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Population viability analysis of the Florida manatee (Trichechus manatus latirostris), 1976-1991

Conservation Biology

By:
, , and
DOI:10.1046/j.1523-1739.1997.96019.x

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Abstract

Recent development of age-determination techniques for Florida manatees (Trichechus manatus latirostris) has permitted derivation of age-specific data on reproduction and survival of a sample of 1212 carcasses obtained throughout Florida from 1976–1991. Population viability analysis using these data projects a slightly negative growth rate (−0.003) and an unacceptably low probability of persistence (0.44) over 1000 years. The main factors affecting population projections were adult survival and fecundity. A 10% increase in adult mortality would drive the population to extinction over a 1000-year time scale, whereas a 10% decrease in adult mortality would allow slow population growth. A 10% decrease in reproduction would also result in extinction. We conclude that management must focus on retaining and improving the conditions under which manatee demography operates. The major identified agent of mortality is boat-manatee collisions, and rapidly increasing numbers of humans and registered boats portend an increase in manatee mortality. Zoning of manatee-occupied waters for reductions in boating activity and speed is essential to safeguard the manatee population. If boating regulations being implemented by the state of Florida in each of 13 key coastal counties are completed, enforced, and effective, manatees and human recreation could coexist indefinitely. If regulation is unsuccessful, the Florida manatee population is likely to decline slowly toward extinction.

Additional publication details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Population viability analysis of the Florida manatee (Trichechus manatus latirostris), 1976-1991
Series title:
Conservation Biology
DOI:
10.1046/j.1523-1739.1997.96019.x
Volume:
11
Issue:
2
Year Published:
1997
Language:
English
Publisher:
Wiley
Contributing office(s):
Southeast Ecological Science Center
Description:
15 p.
First page:
467
Last page:
481
Online Only (Y/N):
N
Additional Online Files (Y/N):
N