Current Research

Impacts of invasive species, climate change, and disturbance on ecological function of Pacific Island streams, coastal wetlands and mangroves; ecology and community dynamics of fish and invertebrates in streams, coastal wetlands, and mangroves; quantifying ecosystems services of mangrove forests.

Video / Multimedia

• Climate Change and Native Hawaiian Shrimp
  

  The life cycle of native Hawaiian shrimp depends heavily on stream flow to carry them out to sea. A warmer, drier climate means less water in the streams, which could jeopardize their viability. In this video, PSW research ecologist Dr. Rich MacKenzie talks about his research on the shrimp and what they tell us about the surrounding ecosystem. [length: 5:13]

• Habitat Value of Mangroves for Fish in Micronesia
  

  Discussing the Kosrae and Yap islands of Micronesia [length: 22:27]

Education

• University of Wisconsin at Milwaukee, Ph.D. Invertebrate Zoology, Biogeochemistry minor 2001
• University of Wisconsin at Eau Claire, B.S. Zoology 1993

Featured Publications & Products

• Atwood, Trisha B.; Wiegner, Tracy N.; MacKenzie, Richard A. 2012. Effects of hydrological forcing on the structure of a tropical estuarine food web.
• MacKenzie, Richard A.; Cormier, Nicole. 2012. Stand structure influences nekton community composition and provides protection from natural disturbance in Micronesian mangroves.
• Donato, D.C.; Kauffman, J.B.; Mackenzie, R.A.; Ainsworth, A.; Pfleeger, A.Z. 2012. Whole-island carbon stocks in the tropical Pacific: Implications for mangrove conservation and upland restoration.

