Jocque et ah Freshwater fauna of rocky outcrops in Western Australia 
human disturbance, climatic or stochastic events (Bussell 
& James 1997). If a species disappears on an outcrop it 
might take a while before it returns through a successful 
colonization and this most probably to a large extent 
explains a large part of the heterogeneity of communities 
on the different outcrops. The best approach would be to 
conserve a considerable number of outcrops scattered 
over a large area. At present relatively few granite 
outcrops Ije in National Parks and/or Nature Reserves, 
though many like Wave Rock and King Rocks, enjoy a 
degree of protection as water catchments or for 
recreation. Terrestrial habitats on many granite rocks are 
compromised by human activities (Main 1997), though it 
seems to us that the pool environments are less affected 
and indeed are often pristine Even the intensive use of 
Wave Rock as a tourist destination seems largely not to 
have degraded the pools, though luckily most of the 
pools on Wave Rock are not on the main tourist routes 
across the rock. For a complete conservation of 
assemblages in gnammas, rocks should encompass a 
regional variation in climate-related variables, directly 
affecting the length of the hydroperiod, and related to 
this, the richness of the community. Based on the average 
length of the hydroperiod, it might be interesting to 
invest slightly more value to some of the outcrops in 
higher precipitation zones. Based on our experience at 
Wave Rock this will increase the more widely occurring 
species, often non-endemic active dispersers. To more 
adequately characterize the endemic passive dispersers, 
attention should be at the other end of the scale as most 
.seem to be strongly adapted to temporary pools and not 
present in the higher rainfall zones. Examples include 
oligochaetes (Finder 2003) and large branchipods 
(Timms, 2006). Two concerns should be mentioned; 
strongly isolated communities (far from other outcrops) 
most probably will hold some special rare species and if 
in the future climatic conditions shift, and especially 
precipitation zones and evaporation rates, then also the 
value of the established protected outcrops will change 
(with the changing length of the inundation period). A 
good strategy to follow now might be 1) an evaluation 
based on a thorough survey of the aquatic fauna present 
in the currently protected Nature Reserves such as 
Boyagen Rock, Yorkakrine Rock, Frog Rock, Cairn Rock, 
Dunn Rock and Yanneymooning Rock, 2) addition of 
other outcrops to the reserve system, aiming to include 
species not present on the already protected rocks and 3) 
appropriate management of rocks outside the reserve 
system by landholders and other interested parties. 
Acknowledgments: Mcrlijn Jocque is supported by an IWT (Institute for 
the I’romotion of Innovation by Science and Teclinology in Flanders) PliD 
scholarship. This research is financially supported by project G.Ol 18.03 of 
the TWO (Fund for scientific Research in Flanders). A travel scholarship 
was provided by the King Leopold 111 Fund for Nature Exploration and 
Conservation. We thank Nicolai Smirnov (Cladocera), Christopher Watts 
(Coleoptera), Koen Martens and David Horne (Ostracoda), Cameron 
Webb (Culicidae), Winston Ponder (Gastropoda) and Ro.salind St Clair 
(Trichoptera) for help with identifications. We thank the residents from 
Hyden for their warm welcome and the science friendly environment. In 
particular we are grateful to the late Russell Mauritz and family for 
providing accommodation during our stay and ready access to Wave 
Rock. We are grateful to Ian Bayly and Adrian Pindcr for helpful 
comments on the manuscript. Merlijii Jocque is a founding member of 
BINCO (Biodiversity Inventory for Conservation). 
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