Rhodolith primary and carbonate production in a changing ocean: The interplay of warming and nutrients
Bercovich, M. Vivanco
Saá, A.C. Almeida
KAUST DepartmentRed Sea Research Center (RSRC)
Online Publication Date2019-04-23
Print Publication Date2019-08
Permanent link to this recordhttp://hdl.handle.net/10754/632548
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AbstractRhodolith beds, like many other marine ecosystems, are affected by climate change that is causing an increase in the magnitude and frequency of extreme high temperature events (heat waves). Unfortunately, this does not represent the sole peril for these communities, as coastal urbanization in conjunction with altered precipitation patterns can increase terrestrial-derived nutrient input. In Brazil, rhodolith beds are among the most extensive coastal benthic ecosystems, but despite their vast distribution and great ecological and economic importance, studies on the productivity of these communities and the impact of changing environmental conditions are almost non-existent. This study addressed the individual and combined effects of increases in temperature and nutrient concentration on the physiological performance of two widely distributed rhodolith species, Lithothamnion crispatum and Melyvonnea erubescens. The results showed species-specific responses in net photosynthetic performance, with no response in L. crispatum, while M. erubescens responded negatively to both increase in temperature and nutrients. In contrast, calcification in both species showed a significant decline at high temperature. No interactive effects were found between temperature and nutrients, yet their combined negative effects were additive, resulting in negative daily-integrated net productivity and a large decline in daily carbonate production in both species. This has strong implications for rhodolith bed primary productivity and carbonate production, as heat waves may potentially cause a strong decline in carbonate production (ca. 50% loss), accompanied by a severe drop in primary productivity that will be even more pronounced under high-nutrient conditions. Also, the species-specific responses to changes in temperature and nutrient concentration suggest that the magnitude of impact of these factors on rhodolith bed productivity will depend on the species dominating the community and may finally result in changes in rhodolith community composition.
CitationSchubert N, Salazar VW, Rich WA, Bercovich MV, Saá ACA, et al. (2019) Rhodolith primary and carbonate production in a changing ocean: The interplay of warming and nutrients. Science of The Total Environment. Available: http://dx.doi.org/10.1016/j.scitotenv.2019.04.280.
SponsorsThis work was supported by grants from FINEP/Rede CLIMA (Grant Number 01.13.0353-00) and CNPq-Universal (426215/2016-8) to PAH and scholarships granted to VWS (Iniciação à Pesquisa- BIP/UFSC 2016/2017, Programa Institucional de Bolsas de Iniciação CientíficaPIBIC/CNPq), to ACAS by PELD-ILOC (Grant Number 403740/2012-6) and to MVB by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brasil (CAPES- Finance Code 001). This study also received Portuguese national funds from FCT- Foundation for Science and Technology through project UID/Multi/04326/2019, to JS. We also greatly appreciate the help of Dr. José Carlos Simonassi and Paulo Manso (Núcleo de Estudos do Mar/UFSC) with the nutrient analysis and the mesocosm system, respectively.
JournalScience of The Total Environment