Without our reefs, Bermuda could not exist, yet worldwide, coral reefs are in decline. Will Bermuda’s meet the same fate? And what more can we do to protect them.
Life on Bermuda’s reefs is bountiful. The major reef fish families include butterflyfish, angelfish, wrasses, parrotfish, surgeonfish, triggerfish, snappers and groupers. There are also smaller species including blennies and gobies.
Dr Joanna Pitt, marine resources officer at the Department for Environment and Natural Resources (DENR), has witnessed firsthand the positive difference resulting from conservation efforts, such as fish pot bans and protected species status. “Parrotfish populations rebounded fairly quickly,” she explains. “The preservation and recovery of these key herbivores has helped maintain the overall health of Bermuda’s reefs by keeping seaweeds under control.” Some larger, predatory fishes are also recovering well, such as red hind and black grouper. Unfortunately, not all the grouper species have recovered, such as the Nassau grouper, despite 30 years of protection. In total, there are over 365 reef-associated fish species recorded here but, Dr Pitt continues, “because there are many species that look fairly similar to each other, additional species are still noticed every now and again.”
The same can be said for the different species of coral found in Bermuda’s waters, too. “We haven’t finished the list,” laughs Dr Robbie Smith, curator of the Natural History Museum at the Bermuda Aquarium, Museum and Zoo (BAMZ). “The corals we consider most significant are the ones that build a reef, our hard corals. We only have twenty-one of those here. The most common ones are the brain corals, star corals and mustard corals. Then, we have the branchy corals on our patch reefs and the deeper water. Then, we have all our soft corals, and there’s probably close to thirty soft corals we see. Sea fans and sea rods in shallow water, but as you go down into deeper water, there’s this whole other community. Things that make skeletons, but don’t actually build reefs.”
And it isn’t just fish that rely on the reefs for food or shelter. Different coral species can provide shelter for a variety of sea creatures. “On the more microscopic scale, when you’re looking at smaller invertebrates, they tend to have niches,” explains Dr Samantha de Putron, associate scientist at the Bermuda Institute for Ocean Sciences (BIOS). “The coral is creating lots of micro habitats around it.
“Our inshore patch reefs have a slightly different invertebrate community because there’s a lot of sediment around the reef area, so you tend to see a lot more bivalves and clams, different mollusc type species, different crustaceans.”
Coral reefs aren’t just valuable because of the species they support. They also protect our coastline by breaking the waves, which allows mangroves and seagrasses to develop. “Those are highly productive systems, with so much life in them as well,” continues Dr de Putron. “Typically, where you have coral reefs, you have seagrasses and mangroves as well, so then you’ve got your three main tropical marine communities all living in fairly close proximity to one another.” Some sea creatures will migrate between these marine communities at different periods during their lifetime, or even during a 24-hour time period.
Stable and Strong
While global coverage of living coral has declined by half since the 1950s due to climate change, overfishing, habitat destruction and pollution, Bermuda’s 280-square-mile reef platform has, continues Dr de Putron, “held really stable and strong.” This is because of our northerly location and positive conservation actions. Bermuda’s reefs are, therefore, often referred to as a “hope spot.”
Being such a high latitude reef means our sea water temperatures don’t stay too high for too long, reducing the risks from coral bleaching. “We’re not seeing the dramatic bleaching events that are being seen at other places in the world,” says Dr de Putron. “When we do see bleaching up here, it’s short-lived, and it’s because the maximum temperature is only towards the end of August, beginning of September.
“We think that we’ve got a very high level of thermal resilience in the corals here and I think that’s because they see wide temperature ranges.”
Other reasons for coral decimation in places such as the Caribbean have been diseases, either of the corals themselves or the creatures the corals rely on for their survival, but again, temperature is on Bermuda’s side. One disease that is found in Bermuda, in the summer, is black line disease. “Corals get stressed when it’s hot,” says Dr Smith. However, once the water cools down, the stress goes away, the disease disappears and the coral can regrow.
Pollution and lionfish also harm coral reef systems, but again, less so in Bermuda. “The majority of the reef platform is protected from not having those big river runoffs from all the fertilisers and nutrients that would fuel the algae,” explains Dr de Putron. And while we do have some “brown water runoff in places,” it only impacts inshore reefs, which have a lot of algae coverage as a result. In terms of the lionfish, Dr Pitt points out that they are “less abundant in the shallower habitats that are important for the juveniles,” and “while we will never be able to get rid of lionfish from our reefs, our efforts to control the local population do seem to be worthwhile.”
Long-term Risks and Continued Protection
Bermuda’s reef platform is healthy now, but this might not always be the case, and Bermuda-based experts, including Drs Smith and de Putron, are at the forefront of monitoring the impact of new disease threats, rising sea levels and ocean acidification. “Thermal pressure is definitely the biggest problem at the moment,” explains Dr de Putron. “Ocean acidification isn’t going to help, but it’s something that is more in the 50-year timeline as opposed to next year.”
“The seas are warming, and I think thermal pressure on the corals is the biggest threat globally, outside of anthropogenic threats.” Anthropogenic threat refers to human impact. While fish pot bans, Marine Protected Areas (MPAs), and protected species status have all proven their worth, the next stage in the conservation process, says Dr Pitt, is Marine Spatial Planning (MSP): “MPAs cannot be created in isolation. The full suite of natural factors and human activities affecting the marine environment must also be taken into consideration. For this reason, MSP is considered the best approach.” A draft MSP has been included in the draft Blue Prosperity Plan, which is part of the Bermuda Ocean Prosperity Programme (BOPP). Dr Smith would also like to see recreational fishing licenses and catch reports come into effect.
While the government is responsible for bringing in conservation legislation, we all have a stake in the health of our coral reef habitats. “Think about sustainable seafood. Respect fisheries laws,” says Dr de Putron. “If you dive and snorkel, don’t touch. Make sure you’re not throwing an anchor on the reef or on the seagrass. Be a marine debris crusader.”
How important is the coral reef to Bermuda? “Bermuda is a coral reef!” she reminds us.