The Effects of Sampling Design on Abundance and Distribution of Bottlenose Dolphins in the St. Johns River, Florida

Content Provider	Semantic Scholar
Author	Nekolny, Samantha Ryanne
Copyright Year	2014
Abstract	Marine mammal management decisions are often based on population abundance estimates, yet the St. Johns River (SJR; Jacksonville, FL) bottlenose dolphin community has not been assessed in over 16 years. To address this data gap, vessel based photo-identification surveys were conducted in a 40 linear km study area within the SJR using two study designs. The first approach consisted of a full year of weekly surveys and the second approach utilized less frequent seasonal surveys for three years. Based on the discovery curve for the full year time period, the identification of new individuals appears to have leveled off with a total of 261 individuals identified, not including calves. In contrast, the discovery curve for the three-year time period indicates that the identification of new individuals was steadily increasing with a total of 200 individuals identified, not including calves. Data from both time periods, which were collected and processed using mark-recapture methods, were analyzed in the program MARK to estimate abundance and temporary emigration rates. The robust design with a Markovian temporary emigration model for a semi-closed population was applied. Estimates from the full year approach varied from 160 (95% CI=151-177) in winter to 250 (95% CI=243-
File Format	PDF HTM / HTML
Alternate Webpage(s)	https://digitalcommons.unf.edu/cgi/viewcontent.cgi?article=1558&context=etd
Language	English
Access Restriction	Open
Content Type	Text
Resource Type	Article