As Lead Scientist at the Natural Capital Project, Katie spearheads several efforts around the world to develop and use science about how nature benefits people to inform problems humans face in managing coastal and marine ecosystems. Katie is particularly interested in the ability of coastal ecosystems to protect vulnerable communities from sea level rise and storms, while providing other services such as nursery habitat for fisheries and tourism opportunities. Her research is informing national development planning, climate adaptation, and investments in restoration and conservation in the United States, Latin America, the Caribbean and Africa. Katie received her Ph.D. in Ecology, Evolution and Marine Biology at the University of California, Santa Barbara and her B.A. in ecology with a minor in Latin American studies from Princeton University. She is a recent recipient of a Fulbright NEXUS scholarship.

Academic Appointments

  • Senior Research Scientist, Academic Units
  • Academic Research Staff, Natural Capital Project

All Publications

  • Linking social, ecological, and physical science to advance natural and nature-based protection for coastal communities. Annals of the New York Academy of Sciences Arkema, K. K., Griffin, R., Maldonado, S., Silver, J., Suckale, J., Guerry, A. D. 2017


    Interest in the role that ecosystems play in reducing the impacts of coastal hazards has grown dramatically. Yet the magnitude and nature of their effects are highly context dependent, making it difficult to know under what conditions coastal habitats, such as saltmarshes, reefs, and forests, are likely to be effective for saving lives and protecting property. We operationalize the concept of natural and nature-based solutions for coastal protection by adopting an ecosystem services framework that propagates the outcome of a management action through ecosystems to societal benefits. We review the literature on the basis of the steps in this framework, considering not only the supply of coastal protection provided by ecosystems but also the demand for protective services from beneficiaries. We recommend further attention to (1) biophysical processes beyond wave attenuation, (2) the combined effects of multiple habitat types (e.g., reefs, vegetation), (3) marginal values and expected damage functions, and, in particular, (4) community dependence on ecosystems for coastal protection and co-benefits. We apply our approach to two case studies to illustrate how estimates of multiple benefits and losses can inform restoration and development decisions. Finally, we discuss frontiers for linking social, ecological, and physical science to advance natural and nature-based solutions to coastal protection.

    View details for DOI 10.1111/nyas.13322

    View details for PubMedID 28370069

  • The Power of Three: Coral Reefs, Seagrasses and Mangroves Protect Coastal Regions and Increase Their Resilience PLOS ONE Guannel, G., Arkema, K., Ruggiero, P., Verutes, G. 2016; 11 (7)


    Natural habitats have the ability to protect coastal communities against the impacts of waves and storms, yet it is unclear how different habitats complement each other to reduce those impacts. Here, we investigate the individual and combined coastal protection services supplied by live corals on reefs, seagrass meadows, and mangrove forests during both non-storm and storm conditions, and under present and future sea-level conditions. Using idealized profiles of fringing and barrier reefs, we quantify the services supplied by these habitats using various metrics of inundation and erosion. We find that, together, live corals, seagrasses, and mangroves supply more protection services than any individual habitat or any combination of two habitats. Specifically, we find that, while mangroves are the most effective at protecting the coast under non-storm and storm conditions, live corals and seagrasses also moderate the impact of waves and storms, thereby further reducing the vulnerability of coastal regions. Also, in addition to structural differences, the amount of service supplied by habitats in our analysis is highly dependent on the geomorphic setting, habitat location and forcing conditions: live corals in the fringing reef profile supply more protection services than seagrasses; seagrasses in the barrier reef profile supply more protection services than live corals; and seagrasses, in our simulations, can even compensate for the long-term degradation of the barrier reef. Results of this study demonstrate the importance of taking integrated and place-based approaches when quantifying and managing for the coastal protection services supplied by ecosystems.

