Coral replanting at COMO Maalifushi
Recently I have had the privilege to be invited to participate in COMO Maalifushi’s Women in Diving and Conservation for the month of July in the Maldives.
Back in 2016, a mass global coral bleaching event decimated an estimated 75% of all coral found across the Maldives. This abnormal weather event was triggered by a prolonged rise in ocean temperatures forcing an estimated increase of 1-2°C above normal local Sea Surface Temperatures (SST). Unfortunately, such increases lead to coral species being subjected to high levels of stress, ultimately leading to the worst mass bleaching event in the past two decades.
Like many other resorts across the Maldives, COMO Maalifushi have recently begun to invest in the restoration of their surrounding coral reefs to help promote and protect their unique tropical marine life. Kris Carrigan, COMO Maalifushi’s resident marine biologist, showed me first-hand the steps the marine biology team are taking to help Maalifushi’s house reef.
To begin with, Kris showed me the fragging method he uses to collect or “harvest” fragments of coral from other more established frames he has in the coral nursery. We started by taking small fragments from colonies that are beginning to overgrow and compete for space (Fig1). We tried our best to harvest as many different fragments from across multiple Genera to help promote a wide variety of different species are grown to help maintain biodiversity. These fragments will then be planted on to new frames to help grow more coral colonies. This method of coral “farming” is taking advantage of the natural ways in which corals reproduce when hit by storms in the wild.
Coral propagation frames are steel frames coated with a mixture of sand and cement in order for the corals to attach and start to grow. The coral fragments are then temporarily attached to the frames and placed underwater around the jetties so other guests are able to see them (Fig 2).
The frames are then placed in the nursery area where the strong currents help oxygenate the corals while protecting them from rapid water temperature increases. The frames are also placed in a position that allows them to get a balance of sunlight and shade every day, further protecting the coral from prolonged changes in temperature. Due to the ideal conditions present, the coral fragments begin to grow and bud in a matter of weeks (Fig 3&4).
The work doesn’t stop here though. Coral are often in direct competition with faster-growing macro algae. Naturally herbivories species of fish often keep this fast-growing competitor at bay. However, like tending to your garden back home sometimes the gardener needs to intervene to remove some stubborn weeds (Algae).
This is why Kris and his team regularly maintain the frames and carefully remove any algae that is growing on the coral fragments and colonies. This is all part of promoting health and fast coral growth (Fig5).
For each frame, the marine biology team send out regular updates to the guest on how their sponsored frame is doing and how much their coral fragments have grown every six months.
After the coral fragments have grown and filled the frame, roughly six months, they are moved to a second nursery that is slightly deeper to allow the coral colonies to acclimate to conditions more similar to their final plantation on the house reef. They are then planted on hanging trees where there are many fish to keep the corals clean of algae (Fig6).
After the coral fragments have spent a few more months in deeper water and grown even bigger, about the size of a small football, they are then collected to be replanted to their new location on the house reef (Fig7). During our dive we were also able to conduct a Dive Against Debris® survey and collected any marine debris we found. #EveryDiveaSurveyDive.
Once the large coral colonies were moved to the COMO Maalifushi house reef, suitable areas were chosen so the corals have the best chance possible. These areas have fewer other coral species nearby so they don’t need to compete for space. The colonies are placed on natural outcrops and other locations that best emulate natural places where each coral species would be found (Fig 8).
After the corals were planted within a matter of minutes the corals started to extend out their tentacles, a good sign that they were not majorly stressed (Fig9).
It was great that Louise from Project AWARE could be part of the very first coral replanting directly back onto the house reef at COMO Maalifushi. Kris Carrigan, Marine Biologist, COMO Maalifushi.
Thank you once again to all the staff at COMO Maalifushi and especially to Kris for taking me through the process of coral planting and allowing me to help and learn more.