Use of the Jolly-Seber model to estimate trends in population size of bottlenose dolphins (Tursiops truncatus) occupying Boca Ciega Bay, Florda
Allen JB. 2001. Use of the Jolly-Seber model to estimate trends in population size of bottlenose dolphins (Tursiops truncatus) occupying Boca Ciega Bay, Florda. Eckerd College
Between June 1993 and August 2000, the Eckerd College Dolphin Project conducted ad libitum surveys of bottlenose dolphins, Tursiops truncatus, in Boca Ciega Bay, Florida, and its peripheral waters. Photographic analysis of dorsal fins demonstrated that at least 510 individuals were observed during 314 surveys conducted during the summer months. Mark-resight analysis using a Jolly-Seber model for open populations, assuming immigration and emigration, provided the following population size estimates: 1994--213 dolphins (95 pecent CI equals 145-281); 1995--294 dolphins (95 percent CI equals 245-343); 1998--413 dolphins (95 percent CI equals 349-477); 1999--286 dolphins (95 percent CI equals 246-327). These estimates show temporal variations in the number of dolphins that utilize this area. Such variations may be associated with environmental changes such as an increase in some inshore fish stocks, a recent (1996-1999) decline in sea grass coverage in Boca Ciega Bay, and a steady increase in the number of commercial dolphin watching programs. My results suggest that local bottlenose dolphin population sizes can change relatively quickly and reinforces the need for regular assessment of dolphin populations occupying coastal and inshore waters where combinations of human and natural factors can alter habitat quality, and thereby, the population status of bottlenose dolphins, quickly. Abstract provided by author.
- Type
- Academic
- Authors
- Allen, Jason
- Date of Issue
- 2001-05-20
- Publisher
- Eckerd College
- Units
- BUIS
- Keywords
- Boca Ciega Bay, Bottlenose dolphins, Ecology, Habitat, Habitat quality, Human Impact, Jolly-Seber model, Population, Population Dynamics, Population Size, Thesis, Tursiops truncatus