Welcome to Krakatau Adventure
The Journey to the islands takes about 2 hours on a good day in a speed boat, and the best time of the year to make the trip is between May and October .During the moon soon season (November to April) the time taken may be very much longer and the journey uncomfortable, although there may be storms in any month of the year, at this time they are frequent and the journey can be dangerous. It is advisable to cover up well during the trip-even on overcast days one can get badly sun burnt it an open boat at sea.
Keep your eyes open, and you may see a Frigate Bird soaring high overhead, flicking its scissor-like tail as it changes direction with hardly a flap of its wrings. You will almost certainly spot flying fish making their long low glides above the sea surface.
Some of them”fly” for tens of meters, and air borne for several seconds. Approaching the archipelago from Java by the route shown, dolphins often come to greet the boat and play alongside it or in front of the prow. You may also be lucky enough to see White-Bellied Sea Eagle as you approach the islands. It has a slow, gliding flight with the wings held in a shallow as it soars, searching for sea-snakes, fish and crabs swimming near the surface.
As you near the archipelago, the triangular silhouette of Rakata looms ahead. The islands takes its name from Krakatau largest volcano, of which it is the remaining half. Cloud often covers the peak down to about 550 m, and above this height the forest begins to take on a different character. Mosses festoon the branches of trees, which are stunted at the peak. To the south (near the left side of the island as you approach) is a bay in which a settler named Hand lived with his family for a few years from about 1915. There have been no other permanent inhabitants on the island since 1883,although fishing boats visit the archipelago regularly, the waters within the island group often being calmer than the open sea.
Panjang, formerly called Lang Island, and sometimes known as Rakata Kecil, was never part of Krakatau, but was once a part of Krakatau huge predecessor, "Ancient Krakatau”. Like Rakata and Sertung, it was covered in tens of meters of hot ash in August 1883, and this has been eroded over the past century into v-shaped galleys separated by sharp ridges. Like the other two islands, it is now covered in forest. Some of the valleys are now ‘hanging’ because the ash cliff has been cut back by the action of the sea so that the valley floor now opens at a considerable height above the shore. To you right, on the south western point or Panjang, the lava rocks of “Ancient Krakatau“ can be seen near the base of small cliff. Now, to your left as you round its northern point, Rakata huge vertical cliff towers above you. Again, towards its base, the layers of Ancient krakatau lava rock may be seen, with ash layers between them, evidence of successive eruptions centuries ago. Casuarinas (cemara) cling to the cliff. They can not tolerate shade, and on most other parts of the island they have been overgrown and thus eliminated by others forest trees. Landslides are frequent on this cliff, and the prominent groove down the cliff face is not the former vent of the volcano, but a landslide channel from close to the summit. Piles of rubble, the result of landslides, can be seen at the base of the cliff. at the far end of the cliff are the black rocks of Zwarte Hoek, where there is a small beach.
As the boat moves under the cliff, remember that you are traveling over the submerged caldera of Krakatau. The cliff continues almost vertically under the water below your to a depth of about 200 meters. To your right, if the sea is calm, you may be able to see Boot smanroots behind you. These rocks, often with seabirds, usually terns, roosting on them area a favorite spot for shark fisherman, and shark’s fins can occasionally be seen cutting the waters over the caldera. The rocks are Krakatau caldera rim which projects above the water at this point.
Apart from Rakata itself, they are the only other piece of Krakatau visible above water today. Of course, no one could have been in this place before August 1883.Your boat is traveling along a line which at the time would have been covered by thousands of tons of the island Krakatau, which extended far to the north beyond the island Anak Krakatau to your right. Moving past Zwarte Hoek and heading towards Sertung, you will notice, beyond the point to your left,a long sandy beach where the green turtle (Chelone mydas) nests, and just out to sea two large isolated ‘stacks’,one of which has been perforated by the sea. These light-colored cliff stacks, and the cliff along Turtle Beach, are composed of ash deposited in the 1883 eruption of Krakatau, and give you an idea of the depth of ash that covered the island at that time. The stacks have been able to persist because they are on a basement of lava which has prevented the sea washing them away.
Ahead is sertung, the third member of the tree of the islands that are remnants of the huge ”Ancient Krakatau” volcano. Sertung was enlarged by Krakatau 1883 eruption to more than twice its size,and is now virtually composed of ash from that eruption. To your right is the presently active volcanic island, Anak Krakatau, “Child of Krakatau”. This is an apt name,for the island emerged from the sea in 1930 from Krakatau caldera, roughly in line with its three former volcanic craters and between the sites of the two northern ones.The lava field you see is composed of a number of different flows,the most recent one ( 1980 ) being the darkest. Lava did not appear until some time in the 1960s,and this was important in protecting the rest of the island from erosion by the southwestern currents. Before the 1960s Anak Krakatau had emitted ash only, but at such a rate and frequently enough for it to grow, in spite of the marine erosion.
