cleaning

On June 17, 2009 Sam and Gary cleaned the stick. Ran calibration. Everything looks good.
Gary

cleaning

Sam and Gary cleaned the stick 05/29/2009. Everything looks good.

cleaning

On wed 04/08/2009 from 9am to 10am Gary cleaned the stick. Everything looks fine.

cleaning

On monday 02/16/2009 Sam and Gary cleaned the stick. Everything looks good.

stick cleaning

On sunday 01/11/2009 Sam and Gary cleaned the stick from around 10am to 11am. The rubber cable protection at the water level if gone now. It was damaged in "omar" and now is gone. Guess some other protection needs to be tried. Everything else looks fine.

Station Maintenance

AOML's Dr. Jim Hendee, Dr. Derek Manzello and Mike Jankulak visited the SRVI2 station on the afternoons of Wednesday, June 18th and Thursday, June 19th, 2008, to replace/remove equipment and inspect the environment (see previous blog post). We were assisted by Gary Trommer and Sam Halvorson of Dive Experience, Christiansted.

The Surface BIC (light sensor) was original to this station's installation in September of 2006, and was replaced on this trip. Its cable was cracked by sun and weather and was also replaced.

The Vaisala WXT510 (Weather Transmitter) was replaced. At the same time, an adjustment was made to the orientation of its mount to correct a 17° error (affecting wind direction readings) introduced during its last replacement in August of 2007.

The Shallow CTD, originally deployed in May of 2007, was replaced by divers.

Perhaps most significantly, the SeaBird SBE-29 Pressure Sensor was disconnected from the station and its cable removed. This instrument's cable was not our standard "fishbite" cable, and in recent months it had worn through to bare wire at the waterline where it had been rubbing up against plastic zip ties wrapped around the pylon. This turned out to have unfortunate effects on the station electronics: many of the analog measurements made by the datalogger were intermittently returning null readings, including the wind speed reported by the Wind Monitor / Electronic Compass, the standalone Air Temperature Sensor's reading, and the datalogger's own voltage readings. It seems likely that the intermittent nature of these problems was due to the action of waves breaking against the damaged part of the cable and occasionally shorting its power/ground wires. Other station functions (logging to memory, transmitting via satellite, and RS-232 serial instrument communications) do not appear to have been impacted.

These issues appear to have been resolved by removing the SBE-29. The datalogger and standalone air temperature sensor were both tested on land and appear to be functioning properly. All analog measurements appear to be reporting correctly now. A sheet of rubber was wrapped around the pylon at the waterline, between the cables and the zip ties, to prevent this problem from recurring.

The orientation of the masts of the wind sensors were visually measured with a compass. The WXT mast is mounted at approximately 97° and the mast of the Wind Monitor / Electronic Compass at approximately 340°. The Wind Monitor and Electronic Compass were last replaced in March of 2008; when they reach their deployment lifetimes, it is anticipated that we will eliminate the Electronic Compass from this station and use a manually-oriented Wind Monitor, with offsets added to the logger programming as required.

All dataparser configurations have been updated and data from the station are once again appearing in the near-realtime web reports.

A qualitative biological survey was performed 18-19 June 2008 adjacent to the ICON pylon located at Salt River Bay, St. Croix, U.S. Virgin Islands. There were no signs of bleaching. Many colonies of Montastraea faveolata exhibited signs of recent tissue mortality associated with 'Yellow-band' disease as first noted last August and September in St. Croix and Jamaica, respectively. This 'yellow-band' event appears to be Caribbean-wide as other confirmed reports have been made in the Dominican Republic, Puerto Rico, and St. Thomas.


Dr. Ernesto Weil will discuss this ongoing and seemingly chronic disturbance at the upcoming International Coral Reef Symposium in Ft. Lauderdale.






Note how cyanobacteria have colonized the recently-dead skeleton of the colony of M. faveolata in this image.











'Yellow-band' is not as aggressive as some of the more well-known coral diseases (e.g., Black-band disease, White plague). It isn't clear if this is related to the high incidence of disease that occurred on those corals which survived the 2005 bleaching or is a separate, unrelated event.

Best regards,
Derek P. Manzello