David M. Lodge - US grants

The relative importance of biotic and abiotic factors in structuring the littoral zone community in northern Wisconsin lakes will be evaluated. The proposed work builds on 5 years of collaborative research examining the major forces controlling the structure and function of the nearshore community. The approach is comprehensive. It evaluates complex interactions, direct and indirect interactions among predators and their prey, and the cascade hypothesis. They have all been recently applied to the pelagia of lakes, but are largely untested in the structurally- complex environment of the benthic, littoral cummunity. The centerpiece for this effort is a mesocosm experiment in which densities of fish predators of crayfish and crayfish are treatment variables. Treatments in which the fish predators of crayfish are reduced to mimic the impact of winterkill on the top trophic level will be used. The mesocosms represent a scale intermediate between laboratory and whole-lake experiments. The approach is tractable, realistic, and absolutely required to make progress toward understanding those forces structuring the littoral community.

9408452 Lodge The study of plant-herbivore interactions in freshwater communities has lagged far behind similar investigations in terrestrial and marine systems. Yet research in the latter two habitats has revolutionized our understanding of plant-animal interactions, ecosystem function, and coevolution. This project extends methods and approaches developed for marine herbivore systems to little-studied freshwater herbivore systems. The investigators are documenting: what plant traits deter herbivore consumption, the selectivity of freshwater herbivores, and the impact of generalist vs. specialist herbivores. This research will allow the testing of important theories of plant defenses and herbivory developed in terrestrial and marine systems, and provide a unique opportunity for valuable comparisons between the three systems. This research will improve our understanding of the ecology of plant-herbivore interactions and the role of macrophyte feeders in the function of aquatic ecosystems. The results have application in the management of aquatic ecosystems.

9520663 LODGE This proposal will test the hypothesis that the relative importance of benthic and pelagic primary production in lake food webs is dependent on lake trophic status and is regulated by fish. Previous results indicate that benthic and pelagic organisms are strongly linked through trophic relationships and form important conduits for carbon and nitrogen flow. Fish structure benthic and pelagic communities and are important vectors of organic material and nutrients between benthic and pelagic habitats. A stable isotope method will be used to integrate this research into a comprehensive understanding of benthic-pelagic trophic links. The stable isotopes will be used to determine the trophic links between pelagic food webs, benthic macroinvertebrate communities, and benthic algae.

9724723 Lodge This is a planning visit award for Dr. David M. Lodge, of the Department of Biological Sciences at the University of Notre Dame, to travel to Kenya to meet with Dr. Kenneth M. Mavuti, of the Department of Zoology at the University of Nairobi, and Dr. Gerald M. Mkoji, of the Biomedical Sciences Research Centre at the Kenya Medical Research Institute. The purpose of the visit is to develop a cooperative research activity to evaluate the impact of the North American crayfish Procambarus clarkii on the biota of Kenya's freshwater lakes and wetlands. This species of crayfish was introduced for aquaculture, but is now being considered as a biological control agent for freshwater snails that are vectors for schistosomiasis (a major cause of disease in Africa). This study should add significant new knowledge about the impact an exotic species of crayfish has had on the local ecosystems in the lakes and wetlands of Kenya. Funding for this project is being provided jointly by the Division of International Programs and the Division of Environmental Biology. ***

In assessing the risk to US society of nonindigenous species (NIS)-species introduced into an ecosystem in which they did not previously exist-this interdisciplinary team will use a model derived from economic theory to integrate ecological, economic, and social benefits and costs of NIS. In the freshwater ecosystems of the world, NIS are the leading cause of biodiversity loss; in most other ecosystems, NIS are one of the top three causes. Not only do NIS cause enormous ecological changes, but they also directly cause large economic losses and social change (e.g., as native harvestable resources are replaced by NIS). Although policies and regulations are being implementing to reduce the occurrence and impact of NIS (e.g., ballast regulations in the Great Lakes and coastal waters), these steps are being taken in the absence of a basic scientific understanding of the biological, economic, and social dimensions of the process of biological invasions. This team of aquatic ecologists, ecological modelers, and social scientists will develop an integrative approach to risk assessment of NIS, using the North American Great Lakes as a case study.

