Who We Are

Dr. John Ehrenberg, President
John has been a Senior Hydroacoustic Engineer for HTI since 1990. He received a BS in Electrical Engineering (1966) from Seattle University, a MS in Electrical Engineering from Massachusetts Institute of Technology (1968), and a PhD from University of Washington (1973). Dr. Ehrenberg has nearly 40 years experience in fisheries acoustics. From 1973 to 1983 he was a research professor in Electrical Engineering and a principal research engineer at the University of Washington Applied Physics Laboratory. While at the University, Dr Ehrenberg developed both the dual-beam and split beam techniques for extracting fish target strength from acoustic echoes. From 1983 to 1986 he was Vice-President of Hydroacoustics at BioSonics, Inc. For HTI, Dr. Ehrenberg conducts equipment and software design and implementation, and advises on consulting projects. He has authored nearly 50 publications and technical reports on fisheries acoustics, underwater acoustics and signal processing, and has taught short courses on fisheries acoustics, underwater acoustics and signal processing for 35 years.

Samuel Johnston, Project Manager
Sam has been a Senior Fisheries Biologist with HTI since 1989, and has 28 years of experience in fisheries acoustics. He manages evaluations of migratory fish in rivers, mobile surveys in lakes, hydropower relicensing projects, and co-directs software development. After receiving a BS in Fisheries from Humboldt State University (1980), he served as fisheries biologist with Oregon Dept. of Fish and Wildlife and California Dept. of Fish and Game from 1980 to 1982. Mr. Johnston was a Senior Scientist with BioSonics, Inc. from 1982 to 1989, where he managed numerous hydroacoustic fisheries studies. At HTI Mr. Johnston serves as Project Manager for acoustic tag and hydroacoustic evaluations of smolt entrainment at dams on the Columbia River, and hydroacoustically counts fish in open rivers in Alaska and California. He has over 28 years of experience collecting and analyzing hydroacoustic and acoustic tag data on salmonid migrants at dams on the Columbia and Snake rivers. Mr. Johnston has authored over 50 publications and technical reports on fisheries acoustics, and has taught short courses on fisheries acoustics for 20 years.

Patrick Nealson, Sr. Fisheries Biologist, VP of Consulting
Pat has been a Senior Fisheries Biologist at HTI since 1992, and currently serves as the Director of the Consulting Division. Pat has 28 years of experience conducting and managing hydroacoustic and acoustic tag evaluations of fish populations in a wide range of environments. His past experience includes numerous studies of fish passage at hydropower dams, hydroacoustic evaluations of migratory fish in open river environments, lake and coastal fish population surveys, and large-scale marine assessments. Mr. Nealson has a BS (1981)and a MS Degree (2007) in Fisheries Biology from the University of Washington. He has authored over 90 publications and technical reports describing acoustic tag and hydroacoustic assessment techniques and study results; and has taught fisheries acoustics short courses for over 20 years.

Bruce Ransom, Senior Fisheries Biologist & VP Program Director
Bruce has 31 years of fisheries experience, 28 years of that as hydroacoustic research experience, and 22 years of that at HTI. As Vice President and Program Manager for HTI, he is responsible for acoustic tag and hydroacoustic evaluations of fish distributions and migrational characteristics at hydropower dams, in rivers, in lakes, and at sea worldwide. The majority of his career has been spent managing and conducting hydroacoustic studies of fish passage at hydropower dams, including evaluations required for Federal Energy Regulatory Commission (FERC) relicensing of hydropower projects, and studies of methods of safely bypassing fish past turbine units. Other studies include evaluations of adult salmon escapement, and marine fisheries stock assessments. Mr. Ransom also oversees management of development and manufacturing of research grade acoustic tag and hydroacoustic equipment. He received a BA in English (1973) and BS in Fisheries (1979) from University of Washington. He has authored over 100 publications and technical reports on fisheries acoustics, and has taught short courses on acoustic tag and hydroacoustic fisheries techniques for over 20 years.