    View details for DOI 10.1371/journal.pone.0158094

    View details for Web of Science ID 000379508300017

    View details for PubMedID 27409584

    View details for PubMedCentralID PMC4943730

  • Embedding ecosystem services in coastal planning leads to better outcomes for people and nature PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Arkema, K. K., Verutes, G. M., Wood, S. A., Clarke-Samuels, C., Rosado, S., Canto, M., Rosenthal, A., Ruckelshaus, M., Guannel, G., Toft, J., Faries, J., Silver, J. M., Griffin, R., Guerry, A. D. 2015; 112 (24): 7390-7395


    Recent calls for ocean planning envision informed management of social and ecological systems to sustain delivery of ecosystem services to people. However, until now, no coastal and marine planning process has applied an ecosystem-services framework to understand how human activities affect the flow of benefits, to create scenarios, and to design a management plan. We developed models that quantify services provided by corals, mangroves, and seagrasses. We used these models within an extensive engagement process to design a national spatial plan for Belize's coastal zone. Through iteration of modeling and stakeholder engagement, we developed a preferred plan, currently under formal consideration by the Belizean government. Our results suggest that the preferred plan will lead to greater returns from coastal protection and tourism than outcomes from scenarios oriented toward achieving either conservation or development goals. The plan will also reduce impacts to coastal habitat and increase revenues from lobster fishing relative to current management. By accounting for spatial variation in the impacts of coastal and ocean activities on benefits that ecosystems provide to people, our models allowed stakeholders and policymakers to refine zones of human use. The final version of the preferred plan improved expected coastal protection by >25% and more than doubled the revenue from fishing, compared with earlier versions based on stakeholder preferences alone. Including outcomes in terms of ecosystem-service supply and value allowed for explicit consideration of multiple benefits from oceans and coasts that typically are evaluated separately in management decisions.

    View details for DOI 10.1073/pnas.1406483112

    View details for Web of Science ID 000356251800033

    View details for PubMedID 26082545

    View details for PubMedCentralID PMC4475972

  • Assessing habitat risk from human activities to inform coastal and marine spatial planning: a demonstration in Belize ENVIRONMENTAL RESEARCH LETTERS Arkema, K. K., Verutes, G., Bernhardt, J. R., Clarke, C., Rosado, S., Canto, M., Wood, S. A., Ruckelshaus, M., Rosenthal, A., McField, M., de Zegher, J. 2014; 9 (11)
  • Coastal habitats shield people and property from sea-level rise and storms NATURE CLIMATE CHANGE Arkema, K. K., Guannel, G., Verutes, G., Wood, S. A., Guerry, A., Ruckelshaus, M., Kareiva, P., Lacayo, M., Silver, J. M. 2013; 3 (10): 913-918
  • Direct and indirect effects of giant kelp determine benthic community structure and dynamics ECOLOGY Arkema, K. K., Reed, D. C., Schroeter, S. C. 2009; 90 (11): 3126-3137


    Indirect facilitation can occur when a species positively affects another via the suppression of a shared competitor. In giant kelp forests, shade from the canopy of the giant kelp, Macrocystis pyrifera, negatively affects understory algae, which compete with sessile invertebrates for space. This raises the possibility that giant kelp indirectly facilitates sessile invertebrates, via suppression of understory algae. We evaluated the effect of giant kelp on the relative abundance of algae and invertebrates by experimentally manipulating kelp abundance on large artificial reefs located off San Clemente, California, USA. The experiments revealed a negative effect of giant kelp on both light availability and understory algal abundance and a positive effect on the abundance of sessile invertebrates, which was consistent with an indirect effect mediated by shade from the kelp canopy. The importance of these processes to temporal variability in benthic community structure was evaluated at 16 locations on natural reefs off Santa Barbara, California, over an eight-year period. Interannual variability in the abundance of understory algae and in the abundance of sessile invertebrates was significantly and positively related to interannual variability in the abundance of giant kelp. Analysis of these observational data using Structural Equation Modeling (SEM) indicated that the magnitude of the indirect effect of giant kelp on invertebrates was six times larger than the direct effect on invertebrates. Results suggest that the dynamics of this system are driven by variability in the abundance of a single structure-forming species that has indirect positive, as well as direct negative, effects on associated species.

