ATOLL RESEARCH BULLETIN 
NO. 455 
NATURAL HISTORY OF BRAMBLE CAY, TORRES STRAIT 
BY 
JOANNA C. ELLISON 
ISSUED BY 
NATIONAL MUSEUM OF NATURAL HISTORY 
SMITHSONIAN INSTITUTION 
WASHINGTON, D.C., U.S.A. 
SEPTEMBER 1998 
NATURAL HISTORY OF BRAMBLE CAY, TORRES STRAIT 
JOANNA C. ELLISON' 
ABSTRACT 
Bramble Cay, a small (3.6 ha) vegetated sand cay, is the most northern island of the 
Great Barrier Reef and the closest to the mouth of the Fly River. It has both volcanic rock 
and a reefal sand cay within its lagoon, and phosphatic rock exposures or1 the cay. The 
sand cay is the most important location for both seabird and turtle breeding in the Torres 
Strait and supports an endemic mammal, the rat Melornys ruhicola. Records indicate that 
numbers of birds and rats have declined over the last century, possibly due to erosiou and 
loss of vegetated area of the cay. The vegetation of the cay, made up of three herbs, is 
heavily disturbed by nesting activities. There is, however, a large and diverse drift flora, 
that is dominated by mangrove propagules exported from the Fly, that bas no overlap 
with the cay's flora. Bramble Cay has a significant human history both from European 
exploration of the New Guinea coast, and from being the entrance marker to the Great 
North East Channel through the Torres Strait. 
INTRODUCTION 
Bramble Cay is the northern extremity of the Great Banier Reef (GBR) before coral 
growth becomes limited by the discharge of the Fly, and is the northerly point of 
Queensland in the Torres Strait (9O08.6 S, 143O52.8 E, Figure 1). It is located 52.8 km SE 
of Kiwai Island, in the delta of the Fly River, Papua New Guinea (PNG), which carries 
an annual sediment load of 85 million tons year-' (Harris, et al., 1993) Bramble Cay, 
however, has clear water and coral reef growth owing to passage of the Fly River plume 
to the north, tracking directly east along the PNG coastline (Harris, et al., 1993). 
Of the island types found in the GBR, Bramble Cay (Plate 1) is within the category of 
low, vegetated sand cays modified by seabird activites described by Stoddart and Fosberg 
(1991) at Coombe, Michealmas, Raine, Stapleton and parts of Stainer, Morris and Magra. 
These are all located between 11-17"s; Bramble Cay is distinguished by its location in 
the wetter and biogeographically more diverse northern sector of the GBR. These types 
of islands feature patchy vegetation cover, with uncommon shrubs, and large bare areas 
resulting from seabird disturbance. 
LSchool of Applied Sciences, University of Tasmania, P. 0. Box 1214, Launceston, 
Tasmania 7250, Australia. 
Rlnwtzscript rcccivcd 6 April 1998; revised 26 Allgllst 1998 
The closest climate station to Bramble Cay is Daru (74 km to the west), which shows a 
mean annual rainfall of 2063 mni, and a range of 1163-3972 mm in the period 1894 to 
1970 (McAlpine et al., 1983). Most rainfall occurs in the summer period, November to 
April. Southeasternly trade winds prevail from March to November, tending to send 
westward currents through the Torres Strait; the Northwest monsoon prevails December 
to March, tending to send an eastward current through the Strait. 
Tides in the Gulf of Papua are semi-diurnal, with a mesotidal range of 2-2.5 in. 
Circulation in the Gulf of Papua is driven by tidal and wind-induced currents. influences 
the distribution of sediment load of the Fly along the coastal zone. The Fly has an annual 
freshwater discharge rate exceeding 235 km3 (Alongi et al., 1992), carrying 85 million 
tons of sediment year - 1  (Harris et al., 1993), of which 47% is discharged from the delta. 
This sediment is largely carried northeast from the delta and along the coast of the Gulf 
of Papua, except during the southeast trade wind season, when a small proportion of 
discharge from the Fly traverses west from the delta and along the southern coastline of 
PNG (Harris et al., 1993). 
GEOLOGY AND GEOMORPHOLOGY 
The island rises from water depths of 35 nl to an oval reef 1.8 x 0.9 km (Figure 2). It is of 
volcanic origin, demonstrated by exposures of Pleistocene Maer volcanics in the lagoon 
(Sardine, 1928; Willmott, et al., 1973). Similar exposures occur at several locations in the 
NE Torres Strait, at the Murray, Darnley and Stephens Islands, and the Black Rocks 6.5 
kin to the SW of Bramble Cay. They result from subaqueous emission of basaltic lava, 
that subsequently was deeply eroded. The largest exposure (about 40 x 40 m) in the 
Bramble Cay lagoon is shown in Plates 1 and 2. 
The sand cay occurs at the western margin of the lagoon, 330 m NW of the large volcanic 
outcrop, and has a vegetated area of 175 x 76m. It is composed of foraminifera1 sand, 
with some coral and shell fragments (Jardine, 1928), with an exposure of phosphatic rock 
on the southeast shore (Figure 3, Plate 3) that rises to 1.9 111 above I-ITM. The vegetated 
area has several raised ridges and lower pools which collect rainwater (Plate 1). 
Stratigraphy was examined at two locations. Location 1, on a ridge in the southeast of the 
island, showed 14 cm of organic peat above hard phosphatic rock. Location 2, adjacent to 
a pool in the center of the island, showed 22 cm of peat above 40 cm of loosely cemented 
calcareous sand. This is similar to stratigraphy reported from Raine (Stoddart et al., 
1981) of moist black peat above calcareous rubble. 
In 1862 a mining lease was granted to the Anglo-Australian Guano Company (Crowther, 
1939), and occasional boats mined the low grade phosphatic rock (Sardine, 1928). The 
quality was poor enough to ensure that a base was not established as at Raine (Stoddart et 
al., 1981), and areas of rock remain today. There is an exposure at the eastern end of the 
cay (Figure 3, Plate 3). A sample of this rock was analysed, and compared with a surface 
soil sample from the interior of the cay. Samples were treated with perchloricl nitric acid 
and analysed by ICP-AES. Owing to their high carbonate and phosphatic content, they 
were diluted for verification. Results are given in Table 1. 
