New Zealand Room 3 Tuesday, December 6th 2011
16:30 Acoustic activity as an index of relative abundance at seabird colonies: a low-cost and scalable tool for measuring conservation outcomes. Borker, AL*, University of California Santa Cruz
; McKown, MW, University of California Santa Cruz; Ackerman, JT, U.S. Geological Survey, Western Ecological Research Center; Eagles-Smith, CA, U.S. Geological Survey, Western Ecological Research Center; Croll, DA, University of California Santa Cruz; Tershy, BR, University of California Santa Cruz
Globally, 30% of seabirds are threatened with extinction. Conservation actions are underway to prevent extinctions, but knowing where and how to intervene is hampered by the global scale of threats to seabirds, the remoteness and inaccessibility of seabird colonies and the dearth of data on the effectiveness of available techniques. Passive acoustic sensors could provide managers with a low-cost, low-impact method for monitoring seabird population trends and measuring conservation outcomes at scale. We tested a key assumption of the technique, that measures of acoustic activity are correlated with the relative abundance of seabirds at breeding sites. Automated acoustic sensors recorded at seven Forsterâ€™s Tern (Sterna forsteri) colonies in San Francisco Bay over two breeding seasons. Tern calls were detected and counted from each site using an automated technique (spectrogram cross-correlation). Traditional nest counts were also conducted at all colonies throughout each breeding season. Our results show that acoustic activity (calls/min) indicated colony size within years, and was a powerful index of change in colony size between years (r2=.92 n=5 p=.005). Quantifying the relationship between acoustic activity and relative abundance is a fundamental step in designing effective acoustic monitoring programs for seabirds and other wildlife. Acoustic monitoring promises to be a low-cost, scalable technique for monitoring population trends and measuring responses to intervention.
16:45 Restoring denuded, post-bleached reefs in Tanzania: testing the second phase of the Gardening Concept Nsajigwa Emmanuel Mbije*, Sokoine University of Agriculture
; Ehud Spanier, Haifa University; Baruch Rinkevich, Israel Limnology Institute
The worldwide decline in coral reefs have prompted search for effective and approved-to-use restoration protocols. Based on the â€˜gardening conceptâ€™ that guides the transplantation of nursery farmed corals, we transplanted 6912 and 7110 corals (Acropora muricata, A. nasuta, A. hemprichii, Pocillopora verrucosa, Porites cylindrica, Millepora sp.) in Changuu reef, Zanzibar and Kitutia reef, Mafia, respectively. In each site we randomly established 12 lots (each 36 m2); three that were transplanted with a mix of the three Acropora spp. (Treatment 1; T1), three with a mix of all six scleractinians (Treatment 2; T2), and six controls. Transplants were monitored for 12 months for survivorship, growth rates and coral recruitment. Within one month of transplantation, an outbreak of Acanthaster planci in Changuu reef caused about 50% mortality while at Kitutia reef; illegal fishing activities caused 25% death. Thereafter, survivorship of transplants in T1 and T2 at Kitutia reached 66.4% and 62.5%, respectively, significantly higher than at Changuu site (p<0.05; t-test). Species-by-species comparisons revealed lower survivorship of P. verrucosa, P. cylindrica, A. muricata, and A. nasuta in Zanzibar as compared to Mafia (p<0.05; t-test) and no significant differences for A. hemprichi and Millepora sp. (p>0.05; t test). After one year, while no significant difference was observed between EV of T1 & T2 in each site (p>0.05; one way Anova), EV differed significantly between sites (p<0.05; one way Anova). Multivariate analysis on density data revealed significant separation in fish assemblage for density data between treatments in Kitutia but weak in Changuu. A within treatment one-way ANOSIM comparing initial and last three months for each treatment showed strong separations for Kitutia than was for Changuu site. For the invertebrate assemblages, multivariate analysis revealed weak separation between treatments for Kitutia site while the same was very strong for Changuu site. One-way ANOSIM comparing large invertebrate on density data between initial and last three months for each treatment in Kitutia revealed weak separations for T1, no separation for T2 and strong for T3 in Changuu site. There were significant differences between initial and last three months in coral recruitment in T1 and T2 central empty plots, reduced recruitment in Kitutia central empty T3 plots and no recruitment in Changuu central empty T3 plots. Cumulatively the results and economic evaluation revealed that the transplantation of nursery-grown colonies might uphold critical ecosystem functions, and promote reef re-colonization.
17:00 Conservation on private lands: the need for a science-based framework Wittmer, HU*, School of Biological Sciences, Victoria University of Wellington, PO Box 600, Wellington 6140, New Zealand
; Marshall, AJ, Department of Anthropology, University of California, Davis, CA 95616, USA
Private lands are playing an increasing role in the conservation of endangered species. Recently, conservation efforts on private lands have expanded in scope and scale, including ambitious initiatives such as the creation of entire National Parks. Private conservation efforts at large spatial scales, however, are more likely to be accompanied by drastic changes in management. Despite the best intentions of managers, such changes can be risky and, at least in the short term, lead to unanticipated negative outcomes. Here we report on the unintended consequences of removing >30,000 domestic sheep for the viability of endangered huemul (Hippocamelus bisulcus) deer during the establishment of the future Patagonia National Park, Chile, on a privately owned Estancia. Following the removal of sheep, predation of huemul fawns and adults from native predators increased dramatically, threatening the viability of one of the endangered species that the Park was intended to protect. Based on these results, we highlight the need for a science-based framework for conservation efforts on private lands to ensure that such initiatives will meaningfully contribute to conservation efforts. Key components of a science-based framework are transparency, accountability, independent assessment, incorporation of sound management practices, and consideration of all relevant ecological processes and interactions.
17:15 Using a state-and-transition model to guide cost-efficient decision making for woodland restoration Rumpff, L*, University of Melbourne
; Vesk, P.A, University of Melbourne; Duncan, D.H., Arthur Rylah Institute, Department of Sustainability and Environment; Keith, D.A., Office of Environment and Heritage NSW; Wintle, B.A., University of Melbourne
Despite significant investments in native vegetation management, there remains substantial uncertainty surrounding the effectiveness and efficiency of management options. There are increasing demands on natural resource management (NRM) agencies to demonstrate the environmental benefits of management to justify the level of investment. Given time and funding constraints, uncertainties often go unresolved, and NRM agencies continue to make decisions based on assumptions about best-practice management. Adaptive management underpinned by quantitative process models can help test assumptions, and improve cost-efficient decision making as new information emerges. In this study we present a quantitative state and transition model (STM) for grassy woodland vegetation dynamics to be used in an adaptive management strategy. The STM was developed with NRM practitioners and ecologists, and implemented as a Bayesian network. We illustrate how the model can be used to identify cost-efficient management strategies given a set budget, under scenarios of varying land-use history and climatic conditions. Our experience in developing this model in collaboration with NRM practitioners indicates that it is a practical approach to capturing and characterizing expert knowledge about system dynamics that is useful in setting restoration priorities.