Education

• B.A., Rutgers University, 1969
• M.S., University of Virginia, 1971
• Ph.D., University of Maryland, 1975

Research Interests

My research focuses on the biology and ecology of seagrasses, principally in the Chesapeake Bay. My current emphasis is on habitat restoration and conservation and understanding the principles and processes governing the dynamics of these plant communities.   One major element of our program is the annual monitoring of the distribution and abundance of submerged aquatic vegetation in the Chesapeake Bay and the seaside bays of the Maryland and Virginia barrier islands, using a combination of low level remote sensing and GIS tools.  Annual reports documenting the patterns of bay grasses are available on our SAV website and these data are being used by federal and state management agencies as one of the measurable products in assessing the success of efforts to clean up the waters of Chesapeake Bay.  The second major element focuses on seed ecology issues, primarily with eelgrass (the only true seagrass in the Chesapeake Bay region), and secondarily with freshwater species found in the less saline portions of Chesapeake Bay, with emphasis on abiotic and biotic processes influencing seed germination and seed dispersal. A third major element is the restoration of seagrasses in Chesapeake Bay and the seaside bays of Virginia’s barrier island lagoon system using a basic and applied research approach primarily using seeds.   The fourth and final element is a strong advisory component to the Commonwealth of Virginia and the EPA’s Chesapeake Bay Program in assuring seagrass beds are protected from direct and indirect impacts.  Our research program emphasizes the dissemination of information in both technical documents as well as scientific peer reviewed journals.

Current Projects

• Submerged Aquatic Vegetation Website

• Global trajectories of seagrasses: Establishing a quantitative basis for seagrass conservation and restoration   R. J. Orth and W. C.  Dennison (UMCES) co-PI’s.  National Center for Ecological Analysis and Synthesis, 1-10-06 to 12-31-07.
• Distribution of SAV in the Chesapeake Bay and Coastal Bays– 2005. US EPA, Maryland Dept. of Natural Resources, NOAA, Virginia’s Coastal Program, VA DEQ, 10-1-04 to 12-31-05.
• Site assessments for future, large-scale submerged aquatic vegetation in Chesapeake Bay (year 3). NOAA-Chesapeake Bay Program.  D. Goshorn (Maryland Dept. of Natural Resources) and R. J. Orth (co-PI’s). 10-1-05 to 9-30-06.
• Restoration of eelgrass communities in Chesapeake Bay with seeds: the emerging issues (year 3). NOAA-Chesapeake Bay Program. 10-1-05 to 9-30-06.
• Large-scale eelgrass restoration in the Piankatank River, Virginia (year 3). NOAA-Chesapeake Bay Program. R. J. Orth and K. A. Moore (Co-PI’s). 10-1-05 to 9-30-06.
• Boat scarring effects on SAV in Virginia. (year 6) Virginia Marine Resources Commission. R. J. Orth. 6-1-05 to 5-31-06.
• Seagrass restoration in VA’s seaside lagoons (year 4). NOAA Virginia’s Coastal Program. R. J. Orth and K.A. Moore (Co-PI’s). 10-1-05 to 12-31-06.
• Large-scale collection, processing and distribution of eelgrass (Zostera marina) seeds for restoration in Chesapeake and Coastal bays (year 2). The Campbell Foundation.  R. Orth and D. Goshorn (Maryland Dept. of Natural Resources) (co-PI’s). 1-1-05 to 12-31-05.
• Chesapeake Bay SAV restoration: Baywide Coordination and Technology Transfer.  National Fish and Wildlife Foundation.   R. Orth and D. Goshorn (Maryland Dept. of Natural Resources) (co-PI’s). 1-1-04 to 12-31-06.
• Technology Development for Achieving Critical Thresholds in Large Scale SAV Restoration. US Army Corps of Engineers.  5-1-05 to 4-15-06
• A Comparative Test of Mechanized and Manual Planting of Eelgrass Seeds.  US Army Corps of Engineers. 5-1-05 to 4-15-06.
• A Comparative Test of Mechanized and Manual Planting of Eelgrass Seeds.   NOAA –Chesapeake Bay Program. 10-1-05 to 9-30-06.
• The Development of Techniques for the Use of Seeds in the Large Scale Propagation and Restoration of Low Salinity SAV in Virginia Tidal Waters.  US Army Corps of Engineers.  K. A. Moore and R. J. Orth (co-PI’s).  5-1-05 to 4-15-06.

