Elevated Temperature Effects on Dynamics of Blade Growth and Erosion in Saccharina Latissima (Laminariales)

Abstract The dynamics of blade growth and erosion in Saccharina latissima (Laminariales) control the final surface area of blades. The negative effects of elevated temperature on the surface area of blades may result from inhibition of growth and stimulation of erosion, eventually leading to release of carbon (C) and nitrogen (N). In this study, we investigated temperature effects on the growth and erosion of S. latissima blades incubated at ambient and elevated temperatures. For the first time, to our knowledge, growth rates of the meristem and total blade and the erosion rate of the distal blades were quantified simultaneously. Additionally, by analyzing the C and N content along with erosion rate, we could calculate the potential release of C and N to seawater. The results show a significant decrease in the relative growth rate and a significant increase in the erosion rate of the distal ends of blades when the temperature reached 23 ˚C. Results of the C and N analyses show that S. latissima released almost twice as much C and N at elevated temperatures than at ambient temperatures.