Canadian born, Sarah attained her Bachelor of Science with distinction in Biology at the University of Victoria, (BC, Canada). During her undergraduate education, Sarah undertook several summer courses and spent time exploring the intertidal zone at the Bamfield Marine Sciences Center, which sparked her keen interest in marine biology. Following her new passion, Sarah moved to The University of Calgary (Canada) where she completed her Masters in Marine Biology. Her Masters works involved intense fieldwork at the Flower Garden Banks (FGB) in the Gulf of Mexico looking at recruitment patterns of scleractinian corals in response to herbivory. Having developed a successful collaboration with Dr. Misha Matz during her Masters, she is now a third year Ph.D. student at the University of Texas at Austin in the Matz lab. Sarah’s broad research interests are in larval dispersal and settlement and how these patterns affect population connectivity and the potential for range shifts in response to climate change.
The larval phase of the coral life cycle enables dispersal, and thus the establishment and potential recovery of coral populations, however is contingent on effective recruitment strategies. Caribbean coral recruitment success has been low in recent years, especially in the northernmost reef in the Gulf of Mexico, the Flower Garden Banks (FGB). In contrast, recruitment success remains relatively high among Pacific corals. We investigated whether these regional differences might be explained by the lack of appropriate Caribbean settlement cue, or by impaired cue perception by Caribbean coral larvae. We collected a natural settlement cue (crustose coralline algae, CCA) from Caribbean (Florida, FGB, Bonaire) and Pacific (Great Barrier Reef (GBR), Pohnpei, Guam) locations. Coral settlement response to these cues was tested on four species from the GBR (Acropora millepora, A. tenuis, Favia lizardensis, and Ctenactis echinata) and three from the FGB (Montastrea franksi, Diploria strigosa, and Stephanocoenia intersepta). Larvae from several species from both the Caribbean and Pacific regions responded strongly to at least some of the cues tested, suggesting that low Caribbean recruitment is not due to impaired cue perception. Additionally, Caribbean CCA induced settlement in both the Caribbean and Pacific coral species, indicating that the appropriate cue is present on Caribbean reefs. Ranking of CCA sources by the magnitude of settlement response differed between coral species, suggesting species-specific settlement preferences. Next-generation sequencing of 16s-ssRNA amplicons from the CCA samples revealed high diversity among CCA samples. There was a positive correlation between the relative proportion of CCA-originating sequences in the amplicon and the magnitude of settlement response. Overall, our results indicate that the lack of coral recruitment observed in the Caribbean is not due to an absence of effective settlement cue or impaired larval responsiveness to cues, and must, therefore, result from some other factor, such as natural cue density on the reef, symbiont availability or post settlement mortality.