Acclimation of bloom‐forming and perennial seaweeds to elevated pCO₂ conserved across levels of environmental complexity

Abstract

Macroalgae contribute approximately 15% of the primary productivity in coastal marine ecosystems, fix up to 27.4 Tg of carbon per year, and provide important structural components for life in coastal waters. Despite this ecological and commercial importance, direct measurements and comparisons of the short-term responses to elevated pCO in seaweeds with different life-history strategies are scarce. Here, we cultured several seaweed species (bloom forming/nonbloom forming/perennial/annual) in the laboratory, in tanks in an indoor mesocosm facility, and in coastal mesocosms under pCO levels ranging from 400 to 2,000 μatm. We find that, across all scales of the experimental setup, ephemeral species of the genus Ulva increase their photosynthesis and growth rates in response to elevated pCO the most, whereas longer-lived perennial species show a smaller increase or a decrease. These differences in short-term growth and photosynthesis rates are likely to give bloom-forming green seaweeds a competitive advantage in mixed communities, and our results thus suggest that coastal seaweed assemblages in eutrophic waters may undergo an initial shift toward communities dominated by bloom-forming, short-lived seaweeds.

The short-term effects of elevated CO2 and ammonium concentrations on physiological responses in Gracilariopsis lemaneiformis (Rhodophyta)

“…We assumed the high stocking density conditions of aquaculture farm to find realistic growth of G. lemaneiformis. In addition, Xu et al (2017a) found that the RGRs of short-time cultivation period were higher than those of long-time cultivation time. They explained that decreased of RGRs resulted from the acclimation to culture conditions.…”

Differential Photosynthetic Response of a Green Tide Alga Ulva linza to Ultraviolet Radiation, Under Short‐ and Long‐term Ocean Acidification Regimes

“…Xu et al . found that ephemeral species of the genus Ulva could increase their photosynthesis and growth rates under elevated CO 2 conditions, while longer‐living perennial species showed smaller responses. In order to protect themselves from the damage caused by UV radiation, macroalgae can utilize escape, repair and barrier mechanisms to protect them during the process of adaptation and evolution.…”

Evolution and Expansion of the Prokaryote-Like Lipoxygenase Family in the Brown Alga Saccharina japonica

“…Although LOX products have been described from Phaeophyceae, to the best of our knowledge, there has been no comprehensive study of LOX genes in brown algae available up to now, and their phylogenetic relationships with LOXs of other phyla remain poorly understood. Brown macroalgae are the dominant vegetation in many benthic marine habitats with high ecological and economic significance ( Xu et al, 2017 ). Particularly, Saccharina japonica is one of the most economically important seaweed in marine aquaculture.…”