 

Selected Publications

• Orth, R. J., G. A. Kendrick, S. R. Marion. In Press.  Posidonia australis seed predation in seagrass habitats of Rottnest Island, Western Australia: patterns and predators Mar. Ecol. Prog. Ser.
• Orth, R. J., M. L. Luckenbach, S. R. Marion, K. A. Moore and D. J. Wilcox. in press. Recovery of the seagrass Zostera marina (eelgrass) in the Delmarva Coastal Bays, USA. Aq. Bot.
• Orth, R. J., M. Harwell, and G. Inglis. In Press. Ecology of seagrass seeds and seagrass dispersal processes. In: A. W. D.. Larkum, R. J. Orth, and C. Duarte (eds). Seagrasses: Biology, Ecology and their Conservation.  Springer. 
• Heck, K. H. and R. J. Orth.  In Press.  Predation in seagrass beds. In: A. W. D.. Larkum, R. J. Orth, and C. Duarte (eds). Seagrasses: Biology, Ecology and their Conservation.  Springer.
• Orth, R. J., J. Bieri, J. R. Fishman, M. C. Harwell, S. R. Marion, K. A. Moore, J. F. Nowak, J. van Montfrans. In Press. A review of techniques using adult plants and seeds to transplant eelgrass (Zostera marina L.) in Chesapeake Bay and the Virginia Coastal Bays.  Proc. Conf. Seagrass Restoration: Success, Failure, and the Costs of Both.  March 11, 2003. Sarasota, Florida.
• Fishman, J. R., R. J. Orth, S. Marion, and J. Bieri. 2004. A comparative test of mechanized and manual transplanting of eelgrass, Zostera marina, in Chesapeake Bay. Restoration Ecology 12:214-219.
• Beck, M. W., K. L. Heck, K. W. Able, D. L. Childers, D. B. Eggleston, B. M. Gilanders, B. S. Halpern, C. G.  Hays, K. Hoshino, T. J. Minello, R. J. Orth, P. F. Sheridan, M. P. Weinstein. 2003. The role of nearshore ecosystems as fish and shellfish nurseries.  Issues in Ecology 11:1-12.
• van Montfrans, J., C. H. Ryer, and R. J. Orth. 2003. Substrate selection by blue crab, Callinectes sapidus, megalopae and first juvenile instars. Marine Ecology Progress Series 260:209-217.
• Heck, K. L., Jr., C. Hays, and R. J. Orth. 2003. A Critical Evaluation of the Nursery Role Hypothesis for Seagrass Meadows. Mar. Ecol. Prog. Ser. 253:123-136.
• Koch, E. W. and R. J. Orth. 2003.  Seagrasses of the Mid-Atlantic coast of the USA.  Pp 216-223. In: E. P. Green and F. T. Short. World Atlas of Seagrasses.  Prepared by the UNEP World Conservation Monitoring Centre.  University of California Press, Berkeley, CA.  324pp.
• Orth, R. J., J. R. Fishman, M. C. Harwell, and S. R. Marion. 2003.  Seed density effects on germination and initial seedling establishment in eelgrass, Zostera marina, in the Chesapeake Bay region. Mar. Ecol. Prog. Ser. 250:71-79.
• Orth, R. J., R. A. Batiuk, P. W. Bergstrom, and K. A. Moore. 2002. A perspective on two decades of policies and regulations influencing the protection and restoration of submerged aquatic vegetation in Chesapeake Bay, USA. Bulletin of Marine Science 71:1391-1403.
• Orth, R. J., K. L. Heck, Jr., and D. J.Tunbridge. 2002. Predation on seeds of the seagrass Posidonia australis in Western Australia. Mar. Ecol. Prog. Ser. 244:81-88.
• Harwell, M. C. and R. J. Orth. 2002. Long distance dispersal potential in a marine macrophyte. Ecology 83:3319-3330.
