Effects of ocean acidification on growth and physiology of Ulva lactuca (Chlorophyta) in a rockpool-scenario, link to supplementary data

Rising atmospheric CO2-concentrations will have severe consequences for a variety of biological processes. We investigated the responses of the green alga Ulva lactuca (Linnaeus) to rising CO2-concentrations in a rockpool scenario. U. lactuca was cultured under aeraton with air containing either preindustrial pCO2 (280µatm) or for the end of the 21st century predicted (700µatm) pCO2 for 31 days. We addressed the following question: Will elevated CO2-concentrations affect photosynthesis (net photosynthesis, rETR(max), Fv/Fm, pigment composition) and growth of U. lactuca in rockpools with limited water exchange? Two phases of the experiment were distinguished: In the initial phase (day 1-4) the Seawater Carbonate System (SWCS) of the culture medium could be adjusted to the selected atmospheric pCO2 condition by continuous aeration with target pCO2 values. In the second phase (day 4-31) the SWCS was largely determined by the metabolism of the growing U. lactuca biomass. In the initial phase, Fv/Fm and rETR(max) were only slightly elevated at high CO2-concentrations whereas growth was significantly enhanced. After 31 days the Chl a content of the thalli was significantly lower under future conditions and the photosynthesis of thalli grown under preindustrial conditions was not dependent on external carbonic anhydrase. Biomass increased significantly at high CO2-concentrations. At low CO2-concentrations most adult thalli disintegrated between day 14 and 21, whereas at high CO2-concentrations most thalli remained integer until day 31. Thallus disintegration at low CO2-concentrations was mirrored in a drastic decline in seawater DIC and HCO3-. Accordingly, the SWCS differed significantly between the treatments. Our results indicated a slight enhancement of photosynthetic performance and significantly elevated growth of U. lactuca at future CO2-concentrations. The accelerated thallus disintegration at high CO2-concentrations under conditions of limited water exchange indicates additional CO2 effects on the life cycle of U. lactuca when living in rockpools.

The literary collaboration and the personal correspondence of Rubén Darío and Juan Ramón Jiménez,

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Cost accounting manual for the knitted outerwear industry [by] Werner Lutz ... in collaboration with Stephen R. Gordon.

Mode of access: Internet.

Chisat I, extension and validation of NOAA's REPEX procedures for habitat diving : a Chinese-American collaboration /

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Head Start and Even Start : greater collaboration needed on measures of adult education and literacy /

"GAO-02-348."

The record of collaboration of King Farouk of Egypt with the Nazis and their ally, the Mufti; the official Nazi records of the King's alliance and of the Mufti's plans for bombing Jerusalem and Tel Aviv. Memorandum submitted to the United Nations June 1948.

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Dictionnaire de chimie pure et appliquée --Avec la collaboration de mm. P. T. Cleve-- E. Demarçay--A. Étard [et des autres] Supplément ...

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Lead poisoning prevention with states in collaboration with local health departments : a model for intervention related to lead poisoning in indoor firing ranges /

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La pierre de touche; a comedy by Eḿile Augier in collaboration with Jules Sandeau;

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How to handle collective bargaining negotiations. This is a confidential manual for management prepared by "bargaining experts" in collaboration with the editorial staff of Executive's labor letter ...

Reproduced from type-written copy.