Coral Reefs Part 8

ISLANDS SOUTH OF THE SANDWICH ARCHIPELAGO.

CHRISTMAS Island (2 deg N., 157 deg W.). Captain Cook, in his "Third Voyage" (Volume ii., chapter x.), has given a detailed account of this atoll. The breadth of the islets on the reef is unusually great, and the sea near it does not deepen so suddenly as is generally the case. It has more lately been visited by Mr. F.D. Bennett ("Geographical Journal,"

volume vii., page 226); and he a.s.sures me that it is low and of coral-formation: I particularly mention this, because it is engraved with a capital letter, signifying a high island, in D'Urville and Lottin's chart.

Mr. Couthouy, also, has given some account of it ("Remarks," page 46) from the Hawaiian "Spectator"; he believes it has lately undergone a small elevation, but his evidence does not appear to me satisfactory; the deepest part of the lagoon is said to be only ten feet; nevertheless, I have coloured it blue.--FANNING Island (4 deg N., 158 deg W.) according to Captain Tromelin ("Ann. Maritim." 1829, page 283), is an atoll: his account as observed by Krusenstern, differs from that given in Fanning's "Voyage" (page 224), which, however, is far from clear; coloured blue.-- WASHINGTON Island (4 deg N., 159 deg W.) is engraved as a low island in D'Urville's chart, but is described by Fanning (page 226) as having a much greater elevation than Fanning Island, and hence I presume it is not an atoll; not coloured.--PALMYRA Island (6 deg N., 162 deg W.) is an atoll divided into two parts (Krusenstern's "Mem. Suppl." page 50, also Fanning's "Voyage," page 233); blue.--SMYTH'S or Johnston's Islands (17 deg N., 170 deg W.). Captain Smyth, R.N., has had the kindness to inform me that they consist of two very low, small islands, with a dangerous reef off the east end of them. Captain Smyth does not recollect whether these islets, together with the reef, surrounded a lagoon; uncoloured.

SANDWICH ARCHIPELAGO.

HAWAII; in the chart in Freycinet's "Atlas," small portions of the coast are fringed by reefs; and in the accompanying "Hydrog. Memoir," reefs are mentioned in several places, and the coral is said to injure the cables.

On one side of the islet of Kohaihai there is a bank of sand and coral with five feet water on it, running parallel to the sh.o.r.e, and leaving a channel of about fifteen feet deep within. I have coloured this island red, but it is very much less perfectly fringed than others of the group.--MAUI; in Freycinet's chart of the anchorage of Raheina, two or three miles of coast are seen to be fringed; and in the "Hydrog. Memoir," "banks of coral along sh.o.r.e" are spoken of. Mr. F.D. Bennett informs me that the reefs, on an average, extend about a quarter of a mile from the beach; the land is not very steep, and outside the reefs the sea does not become deep very suddenly; coloured red.--MOROTOI, I presume, is fringed: Freycinet speaks of the breakers extending along the sh.o.r.e at a little distance from it.

From the chart, I believe it is fringed; coloured red.--OAHU; Freycinet, in his "Hydrog. Memoir," mentions some of the reefs. Mr. F.D. Bennett informs me that the sh.o.r.e is skirted for forty or fifty miles in length. There is even a harbour for ships formed by the reefs, but it is at the mouth of a valley; red.--ATOOI, in La Peyrouse's charts, is represented as fringed by a reef, in the same manner as Oahu and Morotoi; and this, as I have been informed by Mr. Ellis, on part at least of the sh.o.r.e, is of coral-formation: the reef does not leave a deep channel within; red.--ONEEHOW; Mr. Ellis believes that this island is also fringed by a coral-reef: considering its close proximity to the other islands, I have ventured to colour it red. I have in vain consulted the works of Cook, Vancouver, La Peyrouse, and Lisiansky, for any satisfactory account of the small islands and reefs, which lie scattered in a N.W. line prolonged from the Sandwich group, and hence have left them uncoloured, with one exception; for I am indebted to Mr. F.D. Bennett for informing me of an atoll-formed reef, in lat.i.tude 28 deg 22', longitude 178 deg 30' W., on which the "Gledstanes"

was wrecked in 1837. It is apparently of large size, and extends in a N.W.

and S.E. line: very few islets have been formed on it. The lagoon seems to be shallow; at least, the deepest part which was surveyed was only three fathoms. Mr. Couthouy ("Remarks," page 38) describes this island under the name of OCEAN island. Considerable doubts should be entertained regarding the nature of a reef of this kind, with a very shallow lagoon, and standing far from any other atoll, on account of the possibility of a crater or flat bank of rock lying at the proper depth beneath the surface of the water, thus affording a foundation for a ring-formed coral-reef. I have, however, thought myself compelled, from its large size and symmetrical outline, to colour it blue.