Tracey Steig, VP, Hydroacoustic Engineer
Tracey has been a Senior Hydroacoustic Engineer at HTI since 1988. Mr. Steig has 28 years experience conducting and managing hydroacoustic and acoustic tag evaluations at Columbia River hydropower dams, in open rivers, and in lakes and reservoirs worldwide. He has conducted hydroacoustic or acoustic tag studies at Rocky Reach and/or Rock Island dams for Chelan Co. PUD nearly annually since 1982. He received a BS (1978) and MS (1980) in Civil Engineering from the University of Washington. From 1978 to 1981 he was a research engineer at the University of Washington. Mr. Steig was a Senior Scientist at BioSonics, Inc. from 1982 to 1988, managing numerous domestic and international hydroacoustic projects using both fixed-location and mobile survey techniques. He has authored over 100 publications and technical reports on fisheries acoustics, and has taught acoustic tag and fisheries acoustics short courses for 20 years.

Troy Braswell, Database Specialist
Troy joined HTI in 2006 bringing over 20 years of Information Technology experience in different disciplines including software development, database development, and web application design. At HTI, he develops database systems and report generating tools for the acoustic tag and hydroacoustic evaluations at Columbia River hydropower dams. Troy received a B.S. degree in Computer Science from Cal State University of San Bernardino.

Kevin Kumagai, Senior Fisheries Biologist
Kevin began at HTI in 1993 as a Fisheries Biologist. He conducts acoustic tag and hydroacoustic evaluations for HTI at Columbia River hydropower dams and elsewhere. Mr. Kumagai has over 13 years experience conducting fisheries evaluations with hydroacoustic and acoustic tag techniques worldwide in open rivers, at hydropower dams, and in lakes and reservoirs. He conducts acoustic tag or hydroacoustic studies at Wanapum, Priest Rapids, Rocky Reach, Rock Island dams, in central California's Sacramento-San Joaquin River Delta, among other locations. Mr. Kumagai received a BS in Wildlife and Fisheries Biology from the University of California, Davis (1987). From 1986 to 1993 he worked for the University of Washington, University of California, Parametrix, Inc, and other organizations. He has authored over 20 technical reports on projects using acoustic tag and hydroacoustic techniques, and teaches short courses on fisheries acoustics.

Brian McFadden, Senior Fisheries Biologist
Brian began working with HTI as a Fisheries Biologist in 2004, applying hydroacoustic techniques he has studied since 1985. He conducts hydroacoustic evaluations at Columbia River hydropower dams and elsewhere. Brian has over 25 years experience conducting data collection and analysis for open river, hydropower dam, and lake and reservoir projects. He has authored several technical reports on fisheries acoustics. Brian received a BS in Zoology from the University of Alberta (1981) and MS in Natural Resources Fisheries from Humboldt State University (1987). Mr. McFadden was a Fisheries Biologist at BioSonics, Inc. from 1987 to 2004, conducting numerous hydroacoustic projects using fixed-location techniques. Since 2005 he has been a Fisheries Biologist with HTI.

Chris Mott, Fisheries Biologist
Chris began working for HTI in 2002 assisting in acoustic tag and hydroacoustic evaluations on the Columbia River. He has experience in data collection and analysis on hyrdroelectric dams in the Pacific Northwest as well as several mobile river surveys on Rupert River in Quebec. Chris is responsible for aspects of acoustic tag and hydroacoustic evaluations of fish distributions, bypass effectiveness, behavior, and migrational characteristics at hydropower dams on the Columbia River. He also creates 3D fish track animations from data and further data analysis. Chris is highly skilled at conveying patterns of fish behavior in an intuitive manner. He received a BA in Marine Science from the University of Hawai‘i at Hilo.

Colleen Sullivan, Senior Fisheries Biologist
Colleen joined HTI in 2009 bringing with her over 20 years of project management experience. Before coming to HTI, Ms. Sullivan was Senior Scientist at BioSonics through 2003 and worked under contract to the US Bureau of Reclamation through 2008. She specializes in study design, data collection and analysis and report preparation. She has 29 years of experience collecting and analyzing hydroacoustic data. She has authored several publications and taught short courses on hydroacoustics. Her primary responsibilities also include technical proposal and grant application development. She received a BS in Fisheries from the University of Washington (1981) and has completed requirements for the professional Project Management (PMP) certification.