• Harwell, M. C. and R. J. Orth. 2002. Seed bank patterns in Chesapeake Bay eelgrass (Zostera marina L.): A baywide perspective. Estuaries 25:1196-1204.
• Orth, R. J., J. R. Fishman, D. J. Wilcox, and K. A. Moore. 2002. Identification and management of fishing gear impacts in a recovering seagrass system in the coastal bays of the Delmarva Peninsula, USA. J. Coastal Research Spec. Iss. No. 37:111-129.
• Ralph, P., J., S. M. Polk, K. A. Moore, R. J. Orth, W. O. Smith, Jr. 2002. Operation of the xanthophyll cycle in the seagrass Zostera marina in response to variable irradiance. J. Exp. Mar. Biol. Ecol. 271:189-207.
• Orth, R. J. and J. van Montfrans. 2002. Habitat quality and prey size as determinants of postlarval and early juvenile instar blue crab survival. Marine Ecology Progress Series 231:205-213.
• Parker, J. D., J. E. Duffy, and R. J. Orth. 2001. Plant species diversity and composition: experimental effects on marine epifaunal assemblages Marine Ecology Progress Series 224:55-67.
• Beck, M.W., K. L. Heck, K. Able, D. Childers, D. Eggleston, B. Gilanders, B. Halpern, C, Hays, K. Hoshino, T. Minello, R. Orth, P. Sheridan, M. Weinstein. 2001. Towards better identification, conservation, and management of estuarine and marine nurseries for fish and invertebrates. Bioscience 51:633-641.
• Patterson, M. C., M. C. Harwell, L. M. Orth,  and R. J. Orth. 2001.  Biomechanical properties of eelgrass (Zostera marina L.) reproductive shoots: Breaking stress, breaking strain, toughness, and elastic modulus.  Aquat. Bot. 69:27-40.
• Harwell, M.C. and R. J. Orth. 2001. Influence of a tube-dwelling polycaete on the dispersal of fragmented reproductive shoots of eelgrass. Aquat. Bot. 70:1-8.
• Wilcox, D.J., M. C. Harwell, and R. J. Orth. 2000. Modelling dynamic polygon objects in space and time: a new graph-based technique.  Cartography and Geographic Information Systems 27:153-164.
• Orth, R. J., M. C. Harwell, E. M. Bailey, A. Bartholomew, J. T. Jawad, A. V. Lombana,  K. A. Moore, J. M. Rhode, H. E. Woods. 2000. A review of issues in seagrass seed dormancy and germination:  Implications for conversation and restoration. Mar. Ecol. Prog. Ser. 200:277-288.
• Moore, K. A., D. J. Wilcox, and R. J. Orth. 2000. Analysis of the abundance of submersed aquatic vegetation communities in the Chesapeake Bay. Est. 23:115-127.
• Orth, R. J., M. C. Harwell, and J. R. Fishman. 1999. A rapid and simple method for transplanting eelgrass using single, unanchored shoots. Aquatic Botany 64:77-85.
• Harwell, M.C. And R. J. Orth. 1999. Eelgrass (Zostera marina L.) seed protection for field experiments and implications for large scale restoration. Aquatic Botany 64:51-61.
• Pardieck, R. A., R. J. Orth, R.J. Diaz, and R.N. Lipcius. 1999. Ontogenetic changes in habitat use by postlarvae and young juveniles of the blue crab. Marine Ecology Progress Series 186:227-238.
• Luckenbach, M. L. and R. J. Orth. 1999. Effects of a deposit-feeding invertebrate on the entrapment of Zostera marina L. seeds. Aquatic Botany 62:235-247.
• Orth, R. J. 1999. Settling rates of Posidonia coriacea seeds and Posidonia spp. seedling abundance off Rottnest Island, Perth, Western Australia. Pp 51-61. In: D. I. Walker and F. E. Wells (eds). The Seagrass Flora and Fauna of Rottnest Island, Western Australia. Western Australia Museum, Perth.