SAMOA OR NAVIGATOR GROUP.

Kotzebue, in his "Second Voyage," contrasts the structure of these islands with many others in the Pacific, in not being furnished with harbours for ships, formed by distant coral-reefs. The Rev. J. Williams, however, informs me, that coral-reefs do occur in irregular patches on the sh.o.r.es of these islands; but that they do not form a continuous band, as round Mangaia, and other such perfect cases of fringed islands. From the charts accompanying La Peyrouse's "Voyage," it appears that the north sh.o.r.e of SAVAII, MAOUNA, OROSENGA, and MANUA, are fringed by reefs. La Peyrouse, speaking of Maouna (page 126), says that the coral-reef surrounding its sh.o.r.es, almost touches the beach; and is breached in front of the little coves and streams, forming pa.s.sages for canoes, and probably even for boats. Further on (page 159), he extends the same observation to all the islands which he visited. Mr. Williams in his "Narrative," speaks of a reef going round a small island attached to OYOLAVA, and returning again to it: all these islands have been coloured red.--A chart of ROSE Island, at the extreme west end of the group, is given by Freycinet, from which I should have thought that it had been an atoll; but according to Mr.

Couthouy ("Remarks," page 43), it consists of a reef, only a league in circuit, surmounted by a very few low islets; the lagoon is very shallow, and is strewed with numerous large boulders of volcanic rock. This island, therefore, probably consists of a bank of rock, a few feet submerged, with the outer margin of its upper surface fringed with reefs; hence it cannot be properly cla.s.sed with atolls, in which the foundations are always supposed to lie at a depth, greater than that at which the reef-constructing polypifers can live; not coloured.

BEVERIDGE Reef, 20 deg S., 167 deg W., is described in the "Naut. Mag."

(May 1833, page 442) as ten miles long in a N. and S. line, and eight wide; "in the inside of the reef there appears deep water;" there is a pa.s.sage near the S.W. corner: this therefore seems to be a submerged atoll, and is coloured blue.

SAVAGE Island, 19 deg S., 170 deg W., has been described by Cook and Forster. The younger Forster (volume ii., page 163) says it is about forty feet high: he suspects that it contains a low plain, which formerly was the lagoon. The Rev. J. Williams informs me that the reef fringing its sh.o.r.es, resembles that round Mangaia; coloured red.

FRIENDLY ARCHIPELAGO.

PYLSTAART Island. Judging from the chart in Freycinet's "Atlas," I should have supposed that it had been regularly fringed; but as nothing is said in the "Hydrog. Memoir" (or in the "Voyage" of Tasman, the discoverer) about coral-reefs, I have left it uncoloured.--TONGATABOU: In the "Atlas of the Voyage of the 'Astrolabe'," the whole south side of the island is represented as narrowly fringed by the same reef which forms an extensive platform on the northern side. The origin of this latter reef, which might have been mistaken for a barrier-reef, has already been attempted to be explained, when giving the proofs of the recent elevation of this island.-- In Cook's charts the little outlying island also of EOAIGEE, is represented as fringed; coloured red.--EOUA. I cannot make out from Captain Cook's charts and descriptions, that this island has any reef, although the bottom of the neighbouring sea seems to be corally, and the island itself is formed of coral-rock. Forster, however, distinctly ("Observations," page 14) cla.s.ses it with high islands having reefs, but it certainly is not encircled by a barrier-reef and the younger Forster ("Voyage," volume i., page 426) says, that "a bed of coral-rocks surrounded the coast towards the landing-place." I have therefore cla.s.sed it with the fringed islands and coloured it red. The several islands lying N.W. of Tongatabou, namely ANAMOUKA, KOMANGO, KOTOU, LEFOUGA, FOA, etc., are seen in Captain Cook's chart to be fringed by reefs, in several of them are connected together.

