Saturday, July 30, 2016

Gulf Coral Reef Dying From New Unknown Cause - White Matting

Since 2014, our oceans have experienced terrible impacts from red tide and global coral bleaching which have caused global coral mortality events. 

Now, NOAA announced this week that a new menace has been discovered with high capacity for reef and entire ecosystem destruction.

On Monday, July 25, 2016, divers discovered "green, hazy water," over East Flower Garden Bank in Gulf of Mexico. Usually, it is blue and mostly clear. The Banks are about 100 miles off the Texas and Louisiana coast in the Gulf of Mexico.
Source: Google Earth

Arriving at the bottom they "were stunned to find ..... huge patches of ugly white mats coating corals and sponges, and dead animals littering the bottom on the East Flower Garden Bank, a reef normally filled with color and marine life. The reef, which is part of Flower Garden Banks National Marine Sanctuary, is considered one of the healthiest anywhere in the region." 
Source: http://sanctuaries.noaa.gov/news/jul16/noaa-scientists-report-mass-die-off-of-invertebrates-at-east-flower-garden-bank.html

The pictures are appalling:
A white mat of unknown material coats a dying sponge at the East Flower Garden Bank during a large-scale mortality event. Image: FGBNMS/G.P. Schmahl

A massive star coral impacted by a large-scale mortality event at the East Flower Garden Bank. These corals are hundreds and hundreds of years old, and can be lost in a matter of days. Image credit: FGBNMS/G.P. Schmahl

Tissue sloughing off a recently dead brain coral succumbing to a large-scale mortality event at the East Flower Garden Bank. Image credit: FGBNMS/G.P. Schmahl

These photos are not isolated samples. 

According to  Dr. Steve Gittings, NOAA's Chief Scientist of the Office of National Marine Sanctuaries, "The divers and researchers found unprecedented numbers of dying corals, sponges, sea urchins, brittle stars, clams and other invertebrates on large but separate patches of the reef. Sanctuary Research Coordinator Emma Hickerson reported extensive white mats covering corals and sponges, and estimates the mortality of corals to be nearly 50 percent in some of the affected areas. The spatial extent of the event is still being determined, but Hickerson says the die-off has so far been seen at three dive sites that charter boats typically use when they visit the bank."

As NOLA, a New Orleans paper, summarized NOAA's statements, "The bank is undergoing a "large-scale mortality event of unknown cause." 
Source: http://www.nola.com/environment/index.ssf/2016/07/gulf_reef_dying_of_unknown_cau.html

NOAA Quarantine in Place

Gitting stated, "NOAA is recommending the public avoid diving, fishing, and boating activities on the East Flower Garden Bank. This is primarily to prevent the transmission of whatever is causing the mass mortality to unaffected locations, but also could protect divers from ingesting what could be harmful pathogens or toxins." However, with all the unknowns, that quarantine zone may expand to surrounding reefs:
Source: NOAA National Marine Sanctuaries Map

What is sad is that the East and West Flower Garden reefs have not previously experienced major coral bleaching or disease. And, what is happening now is not coral bleaching, since more than corals are being affected. So what is known?

First of regional water has been ranging from 29-31C for many days. The Coral Reef Watch sea surface temperatures for July 28, 2016 follow. A recent SST from a local buoy was 31.0 C.
Source: Coral Reef Watch, Google Earth

These SST's are 1-2 C higher than normal, causing concern that these reefs and others nearby may experience coral bleaching as the summer continues.

The July 28, 2016 CRW sea surface temperature anomalies:
Source: Coral Reef Watch, Google Earth

Also, NOAA's Coral Reef Watch has posted a bleaching warning for the East Flower Garden Bank reefs and others in this area of the Gulf this summer.

According to G.P. Schmahl, the East Flower Gardens Bank Sanctuary Superintendent, ""We know of no spills that have recently occurred near the Flower Garden Banks."  

Dr. Gittings added, "In addition, large plumes of low-salinity coastal water have moved offshore following months of extreme rainfall in the region. That water is rich with plankton, nutrients and chemicals that arrive to the Gulf through runoff and river discharges. As the plumes decay, oxygen levels in the water can decrease."

"Combined, these stressors could make coral reefs animals and plants more prone to disease outbreaks, or simply fuel the growth of bacterial or algae mats that smother the reefs. Scientists from around the world are offering advice and assistance in trying to help discover the cause."

These reefs on the banks are somewhat isolated, which may have protected them from earlier human and natural impacts.  But now they are succumbing to ... to what? 

As Gittings account ends, "The sanctuary and the science community are desperately trying to figure that out."

So now, in addition to red tide, harmful algae bloom, coral bleaching, deoxygenation, and human run-off, we add "white matting" to the onslaught of coral reef decimation. 
A deadly white mat coats a sponge between star and brain coral at the East Flower Garden Banks. Image credit: FGBNMS/G.P. Schmahl.

Sources: 

NOAA: http://sanctuaries.noaa.gov/news/jul16/noaa-scientists-report-mass-die-off-of-invertebrates-at-east-flower-garden-bank.html

Coral Reef Watch: 5 km Google Earth kml

Flower Garden Banks National Marine Sanctuary: http://www.ncddc.noaa.gov/website/google_maps/FGB/mapsFGB.htm

1 comment:

  1. That's very close to the area affected by the BP deepwater horizon oil spill. It's also not that far from the dead zone around the mouth of the Mississippi river caused by nitrogen runoff from agriculture. It's sad to think that was the healthiest area, what's been happening everywhere else??

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