• Williams, S. L. and R. J. Orth. 1998. Genetic diversity of natural and transplanted eelgrass populations in the Chesapeake and Chincoteague Bays. Estuaries 21:118-128.
• Moore, K. A., R. L. Wetzel, and R. J. Orth. 1997. Seasonal pulses of turbidity and their relations to eelgrass (Zostera marina L.) survival in an estuary. Journal of Experimental Marine Biology and Ecology 215:115-134.
• Moore, K. A., H. A. Neckles, and R. J. Orth. 1996. Zostera marina L. (eelgrass) growth and survival along a gradient of nutrients and turbidity in the lower Chesapeake Bay. Marine Ecology Progress Series 142:247-259.
• Pile, A. J., R. N. Lipcius, J. van Montfrans, and R. J. Orth. 1996. Density-dependent settler recruit-juvenile relationships in blue crabs. Ecological Monographs 66:277-300.
• Fishman, J. R. and R. J. Orth. 1996. Effects of predation on Zostera marina seed abundance. Journal of Experimental Marine Biology Ecology. 198:11-26.
• Orth, R. J., J. van Montfrans, R. N. Lipcius, and K. S. Metcalf. 1996. Utilization of seagrass habitat by the blue crab, Callinectes sapidus Rathbun, in Chesapeake Bay: A review. In: Seagrass Biology: Proc. of an Internat. Workshop. Rottnest Island, Western Australia. J. Kuo, R. C. Phillips, D. I. Walker, and H. Kirkman (eds.). Western Australian Museum, Perth. 
• Moore, K. A., H. A. Neckles, and R. J. Orth. 1996. Zostera marina L. Growth and survival along a gradient of nutrients and turbidity in the lower Chesapeake Bay. Marine Ecology Progress Series 142:247-259. 
• Orth, R. J., M. W. Luckenbach, and K. A. Moore. 1994. Seed dispersal in a marine macrophyte: Implications for colonization and restoration. Ecology, 75:1927-1939. 
• Neckles, H. A., R. L. Wetzel, and R. J. Orth. 1993. Relative effects of nutrient enrichment and grazing on epiphyton-macrophyte (Zostera marina L.) dynamics. Oecologia 93:285-295 
• Dennison, W. C., R. J. Orth, K. A. Moore, J. C. Stevenson, V. Carter, S. Kollar, P. Bergstrom, and R. Batiuk. 1993. Assessing water quality with submersed aquatic vegetation. Bioscience 43:86-94. 
• Moore, K. A., R. J. Orth, and J. F. Nowak. 1993. Environmental regulation of seed germination in Zostera marina L. (Eelgrass) in Chesapeake Bay: Effects of light, oxygen and sediment burial depth. Aquatic Botany 45:79-91.

Past Students

• Scott Marion, M.S. Student, awarded 2002., Effects of habitat fragmentation on the utilization of eelgrass habitat by mobile epifauna and macrofauna
• Helen Woods, M.S. awarded 2001, An examination of potential conflicts between SAV and hard clam aquaculture in the lower Chesapeake Bay (co-major professor with C. Hershner)
• Matt Harwell, Ph.D. awarded 2000, Spatial analysis of ecological dispersal mechanisms and patch dynamics of SAV in Chesapeake Bay.
• Al Lombana, M.S. awarded 1999
• John Parker, M.S. awarded 1998

Courses Taught

• MS 656:  Seagrass Ecosystems (with Ken Moore)

Professional Memberships

• American Society of Limnology and Oceanography (ASLO)
• Estuarine Research Federation (ERF)