From the various statements in the first volume of Cook's "Third Voyage,"

and especially in the fourth and sixth chapters, it appears that these reefs are of coral-formation, and certainly do not belong to the barrier cla.s.s; coloured red.--TOUFOA AND KAO, forming the western part of the group, according to Forster have no reefs; the former is an active volcano.--VAVAO. There is a chart of this singularly formed island, by Espinoza: according to Mr. Williams it consists of coral-rock: the Chevalier Dillon informs me that it is not fringed; not coloured. Nor are the islands of LATTE and AMARGURA, for I have not seen plans on a large scale of them, and do not know whether they are fringed.

NIOUHA, 16 deg S., 174 deg W., or KEPPEL Island of Wallis, or COCOS Island.

From a view and chart of this island given in Wallis's "Voyage" (4to edition) it is evidently encircled by a reef; coloured blue: it is however remarkable that BOSCAWEN Island, immediately adjoining, has no reef of any kind; uncoloured.

WALLIS Island, 13 deg S., 176 deg W., a chart and view of this island in Wallis's "Voyage" (4to edition) shows that it is encircled. A view of it in the "Naut. Mag." July 1833, page 376, shows the same fact; blue.

ALLOUFATOU, or HORN Island, ONOUAFU, or PROBY Island, and HUNTER Islands, lie between the Navigator and Fidji groups. I can find no distinct accounts of them.

FIDJI or VITI GROUP.

The best chart of the numerous islands of this group, will be found in the "Atlas of the 'Astrolabe's' Voyage." From this, and from the description given in the "Hydrog. Memoir," accompanying it, it appears that many of these islands are bold and mountainous, rising to the height of between 3,000 and 4,000 feet. Most of the islands are surrounded by reefs, lying far from the land, and outside of which the ocean appears very deep. The "Astrolabe" sounded with ninety fathoms in several places about a mile from the reefs, and found no bottom. Although the depth within the reef is not laid down, it is evident from several expressions, that Captain D'Urville believes that ships could anchor within, if pa.s.sages existed through the outer barriers. The Chevallier Dillon informs me that this is the case: hence I have coloured this group blue. In the S.E. part lies BATOA, or TURTLE Island of Cook ("Second Voyage," volume ii., page 23, and chart, 4to edition) surrounded by a coral-reef, "which in some places extends two miles from the sh.o.r.e;" within the reef the water appears to be deep, and outside it is unfathomable; coloured pale blue. At the distance of a few miles, Captain Cook (Ibid., page 24) found a circular coral-reef, four or five leagues in circuit, with deep water within; "in short, the bank wants only a few little islets to make it exactly like one of the half-drowned isles so often mentioned,"--namely, atolls. South of Batoa, lies the high island of ONO, which appears in Bellinghausen's "Atlas" to be encircled; as do some other small islands to the south; coloured pale blue; near Ono, there is an annular reef, quite similar to the one just described in the words of Captain Cook; coloured dark blue.

ROTOUMAH, 13 deg S., 179 deg E.--From the chart in Duperrey's "Atlas," I thought this island was encircled, and had coloured it blue, but the Chevallier Dillon a.s.sures me that the reef is only a sh.o.r.e or fringing one; red.

INDEPENDENCE Island, 10 deg S., 179 deg E., is described by Mr. G. Bennett, ("United Service Journal," 1831, part ii., page 197) as a low island of coral-formation, it is small, and does not appear to contain a lagoon, although an opening through the reef is referred to. A lagoon probably once existed, and has since been filled up; left uncoloured.

ELLICE GROUP.

OSCAR, PEYSTER, and ELLICE Islands are figured in Arrowsmith's "Chart of the Pacific" (corrected to 1832) as atolls, and are said to be very low; blue.--NEDERLANDISCH Island. I am greatly indebted to the kindness of Admiral Krusenstern, for sending me the original doc.u.ments concerning this island. From the plans given by Captains Eeg and Khremtshenko, and from the detailed account given by the former, it appears that it is a narrow coral-island, about two miles long, containing a small lagoon. The sea is very deep close to the sh.o.r.e, which is fronted by sharp coral-rocks.

