It is indeed with a heavy heart that I bring these sad tidings; the Big Sponge has died here on Roatan. Discovered less than 20 years ago, this millennia old World Treasure 70 feet deep on the underwater plateau called Texas has succumbed to Sponge Orange Band (SOB) disease.
The Big Sponge needed no other moniker, it was the biggest example of Caribbean Giant Barrel sponge, Xestospongia muta, in the region. Estimated conservatively at over one thousand years old, this highlight of dive tours to the Texas dive site was standing tall on its current swept underwater valley when Columbus dropped by the Bay Islands. For centuries it lived surviving storms and earthquakes, for the last couple of hundred years’ anchors, and fish line, to become in the last couple of decades a celebrity, and photo op. Ask any scuba diver who has spent a week diving in West End, Roatan about the Big Sponge (always capitalized) and they might even have a picture of it on their phone.
The Big Sponge contacted the dreaded Sponge Orange Band disease (SOB) in the last week or so, and now no longer with us. We have noticed a small percentage of the barrel sponges here on Roatan becoming afflicted. The onset of the disease is extremely fast, starting as a spot or more often an orange band, in just a matter of a few days the entire brownish red sponge turns a golden yellow, and no longer lives. The sponge’s loose cell structure disintegrates rapidly, and the entire organism turns to fluff and drifts away in the current. Soon, there is absolutely no evidence it ever existed.
Although it would be so easy to get on my soap box to blame the evils of over population, pollution and climate change for the onset of this plague on our ancient treasures, searching the Internet does not bear this out. A Sponge Orange Band disease (SOB) breakout in Florida in 2012 was studied and it was noted, as we observed here, that when a sponge contracted SOB none of the other sponges in the immediate area would be afflicted. One would think that if pollution or warming were the culprit that areas of multiple sponges would be contracting SOB. It also seems that when a sponge contracts SOB, it is not contagious to other sponges. Scientists have taken core samples from sponges with SOB and inserted these into healthy sponges with no detrimental effect.
At this time, it looks like there is no definite smoking gun to blame, and if the 2012 SOB outbreak in Florida is any indication more than 10% of the sponge population of Roatan could be in danger.
If sponges are your thing, and why wouldn’t they be, these giants living to be up to 2500 years old, grow into the most amazing shapes and sizes, each totally unique unto itself standing as silent sentinels in the ocean’s depths; there may be some good news. With the inevitable diminishing presence of coral due to pollution and climate change, in Florida it was noted that sponges are taking over the vacated habitat, and that sponge population is increasing. Perhaps we will need to use the term “Sponge Reef” in the future.