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Man versus Manatee

PostPosted: Thu Mar 27, 2003 10:26 am
by RudyGomez
Here is an article/announcement that appeared in today’s Sun Times:

Man and Manatee meeting Tuesday (Marco, FL):
http://www.zwire.com/site/news.cfm?news ... 5823&rfi=6

I’ve posted this particular article to illustrate a point. In bold letters near the top of this article, it’s written, "preserve a vanishing species".

I take issue with the authors use of "vanishing" which implies the manatee population is on the decline. Why is it that most writers - and readers for that matter - take this as a given when most studies show their population trend as increasing in recent years?

I would like to hear your opinion on this matter. Particularly, is the general public’s perception pertaining to manatees erroneous?

Man vs Manatee

PostPosted: Fri Mar 28, 2003 4:19 pm
by TheGlass
Thank you for your comments on the Manatee article in the Sun Times. I wrote it as a purely informational invitation to the seminar being presented. It sounds as if you are quite knowledgeable on the subject. The meeting
promises to be 'interesting' at the very least, and perhaps controversial,
since there are such divided opinions right now. I would like to address
your comments.

"Why is it that most writers - and readers
for that matter - take this as a given when most studies show their
population trend as increasing in recent years?"

My first reaction would be to say simply that Manatees are not reproducing
as quickly as some other creatures on a 'per capita' basis -- partly that is
the nature of the beast; partly because they are hurt in man-caused
accidents and die off; partly because their foods (sea grasses) are also
endangered as a result of coastal development; of course there are viruses and other sicknesses. Manatees are considered "endangered" and "protected species", and aside from simple semantics, people who care about them seem to apply the word "vanishing" when referring to any species like this.

I have provided a pie chart (based on FMRI statistics) that shows the
estimated causes of death, and as you can see, the majority of known causes of death are man-related. Many of the "unknown" category could also be man-related, but because in these cases carcasses are so far rotted before they are discovered it is not possible to say for sure. Nearly 40% is natural, ranging from perinatal deaths (somewhat common) to cold stress, disease, and Red Tide. Without man's influence on these death tolls, manatees would have a better recovery rate.

Their gestation period is 13 months, and although their lifespan is rather
long, their "childbearing" age window is somewhat limited. They give
birth to only one calf every three (or more) years on average.

I suppose the best answer to the question revolves around improvements in technology. It would appear as though, in general, numbers are increasing:
1999 - 2,353 counted
2000 - 2,223 "
2001 - 3,276 "

HOWEVER, this is specifically due to better counting methods, more
cooperative efforts statewide, and, most recently, optimum counting
conditions. There simply is not enough long-term data on which to
base a reliable hypothesis on any trend toward increase.

I don't think that one can simply label either my perception or the public's as "erroneous"; there are too many variables to make this judgment.

There are some summaries from Coastal Training Programs, such as those
conducted at the Rookery Bay Estuarine Reserve, which relay the scientific
information we do have and how it is improving our knowledge of this animal.
There does seem to be enough evidence that more boats in the area will
logically increase the potential for a collision, meaning the population
could still be in danger.
The bottom line is, more studies are needed to ascertain what would be the
"ideal" population figure so that most effective protective measures can be
established.
In conclusion, we all know that "statistics" are merely numbers that can be
bent and read several ways.
The chart I enclosed could not be uploaded to this site; it shows, percentage-wise, causes of death: Undetermined - 31%; Perinatal - 21%; Other/natural - 17%; Gates/locks - 4%; Watercraft - 24%; Other human - 3%.
I'm a "reporter" and what I write for the newspaper does not necessarily reflect MY opinions; it's just a topic and seminar I was asked to cover. I know a fair amount about both sides of the discussion here -- fishermen, boaters, developers and real estate people versus the environmentalists, and so-called "sneaky" way the dock moratorium suddenly appeared. Perhaps what I write AFTER the April 1st meeting/seminar/debate might have a little more impact, as it could be a little more balanced in representing both sides.
My message at the moment is to consider both sides -- I don't think
there is a "clear winner" here.

Re: Man vs Manatee

PostPosted: Wed Apr 02, 2003 11:28 am
by RudyGomez
First, please don’t perceive my response as an attack – it is not meant to be. Again, I want simply want to separate fact from perception – whatever the result.

TheGlass wrote:My first reaction would be to say simply that Manatees are not reproducing as quickly as some other creatures on a 'per capita' basis...


Your assertion that, “Manatees are not reproducing as quickly as some other creatures on a 'per capita' basis” has absolutely no bearing on whether manatees populations are increasing or decreasing.

Again, my initial query seeks evidence supporting, or refuting, the general public perception that manatee populations are decreasing. In fact, you have provided FACTS that corroborate what little factual evidence I have seen which indicates that manatees populations have never been larger (since record keeping began).

Why is this factual evidence explained away or dismissed altogether?

Manatee numbers

PostPosted: Wed Apr 02, 2003 6:40 pm
by TheGlass
I'm not sure why you consider the manatee population to be so important, other than to incite controversy over some remote fact. Even the so-called experts can only say that it is "stabilizing" at best, & likely declining.

“Manatees are not reproducing as quickly as some other creatures on a 'per capita' basis” has absolutely no bearing on whether manatees populations are increasing or decreasing.

Well, if I didn't think it had a bearing, I wouldn't have said it. They are physically unable to reproduce as quickly as rabbits, so even IF each female manatee could have offspring more often than once every 13 months, they still might not appear to be increasing even if they were.

I suggest you speak to REAL experts at Florida Fish & Wildlife Service, if you want REAL, accurate answers, or the Staff Biologist at the Tampa Bay Manatee Club. I cannot speak, nor would I try, for the "general public". All I am prepared to do here is report what I hear & see.


Again, my initial query seeks evidence supporting, or refuting, the general public perception that manatee populations are decreasing. In fact, you have provided FACTS that corroborate what little factual evidence I have seen which indicates that manatees populations have never been larger (since record keeping began).

Why is this factual evidence explained away or dismissed altogether?

[/b]

Re: Manatee numbers

PostPosted: Thu Apr 03, 2003 10:35 am
by topangler
TheGlass wrote:I'm not sure why you consider the manatee population to be so important, other than to incite controversy over some remote fact.


MANATEE POPULATION is NOT some "remote fact" - it's the CENTRAL point. If Manatees were plentiful, we would not be having this discussion!!! :!:

PostPosted: Thu Apr 03, 2003 12:02 pm
by TheGlass
"If Manatees were plentiful, we would not be having this discussion!!! "

Hmm, I must be forgetful. I thought you said they were plentiful.

" In fact, you have provided FACTS that corroborate what little factual evidence I have seen which indicates that manatees populations have never been larger (since record keeping began). "

By "remote", this is what I mean: what percentage of the population of the US knows what a manatee is, & really gives a hoot as to how many there are? How would the total absence of manatees on the globe affect our welfare.
The world isn't a happy place right now. Debating manatees was "interesting". Splitting hairs over semantics isn't.