Stoddart and Scoffin (1983) reported levels of phosphate of 7.8-35.1% from rock on 
Raine, demonstrating the lower grade quality of the Bramble Cay rock. This is probably 
because Bramble Cay receives substantially more rainfall than Raine. 
Coal is commonly found on Bramble Cay, both inland on the surPace and cxposed in 
wave eroded sand cliffs. Plate 4 shows these as wave-rounded and cobble sized. Thc 
source is ships wrecked on the island (Table 2), the most likely being either t h ~  
Windhover (1889) or the Mutluh. (1915). Both are discussed in the next section. 
EARLY HISTORY 
Thc chronology of human visits to the island is given in Table 2 
Customary tenure of Bramble Cay is held by the inlrabilanls of Darnlcy Island, 45 kin to 
the southwest. The islanders' legend of Rebes describes how Darnley people, using soil 
rafted from Darnley, built Bramble Cay to provide turtle eggs and meat in season. 
Having deposited the soil lo form the Cay, the wind veered and strengthened, and four 
villagers were fixed to form the volcanic rock outcrop, and the rest formed thc 
(phosphatic) stone on the sand cay (Haddon, 1935). Darnley Islanders travel to Bramble 
Cay to collect turtle and bird eggs during the nesting season, and also grant inhahitmts of 
other islauds permission to collect (Johannes and MacFarlane, 1991). 
'The island was uamed after the HMS Brarizhle which under the command of Lieutenant 
C. B. Yule, was engaged in survey work in the Torres Strait and the southern coast of 
Papua New Guinea in 1843 and succeeding years (Jukes, 1847). Accounts of tlicse early 
visits provide iuformation about the island's earlier history and ccology. The F!,) visitcd 
Bramble Cay on 6 May, 1844, and Jukes comments: 
The sand-key on one side of the reef was precisely similar in appearance and 
structure to Raine's Islet, except that it was much smaller. It equally abounded in 
"spinach" and bird's eggs, and any ship corning in from the Pacific in want of 
fresh provisions might get enough for some days' consumption by stopping 
there, taking care to break all the eggs on the island as soon as they arrive, in 
order to have new-laid ones to carry away with them (Jukes, 1847). 
When the Btznzhle returnedto Bramble Cay in April 1846, a junior officer remarked thai 
Mr. Yule considered it to be a good anchorage "because it was free from natives of who111 
he entertained the greatest horror. Here besides a good supply of eggs and spinach we 
also obtained 5 turtle" (Sweatman, 1977). The anchorage was returned to on 3 June, after 
a survey of the south coast of New Guinea. The ship remained 5 days to obtaiu 
observations for ra:ing the chronometers, and took advantage of the stay to obtain a good 
supply of eggs (Sweatman, 1977). 
During the visit of the Rattlesnuke 16-19 December 1849, tern and booby eggs were 
smashed and gathered, and a total of 18 turtles were taken (Huxley, 1935). I-luxley 
comments: "The spinach to my mind is filth; others like it however." 
MacGillivray (1852) comments from the same visit: 
In the afternoon I landed for an hour, passing many t ~ ~ r t l e  on the water both going 
and returning. As usual the island was covered with sea birds, only two species, 
however, of which were breeding. The Brown Booby (Sulafusca) and a large tcrn 
(Tlzalusseus pelecanoides) existed in about equal numbers .... As the tern eggs 
were within a short time of being hatched we broke all we saw in order to ensure 
some newly laid ones in a day or two ... 
The Golden Plover was plentiful on the island during our visit, and one 
afternoon I killed fifteen in about an hour ... 
The weed which in the FIJ we used to call spinach (a species of Boerlzcimio, 
actually B. rluJfusa) being in abundance here, was at my suggestion collected in 
large quantity for the use of the ships company as a vegetable., but it did not seem 
to be generally liked. 
In 1889 four ship wrecks occurred on the island (see Table 2). The Master of one 
requested in a letter to Nautical Mugazine that a lighthouse be located on the cay (Planck, 
1889). He stated that the island is at the entrance to the N.E. channel, is difficult to see 
owing to its low elevation, and because strong and irregular currents occur in the area. 
The Wilzdlzover went ashore on the cay in August 1889 while carrying coal, and was 
abandoned. This wreck could have colitributed some of the coal found today on the cay. 
A James Nourse steamer, the Mrrtlalz, went aground at Bramble Cay on 281811915 on a 
voyage from Port Kembla to Colombo. It was refloated on 13/9/15 (John Foley. pers. 
comm), apparently after some thousands of tons of coal had been jettisoned. This coal is 
referred by Rev. Done, who visited the island on the Herald in 1917, and used some of 
the coal for fuel (Done, 1987). 
Done (1987) was not there in the turtle breeding season, so "On this occasion we had to 
be content with terns' eggs and secured a large quantity ........ They were subscquentely 
used boiled, fried, scrambled or in omelette form, and were not in the least fishy i n  
flavour." 
Bramble Cay was heavily exploited in its early history for bird and turtle eggs by both 
European and Tones Strait Islander visitors. The effects of this exploitation on breeding 
colonies are discussed in the fauna section below. 
Lighthouse History 
Bramble Cay, marking the northern entrance to the Great North East Channel through thc 
Torres Strait, is today dominated by a lighthouse (Plate 5) .  From 1890 it was the 
boarding ground for pilots to guide sailing vessels through the channel to Thursday 
Island (Davenport, 1986). This followed a series of shipwrecks on the cay (Table 2), and 
requests for a lighthouse (see previous section). 
Done records in 1917 that "according to a chart there is a beacon 45 ft high. But that 
beacon has long been in a recumbent position, and is of no value to mariners. It is 
whispered that there is some talk of an unattended light being placed there ...." 
In 1924 (24 October) a 42 ft pyramidal steel tower was erected. Jardine (1928) showed 
this as located in the central eastern end of the island (Figure 6). There are no remains of 
this tower today. According to A.M.S.A. records it was razed in 1954 and replaced by the 
present lighthouse, though Limpus et al. (1983) reported that a temporaly scaffold with 
four wire guys was erected at the southeastern end of the cay in 1958. The remains of this 
structure can be found on the beach at the southeastern end (Fig. 3, Plate 6), the island 
having moved to the northwest. 
