Marine Atlas: Maximizing Benefits for Fiji

STORMY TIMES: CYCLONES Tropical cyclones pose direct threats to Fiji, its people and its marine life. Marine and coastal habitats including mangroves, seagrasses and coral reefs play an important role in offering effective protection and therefore need to be sustainably managed and conserved.

is strongly influenced by the El Niño–Southern Oscillation (ENSO; see also chapters “Go with the flow” and “Hotter and higher”). During El Niño years, cyclones are more likely to form between 6°S and 18°S and 170°E and 170°W. The high- est density is centred over the northern part of Fiji’s islands, where low-level relative vorticity, an upper-level divergent atmosphere and weak environmental wind shear are very conducive to genesis. During La Niña years, slightly fewer tropical cyclones form, originating in the south of Fiji (Chand and Walsh, 2009). Although there is not much difference between El Niño and La Niña years, Fiji’s northern islands have less cyclone inci- dences during La Niña conditions than the coun- try’s southern islands (Chand and Walsh, 2009). The average number of cyclones impacting Fiji from 1969 to 2017 was 7.3 per year. For El Niño years, the average is 8.7 per year, while for La Niña years the average is 6.5 per year. During neutral seasons, the average is slightly less at 6.4 per year (Fiji Meteorological Service, 2016/17). In the past decade, there has been increasing at- tention on the relationship between climate change and the frequency and intensity of cyclones in the region. Diamond et al. (2013) found a statistically significant increase in the number and intensity of cyclones in the period 1991–2010 compared with the period 1970–1990. Rising SSTs are fuelling cyclones (see also chapters “Hotter and higher”)

Stronger than CycloneWinston As a symbol of their strength following the most powerful storm to have made landfall in the southern hemisphere and the dev- astation that it caused throughout Fiji, the villagers of Navitilevu named their youngest child Salomi Winston after the cyclone. Reaching a maximum speed of 306 km/h, Cyclone Winston killed 44 people, damaged and destroyed 40,000 homes, and cost a total of FJ$2.98 billion (US$1.4 billion; Tuilevuka, 2016).

While being the strongest, the category 5 Cyclone Winston is but one track on the map showing all category 1 to 5 cyclones that occurred in the pe- riod from 1980 to 2016. Cyclone Winston formed on 7 February north-west of Vanuatu and moved towards Tonga, before turning 180 degrees and heading for Fiji on 20 February. Cyclones are monitored by the Regional Special- ized Meteorological Centre of the Fiji Meteorolog- ical Service in Nadi and categorized according to the Australian and South Pacific Category System from category 1 (90 km/h gusts) to category 5 (280 km/h gusts). The cyclone season is considered to run from the beginning of November to the end of April, but destructive cyclones can occur outside this period. The formation of cyclones in the region

that are resulting in increasing damage, including to Fiji’s valuable coastal habitats (see small map).

At the same time, conserving habitats such as cor- al reefs and mangroves offers a very effective form of protection against storms. In this way, Fiji can strengthen its defences against cyclones.




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