Sweers Island is situated at 17°06’S, 139°37’E in the south-eastern Gulf of Carpentaria, approximately 32 km offshore. The island consists of remnants of a lateritic peneplain, with recent deposition of calcareous deposits in the form of weakly cemented conglomerate and calcarenite. Most of the island is less than 13 m above high water mark, except for the small area around Inspection Hill, which attains an elevation of 32 m.
With the publication of A Voyage to Terra Australis by Matthew Flinders in 1814, Sweers Island with its safe anchorage, conspicuous elevation and convenient water supply, became an important staging post for numerous subsequent visits. From journals and accounts of those visits, it is possible to identify to what extent changes have occurred in the flora and fauna of the island over the intervening years; this paper is a first attempt to do so.
The use of Sweers Island by the Kaiadilt people (Bentinck Islanders) is well documented (Tindale 1962a; 1962b). As Tindale suggested, historical evidence indicates some occupation of Bentinck, Allen and Sweers Islands with primary use focused on Bentinck Island. The nomadic trips to Allens and Sweers Islands were largely dependent on whim, freshwater supply and specific hunting and gathering expeditions; all were controlled largely by weather. The Kaiadilt people were basically gatherers of sea food, and the wave platform areas and associated shorelands were probably utilised on Sweers Island. Women gathered tjilangind (small rock oysters), kulpanda (mud cockles) and crabs during low tide periods, while the men explored the wider littoral areas spearing fish, turtle, sharks and dugong. On the other hand, Aboriginal fish-traps on Sweers Island suggest a more sedentary use of the island in the recent past (Saenger & Hopkins 1975). The Aboriginal terms describing these places indicate that Bentinck Island was the ‘land of all’ (Dulkawalnged) while Allen, Horseshoe and Sweers Islands were ‘men absent lands’ (Dangkawaridulk). These primary indicators, as well as later observations, suggest that prehistoric use was sporadic and ecologically insignificant. Sporadic visits to the northern Australian coastline by Maccassarese–Buginese fishermen lost and/or seeking trepang and other marine biota did occur, although rarely were Sweers, Allen and Bentinck Islands included in these visits (Macknight 1976). However, some tamarind trees (Tamarindus indicus) on Fowler Island, recorded by Pennefather (1880), and the observations by Flinders (1814) of trees cut with axes, remains of worked timbers of teak, earthenware jugs and skeletons on Bentinck and Sweers Islands, suggest some visitation to the area. Effects of these visits on the islands’ environmental resources are likely to have been short-term and minor.
The Investigator anchored off Sweers Island on 16 November 1802, and remained for 15 days. Peter Good, the gardener of the expedition, described Sweers Island as follows: ‘This island appears very recently formed, chiefly of coral sand and ironstone and a mixture of sandstone and ironstone. There is no luxuriant vegetation or soil capable of producing such on the island. However, there is considerable variety of vegetables … returned on board … with fishing party which had been tolerable successful and had fish served out to the crew’ (Edwards 1981). The Investigator was anchored in Investigator Road between Bentinck and Sweers Islands in order to facilitate caulking. The crew began repairs while Flinders took boat parties to Sweers Island to take fixes from Inspection Hill and dig out a native well on the beach. The botanical gentlemen made useful excursions, which were amply rewarded. Robert Brown (n.d.) noted that ‘during our stay at this anchorage I went several times on the Islands & scarce ever without finding additional plants so that before we left it I had made out a Florule comprehending 190 species of perfect plants … The rise of the spring tides was found to be about 11 or 12 feet & a circumstance very remarkable was that while we remained the low of floods was commenced in the morning continued for 12 hours & the ebb during an equal time in the night. During our stay the ship was supplied with fish & the Island where we watered a Bustard was shot perhaps not essentially different from Charadrius, it weighed 12½ lb & the flesh was well tasted that of the legs was much whiter than the breast …’ Collections of geological specimens were also made by Robert Brown and these were later described by Fitton (1827).
A few days into caulking, Flinders received reports of extensive repairs required due to rotting timbers, and a camp was established on Sweers Island under Lt Fowler. This group supplied fish and freshwater to the Investigator. Despite the parlous state of the ship, Flinders decided to complete a survey of the Gulf, hoping to be able to return to Sydney via the west and south coast in the winter, or retreat to the East Indies if required. When the repairs were completed, Flinders tried to sail out of Investigator Road against south-easterly winds but experienced difficulty getting around Locust Rock, anchoring south of Sweers Island. During this anchorage, Flinders wrote an extensive summary of the fortnight spent in the vicinity of Sweers and Bentinck Islands: ‘The soil, even in the best parts, is far behind fertility; but the small trees and bushes which grow there, and the grass in some of the less covered places, save the larger islands from the reproach of being absolutely sterile. The principal woods are Eucalyptus and Casuarina , of a size too small in general, to be fit for other purposes than the fire; the Pandanus grows almost everywhere, but most abundantly in the sandy parts; and the botanists made out a long list of plants, several of which were quite new to them.’