The present lighthouse, a 17 In stainless steel tower, was converted to solar power on 6 
January 1987. The lighthouse was never manned, but is maintained by A.M.S.A. vessels 
every 3-6 months. 
MOVEMENT OF THE CAY 
Figure 4 shows changes in shape of Bramble Cay between 1978-1979 when it was 
mapped by Applied Ecology (Parmenter, 1980), and 1994-5 when it was mapped by the 
author using tape and compass techniques. Other detailed surveys of the island exist that 
could not be incorporated into this map. Jardine (1928) provided a map of the island from 
his visit in September 1924 (Figure 6), but the remains of the lighthouse shown on this 
map could not be located in 1994-5, hence there is no common reference. 
In 1924 the area of the cay within the tidal level shown by Jardine (1928) was 395 x 183 
m. Limpus et al. (1983) record the dimensions of the island at spring high tide level in 
December 1977 and 1978 as 340 x 150 m. Parmenter (1980) mapped the island area 
above high tide as 281 x 128 m in October 1978, and 223 x 112 tn in March 1979. In 
January 1987 the dimensions of the island above high tide were 320 x 130 m (Walker, 
1988); in Februa~y 1994 it was 272 x 126 m and in February 1995 it was 251 x 104 m. 
The area of the island in 1995 was 1.72 ha in vegetated area, and 3.62 ha above high tide 
mark. 
Limpus et al. (1983) concluded that the cay was moving towards the northwest, and 
losing sand over the edge of the reef flat (see Fig. 2). Parmenter (1980) showed that 
during the south-easterlies (winter) sand is deposited at the northwest shore of the cay, 
which is eroded during the north-westerlies (summer). Figure 4 shows that the shape of 
the cay has not substantially changed since the 1970's, the most significant change being 
reduction in vegetated area. 
In 1924 the vegetated area was 295 x 146 m at its widest dimensions (Jardine, 1928); in 
1978-79 it was 170 x 97 m (Parmenter, 1980); in January 1987 it was 215 x 100 m 
(Walker, 1988); and in 1994-5 it was 175 x 76 m. Figure 4 shows that most of the loss 
has been from the south and north shores. Plate 7 shows how the vegetation margins arc 
limited by the activites of turtle nesting. A former control on turtle nesting would have 
been cliffs of phosphatic rock, the historic removal of this would make more island area 
accessible. The main control today is turtle access. Turtle breeding occurs in the summer 
period, when the island is being eroded from the northwest. Plate 8 shows the sand cliff 
that develops, which discourages turtles from coming ashore. Many failed attempts were 
witnessed at night in Februa~y 1995. The turtles would move along the shore and 
successfully cross the beach on the gentler graded south or north shores. The east shore is 
somewhat protected from turtles by the phosphatic rock outcrop cliffs. 
Thc reliability of Jardine's measurement techniques is demonstrated by his detailed map 
of the volcanic rocks in the lagoon. Therefore his map of the cay can bc used as strong 
evidence that the island has substantially eroded this century. The awa within high tide 
levels is more variable (Figure 4) with seasonal prevailing wind, but the vegctated area 
has consistently declined. 
WATER 
Water collects in pools on Bramble Cay after rainfall and can remain for several days. 
Water samples were tested in February 1995 from two locations: 1 was the large pool in 
the NE of the cay (Figure 5, Plate 5 ) ,  and 2 was the large pool SE of the lighthouse 
(Figure 5 ,  Plate 7). Results in Table 3 show that surface pools are of fresh water. 
VEGETATION AND FLORA 
The vegetation of Bramble Cay consists of low herbaceous cover (Plates I and 5), greatly 
disturbed by nesting activities of birds and turtles. Species present in 1994-5 and past 
records are summarised below. Nomenclature follows Fosberg and Stoddart (1991). 
AIZOACEAE 
Sesuvium portulacastrum (L.) L. 
Limpus et al. (1983) sight. 
AMARANTHACEAE 
Parmenter, s.n. (January, 1984); Queensland Herbarium s.n. (in Walker, 1988); Walker 
(1988); Ellison 1002, 1003, 1005. 
This erect or decumbent annual with weedy habit was occasional on Bramble Cay in 
1994 and 1995. 
ARECACEAE (PALMAE) 
Cocos nuc<ferercr L. 
Walker, sight (dead). Drift seeds were present in both 1994 and 1995 (see later section), 
but none established. Coconuts have been planted on the island by visitors, but have not 
survived long (Walker, 1988). 
CONVULVULACEAE 
Ipomoea pes-cuprae (L.) R. Br. 
Queensland Herbarium s.n. (in Walker 1988) 
CYPERACEAE 
Cyperaceae indet. 
Queensland Herbarium s.n. (in Walker 1988) 
NYCTAGINACEAE 
Boerlzavin tetrandru sensu Walker non Forst. f. 
MacGillivray (1852) sight; Queensland Herbarium s.n. (in Walker 1988); Limpus et al. 
(1983) sight; Parmeter (1980) sight; Ellison 1001, 1004. 
The dominant cover on Bramble Cay, as found by all visitors. This is the "spinach" 
gathered and eaten by early European visitors (MacGillivray, 1852; Sweatman, 1977). 
Forms a lush and dense cover up to 40 cm in height, especially on raised and better 
drained areas of the cay. 
POACEAE (GRAMINEAE) 
Cenchrus echirzmti.c L. 
Queensland Herbarium s.11. (in Walker, 1988). 
Leptrmrs reperzs (Forst. f.) R. Br. 
Queens!and Herbarium s.n. (in Walker, 1988). Limpus et al. (1983) sight; Parmcter 
(1980) sight; Ellison, 1006. 
Not found by Walker in January 1987, but by February 1995 had reestablished on the 
north shore of the cay. 
Poaceae indet. 
Walker, 1988. Unidentified grass found both in January 1984 by C.J. Parmeter and 
January 1987 by T.A. Walker. Not present in 1994-5. 
