUNHAM, SE ;
HORRIGAN, SG ;
DUGUAY, LE .
MARINE ECOLOGY PROGRESS SERIES, 1992, 80 (01) :75-88