Structure of gray whale calls of San Ignacio lagoon and their distribution in the water column. 260 pp.Īnaid Lopez-Urbán, Aaron Thode, Carmen Bazúa-Durán, Melania Guerrera, and Jorge Urbán-Ramírez. Master of Science Thesis, University of San Diego, San Diego, California. Development of Sound Production in the Gray Whale (Eschrichtius robustus). The Gray Whale, Eschrichtius robustus, Academic Press, Orlando. In: Jones, M.L., Swartz, S.L., and Leatherwood,S., editors. Sound production by the gray whale and ambient noise levels in Laguna San Ignacio, Baja California Sur, Mexico. To learn more about the acoustics program at Laguna San Ignacio, please visit our “Acoustics Program” blogs in the “Research” section on this website. You can also use a pair of good quality headphones to accurately hear these recordings on a computer.īelow are some publications on the findings of acoustic research in Laguna San Ignacio. Many of these recording are of low frequency sounds, and they are best heard on a computer sound system that has a wide frequency response including the lower frequencies. Each example includes a brief description of the recorded sound, a “spectrogram” or picture showing the frequency of the sounds over the time, and an audio recording in MP3 format that you can play to hear the sounds. There are also examples of the sounds produced by whale-watching and fishing boats that operate in the lagoon. There are examples of sounds from gray whales, fish, invertebrates, the wind, rain, and the tides. In this “Acoustic Gallery” you may select and listen to examples of the sounds recorded in the lagoon, and learn about what the researchers have discovered about their frequency, intensity, and diversity within Laguna San Ignacio during the winter months. All of these recordings have documented the diversity of sounds in the lagoon and their seasonal trends. Researchers have also recorded and monitored the presence and numbers of fishing and whale-watching boats that operate in the lagoon. Also the sounds of invertebrates like “snapping shrimp”, fish, and of course the vocalizations of gray whales during the winter. Our acoustic researchers have documented the sounds of wind, rain, and the changing tides in the lagoon. Another method is to use a “hydrophone” or underwater microphone to record sounds from a boat drifting in the lagoon, or attached to a whale with suction-cups. The primary method for monitoring and recording underwater sounds in Laguna San Ignacio is to place digital recording devices on the bottom of the lagoon in specific areas, and to record the underwater sounds for a month or more each winter. Special thanks to Kerri Seger and Ludovic Tenorio Hallé for their help preparing this review of the sounds of Laguna San Ignacio. Since the program began in 2005, recordings and descriptions of gray whale sounds from Laguna San Ignacio were published by LSIESP researchers Anaid López Urbán (López et. The goal of the acoustics research program is to document the numerous sources of underwater sound in the lagoon, including gray whale sounds, and to monitor those sources of sound over time to identify trends and changes in physical, biological and man-made noise in the lagoon. Thode and his graduate researchers are continuing these on going investigations today. Aaron Thode of Scripps Institution of Oceanography at the University of California in San Diego, California began investigations of the underwater sounds and noise in Laguna San Ignacio in 2005. Dr. In 1999 Sheyna Wisdom recorded the sounds produced by gray whale females and their calves as part of research for her Master’s Degree at the University of San Diego (Wisdom 2000).ĭr. The first recordings of gray whale calls and other underwater sounds in Laguna San Ignacio were made by Marylin Dahlheim during the 1980s, and she published descriptions of six major sounds types or “calls” (Dahlheim et.
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