Project Summary
---------------
A total of 38 subsurface recording thermographs have been deployed in the Florida Keys National Marine Sanctuary
(FKNMS) and at other selected locations on the Florida Reef Tract and associated hydrologic ecosystems since 1988.
These instruments have been programmed to record at 2 hour intervals and placed in permanent housings attached to
suitable substrate.  Data retrieval, servicing and reprogramming for continuous deployment have occurred, on
average, annually.  The collected data has been made available to FKNMS Managers and others who monitor and assess
environmental conditions that influence FKNMS areas of the Florida Reef Tract.

Project Objectives
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The purpose of this project is to document bottom seawater temperature in strategic areas of the Florida Reef
Tract on a continuing basis and make that information available to management and research user groups.  This is
an ongoing project.

Project Background
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It is well understood that temperature is a major factor controlling distribution, growth and survival of the
world's coral reefs.  This is especially true of high latitude reefs such as those of the Florida Reef Tract
where seasonal temperature extremes detrimental to coral health frequently occur.  Past environmental
perturbations in the Caribbean and southeast Florida that may be linked to elevated seawater temperature include
coral bleaching, a sea urchin die-off, black band coral disease and a seagrass die-off.  The first 3 disturbances
occurred on a massive scale throughout the Caribbean and southeast Florida.  Large-scale die off of seagrass has
thus far only been documented in the Florida Bay area of the Florida Keys.  This project is a cost-effective and
integral part of an overall plan to monitor the Florida Keys coral reef ecosystem.

Project Methods
---------------
Ryan Industries, Inc. recording thermographs were deployed at strategic locations on the Florida Reef Tract
during 1988*.  Due to the Ryan Industries discontinuing their product line during the course of the project, a
change to another manufacturer's thermograph was implemented.  Now, Sea-Bird Electronics, Inc.* recording
thermographs are used.  To date, 38 thermographs have been deployed, completing a permanent network of these
sensors from southern Broward County to the Dry Tortugas.  In response to extreme anthropogenic events on the
Florida Reef Tract and surrounding hydrologic ecosystems (e.g. Massive shipwreck groundings and associated reef
restoration), monitoring stations have been positioned to provide project managers additional data for ongoing
studies.

A hollow, pre-cast concrete coral head or concrete and PVC monument have been used to protect and conceal
thermographs.  Where appropriate, bolt-on stainless steel brackets were used to secure instruments to structural
supports (e.g. concrete or steel pilings) of fixed bridges or navigational aids.

Experience has shown that a 2 hour recording mode is adequate to monitor changes in reef tract bottom water
temperature.  Data has been collected, on average, annually from all instruments.  Due to mechanical problems
with some instruments, there are occasional gaps in the data streams from some of the monitoring stations.

Project Coordinator
-------------------
James Harold Hudson
Sanctuary Biologist
Florida Keys National Marine Sanctuary
P.O. Box 1083
95230 Overseas Hwy.
Key Largo, FL  33037  USA
305-852-7717, ext. 29
harold.hudson@noaa.gov

* Selection of this manufacturer's product does not constitute an official product endorsement by the Florida
Keys National Marine Sanctuary or the National Oceanic and Atmospheric Administration.





