PORTULACEAE 
Portulaca oleracea L. 
Parmeter, 1984, sight; Walker, 1987. Not present in 1994-5 
ZYGOPHYLLACEAE 
Tribulus cistoides L. 
Queensland Herbarium s.n. (in Walker, l988), 
There are records of 11 species of flora from Bramble Cay, but only 3 were found in 
1994-5, Boerhavia tetrandra , Amaranthus siridus and Lepturus repens . Limpus and 
Parmenter found 5 species in 1984, and Walker found 4 species in 1987 (Walker, 1988). 
The record for Lepturus repens indicates that species may be lost from the cay and re- 
establish, and the later section on drift seeds indicates that there is a plentiful and diverse 
supply of seeds. 
There is intense disturbance of the periphery of the vegetated area of the cay from the 
nesting activities of turtles, illustrated in Plate 7. Figure 4 shows change in the vegetated 
area of the cay from 1983 to 1995, indicating that the area has been substantially reduced. 
This provides an explanation for the reduction in species numbers recorded here. 
FAUNA 
Coral 
The coral communities at Bramble Cay were surveyed by Babcock (1988), who found 
117 species, and described coral communities as a mixture of inshore types (of more 
turbid water), and those more typical of exposed mid and outer shelf reefs of the central 
GBR. This is due to the combination of proximity to the Fly and exposure of the island to 
southeasterly swell fom the Coral Sea (see Fig. I ) .  
Some dcad coral seen during the survey was attributed to predation by thc crown-of- 
thorns Acanthasterplanci, of which 7 were observed. 
Birds 
Bramble Cay is a major breeding colony for seabirds in the Torres Strait islands 
(Cameron, et a]., 1978), particularly Sooty Terns, Crested Terns, Common Noddies and 
Brown Boobies. Draffan et al. (1983) show a total of 24 species in a summary table, but 
only 20 species arc named as present on Bramble Cay in the listings by species. Walker 
(1988) recorded 10 species present in January 1987. On 19 February 1995 there were 11 
species present, of which one was a new one for the island (Black-Fronted Dotterel). 
There have been a total of 23 birds recorded on the island, of which one is almost 
certainly a mistake (Lesser Noddy). 
ALCEDINIDAE 
Hulcyorz .scrrzcta Sacred Kingfisher 
Recorded by Draffan et al. (1983), a common passage migrant and winter resident in the 
Strait. 
ARDEIDAE 
Egi-etru snccn Eastern Reef Egret 
Recorded by Draffan et al. (1983) as breeding during the wet season. Walker (1988) 
recorded 2 on the volcanic rocks. On 19 February 1995 there was 1 present on the rocks. 
Nycticorax cu1edotiicu.s Rufous Night Heron 
Recorded by Draffan et al. (1983), connnon in the Strait. Walker (1988) recorded 1 on 
the volcanic rocks. Not recorded on 19 February 1995. 
CHARADRIIDAE 
1'lu.vicdi.s dorii.irzicu L,esser Golden Plover 
Recorded by Draffan et al. (1983), colnnion in the Strait. Walker (1988) recorded 20 
present. On 19 February 1995 there was one present on the beach, in non-breeding 
plumage. MacGillivray (1852) records that they wcre plentiful on the Cay in December 
1849, such that he was able to kill 15 in about an hour. Done (1987) notes "half a dozen 
Plover" prescnt in September 1917. 
Chi-udriu.~ morzgolus Mongolian Plover 
Recorded by Draffan ct al. (1983), common in the Strait. Not recorded by Walker (1988) 
or in February 1995. 
C11~11~ndriu.s t?relc~no[~s Black-Fronted Dottel-el 
On 19 February 1995 4 wcre seen feeding in niud areas adjacent to a freshwater pool. 
This species is previously ~~nrecorded on Bramble Cay. 
Subfamily CIRCINAE 
Circus assimilis Allied Harrier 
MacGillivray (1914) records this present at Brainblc Cay on 27 July 191 1 
COT .'IIMRIDAE 
Pcilinopus superbus Superb Fruit Dove 
Recorded by Draffan ct al. (1983), nocternal movement across the Strait Septcmbcr to 
April, not brceding. 
FREGATIDAE 
Fregoto ariel Lesser Frigatebird 
MacGillivray (1914) recorded 2 present at Bramble Cay on 27 July 191 1. Draffaii et al. 
(1983) recorded presence, but not breeding. Walkcr (1988) recorded 12 circling overhead 
or roosting on the volcanic rocks. On 19 February 1995 there were 20 circling overhcad 
or roosting on the volcanic rocks. 
Fregcifu rninor Greater Frigatcbird 
Draffan et al. (1983) recorded presence, but not brceding. Not recorded by Walker (1988) 
or in February 1995. 
LARIDAE 
a) Noddics 
A m u s  stolidus Co~nmon Noddy 
MacGillivray (1914) records these as 'very numerous" at Bramble Cay on 27 July 191 1 .  
Draffan et al. (1983) record that more than ten thousand birds breed at Bramble Cay 
during the wet season. However, in January 1987 Walker (1988) recorded only 30, with 
10 unfledged juveniles on the eastern end of the cay, noting that this was not the peak of 
the breeding season. On 19 February 1995 approximately 3300 were prcscnt, with 
nesting colonies dispersed across the cay (Figure 5). These were in raised and vegetated 
areas, and occasionally shared the nest of Sulr~ lelrcogcr.s/er. 
Arzous terzuiroslris Lesser Noddy 
Noted by Draffan et a]. (1983) as probably an elroncous record made by Masters (1875), 
an crror for At~ous tolidus. 
b) Terns 
Sterna hergii Crested Tern 
MacGillivray (1914) records 'great numbers" present at Bramble Cay on 27 July 1911, 
but not breeding. Draffan el. al. (1983) record that over a thousand pairs nest regularly 
from December to March, despite human predation. Walker (1988) recorded 
approximately 1800 nests in 4 large colonies on the eastern end of the cay. On 19 
February 1995 this was the most common bird present on the cay, with approximately 
6400 present in nesting colonies (Figure S), with the largest colonies at the northwest end 
and the northeast end suxounding a freshwater pool. The Crested Tern colonies were in 
lower elevation, unvegetated locatio~is adjacent to areas that flooded after rainfall. 
