The Nai'a Kuwili Project is a long-term study of spinner dolphins (Stenella longirostris) resident along the inshore waters of Oahu. The project's goals are to decipher the behavior and ecology of this species and determine the effects of human interactions on local populations and their habitat. Current research efforts are focued on the acoustic behavior of these animals. This represents an effort to gain a deeper understanding of their complex social structure and sensory biology. A secondary focus is on the spinner dolphin's use of the near-shore habitat. The movements and behavioral patterns of dolphin groups are recorded and quantified to better understand the dynamics of resident populations. Most of the work for the Nai'a Kuwili project is conducted aboard the vessel Meleana, a 32' motor boat. Fundraising activities for the project are ongoing.

An important aspect of the Nai'a Kuwili Project has been to develop new tools for the investigation of dolphin signaling and behavior. Two of the tools recently developed are the Underwater Dolphin Data Acquisition System (UDDAS) and 4-channel UDDAS. These systems are diver operated digital video/broadband acoustic recorders that have the ability to record simultaneous video and acoustic signals up to 200 kHz. This is a vast improvement over the traditional audio (< 20 kHz) limits of conventional recorders, considering that most dolphin species produce signals that are ultrasonic (i.e., above the human frequency hearing range). These systems are being used in Hawaii to study spinner dolphins, as well as in the Bahamas in collaboration with Dr. Denise Herzing of the Wild Dolphin Project (WDP) to study spotted dolphins (Stenella frontalis). The Nai'a Kuwili Project has worked in collaboration with WDP since 1999 in order to establish a comparative perspective on behavior with a different species.

SPLASH

SPLASH (Structure of Populations, Levels of Abundance and Status of Humpback Whales) is an international cooperative effort to understand the population structure of humpback whales (Megaptera novaeangliae) across the North Pacific, and to assess the status, trends and potential human impacts to this population. As part of this effort, OSI has been contracted by the Hawaiian Islands Humpback Whale National Marine Sanctuary (HIHWNMS) to survey humpback whales occurring off the island of Oahu. OSI is building a database of the whales visiting Oahu by employing photo identification and tissue sampling techniques that yield a unique record of each whale. These data are then shared with other SPLASH researchers to develop a comprehensive understanding of the aboundance, movements and associations of humpback whales throughout the North Pacific. A SPLASH fact sheet is availableby clicking here.

To listen to the December 15, 2004 Hawaii Public Radio interview click here.

Whale/Vessel Collision Study

As the North Pacific humpback whale population continues to recover from past decades of whaling there is a concern that whales and boats/ships will increasingly finding themselves on a collision course. To address this concern, the Hawaiian Islands Humpback Whale National Marine Sanctuary (HIHWNMS) is examining this issue and organizing an outreach campaign to inform and sensitize local vessel operators. OSI is an active contributor in this effort and recently completed an assessment of the incidence of whale/vessel collisions in Hawaiian waters over the past three decades. Download the final report (320 kb)

Publications and Reports:

Lammers, M.O., Brainard, R.E. and Au, W.W.L (2006). “Diel trends in the mesopelagic biomass community of the Northwestern Hawaiian Islands observed acoustically”. Atoll Research Bulletin, 543:391-407. Download PDF (1,816 kb)

Rasmussen M.H., Lammers M.O., Beedholm K. and Miller L.A. (2006). “Source levels and directionality of white-beaked dolphin (Lagenorhynchus albirostris) whistles”. J. Acoust. Soc. Am. 120:510-517. Download PDF (330 kb)

Au, W. W. L., Pack, A.A., Lammers, M.O., Herman, L.M., Deakos, M. and Andrews, K. (2006). “Acoustic properties of humpback whale song”. J. Acoust. Soc. Am. 120:1103-1110. Dowload PDF (618 kb)

Au, W. W. L. and Lammers, M.O. (2006). “Cetacean acoustics” In: Handbook of Acoustics. Ed. T. Rossing. Springer-Verlang. 1000p

