The following is a synopsis of the Imperiled
Species Management Section (ISM) endeavors regarding the topic of
artificial warm water refuges.
The Florida Department of Environmental Protection
assumed the permitting duties for the federal National Pollutant
Discharge Elimination System (NPDES) in 1995. Included in this
permitting process are power plants, which have warm water
discharges that empty into the coastal waters of Florida. These
power plants are issued permits for five-year periods. The Bureau
of Water Facilities is primarily responsible for the Department's
NPDES permitting. However, the permitting process requires a
determination of whether a power plant provides critical manatee
habitat pursuant to the Federal Manatee Recovery Plan. The
Imperiled Species Management Section (ISM) and the U.S. Fish and
Wildlife Service (USFWS) jointly make this determination. Those
power plants identified as providing critical manatee habitat are
required to create and implement an approved manatee protection
plan (not to be confused with county-based manatee protection
plans). These plans will address issues such as, consistency of
warm water discharges, disruptions to warm water outflows during
the cold season, outfall water temperatures and timely
communication and coordination with state and federal agencies.
ISM has recently been faced with legitimate,
complex questions regarding artificial warm water refuges and
manatee use of these systems. Questions have been raised about the
life span of power plants, their safety, reliability, and
location:
-
Is there a long-term benefit to regional manatee
populations using artificial warm water refuges?
-
Have manatees benefited from artificial warm water
refuges?
-
Are manatees at greater risk by wintering north of
areas where we would typically expect them to be?
The intuitive answer to these questions is,
"Probably." Discussions regarding these issues have been initiated
by state and federal agencies as well as by the general public and
effected industries.
To put these questions in perspective, a little
power plant history is necessary. Many of the existing Florida
power plants have been operating and discharging warm water into
the coastal waters of Florida for over 30 years. During that time,
manatees have gradually become habituated to wintering at these
artificial warm water discharges. The number of manatees using
power plant discharges has also increased during this time
frame.
Research indicates that manatees often come back to
the same discharge(s) year after year, and that calves may learn
this routine from their mothers. Satellite telemetry has shown that
some manatees know where a number of discharges are, and that they
may travel from one power plant to another during the winter.
Obviously, this is not the historical situation, but the winter
distribution of manatees prior to the creation of these artificial
warm water refuges is unknown. Many hypothesize that prior to the
creation of these artificial warm water refuges the migration for
manatees was more direct--north to south during the winter. It is
further hypothesized that the majority of manatees gathered in
extreme south Florida during the winter. However, it is also
possible that manatees used natural warm water areas that over time
have been lost due to human development. The presence of power
plants have permitted manatees to spend the winter in areas like
Brevard County and Tampa Bay, which are considered to be north of
their historical range. Manatees that winter this far north are
much more reliant on these refugia for survival than those manatees
using a power plant in south Florida. Conceivably, manatees that
habituated to artificial warm water sites in north Florida may be
in greater peril in the event of a power plant failure during the
cold season when compared to those manatees that initially migrated
to southern Florida with the onset of winter.
During the winter of 1997-1998, cooperating state
and federal agencies had the chance to initiate a research project
that addressed the loss of an artificial thermal refuge in
Northeast Florida. An artificial warm water discharge, on Amelia
Island, was modified to meet water quality standards by moving it
to deeper water, effectively eliminating its use by manatees as a
warm water refuge. State and federal agencies, responsible for
manatees, consented to this modification because it affected a
small number of manatees and it provided a unique research
opportunity. Specifically, this provided an opportunity to gain an
understanding of what behavior would be exhibited by manatees when
a warm water source was eliminated. When the warm water discharge
was eliminated on November 10, it was anticipated that the manatees
using this site would head south to known warm water refugia.
Although the results of this study are still being analyzed, we do
know that some tagged and untagged manatees died of what is
suspected to be cold stress. Most of the animals that were known to
use this site did not leave the northeast Florida and southeast
Georgia area as winter approached, even though their warm water
refuge had disappeared. It appears that these manatees went to
secondary sites in Georgia that may not have provided adequate
amounts of warm water rather than migrating south. These
preliminary observations have considerable implications for
manatees and their management in regard to artificial warm water
discharges--especially in the northern extremes of their current
winter range.
In February of 1997, some of the same issues were
also raised by the Southwest Florida Marine Trade Association
(SWFMTA) during their challenge of the issuance of the NPDES permit
for the FPL Fort Myers power plant. In their petition the SWFMTA
maintained that FDEP did not know what long-term effects the warm
water discharge were having on manatees. Additionally, the SWFMTA
maintained that the warm water discharge may be detrimental to
manatees because it interrupted historic manatee migration
patterns, it concentrates numerous manatees in a high boat use
area, and close to an area with historically high incidences of red
tide. This permit challenge was settled in March of 1998 (see page
10 of volume 2, issue 1 of the Manatee News Quarterly for details).
One thing is apparent from this challenge and settlement, it has
spurred further discussions, and potential resolutions for some of
the issues surrounding manatees and their use of artificial warm
water.
Other important questions and concerns also loom in
the future. There is a distinct possibility that within the next
five years the Florida Legislature will introduce legislation that
will deregulate the power industry. With deregulation may come
changes in how power is supplied by individual power plants.
Although it is unclear exactly what effects this will have on
manatees-it will require the power industry to be more efficient.
This may mean older less efficient plants will operate
inconsistently, resulting in limited warm water discharges.
Interruptions in warm water outfalls during winter cold fronts may
jeopardize the survival of manatees habituated to these areas. One
possibility, to minimize potential adverse effects, is for State
and Federal agencies to be involved in the creation of deregulation
legislation. This may help to insure that manatee protection is an
important consideration of any legislation that may be ratified.
The Marine Mammal Commission has suggested additional ideas such
as, a new network of artificial thermal refuges and/or enhancing
existing secondary refuges or potential warm water sites to reduce
the cold weather risks facing manatees. While these are legitimate
ideas, a better understanding of manatee behavior and warm water
physiological requirements is need before they can be considered as
management strategies. It is of the utmost importance that before
we embark on a specific course of action, we develop a strategy
that is in the best interest of the manatee population's recovery
and stability over the long term.
In addition to the development of the power plant
protection plans for manatees, state and federal agencies have
begun a series of meetings to discuss artificial warm water refuge
issues and develop a long-term strategic plan. The participants of
these meetings contemplated research needs and discussed the pros
and cons of possible courses of actions related to warm water
refuges. Future meetings are planned so a long-term strategy
involving artificial warm water refugia and manatees can be
developed.
While it is recognized that power plants are not
natural, manatees have become dependent on their existence. Due to
this documented fact, it is imperative that for the foreseeable
future a power plant with significant manatee use provide a safe
and consistent refuge. Without that assurance, the combination of a
severe cold front and the temporary loss of a high use artificial
warm water site could cause catastrophic losses to a regional
manatee population. In most instances, the NPDES required manatee
protection plans (developed in cooperation with the power
companies) should help reduce the risk of this from happening.
Finally, research is being planned by recovery team members to
focus on the long-term ramifications of power plant discharges on
manatees. As these issues unfold we will inform interested parties
of all new information and actions.
Persons with Disabilities