I. INTRODUCTORY COMMENTS
For nearly 20 years, state and federal agencies have been adopting speed zone and sanctuary regulations without any measurable biological goal for manatee protection. In addition, there are no means to determine the effectiveness of existing regulations. Environmental and animal rights groups continue to claim that manatees are endangered and “declining toward extinction.” However, a scientific assessment commissioned by CCA Florida concluded that manatee populations throughout
Florida
have been steadily increasing for the last 25 years. Earlier this year state and federal scientists counted an all time record 3,276 manatees in statewide aerial surveys; more than double the number counted 10 years ago. Yet, state and federal lawsuit settlement agreements are designed to establish more boating restrictions. Are the current regulations sufficient to sustain the expanding manatee populations? That will never be determined unless there is a stated and measurable biological goal. Without such a goal and a means to analyze the effectiveness of existing regulations,
Florida
’s boaters and fishers will continue to be faced with a never ending procession of new boating restrictions.
Developing the measurable biological goal should be a high priority issue for federal and state agencies. In that regard, the majority of our following comments and recommendations are directed to the USFWS “benchmarks” and “vital signs” recovery criteria.
II. RECOMMENDATIONS
1. FWS should modify the requirement that the benchmarks must be achieved “in each of the four regions” to instead, achieving the benchmarks by the entire statewide population as one aggregate population.
- Dividing the state into four regions creates an artificial impediment which would arbitrarily prevent reclassification. For instance, a ten percent population decline in the
Upper St. Johns River
region should not prevent reclassification if overall growth in the total state population exceeds the decline in a single region. The manatees in the four regions are not separate subspecies. The biological goal and benchmarks should measure and evaluate the entire state population as a single population.
2. FWS should clearly identify the specific means and techniques which will be used in determining whether the benchmark goals are being achieved.
- In other words, the biological goals must be able to be measured by existing techniques in all the regions of the state; otherwise, by default, the benchmarks cannot be achieved.
3. We concur with the FWS statement that the MPSWG benchmarks for reclassification to threatened status are a higher standard than statutory requirements.
- In the real world, manatee populations cannot continue to increase without limits. The MPSWG’s recommendation for an adult survival rate of 94% and an annual population growth rate of 4% does not reflect the reality of a finite carrying capacity for manatees. Population growth curves for animals do not increase forever, eventually the animals reach carrying capacity with their environment and the growth curve becomes flat. Populations then fluctuate up and down around a stable level.
The current annual growth rate of
Florida
’s human population is 2.35%. Manatee populations have already substantially increased over the last 25 years. Thus, it is difficult to believe any scenario in which manatee populations could sustain annual growth rates of 4%, which would be greater than
Florida
’s human population growth rate. The FWS recommendation for an average annual growth rate equal to or greater than zero more accurately reflects reality.
In addition, the Marine Mammal Protection Act defines the term “optimum sustainable population” for any population stock to mean “the number of animals which will result in the maximum productivity of the population or species, keeping in mind the carrying capacity of the habitat and the health of the ecosystem of which they form a constituent element.” (emphasis added)
Florida
manatees exist at the most northern extreme of their temperature tolerance. Manatee populations have become dependent upon, and artificially expanded by, the creation of man-made thermal refuges. Population carrying capacity will be limited during very cold winters by the amount of available forage within the vicinity of the thermal refuges.
4. The FWS should amend the text of the recovery plan to more fairly and accurately place watercraft mortalities into an overall context of total mortalities; perhaps as numbers of deaths per 100 animals. Too much of the boating impact debate is focused on just “body counts,” the number of animals killed each year by boats, as opposed to a percentage of a growing population.
- CCA Florida provided a grant to Dr. Thomas Fraser to produce a report entitled “Manatees in
Florida
: 2001.” Fraser’s report contains the following excerpts which should be examined and used by FWS to place boating mortalities into perspective with increasing manatee populations and total mortalities.
· Increases in the manatee population should be expected to show increasing numbers of dead manatees from all causes including boats over time.
· Mortality data is consistent with an increasing population of manatees. If the natural mortality rate has remained relatively unchanged over the past several decades, then relative change should reflect trends in the general population.
· An examination of per capita manatee deaths more accurately determines relative mortality trend issues than simply just the use of annual numerical totals. Analysis shows that while the annual deaths are increasing, the annual deaths per 100 manatees are not trending up. Additionally, annual perinatal deaths (natural deaths at or near birth) are increasing over time, but the annual deaths per 100 manatees are not trending up.
· The rate of boating deaths is not changing faster than the number of boat registrations with respect to the population. The manatee population is growing much faster than the number of boating deaths. When boat-related mortality is adjusted per 100 manatees there is no apparent change with time.
· The manatee boating deaths per capita analysis shows a variable, but stable rate, without an increasing trend. Increases in the population have a significant effect on the annual number of deaths. Unfortunately,
Florida
should expect the increasing annual numeric trend to some extent. This is not a sign of failure to adequately protect manatees, but a positive indication of successful population growth as long as there is no sign of increasing per capita mortality rate. The perceived failure (measured only by total body count) is a repeating loop for more regulation that must be restructured.
A complete copy of Fraser’s report was sent to FWS Jacksonville staff in April, 2001.
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