Mote Postdoctoral Research Fellow Dr. Heather Page and colleagues advanced research on ocean acidification impacts to multiple species and their interactions in 2018. Coral reef ecosystem health has been declining worldwide, and ocean acidification (OA) — decreasing seawater pH owing to human-contributed carbon dioxide entering the ocean — may further challenge reefs. To better predict coral reefs’ fate amid OA, scientists must understand how multiple living things — corals, seaweeds and more — will respond and how their interactions will be influenced. These interactions shape coral reef community structure and resilience to environmental changes.

In summer 2018, Page and colleagues conducted a month-long experiment studying OA effects on interactions between corals, macroalgae (seaweeds) and sponges. “Our results provide limited support for the hypothesis that ocean acidification may facilitate shifts towards increased sponge and macroalgae abundance on reefs,” Page said.

As a follow-up, the team is currently exposing the same macroalgae species to OA for one month, and then they will test sea urchins’ preference for and consumption rates of macroalgae grown under different pH conditions. This research, in collaboration with Mote Postdoctoral Research Fellow Dr. Rob Nowicki, investigates sea urchins’ ability to control macroalgae populations under future OA. Later research will build on these experiments by including additional species, response variables and environmental conditions. The team will also set up “mini coral reefs” in outdoor mesocosms to study how these communities respond to OA over six to 12 months and to test whether different management strategies can boost coral reef resilience to acidification

OA also may alter species interactions by affecting how well marine invertebrates can “smell” important cues associated with habitat, predators and prey. Page is working with Mote Postdoctoral Research Fellow Dr. Phil Gravinese and scientists at the Florida Fish and Wildlife Conservation Commission in Marathon to investigate the ability of post-larval Caribbean spiny lobsters to smell appropriate settlement habitats, such as loggerhead sponges and red macroalgae, where they will live until they grow to juveniles and adults. The Caribbean spiny lobster fishery is one of the most profitable in the Caribbean region and Florida Keys. Therefore, it’s important to understand any potential bottlenecks to adult populations such as failure of lobsters to successfully recruit to the Florida Keys. Project scientists have been collecting post-larval lobsters via plankton tows, under a permit from NOAA’s Florida Keys National Marine Sanctuary, and conducting experiments on chemotaxis (how a living thing moves in response to a chemical cue) around the new moon each month this fall. They plan to continue this work through spring of 2019.

These studies are funded through Mote Postdoctoral Research Fellowships held by Page, Nowicki and Gravinese.