Sterna fuscatu Sooty Tern 
MacGillivray (1914) records "great numbers" present at Bramble Cay on 27 July 1911, 
with two small colonies of fledged young. Draffan ct al. (1983) recorded this as the most 
common species at Bramble Cay, with 40,000 breeding in the summer, despite heavy 
human predation. Walker (1988) recorded 700, with 300 nests containing eggs. On 19 
February 1995 there were approxin~ately 1300 present, in four separate colonies on the 
northwest end of the cay (Figure 5). Like the Crested Terns, the Sooty Terns nested in 
lower elevation areas. 
Sterna ltirurzdo Common Tern 
Recorded by Draffan et al. (1983), noted as an uncommon summer visitor to the Torres 
Strait. They were not recorded by Walker in 1987; on 19 February 1995 there were 10 
present. 
Sterrza urzcrethetus Brindled Tern 
10 pairs are recorded by D~affafan et al. (1983) as breeding on Bramble Cay. Not recorded 
by Walker (1988) or in January 1995. 
c) Gulls 
Lorus ~zovaehollandiae Silver Gull 
Recorded by Draffan et al. (1983), who notes that the species breeds on small islauds 
during the winter months. Walker (1988) recorded 24 present. On 19 February 1995 there 
were 10 present. 
PHAETHONTIDAE 
Phaeton 1epturu.s White-tailed Tropicbird 
Vagrant seen at Bramble Cay November 1989 (Draffan et al., 1983). 
PLATALEIDAE 
Tlzreskiornis eathiopica Sacred Ibis 
Recorded by Draffan et al. (1983), who notes that the species is an irregular visitor to 
eastern islands. 
SCOLOPACIDAE 
Arenuria irzterpres Ruddy Turnstone 
Recorded by Draffan et al. (1983), passage migrant found throught the Strait. Walker 
(1988) recorded 50 present. On 19 February 1995 there were 30 seen on the beach, in 
breeding plumage. 
Tringa brevipes Wandering Tattler 
Recorded by Draffan et al. (1983), uncommon migrant. 
STURNIDAE 
Aplonis nzetallicu Metallic Starling 
Recorded by Draffan et al. (1983), nomadic in the Strait. 
SULIDAE 
Sula leucogaster Brown Booby 
MacGillivray (1914) records only two nests present at Bramble Cay on 27 July 1911, but 
notes that this was just after a major feast by visiting islanders. Draffan et al. (1983) 
recorded that about 10 pairs breed on Bramble Cay during the wet season, and cites a 
report of breeding in July. Walker (1988) recorded 70 present. On 19 February 1995 
there were 92 present, nesting in raised vegetated areas mostly on the north and east sides 
of the island (Figure 5). 
Patterns in the bird communities 
Bird nesting was limited at its outer perimeter by turtle nesting disturbance, which also 
controlled the outer limit of vegetation, shown in Figure 5. Turtle nesting activities were 
limited by occurrence of phosphatic rock. Most bird nesting was on the north side of the 
cay, with virtually no nesting on the south side, as shown in Figure 5. There was 
microelevational control of nesting patterns, with Terns nesting in lower elevation areas 
and Noddies and Boobies nesting in areas of raised elevation. The lowest areas were not 
used because these flood and hold pools of water after rainfall. Sooty Terns only nested 
on the west end of the cay in 1995, Walker (1988) recorded in 1987 that they only nested 
on the eastern end. 
Walker (1988) comments on the impact o f  human predation on bird numbers, particularly 
on Brown Boobies which have a longer incubation and fledgeling period. Early ships 
visiting the island commonly smashed all eggs in order to gather fresh ones the next day 
(Jukes, 1847; Huxley, 1935; Sweatman, 1977). Johannes and MacFarlane (1991) describe 
the traditional harvesting o f  Boobies, Terns and Noddies, and their eggs by Darnley 
Islanders on Bramble Cay. Thousands o f  eggs could be collected on one trip by Darnley 
islanders, and frequently 14 or 15 turtles are brought back in addition. Walker (1988) 
witnessed thousands o f  eggs removed by people who arrived in speedboats from 
Stephens Island. The Booby numbers recorded in Februa~y 1995 were higher than other 
recent records (Draffan et al., 1983; Walker, 1988), but far less than the records o f  early 
ships visiting the cay. MacGillivray (1852) from a visit in December 1849 records 
Boobies nesting in equal numbers to Terns. 
Turtles 
Bramble Cay is one o f  Australia's larger green turtle (Chelonia mydas), rookeries 
(Limpus, 1981), though numbers recorded are variable. The nesting season in the Torres 
Strait i s  approximately October to February (Kowarsky, 1978). 
In the early 1970's a federally-funded project by Applied Ecology Pty. Ltd. attempted to 
establish turtle farming in the Torres Strait islands. A research team spent 3 seasons (Oct- 
March) on Bramble Cay studying breeding habits (Onions, 1979), and turtle eggs from 
Bramble Cay and other islands were gathered to establish commercial turtle farms on 
inhabited islands (Kowarsky, 1977; Johannes and MacFarlane, 1991). Applied Ecology 
built a house on the southwestern end o f  the island, the foundations o f  which were still 
there in 1995 (Figure 3) .  The project had failed by 1980 owing to insufficient research 
and economic inviability (Johannes and MacFarlane, 1991). 
Over their two years research Applied Ecology found a maximum nightly count o f  60 
turtles nesting. Numbers were generally lower: Kowarsky (1978) recorded 1 turtle 
nesting on 7 November 1975, and 9 , 4  and 5 nesting on the nights 3-5 January 1976. The 
maximum count was Walker (1988) in Janua~y 1987, who recorded a minimum o f  290 
nesting. From 17-19 February 1995, 20 and 24 turtles nested each night, which was 
relatively low numbers. 
