SARGASSUM (S. FILIPENDULA) GROWTH, PHOTOSYNTHESIS, AND BIOCHEMICAL RESPONSE TO TEMPERATURE INCREASE

Rising global temperatures from climate change have altered ecosystems. This effect may be triggering observations of brown macroalgae bloom formations of the genus Sargassum. The response of the Cape Cod species, S. filipendula, was observed over a 16-day tank experiment testing increasing temperature on growth and physiology. Biomass accumulation and loss, specific growth rates, photosynthetic performance via PAM chlorophyll fluorometry, and biochemical tissue, components of S. filipendula were measured. Lower temperature treatments of 14°C and 18°C had the most accumulated biomass compared to higher temperatures, as well as less biomass loss. There was no statistical significance between treatments and photosynthetic yields (F_v/F_m), while the treatment of 23°C and 28°C showed the highest maximum relative electron transport rates (rETRmax). Treatments of 18°C and 23°C had the highest rates of non-photo quenching (NPQ). Biochemical components showed variation with temperature: 18°C having the highest percent carbon content, 14°C having the highest percent of nitrogen, carbohydrate, and protein content. These results suggest that an extended growing season with temperatures ~14-18 °C could increase growth and carbon assimilation by S. filipendula. If there happens to be a heat wave late in the season, S. filipendula could remain resilient, although at the cost of a higher turnover rate. The lack of statistical significance for the different treatments alludes that temperature may not be the most significant factor contributing to the changes in Sargassum proliferation.

Presentation Preference: Oral

Primary Presenter: Jessalin Nguyen, University of Chicago (jessalinnguyen@uchicago.edu)

Authors:

Jessalin Nguyen, University of Chicago  (jessalinnguyen@uchicago.edu)

Sarah Merolla, Marine Biological Laboratory  (smerolla@mbl.edu)

Rut Pedrosa Pàmies, Marine Biological Laboratory  (rpedrosa@mbl.edu)

Loretta Roberson, Marine Biological Laboratory  (lroberson@mbl.edu)

Mirta Teichberg, Marine Biological Laboratory  (mteichberg@mbl.edu)