Meeting Abstract
7.1 Friday, Jan. 4 Developing molecular techniques to assess resilience in large benthic foraminiferan communities DOO, SS*; FAN, TY; FUJITA, K; MAYFIELD, AB; CHEN, HK; NGUYEN, HD; BYRNE, M; National Museum of Marine Biology and Aquarium; National Museum of Marine Biology and Aquarium; University of the Ryukyus; National Museum of Marine Biology and Aquarium; National Museum of Marine Biology and Aquarium; University of Sydney; University of Sydney stevedoo@gmail.com
Large benthic Foraminifera (LBFs) compose a significant portion of calcareous sediments in coral reef ecosystems, buffering against diel changes in seawater chemistry and contributing to maintenance of coral sand cays. The vast majority of recent studies on biological responses of large benthic Foraminifera (LBF) to changing climates have indicated deleterious effects on these crucial organisms. In this study, we present new techniques developed to monitor effects of changing climates to the foraminferal holobiont. Western blotting technique was used to determine protein expression of RuBiSCO, a highly conserved rate-limiting photosystem II enzyme, in Baculogypsina sphaerulata collected from intertidal algal flats of the coral island Xiao Liu Chiu, Taiwan. Data indicated reduced protein expression (~50% decrease) of RuBiSCO in response to an acute heat stress (5hr) at +8°C. In a separate project, the potential for recovery in two common LBFs, Calcarina gaudichaudii (diatom-bearing) and Amphisorus hemprichii (dinoflagellate-bearing) was assessed by subjecting specimens to 24 h heat stress (amb, +4°C, +8°C), then returning foraminiferans to ambient conditions for an additional 24h. Maximum dark adapted yield (Fv/Fm) measurements of C. gaudichaudii indicate increased Fv/Fm values in mild heating (+4°C) treatments, while no significant effects were observed after return to ambient temperatures. The response of A. hemprechii indicated no significant effects of heat stress up to +8°C to Fv/Fm values after 24h heating, but deleterious effects were observed in our +8°C treatment after 24h of return to ambient temperatures.