As well as harvesting o f  bird eggs, early ships (see Table 1 )  visiting Bramble Cay 
comnlonly took turtles (MacGillivray , 1852; Sweatman, 1977; Done, 1987). Limpus 
(1980) noted that with all the taking o f  green turtles in the GBR area since European 
* colonisation, Bramble Cay is the only island with evidence o f  a major decline in nesting 
populations. Parmenter (1980) commented that in the early 1970's government social 
programmes permitted dinghy1 outboard ownership beyond Thursday Island to allow 
easier turtle harvest in the Bramble Cay area o f  the Torres Strait. 
Rats 
Sweatman in April 1845 describes a number of large rats that ran from under dead turtle 
shells. This is Melornys rubicola, an endemic rodent that is only recorded on Bramble 
Cay, first described by Thomas (1924) from a specimen collected by MacGillivray in 
May 1845. 
In 1977 and 1978 Limpus et al. (1983) describe several hundred rats as present, foraging 
in the vegetation at night. They found no evidence of the rat preying on eggs or young 
birds on the island. Walker (1988) found only one mother with two young near the 
lighthouse, though he did not visit after dark, when the rats are active. 
In February 1995 rat tracks were seen around a small cave entrance beneath the 
phosphate rock on the southeast shore of the island, close to the 1958 lighthouse base. 
Tracks could be seen leading into fresh turtle nests, suggesting that the rats may not be 
vegetarian as was previously thought (Limpus et al., 1983; Walker. 1988). Nests with rat 
tracks approaching had uncovered and broken turtle eggs. On the night of 16/2/96 the 
WV Harry Messel's engineer reported seeing rats feeding on turtle eggs (Craig Rawson, 
pers. comin.). Despite a search for two nights with torches, this was the only individual 
seen during the visit, suggesting that nunlbers are much reduced from the 1970's. 
DRIFT DISSEMENULES 
The diversity of species occurring on Bramble Cay as drift seeds was considerably more 
than that of the island's flora, with no common species. All seeds stranded during low 
tide on 6 Febrau~y 1994 and 17 February 1996 were collected and identified. Results are 
given in Table 4. 
In 1994 (6 February) the shoreline length was 886 m, and there were a total of 647 drift 
seeds, of which 79% were mangrove. This gave a seedling density of 0.73 seeds/m. In 
1995 (17 February) the shoreline length was 809 m, and there were a total of 3206 drift 
seeds, of which 8 1 % were mangrove. This gave a sced density of 3.96 seeds/ m. 
In addition to seeds, there was a diversity of other debris along the strand-line, including 
whole Nypa trees, other large tree trunks, old turtle eggs, pumice, Sargnssunz seaweed, 
cuttlefish and coal. There were mangrove plant parts such as Bruguiera buds, Soizizercitin 
and Rruguiera flowers, and Rhizophora leaves. 
The domination of Bramble Cay's drift flora by mangroves, particularly Nypn, suggests a 
source from the Fly River. Sedimentation stndies by Harriss et al. (1988) showed that the 
vast majority of discharge of the Fly is carried northeast from the delta and along the 
coast of the Gulf of Papua. During the southeast trade wind season, a small proportion of 
discharge from the Fly traverses west from the delta and along the southern coastline of 
PNG. Both drift seed counts here were from February, when prevailing Northerlies 
should keep Fly discharge from affecting Bramble Cay. The drift species and quanitity, 
however, suggest that large amounts of debris from the Fly are caught in eddies away 
from the main direction of the plume, to deposit material on Bramble Cay. 
D~lring the author's visits to Bramble Cay the Australian Institute of Marine Science 
cored several large Porite.~ colonies. Data shows complex interactions between river 
plumes and coral crowth band fluorescence., as well as stable isotope and trace element 
variations thought to be associated with sea surface temperature (Gregg Brunskill, pers. 
comm. 8/98). This confirms the drift seed record that Fly discharge influences Bramble 
Cay. 
CONCLUSION 
This review has established that for its small size (3.62 ha), Bramble Cay has particular 
interest in its location and geomorphology, flora and fauna, and human history. It is both 
the most northern island of the Great Barrier Reef and the closest to the mouth of the Fly 
River. It has both volcanic rock and a reefal sand cay within its lagoon, and phosphatic 
rock exposures on the cay. 
Records show 23 species of seabirds on the sand cay, and it is a major breeding location 
for Crested and Sooty Terns, Common Noddies and Brown Boobies. It is one of 
Australia's most important grcen turtle rookeries, and also has an endemic mammal, the 
rat Meloni.y.s rubicola. Records indicare that numbers of birds and rats have declined over 
the last century, possibly due to erosion and loss of vegetated area of the cay. The 
vegetation of the cay is heavily disturbed by nesting activities, and is limited to three 
herbs, though there are records of eleven in total over time. There is, however, a large 
and diverse drift flora, dominated by mangrove propagules exported from the Fly, that 
has no overlap with the cay's flora. 
Bramble Cay has a significant human history both as a site of European exploration of 
the New Guinea coast, and as the entrance marker to the Great North East Channel 
through the Torres Strait. It has records of five shipwrecks that have resulted in 
significant deposits of coal on the cay. and a history of four lighthouses which are lost 
over time due to movement of the cay. 
ACKNOWLEDGEMENTS 
The opportunity to visit Bramble Cay in 1994 and 1995 was provided by Dr. Gregg 
Brunskill of the Australian Institite of Marine Science, and the Masters arid crews of the 
R N  Lady Hasten and W Harry Messel. I thank Dl.. Betsy R. Jackes and Mr. Osia 
Gideon of the Department of Botany, James Cook University, for assistance in 
identification of seeds. I am indebted to Capt. John Foley of the Torres Strait Pilot 
Service for information on the grounding of the Molloh. This research was undertaken 
during tenure of an Australian Postdoctoral Research Fellowship. 
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Alleyne, H.G. and Macleay, W., 1876. The ichthyology of the Chevert expedition. Proc. 
Linnean Societv of New South Wales 1, 321-359. 
Alongi, D.M., Christoffersen, P., Tirendi, F. & Robertson, A.I., 1992. The influence of 
freshwater and material export on sedimentary facies and processes within the Fly Delta 
and adjacent Gulf of Papua (Papua New Guinea). Continental Shelf Research 12, 287- 
326. 
