Turning up the lights Ocean acidification may increase light intensity of secretory bioluminescent signaling


SOCIETY FOR INTEGRATIVE AND COMPARATIVE BIOLOGY
2021 VIRTUAL ANNUAL MEETING (VAM)
January 3 – Febuary 28, 2021

Meeting Abstract


21-2  Sat Jan 2  Turning up the lights: Ocean acidification may increase light intensity of secretory bioluminescent signaling Iwanicki, T*; DeTurk, H; Porter, ML; University of Hawai’i at Mānoa; University of Hawai’i at Mānoa; University of Hawai’i at Mānoa iwanicki@hawaii.edu https://tomiwanicki.wixsite.com/iwanickiresearchpage

Bioluminescence – when a living organism produces light by oxidizing a luciferin with luciferase – is a prevalent phenomenon in the world oceans. As many as 75% of organisms in the pelagic are capable of bioluminescence, which is used for offense, defense, and courtship behaviors. Having evolved independently upwards of 50 times, there are a correspondingly large number of factors that can influence the color, intensity, or kinetics of the bioluminescence reaction. One factor often described in the primary literature on novel luciferin-luciferase reactions is the pH of the reaction media. For internally emitting organisms, e.g., scintillon-bearing dinoflagellates, changes in cellular pH are used to trigger bioluminescence; however, secreting organisms must rely on the ocean as their reaction buffer. Anthropogenic climate change brings with it many unanticipated consequences. Under the IPCC worst-case scenario (RCP8.5), the average ocean pH will decrease from its pre-industrial average of 8.2 to 7.7 by the end of the 21st century. Under these conditions, secretory bioluminescence systems may be affected by this change in the reaction medium, ocean water pH. This meta-analysis surveyed 365 primary literature papers, books, and chapters for data on the impact of pH ranging from 7.7-8.2 on native luciferase-luciferin bioluminescence reactions. This study covers a taxonomically diverse group including Bacteria, Dinoflagellata, Cnidaria, Mollusca, Arthropoda, Ctenophora, and Chordata. Preliminary data suggest that secretory bioluminescence systems will increase light intensity or total quantum yield by approximately 5-15%. The rapid (in an evolutionary timescale) increase in light intensity would have a multitude of knock-on effects for the sensory ecology of marine communities.

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