Flinders (1814) named Bentinck Island after Lord William Bentinck, former Governor of Madras; Allen Island ‘after the practical miner of the expedition’ and Horseshoe Island ‘from its form’. He named Sweers Island after Cornelius Sweers, one of the Councillors of Batavia, who had authorised Tasman’s 1644 voyage.
The next glimpse of Sweers Island was provided by Stokes in the Beagle on her third voyage in Australian waters, charting the shores of Australia not investigated by Flinders or King. The Beagle sailed into Investigator Road from the Cape Van Diemens area early in July 1841, and charted much of the Wellesley Islands. Stokes (1846) noted that ‘Sweers Island appeared to be very woody, and bounded by low dark cliffs on the north-east side. We found a long extent of foul ground, with a dry reef near its outer end, extending off two miles in a S. 33°E. direction from the S.E. extreme … A party was immediately dispatched in search of the Investigator’s well.’ Stokes also recorded a cloud of locusts which enveloped Sweers but which later moved to Bentinck Island, and observed that ‘Investigator Road … possesses an equal supply of wood, fish, and birds, with turtles close at hand on Bountiful Islands … The soil is chiefly a mixture of sand and decomposed vegetable matter; but it cannot boast of fertility. The wood on the island, which consisted for the most part of gums, wattles, a few acacias, palms, and, near the beach, a straggling casuarina or two, bespoke this by its stunted appearance; but as cotton grows well at Port Essington, there can be little doubt that it will thrive here. Several of the bustards spoken of by Flinders, were noticed; but too wary to be killed. They were as large as those seen in the neighbourhood of Port Phillip, but much browner. The other birds, most common, will be found in an extract from the game book … We saw no animals, except some large iguanas.’
The extract from the game book indicates that the island supported an abundant avifauna, with ‘151 quails, 87 doves, 20 pigeons, 3 pheasants, 8 white and 2 black cockatoos, 5 spur-wing plovers’ being taken in the fortnight of the visit.
By June, 1856, in Sydney, there had been apprehension concerning the safety of the North Australia Expedition (NAE) under A.C. Gregory, which had left Brisbane for the Victoria River in the Tom Tough and Monarch on 12 May 1855. Lieutenant W. Chimmo, R.N. was ‘… sent to render assistance to the above expedition by his Excellency, the Governor General of New South Wales’ (Chimmo 1856; 1857). The paddle steamer Torch sailed north from Newcastle on 24 June to gain news of the explorers.
The Torch arrived off Sweers Island in the evening of 30 July, and before dawn ‘… all hands were on shore looking for water … By afternoon we had completed water (although somewhat brackish) to about five tons; and in return deposited pumpkin seeds and Indian corn round the well, where the soil was rich’ (Chimmo 1857).
The next day, the Torch departed Sweers Island and headed for the Albert River mouth. Lt Chimmo found no signs of the NAE, of which the main party was travelling overland to the Albert River, reaching it some two months later. As the NAE’s support party had failed to rendezvous with the main party at the Albert River, Gregory departed overland for Moreton Bay. The support party had taken the Tom Tough to Coepang and Sourabaja, and replaced it with the Messenger, arriving off Sweers Island in mid-November.
Thomas Baines, the artist of the NAE, reported landing ‘on the shore three quarters of a mile north of them [the wells] under a Cliff … Captain Devine and I walked some miles to the North passing over plains with silverleafed iron bark, Eucalyptus and a long but shallow gully filled with green grass moist soil and clumps of pandanus but we could find no water though we saw several cockatoos. We returned along the beach … We picked up a plank carved with rosettes and other devices … We kept the long boat going between the vessel and the shore with heavy loads of wood all day’ (Baines n.d.).
Once loading of wood and water had been completed, the Messenger prepared to depart, and Baines (1857) noted that ‘I had a pair of goats which I intended to leave, but the female unfortunately died. I planted cocoa-nuts in a variety of places on Sweers Island.’
From these early accounts, it seems that the vegetation was generally stunted, dominated by Eucalyptus and Casuarina, but sufficient to meet the visitors’ firewood needs. However, the shruband ground-layers were floristically diverse and of considerable botanical novelty. It also appears that birds and fish were remarkably abundant. Although it is unlikely that the corn and pumpkin planted by Chimmo survived, later reports of large coconut palms on the island (Pennefather 1880) suggest that Baines’ coconuts may constitute the first successful plant introductions to the island.
The first recorded impressions