Babcock, R.C., 1988. A preliminaly study of the coral communities at Bramble Cay and 
Warrior Reefs. Sixth Su~plemental Agreement Environmental Study, OK Tedi Mining 
Ltd., Papua New Guinea, 18pp. 
Brazier, J., 1877a. Continuation of the Mollusca collected during the Chevert expedition. 
Proc. Linnean Society of New South Wales 2, 1-6. 
Brazier, J., 1877b. Continuation of the Mollusca collected during the Chevert expedition. 
Proc. Linnean Society of New South Wales 2.74-89. 
Cameron, E., Cogger, H. and Heatwole, H., 1978. A natural laboratory. Australian 
Natural Histoiy 19, 190-197. 
Crowther, W.E.L.H., 1939. The development of the guano trade from Hobart Town in the 
fifties and sixties. Paoers and Proceedings of the Royal Society of Tasmania 1938, 213- 
220. 
Davenport, W., 1986. Harbours and Marine. Port and Harbour development in 
Oueensland from 1824-1985. Department of Harbours and Marine, Queensland, 883pp. 
Done J.J.E., 1987. Wings across the sea. Brisbane, Boolarong Publications, 103pp. 
Draffan, R.D.W., Garnett, S.T. and Malone, G.J., 1983. Birds of the Torres Strait: An 
annotated list and biogeographic analysis. Emu 83: 207-234. 
Fosberg, F.R. and Stoddart, D.R., 1991. Plants of the reef islands of the northern Great 
Barrier Reef. Atoll Research Bulletin 348, 1-82. 
Haddon, A.C., 1935. General ethnography. Reports of the Cambridge Anthropolo~ical 
Expedition to T o m s  Straits, vol 1. London, Cambridge University Press. 
Harris, P.T., Baker, A.R., Cole, A.R. and Short, S.A., 1993. A preliminary study of 
sedimentation in the tidally dominated Fly River delta, Gulf of Papua. Continental Shelf 
Research 13,44 1-472. 
Huxley, T.H., 1935. T.H. Huxlev's diary of the voyage of the H.M.S. Rattlesnake. Chatto 
and Windus, London, 372pp. 
Jardine, F., 1928. Bramble Cay, Torres Strait: Geological notes. Reports of the Great 
Barrier Reef Committee 2,93-100. 
Johannes, R.E. and MacFarlane, J.W., 1991. Traditional fishing, in the Torres Strait 
Islands. Hobart, CSIRO Division of Fisheries, 268pp. 
Jukes, J.B., 1847. Narrative of the surveying voyage of H.M.S. Flv commanded by 
Captin F.P. Blackwood R.N. in Torres Strait, New Guinea and other islands of the 
Eastern archipelago during the years 1842-1846 together with an excursion into the 
interior of Java. London, Boone, vol~lme 1: 423pp; volume 2: 362pp. 
Kowarsky, J., 1977. Culture trials of young green turtles, Chelonia mydas, in Torres 
Strait, Northern Australia. Aauaculture 11, 197-215. 
Kowarsky, J., 1978. Observations on green turtles (Chelorzia tnydas) in North-eastern 
Australia during the 1975176 nesting season. Biol. Conserv. 13,51-62. 
Limpus C.J., 1980. The green turtle Chelonia nzydas L. in Eastern Australia. James Cook 
Universitv of North Queensland Research Monograph 1, 5-22. 
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Project. Report to Queensland National Parks and Wildlife Service, cited by Johannes 
and Macfarlane (1991). 
Limpus, C.J., Parmeter, C.J. and Watts, C.H.S., 1983. Me1onzy.r rubicola, an endangered 
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W. Broome. Volume 2. 
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New South Wales 1,44-64. 
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Parmenter, J., 1980. Environmental factors in turtle farming. In Management of Turtle 
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Dept of Tropical Veterinaly Science, James Cook University, 23-3 1. 
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AS. and Pye, K. Eds. Chemical sediments and geomorphology: Precipitates and residua 
in the near-surface environment. London, Academic, pp. 369-425. 
Sweatman, J., 1977. The Journal of John Sweatman. St. Lucia, University of Queensland 
Press. 208pp. 
Walker, T.A., 1988. The flora and fauna of Bramble Cay, January 1987. Quecnsland 
Naturalist 28, 32-36. 
Willmott, W.F., Whitaker, W.G., Palfreyman, W.D. and Trail, D.S., 1973. Igneous and 
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Resources, Geology and Geophysics Bulletin 135. 

Plate 3. Phosphatic rock exposure (to 1.9 m above HTM) on the SE shore. 
Plate 4. Coal collected from wave cut sand exposures. Bramble c a ~  
Plate 5. Inland of Bramble Cay, showinq Boobies nestinq on higher qround in 
the foreqround, crested terns nestinq on lower qround adiacent to water ~ools,  
and the lighthouse. 
plate 6 Remains of the 1958 llqhthouse. 
-- 
the southern maram of the cay. 
Table 1 .  Major element analvsis of rock and soil from Bramble Cav. 
Phosphatic rock Soil surface 
Table 2 Chronolo~~cal record of  human vlsltors to Bramble Cay 
.. 
