The impacts of coral and shell collecting - The Great Barrier Reef: An Environmental History - page 148

number of reefs depleted by commercial shell collectors, the Wildlife Preservation
Society of Queensland requested increased protection of Lizard Island reefs
and the other reefs in the vicinity of Cairns, especially Green Island reef and
Michaelmas Reef; over-collection of shells was also reported at the fringing reef
at Orpheus Islan d. 39 Oral history evidence provided by shell collectors generally
corroborates the documentary reports of their impact on coral reef s. 40
Taken together, the evidence presented above indicates that extensive
degradation has occurred both to shell populations and to some coral reefs as
a result of shell collecting. The long time period during which collecting has
taken place in the Great Barrier Reef, the lack of protection of shells during the
early period of European settlement in Queensland, the considerable difficulties
in enforcing restrictions of shell collecting and the desire of the Queensland
government to promote tourism in the Great Barrier Reef have resulted in impacts
on shell populations that have been sustained for many decades. Those impacts
were concentrated around the major tourist resorts in the Cairns, Whitsunday
and Capricorn-Bunker areas: especially at Green Island, Heron Island, Wistari
Reef, Lady Musgrave Island and the Lizard Island reefs. To those recreational
shell collecting impacts has been added the influence of the commercial shell
trade, which also removed large quantities of shells. Therefore, the cumulative
impact of shell collecting has probably substantially depleted some locations of
their shells, with unknown consequences for the ecology of those reefs.
Impacts on giant clams
Giant clams, Tridacna spp. - in particular, Tridacna gigas - have attracted the
attention of shell collectors since the early period of European settlement. In
1892, the existence of huge Tridacna shells in the Great Barrier Reef, 'four of
them to a ton', was reported by Bartley (1892, p218). The animals attracted
attention for their size and also because of the mistaken belief that they presented
a danger to swimmers by trapping their feet, or even swallowing them completely
(Thomson, 1966, p38). That perception was articulated in a report of 1935,
describing the giant clam population at Low Isles, which also drew attention to
the destruction of the animals by visitors:
At Clam Spit the latest count of the clams that had been rolled there, and
that numbered 80 a year ago, now stands at 69. The majority of these animals
are favourably situated so that few deaths should normally occur from now
on. Unfortunately, visitors to the Island seeing these 'dangerous' animals
have a tendency to slash them across, saying as they do, 'You'll never drown
another person.' It is an extremely childish action, that results from the
continued publishing of the childish story that once upon a time a person
put his [ sic ] foot in a clam which closing on it held him prisoner until the tide
came in and drowned him.
(Moorhouse, 1935, p2)