A new study indicates that reducing invasive algae in Maunalua Bay may help in the recovery of nearshore corals being fed by moderate amounts of submarine groundwater discharge.
Katie Lubarsky and Megan Donahue of the Hawai’i Institute of Marine Biology and Nyssa Silberger of California State University, Northridge, conducted the year-long study of two nearshore reef flats in the bay that had not been subjected to invasive algae removal efforts. Their results are detailed in their paper, “Effects of Submarine Groundwater Discharge on Coral Accretion and Bioerosion on Two Shallow Reef Flats.”
The scientists found that moderate levels of submarine groundwater discharge (SGD) provided important nutrients that increased coral growth and bioerosion. The latter is an important process in the development and maturation of reefs, as it involves the breaking down of coral into sand – thus making room for new corals to grow.
The findings “indicate that if corals are able to settle on these reef flats, they may sustain relatively high rates of growth near SGD seeps,” the researchers wrote in the paper.
They also wrote that “in the absence of algal competition, corals can thrive on SGD-impacted reef flats, and suggest that management of these and similar local stressors such as sedimentation could aid in the recovery of coral populations on Maunalua Bay reef flats.”
The paper was published in the most recent issue of Limnology and Oceanography, a journal published by the Association for the Sciences of Limnology and Oceanography.
“As Mālama Maunalua continues to collect scientific and historical information about the bay, this study underscores the importance of our mission to restore Maunalua’s ecological health,” Executive Director Doug Harper said.