Ongoing Darnley Islanders collect turtles, birds, eggs Johannes & 
MacFarIane, 1991 
Capt. E. Edwards passed island Haddon, 1935 
Sweatman 1977 1845 Midge 
(April) 
Blackwood noted Igneous rock 
Jukes in center of coral ring 
Blackwood on way to N.G. coast 
Jukes 
Jukes 1847 1845 Fk' 
(6-7 May) 
1845 Fly & Prince 
28-29 May George 
Jukes while surveying N G  
Blackwood coast 
Logan Jack, 1921 
1846 Bramble 
4-9 April 
Yule collected eggs, spinach 
Sweatman 5 turtle taken 
Sweatman 1977 
1846 Bramble 
3-8 June 
Yule collected eggs 
Sweatman 
Sweatman 1977 
1849 Bramble 
(28-29 Sept) Rattlesnake 
Yule en route N.G. to Cp York 
to get supplies 
Logan Jack. 1921 
Huxley, 1935 
MacGillivray. 1852 
Huxley, 1935 
1849 Rattlesnake 
(16-19 Dec) 
Capt. Stanley collected turllei bird eggs 
MacGillivray noted many boobies 
1873 (?April) Basilisk Rev. A.W. Murray trading paddiesleamet 
1875 Chevert G. Masters Ornithology 
J. Brazier Shells, molluscs 
Masters, 1875 
Brazier, 1876, 1877a,b 
Loney, 1982 
I-oney. 1982 
Loney, 1982 
1889 (24.3) Janbaas shipwrecked on cay 
1889 (July) Kenilworth shipwrecked NW of cay 
1889 (20.8) Windhover wrecked on cay 
carrying coal 
Loney. 1982 1889 (Sept.) Rosie Welt shipwrecked near cay 
ran aground, unloaded 
thousands of tons of coal 
Done 1987 
J. Foley, pers, comm 
WMacGilIivray Ornithology MacGillivray 1914 191 i  ? 
(27 July) 
Done 1987 191 7 Herald 
S S d  
Rev. J J E Done used sotne coal for fuel 
- tooklud!_e . ,_eqgs  ~..-~ 
-- 
DATE V E S S i . - . ~ ! ~ o F i L  NOTES REFERENCES 
1924 ? C. Hedley collection of corals Nathan. 1924 
(Sept) water quality Hedley. 1925 
F. Jardine geomorphology Jardine, 1928 
1927-1934 M Murray visits with Darnley Johannes & 
Islanders MacFarlane, 1991 
1950's Trader Horn B. Whiltaker mackeral fishing Anon, 1955 
ongoing others 
1954-1 987 AMSA vessels acteylene replacement AMSA records 
lighthouse maintenance 
1975 (7 Nov) Dinghy from Applied Ecology Turtle nesting count Kowarsky, 1978 
1976 (3-511 ) York Island 
1978-79 (resident) Applied Ecology Turlle research, Onions, 1979 
Oct-March Island mapping Parmenter 1980 
1987 (Dec) (dinghy) C. J. Litnpus Limpus, et al., 1983 
1988 (Dec) (dinghy) C. J. Limpus Limpus, et al., 1983 
1984 (dinghy) C.J. Parmeter Walker, 1988 
1987 M. V. Lumen T. A. Walker island survey Walker, 1988 
(4-6 Jan) A.M.S.A. LH conversion to solar 
1988 (July) Western OK Tedi Coral survey Babcock 1988 
Venturer R.C. Babcock 
1994 RNLady A.I.M.S. Coral coring 
5-7 Feb Basfen Island survey 
Brunskill. in prep. 
This study 
1995 RNt-larry A.I.M.S. Coral coring Brunskill, in prep. 
17-19 Feb Messel Island survey This studv 
Table 3. Propertiesof water pooled on Barn-. 
- 
Location TirneLern!xrature 
- Salinitv Cotiductivity- 
"C 
I 1440 39.7 0.8 9.0 
2 1500 42.2 2.8 4.7 
Table 4. Drift dissemenules on Bramble Cay 
S~ec ies  1994 1995 
Mangrove 
A vicennia marina 12 128 
Bruguiera existata 10 7 5 
Bruguiera gymnorrhiza 10 50 
Bruguiera parviflora 1 1 
Ceriops australis 4 11 
Ceriops decandra 3 16 
Ceriops tagal 3 7 
Cynometra iripa 2 
Heritiera littoralis 33 660 
Nypa fruticans 302 374 
Rhizophora apiculata 8 1 163 
Rhizophora mucronata 45 
Rhizophora stylosa 2 7 87 
Xylocarpus granatum 845 
Xylocarpus moluccensis 123 
Xylocarpus sp. 2 7 
SUB-TOTAL 513 2587 
Non-mangrove 
Aleurites moluccana 2 14 
Barringtonia asiatica 3 15 
Barringtonia racemosa 1 
Caesalpina bonduc 1 6 
Calophyllum inophyllum 1 
Canavalia sp. 2 
Cerbera manghas 17 
Cerbera odollam 12 11 
Cocos nucifera 12 10 
Dalbergia canadensis 2 
Dendrodium sp. 1 
Entada phaseolus 3 16 
Euphorbiaceae 3 0 102 
Guettarda speciosa 7 
lnocarpus fagifer 25 0 
lpomoea sp. 2 
Leguminosae 3 2 333 
Mangifera indica 1 5 
Pandanus sp. 4 14 
Pongomia pinnata 1 5 5 
Pterocarpus sp. 2 
Terminalia sp. 11 
SUB-TOTAL 134 619 
TOTAL 6 4 7  3206 
0 513 lo@ 
I I 
Scale: Km. 
I I _ ~ J E  1. Location of Bramble Cay in the Toms Strait. 
2 
1' Volcan ic  rocks  
\ 
' 
\ 
, 
\, 
M.N. 
T 
200 
Lagoon 
Scale: M 
Figure 2. Map ofthe Bramble Cay Lagoon 
- 
...... 
...... 
...... 
...... 
::? Vegeta ted  area 
.,.... 
Scale:  M 
Figure 3 .  Map o f  Bramble  Cay i n  February 19'35, show ing  man made s t r u c t u r e s  
- 
M , N ,  O 20 40 60 80 
Scale:  M 
F i g u r e  4. Change i n  shape o f  E;ramble Cay 1'378- 1W 5  
- 
. .. . 
. . . . . . . . 
...... 
. . . . .  
:::::::::::; .. . . . .  
- -  
- 
1978-79 V e g e t a t i o n  Marg in  
15 O c t  78 H.T.L. 
29 M a r  79 H.T.L. 
1 994-5 V e g e t a t i o n  r la rq i r l  
. 
6 Feh 94 H.T.L. 
18 Feb 95 H.T.L. 
Figure  5. B i r d  nes t i ng  co lon ies on Bramble  Cay, February 1 9 9 5  
- 
Fiaure 6 .  Map 13 Bratnble Cav in September 1 924 fror?? Jar4dir1e i.19231. 
- . .- -,,- 
Scale: 4 chains = 80.43 rn.