Captain Eeg compares the lagoon with that of other coral-islands; and he distinctly says, the land is "very low." I have therefore coloured it blue. Admiral Krusenstern ("Memoir on the Pacific," Append., 1835) states that its sh.o.r.es are eighty feet high; this probably arose from the height of the cocoa-nut trees, with which it is covered, being mistaken for land.

--GRAN COCAL is said in Krusenstern's "Memoir," to be low, and to be surrounded by a reef; it is small, and therefore probably once contained a lagoon; uncoloured.--ST. AUGUSTIN. From a chart and view of it, given in the "Atlas of the 'Coquille's' Voyage," it appears to be a small atoll, with its lagoon partly filled up; coloured blue.

GILBERT GROUP.

The chart of this group, given in the "Atlas of the 'Coquille's' Voyage,"

at once shows that it is composed of ten well characterised atolls. In D'Urville and Lottin's chart, SYDENHAM is written with a capital letter, signifying that it is high; but this certainly is not the case, for it is a perfectly characterised atoll, and a sketch, showing how low it is, is given in the "'Coquille's' Atlas." Some narrow strip-like reefs project from the southern side of DRUMMOND atoll, and render it irregular. The southern island of the group is called CHASE (in some charts, ROTCHES); of this I can find no account, but Mr. F.D. Bennett discovered ("Geographical Journal", volume vii., page 229), a low extensive island in nearly the same lat.i.tude, about three degrees westward of the longitude a.s.signed to Rotches, but very probably it is the same island. Mr. Bennett informs me that the man at the masthead reported an appearance of lagoon-water in the centre; and, therefore, considering its position, I have coloured it blue.

--PITT Island, at the extreme northern point of the group, is left uncoloured, as its exact position and nature is not known.--BYRON Island, which lies a little to the eastward, does not appear to have been visited since Commodore Byron's voyage, and it was then seen only from a distance of eighteen miles; it is said to be low; uncoloured.

OCEAN, PLEASANT, and ATLANTIC Islands all lie considerably to the west of the Gilbert group: I have been unable to find any distinct account of them. Ocean Island is written with small letters in the French chart, but in Krusenstern's "Memoir" it is said to be high.

MARSHALL GROUP.

We are well acquainted with this group from the excellent charts of the separate islands, made during the two voyages of Kotzebue: a reduced one of the whole group may be easily seen in Krusenstern's "Atlas," and in Kotzebue's "Second Voyage." The group consists (with the exception of two LITTLE islands which probably have had their lagoon filled up) of a double row of twenty-three large and well-characterised atolls, from the examination of which Chamisso has given us his well-known account of coral-formations. I include GASPAR RICO, or CORNWALLIS Island in this group, which is described by Chamisso (Kotzebue's "First Voyage," volume iii., page 179) "as a low sickle-formed group, with mould only on the windward side." Gaspard Island is considered by some geographers as a distinct island lying N.E. of the group, but it is not entered in the chart by Krusenstern; left uncoloured. In the S.W. part of this group lies BARING Island, of which little is known (see Krusenstern's "Appendix," 1835, page 149). I have left it uncoloured; but BOSTON Island I have coloured blue, as it is described (Ibid.) as consisting of fourteen small islands, which, no doubt, enclose a lagoon, as represented in a chart in the "'Coquille's'

Atlas."--Two islands, AUR KAWEN and GASPAR RICO, are written in the French chart with capital letters; but this is an error, for from the account given by Chamisso in Kotzebue's "First Voyage," they are certainly low.

The nature, position, and even existence, of the shoals and small islands north of the Marshall group, are doubtful.

NEW HEBRIDES.

Any chart, on even a small scale, of these islands, will show that their sh.o.r.es are almost without reefs, presenting a remarkable contrast with those of New Caledonia on the one hand, and the Fidji group on the other.

Nevertheless, I have been a.s.sured by Mr. G. Bennett, that coral grows vigorously on their sh.o.r.es; as indeed, will be further shown in some of the following notices. As, therefore, these islands are not encircled, and as coral grows vigorously on their sh.o.r.es, we might almost conclude, without further evidence, that they were fringed, and hence I have applied the red colour with rather greater freedom than in other instances.--MATTHEW'S ROCK, an active volcano, some way south of the group (of which a plan is given in the "Atlas of the 'Astrolabe's' Voyage") does not appear to have reefs of any kind about it.--ANNATOM, the southernmost of the Hebrides; from a rough woodcut given in the "United Service Journal" (1831, part iii., page 190), accompanying a paper by Mr. Bennett, it appears that the sh.o.r.e is fringed; coloured red.--TANNA. Forster, in his "Observations"