    View details for Web of Science ID 000271457300016

    View details for PubMedID 19967868

  • Evaluating the Benefits of Green Infrastructure for Coastal Areas: Location, Location, Location COASTAL MANAGEMENT Ruckelshaus, M. H., Guannel, G., Arkema, K., Verutes, G., Griffin, R., Guerry, A., Silver, J., Faries, J., Brenner, J., Rosenthal, A. 2016; 44 (5): 504-516
  • Integrated modeling framework to quantify the coastal protection services supplied by vegetation JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS Guannel, G., Ruggiero, P., Faries, J., Arkema, K., Pinsky, M., Gelfenbaum, G., Guerry, A., Kim, C. 2015; 120 (1): 324-345
  • Key lessons for incorporating natural infrastructure into regional climate adaptation planning OCEAN & COASTAL MANAGEMENT Langridge, S. M., Hartge, E. H., Clark, R., Arkema, K., Verutes, G. M., Prahler, E. E., Stoner-Duncan, S., Revell, D. L., Caldwell, M. R., Guerry, A. D., Ruckelshaus, M., Abeles, A., Coburn, C., O'Connor, K. 2014; 95: 189-197
  • Characterizing coastal foodwebs with qualitative links to bridge the gap between the theory and the practice of ecosystem-based management ICES JOURNAL OF MARINE SCIENCE Carey, M. P., Levin, P. S., Townsend, H., Minello, T. J., Sutton, G. R., Francis, T. B., Harvey, C. J., Toft, J. E., Arkema, K. K., Burke, J. L., Kim, C., Guerry, A. D., Plummer, M., Spiridonov, G., Ruckelshaus, M. 2014; 71 (3): 713-724
  • From mountains to sound: modelling the sensitivity of Dungeness crab and Pacific oyster to landsea interactions in Hood Canal, WA ICES JOURNAL OF MARINE SCIENCE Toft, J. E., Burke, J. L., Carey, M. P., Kim, C. K., Marsik, M., Sutherland, D. A., ARKEMA, K. K., Guerry, A. D., Levin, P. S., Minello, T. J., Plummer, M., Ruckelshaus, M. H., Townsend, H. M. 2014; 71 (3): 725-738
  • Climate change's impact on key ecosystem services and the human well-being they support in the US FRONTIERS IN ECOLOGY AND THE ENVIRONMENT Nelson, E. J., Kareiva, P., Ruckelshaus, M., Arkema, K., Geller, G., Girvetz, E., Goodrich, D., Matzek, V., Pinsky, M., Reid, W., Saunders, M., Semmens, D., Tallis, H. 2013; 11 (9): 483-493

    View details for DOI 10.1890/120312

    View details for Web of Science ID 000326363900005

  • Quantifying wave attenuation to inform coastal habitat conservation ECOSPHERE Pinsky, M. L., Guannel, G., Arkema, K. K. 2013; 4 (8)
  • Catching the Right Wave: Evaluating Wave Energy Resources and Potential Compatibility with Existing Marine and Coastal Uses PLOS ONE Kim, C., Toft, J. E., Papenfus, M., Verutes, G., Guerry, A. D., Ruckelshaus, M. H., Arkema, K. K., Guannel, G., Wood, S. A., Bernhardt, J. R., Tallis, H., Plummer, M. L., Halpern, B. S., Pinsky, M. L., Beck, M. W., Chan, F., Chan, K. M., Levin, P. S., Polasky, S. 2012; 7 (11)


