首页 | 本学科首页   官方微博 | 高级检索  
   检索      


Chronic low-level nutrient enrichment benefits coral thermal performance in a fore reef habitat
Authors:Becker  Danielle M  Putnam  Hollie M  Burkepile  Deron E  Adam  Thomas C  Vega Thurber  Rebecca  Silbiger  Nyssa J
Institution:1.Department of Biology, California State University, Northridge, CA, 91330, USA
;2.Department of Biological Sciences, University of Rhode Island, 120 Flagg Rd, Kingston, RI, 02881, USA
;3.Marine Science Institute, University of California, Santa Barbara, CA, 93106, USA
;4.Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, CA, 93106, USA
;5.Department of Microbiology, Oregon State University, Corvallis, OR, 97333, USA
;
Abstract:

Global- and local-scale anthropogenic stressors have been the main drivers of coral reef decline, causing shifts in coral reef community composition and ecosystem functioning. Excess nutrient enrichment can make corals more vulnerable to ocean warming by suppressing calcification and reducing photosynthetic performance. However, in some environments, corals can exhibit higher growth rates and thermal performance in response to nutrient enrichment. In this study, we measured how chronic nutrient enrichment at low concentrations affected coral physiology, including endosymbiont and coral host response variables, and holobiont metabolic responses of Pocillopora spp. colonies in Mo'orea, French Polynesia. We experimentally enriched corals with dissolved inorganic nitrogen and phosphate for 15 months on an oligotrophic fore reef in Mo'orea. We first characterized symbiont and coral physiological traits due to enrichment and then used thermal performance curves to quantify the relationship between metabolic rates and temperature for experimentally enriched and control coral colonies. We found that endosymbiont densities and total tissue biomass were 54% and 22% higher in nutrient-enriched corals, respectively, relative to controls. Algal endosymbiont nitrogen content cell?1 was 44% lower in enriched corals relative to the control colonies. In addition, thermal performance metrics indicated that the maximal rate of performance for gross photosynthesis was 29% higher and the rate of oxygen evolution at a reference temperature (26.8 °C) for gross photosynthesis was 33% higher in enriched colonies compared to the control colonies. These differences were not attributed to symbiont community composition between corals in different treatments, as C42, a symbiont type in the Cladocopium genus, was the dominant endosymbiont type found in all corals. Together, our results show that in an oligotrophic fore reef environment, nutrient enrichment can cause changes in coral endosymbiont physiology that increase the performance of the coral holobiont.

Keywords:
本文献已被 SpringerLink 等数据库收录!
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号