FHTA, 16 April 2020 – Severe Tropical Cyclone Harold has come and gone. This cyclone ripped through our outer islands and caused significant damages to structures and food supplies.
But one lesser known impact of cyclones lies beneath the ocean waves.
Severe weather patterns can cause extensive damage to individual corals and to the structure of the reef. These impacts are known to last a long time.
The powerful waves generated during these cyclones can cause serious damage to our habitats and landforms, especially our coral reefs and shorelines. The strong winds of a cyclone can also cause significant changes to ocean currents and increase inshore ocean turbidity through suspension of sediments.
These cyclones also have long-lasting effects on our reef fish stocks. Coral provides important fish habitat and protection for reef fish such as coral trout so when a cyclone affects reefs, it affects the ability of these fish to protect themselves and these causes a dwindling in numbers.
Along with severe weather, our coral reefs face a massive threat by way of bleaching.
We have an amazing 10,000 square kilometres of coral reefs flourishing in our waters. About 42 percent of the world’s coral species can be found right here in Fijian waters.
These reefs provide a buffer, protecting the coasts from waves and storms. They are formed from important reef builders, corals, who secrete calcium carbonate to form coral reefs.
The corals form barriers to protect the shoreline. Corals live in a mutualistic relationship with symbiotic algae, which use sunlight to produce food for corals and get shelter in return. When water is too warm, corals will expel the algae
(zooxanthellae) living in their tissues causing the coral to turn completely white. This is called coral bleaching.
Corals can survive a bleaching event, but they are under more stress and are subject to mortality. This not only has negative impacts on coral communities, but they also impact fish communities and the human communities that depend on coral reefs and associated fisheries for livelihoods and well-being.
The bleached corals are likely to have reduced growth rates, decreased reproductive capacity, increased susceptibility to diseases and elevated mortality rates.
Tropical Cyclone Harold struck Fiji on the day of an especially high spring tide, known as a king tide. These tides occur a few times every year, when the gravitational pull of the sun and moon upon the earth is strongest. This results in higher-than-usual water levels during high tides.
Island resorts around the Sun Coast, Coral Coast and in the Mamanuca Islands experienced more damages from storm surges from higher than usual water levels brought about by the king tide, than TC Harold. This brought seawater onto their properties, washed away roads, damages sea walls and jetties and caused water-damage in areas that wouldn’t normally be submerged under water.
General Manager of Fiji’s first landowner-owned four-star resort Nakelo Treasure Island’s Jim Saukuru shared details of the damage caused by the unusually high sea level on his property.
“Our seawall has been washed away and the water levels have damaged our helipad and all our trees near the beach area.”
He says that even their desalination plant, which pumped seawater from the lagoon for processing, suffered irreparable damage as the seawater submerged the essentials motors and it’s housing.
Jim estimates that his resort suffered more than $3M in damages from both the cyclone and the king tide. This comes in the middle of a $2.3M refurbishment works being conducted on the island and exacerbates the pain of having no incoming revenue from visitors to Fiji since the beginning of April and throughout the next 3 months.
Other island resorts also reported their beaches being washed away as well as their seawalls inundated with seawater and jetties shifting due to the tide. Damage to many of the outer island jetties that are critical to our maritime communities has been noted by the Fiji Roads Authority to run into the millions.
The inundating effects from the biannual king tides is usually stopped by the construction of concrete sea walls in strategic parts of an island. And for the most part these would be sufficient to hold back storm surges.
Changes in coral communities also affect the species that depend on them, such as the fish and invertebrates that rely on live coral for food, shelter, or recruitment habitat.
Change in the abundance and composition of reef fish assemblages may occur when corals die as a result of coral bleaching.
As mentioned, something as simple as the sea water heating up past its normal temperature has ripple effects that cascade outward. Add cyclones and storm surges and coral damage is increased exponentially.
Fishermen from island villages whose families rely on them to provide sustenance rely heavily on fish stock levels staying constant. Reduced fish stocks affect the communities that rely on this food and livelihood source.
Imagine the divemaster who is awaiting the end of coronavirus to get his much loved job back of taking PADI-certified tourists scuba diving. There would be no diving and no tourists if Fiji’s coral reefs started losing their world renown colours and viridity. It would add another layer to the disturbing reality happening under the ocean’s surface.
As the world’s borders remain closed for an indefinite period and everyone stays home, perhaps we too will start to see a period of healing and repairing taking place below our now calm waters.
By: Fantasha Lockington – CEO, FHTA
Published in the Fiji Times on 16 April 2020