Jeff’s experience in transportation-related environmental impact analysis meets NEPA and the Federal Highway Administration’s regulations. He uses this experience to lead TYLin’s environmental efforts across all segments of our Transportation and Water Sectors. Clearly passionate about protecting the environment, Jeff has a focused interest on sea-level rise impacts to coastal tropical ecosystems. He believes in designing living shorelines with resilience to changing water levels and salinity regimes.

Jeff is a strong advocate of empowering others to fulfill and expand their potential in career growth opportunities.

Professional affiliations:

• Freshwater Biological Association (England)
• The Explorers Club, South Florida Chapter
• South Florida Association of Environmental Professionals (Past President)

Areas of expertise: 

• Freshwater and marine ecology/ coastal and wetland permitting
• Wetland restoration and enhancement
• Environmental assessments and impact statements

Publications and presentations: 

• Marcus, J.H. and L.G. Willoughby. 1978. Fungi as food for the aquatic invertebrate Asellus aquaticus. Trans. Br. Mycol. Soc. 70:143-146.
• Marcus, J.H., D.W. Sutcliffe and LG. Willoughby. 1978. Feeding and growth of Asellus aquaticus (Isopoda) on food items from the littora1 of Windermere, including green leaves of Elodea canadensis. Freshwater Biol. 8:505-519.
• Willoughby, L.G. and J.H. Marcus.1979. Feeding and growth of the isopod Asellus aquaticus on actinomycetes, considered as model filamentous bacteria. Freshwater Biol. 9:441-449.
• Marcus, J.H. 1980. Laboratory experiments on growth and reproduction of Asellus aquaticus (Crustacea: Isopoda) from development in the brood pouch to death. Florida Scientist, 43(l):6 (presented at Florida Academy of Sciences, Tampa, Florida - March 1980).
• Marcus, J.H. and A. Thorhaug.1980. Effect of Ocean Thermal Energy Conversion (OTEC) plants on growth and survival of attached macroalgae. Proc. Assoc.Is. Mar. Labs. Carib.15:20 (presented in Jamaica - 1980).
• Marcus, J.H. and A. Thorhaug. 1980. Macrofouling problems associated with Ocean Therma Energy Conversion (OTEC) units. IN Proceedings of the Fifth International Congress on Marine Corrosion and Fouling, Barcelona, Spain. May 1980, pp.225-230 (presented in Barcelona - May 1979).
• Thorhaug, A. and J.H. Marcus. 1980. Potential artificial reefs created by the presence of Ocean Thermal Energy Conversion (OTEC) plants. Florida Scientist, 43(1):6 (presented at Florida Academy of Sciences, Tampa, Florida - March 1980).
• Marcus, J.H. and A. Thorhaug. 1981. Comparison of sublethal and lethal effects of temperature, salinity, and light on finger coral (Porites spp.) from the Florida Keys and Hawaii. Florida Scientist, 44 (1):15 (presented at Florida Academy of Science, Orlando, Florida - April 1981).
• Marcus, J.H. and A. Thorhaug. 1981. Pacific versus Atlantic responses of the subtropical coral Porites spp. to temperature and salinity effects. IN Proc. IV International Coral Reef Symposium, Manilla, Philippines, Vol. 2:15-20.
• Marcus, J.H. and A. Thorhaug. 1981. Lethal and sublethal effects on seagrass seedings Thalassia testudinum, created by 1ight, salinity and temperature. Bot. Soc. America, Pub.160, p.51(presented the American Botanical Society, Bloomington, Indiana - August 1981.
• Thorhaug, A. and J.H. Marcus. 1981. The effects of temperature and light on attached forms of macro algae potentially associated with OTEC (OceanTherma1Energy Conversion) machine operation. Botanica Marina, 24:393-398.
• Marcus, J.H. and A. Thorhaug. 1981. Comparative investigation of tropical nearshore ecosystem's tolerance to temperature, salinity, and light. Bulletin of Eco 1. Society of America 62(2):115 (presented at Ecological Soc. of America, Bloomington Indiana - August 1981).
• Willoughby, L.G. and J.H. Marcus. 1981. Aquatic fungi and actinomycetes as foods for freshwater crustacea. Keiler Meereshforsh, Sonderh. 5,433.
• Marcus, J.H. 1982. Feeding and growth of Asellus aquaticus (Crustacea: Isopoda) on green plan tissue in the English Lake District. Florida Scientist, 45 (1):29.
• Marcus, J.H 1984. Classroom of Coral. Skin Diver Magazine, December issue. Pp 69-70.
• Thorhaug, A and J.H. Marcus. 1985. Cleaning Up Oil Spills. The Siren-UNEP's Regional Seas Programmer. No. 29, pp 36-38.
• Thorhaug, A and J.H. Marcus. 1986. Oil and dispersed oil on subtropical and tropical seagrasses in laboratory studies. Marine Pollution Bulletin, 17 (8):357-361
• Thorhaug, A. and J.H. Marcus. 1987. Oil Spill Clean-up: The effect of three dispersants on three subtropical/tropical seagrasses. Marine Pollution Bulletin, Vol. 18, No.3, pp 124-126.