Authors

Blakely Rice

Document Type

Internship Report

Publication Date

Fall 2014

Abstract

This preliminary investigation was aimed at identifying the distribution, and factors influencing distribution, of bottlenose dolphins in Biscayne Bay, FL with a focus on the Port of Miami. Point density analysis indicated there is a high likelihood of a sighting occurring at the mouth of the Miami River, south of Dodge Island. Hot spot analysis reflected this spatial clustering seen in the point density analysis showing that the clustering of sightings is statistically significant. Analysis of environmental parameters revealed that distribution within the port study area is not influenced by temperature (p=0.120). Salinity ranges were determined for the port area from 2008-2014, the highest proportion of sightings was seen in the 32.51 _ 35.70 ppt range which could reflect the salinity profile of the study area. After reviewing the sighting histories it was determined that 7 individuals were seen more than 10 times in the port study area from 1990 _ 2009, which is considered a frequent user. The majority of animals have less than 50% of their total sightings in the port area. 3 of the individuals are related, dolphins 130 and 175 were both calves of dolphin 69. Sighting histories of the 7 individuals indicate that the area south of Dodge Island and the mouth of the Miami River may be an important area for them. This study highlights the need to explore the spatial and temporal distribution of bottlenose dolphin in Biscayne Bay to outline a baseline assessment that may be helpful to wildlife managers consulting on projects, such as the Port Miami expansion project, that impact the bay. Results from this projects should be interpreted with caution as there is a need for further analysis including normalizing the sighting data by survey effort and expanding the analysis of environmental parameters including temperature and salinity.

Comments

Department: MBF

MPS Track: MMS

Location: NOAA NMFS (MIami, FL)

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