Lammers, M.O., Schotten, M., and Au, W.W.L (2006). "The spatial context of free-ranging Hawaiian spinner dolphins (Stenella longirostris) producing acoustic signals" J. Acoust. Soc. Am. 119(2):1244-1250. Download PDF (320 kb)

Lammers, M.O. (2004). “Occurrence and behavior of Hawaiian spinner dolphins (Stenella longirostris) along Oahu’s leeward and south shores.” Aqua. Mamm. 30:237-250. Download PDF (1,347 kb)

Lammers, M.O., Au, W.W.L., Aubauer, R., and Nachtigall P. (2004). "A comparative analysis of echolocation and burst-pulse click trains in Stenella longirostris." Echolocation in Bats and Dolphins. Eds. Thomas, J., Moss, C. & Vater, M. University of Chicago Press. pp. 414-419. Download PDF (2,374 kb)

Schotten, M., Au, W. W. L., Lammers M. O., and Aubauer R. (2004). "Echolocation recordings and localizations of wild spinner dolphins (Stenella longirostris) and pantropical spotted dolphins (Stenella attenuata) using a four hydrophone array." Echolocation in Bats and Dolphins. Eds. Thomas, J., Moss, C. & Vater, M. University of Chicago Press. pp. 393-400.

Lammers, M.O., Au, W.W.L and Herzing, D.L. (2003). "The broadband social acoustic signaling behavior of spinner and spotted dolphins." J. Acoust. Soc. Am. 114(3):1629-1639. Download PDF (1,229 kb)

Lammers, M.O., Pack A.A. and Davis L. (2003). "Historical evidence of whale/vessel collisions in Hawaiian waters (1975 - Present)" OSI Technical Report 2003-01. Prepared for NOAA's Hawaiian Island Humpback Whale National Marine Sanctuary. Download PDF (320 kb)

Lammers M.O. and Au W.W.L. (2003). "Directionality in the whistles of Hawaiian spinner dolphins (Stenella longirostris): A signal feature to cue direction of movement?" Mar. Mamm. Sci. 19(2):249-263. Download PDF (162 kb)

Lammers, M.O., Albinsson, L., Benoit-Bird, K. and Davis, L. (2001). "The occurrence and behavior of whales and dolphins near Kalaeloa Barbers Point Harbor: A study to assess the potential interactions with proposed harbor modification activities." OSI Technical Report 2001-01. Prepared for the Hawaii State Department of Transportation - Harbors Division. Download PDF (998 kb)

Benoit-Bird, K.J., Au, W.W.L., Brainard, R.E. and Lammers, M.O. (2001). "Diel horizontal migration of the Hawaiian mesopelagic boundary community observed acoustically." Mar. Ecol. Prog. Ser. 217:1-14.

Lammers, M.O., W.W.L. Au, and D. Feinholz (2000). "The occurrence and distribution of marine mammals along Oahu's Ewa/Honolulu coast: a study to assess the potential interactions between high-speed ferry traffic and local populations." MMRP/HIMB Technical Report 20001. Prepared for Pacific Marine & Supply Co., LTD.Download PDF (587 kb)

Au, W. W. L., Mobley, J., Burgess, W. C., Lammers, M. O., Nachtigall, P. E. (2000). "Seasonal and diurnal trends of chorusing humpback whales wintering in waters off west Maui." Mar. Mamm. Sci. 16(3):530-544.

Aubauer, R., Lammers, M. O. and Au, W. W. L. (2000). "One-hydrophone method of estimating distance and depth of phonating dolphins in shallow water." J. Acoust. Soc. Am. 107(5):2744-749. Download PDF (100 kb)

Au, W. W. L., Lammers, M. O. and Aubauer, R. (1999). "A Portable Broadband Data Acquisition System for field studies in bioacoustics," Mar. Mamm. Sci. 15(2):526-531.

All research and photographs of dolphins were conducted/obtained under NMFS General Letter of Authorization No.11 and No.707-1478.