(page 22), says Tanna has on its sh.o.r.es coral-rock and madrepores; and the younger Forster, in his account (volume ii., page 269) speaking of the harbour says, the whole S.E. side consists of coral-reefs, which are overflowed at high-water; part of the southern sh.o.r.e in Cook's chart is represented as fringed; coloured red.--IMMER is described ("United Service Journal," 1831, part iii., page 192) by Mr. Bennett as being of moderate elevation, with cliffs appearing like sandstone: coral grows in patches on its sh.o.r.e, but I have not coloured it; and I mention these facts, because Immer might have been thought from Forster's cla.s.sification ("Observations," page 14), to have been a low island or even an atoll.-- ERROMANGO Island; Cook ("Second Voyage," volume ii., page 45, 4to edition) speaks of rocks everywhere LINING the coast, and the natives offered to haul his boat over the breakers to the sandy beach: Mr. Bennett, in a letter to the Editor of the "Singapore Chron.," alludes to the REEFS on its sh.o.r.es. It may, I think, be safely inferred from these pa.s.sages that the sh.o.r.e is fringed in parts by coral-reefs; coloured red.--SANDWICH Island.

The east coast is said (Cook's "Second Voyage," volume ii., page 41) to be low, and to be guarded by a chain of breakers. In the accompanying chart it is seen to be fringed by a reef; coloured red.--MALLICOLLO. Forster speaks of the reef-bounded sh.o.r.e: the reef is about thirty yards wide, and so shallow that a boat cannot pa.s.s over it. Forster also ("Observations,"

page 23) says, that the rocks of the sea-sh.o.r.e consist of madrepore. In the plan of Sandwich harbour, the headlands are represented as fringed; coloured red.--AURORA and PENTECOST Islands, according to Bougainville, apparently have no reefs; nor has the large island of S. ESPIRITU, nor BLIGH Island or BANKS' Islands, which latter lie to the N.E. of the Hebrides. But in none of these cases, have I met with any detailed account of their sh.o.r.es, or seen plans on a large scale; and it will be evident, that a fringing-reef of only thirty or even a few hundred yards in width, is of so little importance to navigation, that it will seldom be noticed, excepting by chance; and hence I do not doubt that several of these islands, now left uncoloured, ought to be red.

SANTA CRUZ GROUP.

VANIKORO (Figure 1, Plate I.) offers a striking example of a barrier-reef: it was first described by the Chevalier Dillon, in his voyage, and was surveyed in the "Astrolabe"; coloured pale blue.--TIKOPIA and FATAKA Islands appear, from the descriptions of Dillon and D'Urville, to have no reefs; ANOUDA is a low, flat island, surrounded by cliffs ("'Astrolabe'

Hydrog." and Krusenstern, "Mem." volume ii., page 432); these are uncoloured. TOUPOUA (OTOOBOA of Dillon) is stated by Captain Tromelin ("Annales Marit." 1829, page 289) to be almost entirely included in a reef, lying at the distance of two miles from the sh.o.r.e. There is a s.p.a.ce of three miles without any reef, which, although indented with bays, offers no anchorage from the extreme depth of the water close to the sh.o.r.e: Captain Dillon also speaks of the reefs fronting this island; coloured blue.-- SANTA-CRUZ. I have carefully examined the works of Carteret, D'Entrecasteaux, Wilson, and Tromelin, and I cannot discover any mention of reefs on its sh.o.r.es; left uncoloured.--TINAKORO is a constantly active volcano without reefs.--MENDANA ISLES (mentioned by Dillon under the name of MAMMEE, etc.); said by Krusenstern to be low, and intertwined with reefs. I do not believe they include a lagoon; I have left them uncoloured.--DUFF'S Islands compose a small group directed in a N.W. and S.E. band; they are described by Wilson (page 296, "Miss. Voy." 4to edition), as formed by bold-peaked land, with the islands surrounded by coral-reefs, extending about half a mile from the sh.o.r.e; at a distance of a mile from the reefs he found only seven fathoms. As I have no reason for supposing there is deep water within these reefs, I have coloured them red.

KENNEDY Island, N.E. of Duff's. I have been unable to find any account of it.