    Many hope that ocean waves will be a source for clean, safe, reliable and affordable energy, yet wave energy conversion facilities may affect marine ecosystems through a variety of mechanisms, including competition with other human uses. We developed a decision-support tool to assist siting wave energy facilities, which allows the user to balance the need for profitability of the facilities with the need to minimize conflicts with other ocean uses. Our wave energy model quantifies harvestable wave energy and evaluates the net present value (NPV) of a wave energy facility based on a capital investment analysis. The model has a flexible framework and can be easily applied to wave energy projects at local, regional, and global scales. We applied the model and compatibility analysis on the west coast of Vancouver Island, British Columbia, Canada to provide information for ongoing marine spatial planning, including potential wave energy projects. In particular, we conducted a spatial overlap analysis with a variety of existing uses and ecological characteristics, and a quantitative compatibility analysis with commercial fisheries data. We found that wave power and harvestable wave energy gradually increase offshore as wave conditions intensify. However, areas with high economic potential for wave energy facilities were closer to cable landing points because of the cost of bringing energy ashore and thus in nearshore areas that support a number of different human uses. We show that the maximum combined economic benefit from wave energy and other uses is likely to be realized if wave energy facilities are sited in areas that maximize wave energy NPV and minimize conflict with existing ocean uses. Our tools will help decision-makers explore alternative locations for wave energy facilities by mapping expected wave energy NPV and helping to identify sites that provide maximal returns yet avoid spatial competition with existing ocean uses.

    View details for DOI 10.1371/journal.pone.0047598

    View details for Web of Science ID 000311935800024

    View details for PubMedID 23144824

    View details for PubMedCentralID PMC3492388

  • Linking Ecosystem Health and Services to Inform Marine Ecosystem-Based Management Gulf of Maine Symposium: Advancing Ecosystem Research for the Future of the Gulf Arkema, K. K., Samhouri, J. F. AMER FISHERIES SOC. 2012: 9–25
  • Density derived estimates of standing crop and net primary production in the giant kelp Macrocystis pyrifera MARINE BIOLOGY Reed, D., Rassweiler, A., Arkema, K. 2009; 156 (10): 2077-2083
  • Flow-mediated feeding in the field: consequences for the performance and abundance of a sessile marine invertebrate MARINE ECOLOGY PROGRESS SERIES Arkema, K. K. 2009; 388: 207-220

    View details for DOI 10.3354/meps08140

    View details for Web of Science ID 000269892700018

  • Density derived estimates of standing crop and net primary production in the giant kelp Marine biology Reed, D., Rassweiler, A., Arkema, K. 2009; 156 (10): 2077-2083


    Assemblages of macroalgae are believe to be among the most productive ecosystems in the world, yet difficulties in obtaining direct estimates of biomass and primary production have led to few macroalgal data sets from which the consequences of long-term change can be assessed. We evaluated the validity of using two easily measured population variables (frond density and plant density) to estimate the more difficult to measure variables of standing crop and net primary production (NPP) in the giant kelp Macrocystis pyrifera off southern California. Standing crop was much more strongly correlated to frond density than to plant density. Frond density data collected in summer were particularly useful for estimating annual NPP, explaining nearly 80% of the variation in the NPP from year to year. Data on frond densities also provided a relatively good estimate of seasonal NPP for the season that the data were collected. In contrast, estimates of seasonal and annual NPP derived from plant density data were less reliable. These results indicate that data on frond density collected at the proper time of year can make assessments of NPP by giant kelp more tractable. They also suggest that other easily measured variables that are strongly correlated with standing crop, such as surface canopy area, might serve as similarly useful proxies of NPP.

    View details for PubMedID 24391235

    View details for PubMedCentralID PMC3873067

  • Spatial patterns of flow and their modification within and around a giant kelp forest LIMNOLOGY AND OCEANOGRAPHY Gaylord, B., Rosman, J. H., Reed, D. C., Koseff, J. R., Fram, J., Macintyre, S., Arkema, K., McDonald, C., Brzezinski, M. A., Largier, J. L., Monismith, S. G., Raimondi, P. T., Mardian, B. 2007; 52 (5): 1838-1852