Publications

• Strauch, Ayron M.; MacKenzie, Richard A.; Giardina, Christian P.; Bruland, Gregory L. 2018. Influence of declining mean annual rainfall on the behavior and yield of sediment and particulate organic carbon from tropical watersheds.
• Povak, Nicholas A.; Hessburg, Paul F.; Giardina, Christian P.; Reynolds, Keith M.; Heider, Chris; Salminen, Ed; Salter, R. Brion; MacKenzie, Richard A. 2017. A watershed decision support tool for managing invasive species on Hawai i Island, USA.
• Strauch, Ayron M.; MacKenzie, Richard A.; Tingley, Ralph W. 2017. Base flow-driven shifts in tropical stream temperature regimes across a mean annual rainfall gradient.
• MacKenzie, Richard A.; Strauch, Ayron M.; Wiegner, Tracy N.; Colbert, Steven L.; Stets, Edward G.; Streigl, Robert G. 2017. Baseline and projected future aquatic carbon fluxes to nearshore waters in Hawai i.
• Dudley, Bruce D.; MacKenzie, Richard A.; Sakihara, Troy S.; Riney, Michael H.; Ostertag, Rebecca. 2017. Effects of invasion at two trophic levels on diet, body condition, and population size structure of Hawaiian red shrimp.
• Selmants, Paul C.; Giardina, Christian P.; Jacobi, James D.; Fortini, Lucas B.; Hughes, R. Flint; Hawbaker, Todd J.; MacKenzie, Richard A.; Sleeter, Benjamin M.; Zhu, Zhiliang. 2017. Executive Summary Baseline and projected future carbon storage and carbon fluxes in ecosystems of Hawai i.
• Strauch, Ayron M.; Giardina, Christian P.; MacKenzie, Richard A.; Heider, Chris; Giambelluca, Tom W.; Salminen, Ed; Bruland, Gregory L. 2017. Modeled effects of climate change and plant invasion on watershed function across a steep tropical rainfall gradient.
• El-Sabaawi, Rana W.; Frauendorf, Therese C.; Marques, Piata S.; Mackenzie, Richard A.; Manna, Luisa R.; Mazzoni, Rosana; Phillip, Dawn A. T.; Warbanski, Misha L.; Zandon, Eugenia. 2016. Biodiversity and ecosystem risks arising from using guppies to control mosquitoes.
• Roberts, Megan; Strauch, Ayron M.; Wiegner, Tracy; Mackenzie, Richard A. 2016. Leaf litter breakdown of native and exotic tree species in two Hawaiian streams that differ in flow.
• MacKenzie, Richard A.; Foulk, Patra B.; Klump, J. Val; Weckerly, Kimberly; Purbospito, Joko; Murdiyarso, Daniel; Donato, Daniel C.; Nam, Vien Ngoc. 2016. Sedimentation and belowground carbon accumulation rates in mangrove forests that differ in diversity and land use: a tale of two mangroves.
• Strauch, Ayron M.; Bruland, Gregory L.; MacKenzie, Richard A.; Giardina, Christian P. 2016. Soil and hydrological responses to wild pig (Sus scofa) exclusion from native and strawberry guava (Psidium cattleianum)-invaded tropical montane wet forests.
• Strauch, Ayron M.; MacKenzie, Richard A.; Giardina, Christian P.; Bruland, Gregory L. 2015. Climate driven changes to rainfall and streamflow patterns in a model tropical island hydrological system.
• MacKenzie, Richard A.; Dionne, Michele; Miller, Jeremy; Haas, Michael; Morgan, Pamela A. 2015. Community structure and abundance of benthic infaunal invertebrates in Maine fringing marsh ecosystems.
• Sakihara, T.S.; Dudley, B.D.; MacKenzie, R.A.; Beets, J.P. 2015. Endemic grazers control benthic microalgal growth in a eutrophic tropical brackish ecosystem.
• Strauch, Ayron M.; Mackenzie, Richard A.; Bruland, Gregory L.; Tingley, Ralph; Giardina, Christian P. 2014. Climate change and land use drivers of fecal bacteria in tropical Hawaiian rivers.
• Dudley, B. D.; MacKenzie, Richard; Sakihara, T. S.; Dulaiova, H.; Waters, C. A.; Hughes, Flint; Ostertag, R. 2014. Influences of N-fixing and non-N-fixing vegetation and invasive fish on water chemistry of Hawaiian anchialine ponds.
• Cannon, Phil G.; Falanruw, Margie; Ruegorong, Francis; MacKenzie, Rich; Friday, Katie; Ross-Davis, Amy L.; Ashiglar, Sara M.; Klopfenstein, Ned B.; Liu, Zhangfeng; Golabi, Mohammad; Iyekar, Chancy Thomas. 2014. The causes of mangrove death on Yap, Palau, Pohnpei and Kosrae Chapter II.
• Dalton, C. M.; Mokiao-Lee, A.; Sakihara, T. S.; Weber, M. G.; Roco, C. A.; Han, Z.; Dudley, B.; MacKenzie, R. A.; Hairston Jr., N. G. 2013. Density- and trait-mediated top-down effects modify bottom-up control of a highly endemic tropical aquatic food web.
• Holitzki, Tara; MacKenzie, Richard A.; Wiegner, Tracy N.; McDermid, Karla J. 2013. Differences in ecological structure, function, and native species abundance between native and invaded Hawaiian streams.
• MacKenzie, Richard A.; Kryss, Cailtin L. 2013. Impacts of exotic mangroves and mangrove control on tide pool fish assemblages.
• MacKenzie, Richard A.; Wiegner, Tracy N.; Kinslow, Frances; Cormier, Nicole; Strauch, Ayron M. 2013. Leaf-litter inputs from an invasive nitrogen-fixing tree influence organic-matter dynamics and nitrogen inputs in a Hawaiian river.
• MacKenzie, Richard Ames; Bruland, Gregory L. 2012. Nekton communities in Hawaiian coastal wetlands: The distribution and abundance of introduced fish species.
• Bruland, Gregory L.; Mackenzie, Richard A. 2010. Nitrogen source tracking with 15N content of coastal wetland plants in Hawaii.
• Atwood, Trisha B.; N. Wiegner, Tracy; P. Turner, Jason; MacKenzie, Richard A. 2010. Potential effects of an invasive nitrogen-fixing tree on a Hawaiian stream food web.
• Bantilan-Smith, Meris; Bruland, Gregory L.; MacKenzie, Richard A.; Henry, Adonia R.; Ryder, Christina R. 2009. A comparison of the vegetation and soils of natural, restored, and created coastal lowland wetlands in Hawai i.
• Wiegner, Tracy N.; Tubal, Randee L.; MacKenzie, Richard A. 2009. Bioavailability and export of dissolved organic matter from a tropical river during base- and stormflow conditions.
• MacKenzie, R.A.; Dionne, M. 2008. Habitat heterogeneity: importance of salt marsh pools and high marsh surfaces to fish production in two Gulf of Maine salt marshes.

Research Highlights

Highlight	Title	Year
PSW-2015-218	Impacts of Cimate Change on Pacific Island Streams Forest Service scientists studied how various ecological and hydrological functions responded to changes in rainfall. Streamflow and metrics all ...	2015
PSW-2014-103	Keeping Out Exotic Fish Improves Endangered Hawaiian Waterbird Habitat Exotic tilapia and mosquito fish are found in aquatic ecosystems throughout the Hawaiian Islands where they degrade native fish and waterbird ha ...	2014