As young pass north along the east coast of Sertung, you will see the PHPA post in the trees near the shore, below what is probably the only permanent spring on the islands. A few hundred meters beyond the PHPA building the vegetation changes quite abruptly from mixed secondary tropical forest to a Casuarina (cemara) woodland. The cemara are growing on a very young part of Sertung. Its northern narrow tongue or ‘spit’. The spit has been formed by the sea wearing away the ash cliffs of Sertung west coast, and the southern currents carrying the material to Sertung northern point and depositing in there. The spit is “moving”, the beach that you see is being added to, and if you have time to walk the 100 meters or so across the narrow neck of the spit you will see that the west coast is being cut back by the surf. So the cemara trees, which were also an early stage in the colonization of Rakata by plants, are never subjected to shade by the other trees establish themselves. In fact, at the present rate of movement, no particular point on the spit can ever become more than 10 to 20 years old before becoming part of the west coast, and being washed away.
As you leave Sertung and move back towards the northern fore land of Anak Krakatau, with Rakata cliff looming up beyond in the middle distance, you are traveling over the northern end of the submerged remains of Krakatau itself. Anak Krakatau is largely barren, being made up of ash fields or lava, but on the northern fore land you can see a number of cemara trees and an extensive grassland of “alang-alang” and wild sugarcane. This grassland was very early stage (before the cemara) in the plant colonization of the other islands, and the process is being repeated here on Anak Krakatau. Moving around to Anak Krakatau landing beach on the eastern fore land, you see more cemara woodland-this fore land is at a later stage of plant succession than the northern one.
Going ashore, you will notice other trees and saplings here and there among the cemara and wild sugarcane the forest is beginning to change to mixed secondary forest. Two species of fig trees are present, and they were first seen fruiting in 1985.There are three species of bats on the island, two kinds of Dog-faced Fruit Bat and a Rosette. All three are fig eaters. Also two species of fruit-eating pigeons ( Pink-necked Pigeon and Cuckoo Dove ) as well as the yellow-vented Bulbul and the striking, yellow and black, Black-napped Oriole now live on the island. These birds and bats spread figs by drooping or excreting their seeds, and probably were responsible for bringing the fig species to the Krakatau from the mainland, and to Anak Krakatau from the other islands. They will probably bring more fig species to Anak Krakatau, and the change towards mixed forest is likely to accelerate in the next few years.
You may see the right yellow breast of the tiny Olive-backed Sunbird as it seeks nectar and insects, clicking as it goes, and perhaps, its nest hanging from a cemara branch. Keep a lookout also for another very small, yellow-breasted bird, the Fly eater, flying from branch to branch in the cemara, or a small flock of a larger bird, the white-breasted Wood-swallow, perhaps six or seven of them perching together along a high cemara branch. Almost certainly you will see (and hear ) the Collared Kingfisher, greenly-blue with a white “collar”. This is one of the most successful colonists on the islands. It makes nest holes in the large spherical termite nests that you see here and there in the cemara trees, and noisily and aggressively defends its nest-site from other intruding birds, such as the Wood-swallows.
Only about 14 hectares of Anak Krakatau are vegetated, and you will get an idea what a small part of the island this is if you climb to the marker on the rm of the outer ash-cone, a strenuous walk, to be attempted at mid-day only by the fit. Yet this small area of woodland supports about 22 of the 36 species of land birds ( not counting migrants) now known on the island.So of the 36 land bird species that have colonized the islands from Java and Sumatra in the hundred years or so since 1883,22 of them have managed to establish themselves on Anak Krakatau eastern fore land in the past 30 years or so (Anak Krakatau 1952 eruption destroyed all the islands have also become established on Anak Krakatau. The large, very common monitor (Varanus Salvator) a relative of the famous Komodo dragon, is a good swimmer and feeds on crabs and turtle eggs. The common Checak gecko (Hemidactylus frenatus)and the “flying”(really giding) Paradise Three Snake (Chrysopelea paradisi) have also colonized Anak Krakatau, the last two probably by means of floating vegetation or logs, which you will have already noticed are common on the beaches. Only one of the 19 species of land snails on the islands has yet reached Anak Krakatau-it was first noticed on Rakata in 1993. There are rats on the archipelago-the House Rat (Rattus rattus) on Rakata, and the country rat (Rattus tiomanicus) on Panjang and Sertung. Only one individual (a House Rat) has ever been found on Anak Krakatau in 1985.
The Tokay (Gekko), which is a gecko-eater, and the Black Eagle, python, and False Vampire Bat (which are also predators) are present on the other islands but have not yet been found on Anak Krakatau. Probably they have not colonized it because they do not yet have a sufficiently reliable food supply there. Also, several forest birds, such as the Brown-capped Woodpecker and Orange bellied Flower pecker, which require large trees, have not yet colonized this island although they are present on the others.
For the study of change, the Krakatau are a natural laboratory-in fact two laboratories in one. Changes both in the archipelago since 1883, and on Anak Krakatau since 1903, are being studied. So that this work is not made more difficult by artificial changes brought about by humans, please keep to the trails, do not wander about the archipelago without a Guide, and make sure that you neither bring to, nor take from the islands any living things (seeds, fruits, insect etc). Please take you refuse back with you, so that other visitors may enjoy the natural beauty and ponder the fascinating history of this unique group of islands.