Intellectual merit. Numbers of nonindigenous species--species introduced from elsewhere - are
increasing rapidly worldwide. They are a major cause of biodiversity loss and environmental
change, and are estimated to cost the US $137 billion/yr. The 2001 National Invasive Species
Management Plan (www.invasivespecies.gov) highlighted the urgent need for more rigorous and
comprehensive risk analysis frameworks for nonindigenous species so that prevention and
control strategies can be targeted appropriately. The central public policy consideration is how
much of society's resources should be expended in response to nonindigenous species, and how,
for example, should it be allocated between prevention and control? These considerations,
though, include a nexus of interacting ecological and economic factors that require
interdisciplinary effort. Species invasions are caused by economic activities, and in turn affect
economic activities. This ecological and economic linkage and feedback means that the
assessment of risk interacts with the management of risk, which contradicts the common notion
that risk assessment and risk management are independent. Social welfare and risk assessment
are both determined jointly by ecological and economic processes.
In response to the need for interdisciplinary risk analysis, this project brings together
experts from invasion biology, mathematical modeling, and economics. The main goal is to
develop and apply a bio-economic modeling framework for nonindigenous species that
integrates risk assessment and risk management, includes uncertainty distributions, and
optimizes prevention and control strategies in a landscape context. The overall bio-economic
model uses Stochastic Dynamic Programming, which allows the investigators to incorporate
ecological-economic feedbacks in such a way to optimize combinations of prevention and
control strategies to maximize social welfare. This framework will be extended to the landscape
scale with Neural Network models.
The applications will focus on freshwater nonindigenous species in the Great Lakes
region. A preliminary application to zebra mussels suggested, for example, that society should
be spending about $240,000/yr to keep zebra mussels from invading each lake with a power
plant (to prevent fouling of pipes). This is in sharp contrast to the $825,000 that the Fish &
Wildlife Service spent in FY2001 for prevention and control efforts for all aquatic nuisance
species for all lakes. Our analyses will be directly relevant to policymakers and natural resource
managers.
Broader impacts. The investigators will partner with the Shedd Aquarium in Chicago to
educate schoolchildren and the public about the general problem of nonindigenous species, about
what individuals can do to reduce the problem, and about the role that science plays in public
policy decisions. By partnering with an educational software firm, they will convert research
models into user-friendly formats for use by schoolchildren, the public, policymakers, resource
managers, and stakeholders. In partnership with the Great Lakes Commission, research methods,
results, and user-friendly products will be disseminated in workshops to policymakers, managers,
and stakeholders. Finally, they will develop international collaborations and a reciprocal
exchange of information and techniques with top researchers in Australia, where NIS research is
advanced relative to North America.

Abstract
DISSERTATION RESEARCH: Invasion Risk in the Great Lakes: Estimating Propagule Pressure with Molecular Tools
Lodge
DEB-0308934

Biological invasions by organisms transported in ship ballast water are an increasing cause of environmental degradation and a significant source of economic costs to society. In preliminary research, the P.I. have adapted probabilistic models to estimate invasion risk from propagule pressures, and enumerated adult organisms from samples of Great Lakes ship ballast water. Though invasion risk from resting stages of invertebrates is generally believed to be considerable, it has not yet been quantified due to the technical difficulty of identifying resting eggs from morphological characters. Thus, the goals of this research are to identify and enumerate resting eggs in samples through a combination of molecular and statistical techniques. Pilot studies to assess the feasibility of this approach indicated that high-quality quantitative estimates of propagule pressure can be obtained through a four step process: (1) extraction of nuclear and mitochondrial DNA; (2) separation of gene sequences using denaturing gradient gel electrophoresis; (3) identification of taxonomic groupings based on gene sequences; and (4) estimation of species relative abundance with statistical models. The proposed research will use this method to provide estimates of propagules pressure from 20 ships and to conduct risk assessments of invasion.