Cherylyn (Chez) Tunnicliffe, Fisheries Biologist
Cherylyn joined HTI in 2009. Since 2004 she has been involved in fish passage studies, toxicology and habitat evaluation throughout the Pacific Northwest. She also has experience conducting studies in the Irish Sea and Yangtze River. She is responsible for aspects of acoustic tag and hydroacoustic evaluations of fish distributions, bypass effectiveness, behavior, and migrational characteristics at hydropower dams on the Columbia River. She graduated in 2004 from University of Wales, Aberystwyth with a Bsc(Hons) in Marine and Freshwater Biology. Cherylyn has worked for Pacific Northwest National Laboratory and Washington Dept. of Fish and Wildlife.

Caroline Mercado, Director
Caroline joined HTI in 2004. She is responsible for media, events, and all things creative. Her primary role manages media (television, web, print, social) and international events (training, conferences, and workshops). Most recently, she worked with the socials committee for the American Fisheries Society (AFS) Annual Conference, in addition to hosting Fish Fest! for HTI at the Seattle Aquarium. Both events had record breaking attendance with 4,300 attendees at AFS and 3,000+ attendees at Fish Fest! Her career began in graphic design and later developed into directing various national and international marketing efforts. She is an active member of the AFS, Association of Environmental Professionals, and is a big fan of Surfrider Foundation. She received her BA as well as an Integrated Marketing Communications Certificate from University of Washington and a Business Administration certificate from University of London. She's currently enrolled in a masters certificate program at the University of San Francisco that concludes late 2011.

Janardhana (Jani) Dikkala, Senior Software Engineer
Jani joined HTI in 2007 as software engineer. He develops drivers for acoustic tags, sonar systems and other electronics for specifically used for advanced fisheries research. Also, he is responsible of integrating tag application software on different versions of Windows CE platforms. He has been involved in the software industry for over 18 years. He has worked for over 12 years with the Windows CE operating system, aside from working on other operating systems such as Unix and pSOS. He received his Bachelors of Science degree and his Masters in Computers from Andhra University.

Anthony (Tony) Johnson, P.E., Chief Engineer
Tony came to HTI in 2000, since then he has managed the design, development, and testing of HTI hydroacoustic and acoustic tag systems. He also assists with deployment and testing for evaluations at Columbia River hydropower dams, at Sacramento River locations in California, and elsewhere. He received a BS (1982) and MS (1998) in Electrical Engineering from the University of Washington. He has worked with Universal Avionics Systems Corporation, Kistler-Morse, John Fluke Manufacturing, and the University of Washington Applied Physics Laboratory.

Bob Kapinos, Manufacturing Manager
Bob has been involved in the design and manufacture of a variety of electronic, acoustic, and medical devices over the last thirty plus years. He graduated from the University of Washington (1970) with a BS degree in Materials Engineering. He brings a broad-based background in product introduction, production control, materials management, and business systems design. He has been involved in the design and manufacture of products ranging from implantable intraocular lenses and in-vivo blood gas sensors to professional sound mixers and defibrillators. He oversees all manufacturing, servicing, and testing of HTI equipment.

Christopher Odum, Senior Technician
Chris joined HTI in 2003 where he has been responsible for the build, test, repair, and calibration of all acoustic tag and hydroacoustic equipment. He oversees new product development, documentation and transition to manufacturing. Chris also provides customer support for training and in-field troubleshooting.
He obtained a BS in Oceanography (2003) from the University of Washington. Chris was trained in Electronics and Satellite Communications through the US Navy (1989-1995).

Steve Schuler, Information Systems Manager
Steve joined HTI in 2005. Bringing over 15 years experience in I.T., he maintains and supports 100 User Network, including several remote Project sites (average 30 employees each site). He maintains between 50 and 100 Workstations all running Windows XP/Vista/W7. Maintain WAN (Wide Area Network) for 3 remote sites, including firewall configuration and updates + VPN tunnel. Also, deployed and configured satellite systems for remote data collection/retrieval for data processing.

Executive Staff

Fisheries Consultants

Conferences, Symposia, Publications + Creative

Software Development

Engineering