NEW CALEDONIA.

The great barrier-reefs on the sh.o.r.es of this island have already been described (Figure 5, Plate II.). They have been visited by Labillardiere, Cook, and the northern point by D'Urville; this latter part so closely resembles an atoll that I have coloured it dark blue. The LOYALTY group is situated eastward of this island; from the chart and description given in the "Voyage of the 'Astrolabe'," they do not appear to have any reefs; north of this group, there are some extensive low reefs (called ASTROLABE and BEAUPRE,) which do not seem to be atoll-formed; these are left uncoloured.

AUSTRALIAN BARRIER-REEF.

The limits of this great reef, which has already been described, have been coloured from the charts of Flinders and King. In the northern parts, an atoll-formed reef, lying outside the barrier, has been described by Bligh, and is coloured dark blue. In the s.p.a.ce between Australia and New Caledonia, called by Flinders the Corallian Sea, there are numerous reefs.

Of these, some are represented in Krusenstern's "Atlas" as having an atoll-like structure; namely, BAMPTON shoal, FREDERIC, VINE or Horse-shoe, and ALERT reefs; these have been coloured dark blue.

LOUISIADE.

The dangerous reefs which front and surround the western, southern, and northern coasts of this so-called peninsula and archipelago, seem evidently to belong to the barrier cla.s.s. The land is lofty, with a low fringe on the coast; the reefs are distant, and the sea outside them profoundly deep.

Nearly all that is known of this group is derived from the labours of D'Entrecasteaux and Bougainville: the latter has represented one continuous reef ninety miles long, parallel to the sh.o.r.e, and in places as much as ten miles from it; coloured pale blue. A little distance northward we have the LAUGHLAN Islands, the reefs round which are engraved in the "Atlas of the Voyage of the 'Astrolabe'," in the same manner as in the encircled islands of the Caroline Archipelago, the reef is, in parts, a mile and a half from the sh.o.r.e, to which it does not appear to be attached; coloured blue. At some little distance from the extremity of the Louisiade lies the WELLS reef, described in G. Hamilton's "Voyage in H.M.S.

'Pandora'" (page 100): it is said, "We found we had got embayed in a double reef, which will soon be an island." As this statement is only intelligible on the supposition of the reef being crescent or horse-shoe formed, like so many other submerged annular reefs, I have ventured to colour it blue.

SOLOMON ARCHIPELAGO.

The chart in Krusenstern's "Atlas" shows that these islands are not encircled, and as coral appears from the works of Surville, Bougainville, and Labillardiere, to grow on their sh.o.r.es, this circ.u.mstance, as in the case of the New Hebrides, is a presumption that they are fringed. I cannot find out anything from D'Entrecasteaux's "Voyage," regarding the southern islands of the group, so have left them uncoloured.--MALAYTA Island in a rough MS. chart in the Admiralty has its northern sh.o.r.e fringed.--YSABEL Island, the N.E. part of this island, in the same chart, is also fringed: Mendana, speaking (Burney, volume i., page 280) of an islet adjoining the northern coast, says it is surrounded by reefs; the sh.o.r.es, also of Port Praslin appear regularly fringed.--CHOISEUL Island. In Bougainville's "Chart of Choiseul Bay," parts of the sh.o.r.es are fringed by coral-reefs.-- BOUGAINVILLE Island. According to D'Entrecasteaux the western sh.o.r.e abounds with coral-reefs, and the smaller islands are said to be attached to the larger ones by reefs; all the before-mentioned islands have been coloured red.--BOUKA Islands. Captain Duperrey has kindly informed me in a letter that he pa.s.sed close round the northern side of this island (of which a plan is given in his "Atlas of the 'Coquille's' Voyage"), and that it was "garnie d'une bande de recifs a fleur d'eau adherentes au rivage;"

and he infers, from the abundance of coral on the islands north and south of Bouka, that the reef probably is of coral; coloured red.

Off the north coast of the Solomon Archipelago there are several small groups which are little known; they appear to be low, and of coral-formation; and some of them probably have an atoll-like structure; the Chevallier Dillon, however, informs me that this is not the case with the B. de CANDELARIA.--OUTONG JAVA, according to the Spanish navigator, Maurelle, is thus characterised; but this is the only one which I have ventured to colour blue.