This Integrative Graduate Education and Research Training (IGERT) award supports the establishment of a new interdisciplinary graduate program in Global Linkages of Biology, Environment and Society (GLOBES) at the University of Notre Dame. The program integrates research, training, and educational activities among complementary faculty in ecology, evolution and environment, infectious disease, and social science, ethics, law and economics. The goal of the program is to train a new generation of Ph.D. scientists capable of designing and implementing sound scientific solutions to environmental problems within the framework of human culture, economics, policy, and law. Human practices and activities affecting environmental and global health have interrelated causes and feedbacks. These feedbacks are both biological and social, and exacerbate environmental degradation and the spread of invasive species and disease. Consequently, solutions to increasingly linked environmental and health problems require the coordinated interaction of biological and social scientists with expertise in ecology, evolution, infectious disease, anthropology, ethics, law, policy, and economics. The intellectual merit of this IGERT consists of the integration of the research and education activities of life and social scientists at the University of Notre Dame in a concerted effort to understand and find solutions to five specific problems: (1) invasive species in the Great Lake and their cascading effects on ecosystems (2) interactions of human land-use change and malaria transmission in West Africa; (3) cross-primate exchange of disease on the island of Bali, (4) resurgence of schistosomiasis in China driven by changes in water- and land-use patterns, and (5) impacts of invasive Sudden Oak Death as it spreads across the U.S. Without interdisciplinary thinking, relatively simple and effective measures to reduce environmental damage and disease transmission can go unrecognized. Most analyses suffer from concentrating on only one aspect of the question (e.g., ecology, culture, or disease). This IGERT will foster cross-disciplinary conversation and guide research directed at developing prevention and control responses to invasive species and disease that are scientifically sound, culturally acceptable, and cost-effective. The IGERT will use a coordinated set of approaches ranging from team-based research projects to outreach service activities to provide students with the interdisciplinary skills and knowledge they need to tackle the increasingly complex environmental and global health problems of our nation and the planet. The broader impacts of this proposal include finding solutions to these environmental and health problems. IGERT is an NSF-wide program intended to meet the challenges of educating U.S. Ph.D. scientists and engineers with the interdisciplinary background, deep knowledge in a chosen discipline, and the technical, professional, and personal skills needed for the career demands of the future. The program is intended to catalyze a cultural change in graduate education by establishing innovative new models for graduate education and training in a fertile environment for collaborative research that transcends traditional disciplinary boundaries.

Controversy surrounds the global dissemination of Nile tilapia (Oreochromis niloticus), reflecting tension between possible negative impacts on native fish production relative to the socio-economic benefits of Nile tilapia aquaculture. The objective of this Doctoral Dissertation Enhancement Project is to inform this global debate by quantifying the impact of Nile tilapia introduction on a native Oreochromis fishery. The central hypothesis of this case study on the Kafue River, Zambia, is that introduced O. niloticus out-compete native O. andersonii males for mates, driving directional hybridization which may alter fisheries production in the long term. Field sampling for genetic detection of hybridization coupled with competition experiments will test this hypothesis by quantitatively parameterizing models which will estimate the differences in somatic and population growth rates between parental and hybrid types.

By developing collaborative research with foreign partners, such as University of Zambia lecturer Dr. Cyprian Katongo and Zambian master's students, this project contributes to the underlying doctoral dissertation through advising, planning and experimental execution. This will be the first research to experimentally investigate ecological linkages between Nile tilapia invasion in Africa and sustainable fisheries production, thus improving the intellectual merit of the dissertation. Moreover, field sampling will extend the long term fishery dataset for the Kafue, which is essential to developing this river as a case study.

Broader impacts derive from strong collaborative partnerships with the University of Zambia, Zambian Department of Fisheries, and The World Fish Center. These partnerships ensure research will inform decisions about the introduction of Nile tilapia relative to the sustainable development of aquatic resources in Zambia and worldwide. This proposal serves as the seed for a larger collaboration and further NSF support by informing the specific design of experiments in a future proposal. Further, it provides a US graduate student the opportunity to engage in international collaborative research.

This award is being funded by NSF's Office of International Science and Engineering.