We spent the day exploring both the marine and terrestrial worlds of Flint Island, an isolated speck of land in the eastern-most region of the vast oceanic territory of the island nation of Kiribati. Flint Island is not technically an atoll, like the other Southern Line Islands, because there is no central lagoon. It is a slightly raised, long, narrow island that measures 4 km by 0.8 km (2.5 miles by 0.5 mile) and is surrounded by a reef flat, which gives way to a precipitously steep coral-covered slope that disappears into the depths. There are no known prehistoric Polynesian settlement sites on the island, although there is evidence it was visited by Polynesians who may have passed by occasionally to perhaps utilize various resources, such as coconut crabs, giant clams, etc. 

The island was discovered by Europeans in 1520 when Ferdinand Magellan, sailing on behalf of Spain, was seeking a westward route to the Spice Islands. His voyage was of utmost importance to Spain, because Portugal already controlled the eastward route around Africa to the Spice Islands. Magellan’s expedition set off from Seville on August 10, 1519, with five vessels and 280 men and eventually returned three years later with only one remaining ship, Victoria, with just 18 survivors (which did not include Magellan). This was the first expedition to have circumnavigated the globe. An interesting aspect of this voyage, which is the point of this historic synopsis, is after making his way past South America via the Strait of Magellan (named for him), he was the first European to cross the Pacific Ocean (named by him). Magellan somehow managed to sail from the southern part of South America all the way to Guam and the Philippines without discovering any land in between…with the exception of an atoll in the Tuamotus and tiny Flint Island, where we were today. At first glance, one would think Flint Island, with its extensive coconut plantation, must have been a godsend to his starving and scurvy-ridden men, but we have to remember that the coconuts were not here during Magellan’s time. The palms were planted in the late 19th century by a British company wanting to produce copra. Nor were there any people inhabiting the island during Magellan’s time who could give them aid. The survivors were able to catch several sharks here, which inspired them to give the island the name Tiburones (the Spanish word for sharks). It was later renamed by ensuing European explorers.

Our expedition stop today lacked the desperation of Magellan’s visit so long ago, but we were no less excited to be here. We devoted the morning to activities in the gin-clear waters…SCUBA diving, snorkeling, and tours in the glass-bottom Zodiac. The upper-most region of the reef appears to have suffered from coral bleaching in the last couple years, because most of the short finger coral structures were coated with calcareous algae. However, from a few meters lower, the rest of the coral reef located on the slope is very healthy, with near total coral coverage dominated by platelet corals. The most common fishes in the shallows were black trigger fishes and various dark-colored surgeon fishes, but deeper waters held numerous larger predators, such as snappers, trevally jacks, and at least three species of sharks (blacktip reef sharks, whitetip reef sharks, and grey reef sharks). It is noteworthy that the species diversity of both corals and fishes have definitely decreased as we have gotten more remote and isolated from where we began this voyage in the Tuamotus of French Polynesia, but that is to be expected as demonstrated by the study of biogeography.

We made a landing soon after lunch onto the exposed reef flat, and then spent a couple hours or so exploring this densely vegetated island with an amazing, hard-packed coral rubble beach all around the outer edge. Some interesting sea turtle tracks were noted right near the landing, showing us that this must be an important breeding site for these beautiful creatures (at least one green sea turtle was seen earlier by some of the snorkelers). Those who went ashore this afternoon were able to walk on the beach and meander through the narrow band of tournefortia bushes that seemed almost as though they had been planted for someone’s pleasure. Most of the island is covered with coconut palms, including both mature trees and countless thousands of sprouted coconuts that have filled in most of the gaps between the trees. It was actually difficult walking over the coconuts that nearly covered the ground in some places. Inside the dense forest, we were able to view many white terns and black noddy terns perched or nesting overhead in the cordia and pisonia trees, as well as lots of tiny skinks crawling around the leaf litter. However, the most exciting creatures encountered onshore were the immense and somewhat creepy coconut crabs. These impressive beasts are the largest terrestrial arthropods on earth. They can tear open coconuts with their huge pincers! Many of us also enjoyed a walk/wade in the shallow reef water where several young black-tipped reef sharks, finger-lipped mullet, and a peppered moray eel were spotted in the large, open tide pools.