Download Do marine prey resources support invasive pest species in coastal

 Do marine prey resources support invasive pest species in coastal national parks?
Background & Rationale
Invasive pest species are major threats to nature reserves (e.g. national parks and marine
protected areas), which are designed to safeguard biodiversity and ecosystem
functioning1. Because invasive species can have catastrophic ecological impacts (e.g.
species extinctions, biodiversity loss and altered food webs), they can undermine the
effectiveness of conservation areas2. Effects of invasive species have been welldocumented in both terrestrial and marine ecosystems, but are poorly understood for
species that invade the interface between the land and sea.
Situations where invasive terrestrial species supplement their diet with marine prey are
predicted to be of high conservation concern: such marine subsidies to exotic species are
expected to impact on the size and viability of pest populations and the composition of
coastal communities: this is the core question addressed here. Consequently, this project
will examine the contribution of marine carbon to pest populations, using cane toads on
Fig. 1 The cane toads (Bufo marinus), a
common invasive pest species in the
Great Sandy National Park and Fraser
Island World Heritage Area.
Fraser Island as a model system to test the role of marine subsidies to terrestrial pest species in national parks more generally.
Fraser Island supports a large population of cane toads (Bufo marinus), a pest species that poses a significant threat to biodiversity
in Australia3. Cane toads are widespread throughout coastal Queensland, New South Wales and the Northern Territory, are
omnivorous, and are found in a range of habitats, including beaches on Fraser Island where they have been observed to feed on
marine invertebrates (Andrew Olds pers. obs.). Because the question of marine subsidies to pest species has clear and important
implications for the control of other pest species, this project will directly benefit the management of the Great Sandy National Park
and Fraser Island World Heritage Area and will apply to similar coastal conservation areas in Queensland.
Objective(s)
1.) Quantify the degree to which cane toads consume marine prey and rely on marine food sources on Fraser Island; and
2.) Contrast the importance of marine and terrestrial carbon sources to cane toads between coastal and inland locations.
Approach
Cane toads will be collected for dietary analysis (using stable isotope and gut content analysis) from twelve (12) locations on Fraser
Island. Sites will be distributed in two (2) treatment groups (i.e. beach and inland) and toad diet will be compared between these.
Six (6) sites will be examined in each treatment group, with three (3) beach-inland site pairs distributed on both the east and west
sides of Fraser Island. Beach sites will be positioned at creek mouths; inland sites will be positioned on the same creeks, but over 1
km inland (i.e. well over the distance of toad home ranges). Ten (10) cane toads will be collected from each location, euthanized
immediately onsite and transported to the University of the Sunshine Coast for dietary analysis. We have extensive experience
working on Fraser Island, and have conducted many experimental studies using stable isotope and gut content analysis; we are thus
very confident that the proposed methods will yield high-quality data consistent with the objectives of the proposal.
Project Team & Collaboration
This is a joint proposal by the ‘Collaborative Research Network (CRN) – Water Science’ of Griffith University (GU) and the University of the Sunshine Coast. (http://youtu.be/-1fea7mFpf8 ). Our team has wide‐ranging and extensive experience in environmental assessments, conservation biology, and coastal ecology, with matching and complementary expertise directly relevant to this proposal. The CIs working on this project are: Supervisors: Primary: Dr Andrew OIds (USC): marine conservation planning; reserve design, reefs and reef fishes, estuarine food webs; Secondary: A/Prof Thomas Schlacher (USC): coastal ecology, food webs of beaches and estuaries, scavenger biology ‐ raptors; Collaborators: Prof Rod Connolly (GU): food‐webs, coastal carbon processing, conservation planning, mangroves; Dr Chantal Huijbers (GU): urbanisation effects; animal movement; nearshore scavengers; isotope tracing; A/Prof David Schoeman (USC): numerical analysis, beach food webs, modelling, statistics, Key Literature
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Gurevitch J et al. Trends in Ecology and Evolution 19, 470-474 (2004);
Butchart SHM et al. Science 328, 1164-1168 (2010);
Shine R. Quarterly Review of Biology 85, 253-291 (2010);