Abundance of bottlenose dolphins in Corpus Christi Bay and coastal southern Texas.

Date

1983

Authors

Leatherwood, S.
Reeves, R.R.

Journal Title

Journal ISSN

Volume Title

Publisher

Abstract

Aerial survey sightings were used to estimate the number of bottlenose dolphins (Tursiops truncatus) present in coastal waters between Aransas Pass and Brownsville, Texas, from 21 to 30 September 1979. Using line-transect methods, the populations in Corpus Christi Bay and in the coastal Gulf of Mexico were estimated, with 95% confidence limits, as 103.4 (67.3, 139.5) and 300.5 (226.6, 374.4), respectively. Average counts of dolphins actually observed in the major passes were 29.3 (Aransas), 17.7 (Mansfield), and 32.4 (Brazos Santiago). Shore observers stationed at the three passes provided data concerning herd size and numbers of dolphins present that were in good agreement with the aerial data. The total population in the study area at the time of the surveys was estimated at 373 to 593. Calves comprised 6.3-6.9% of all animals observed from the aircraft. In general, the dolphins were concentrated in or near the passes and dredged ship channels. Only three sightings were made in Laguna Madre proper. Feeding was observed in association with shrimp boats in or along the edges of mud boils, tide rips, and surf lines.

Description

p. 179-199.

Keywords

aerial surveys, bottlenose dolphin, Tursiops truncatus, animal populations, feeding, feeding behavior, population density, population number

Citation