The Interaction of Mangroves, Coral Reefs, Salt Ponds and Beaches
Ecological environments everywhere depend upon one another for their survival. This is elegantly and plainly illustrated in the mangrove habitats of St. John as they quietly preside over the orderly transition of life between land and sea…. read more
Mostly cloudy in the morning then becoming variably cloudy. Scattered showers. Highs around 83. East winds 10 to 15 mph. Chance of rain 50 percent.
HIGH SURF ADVISORY
A HIGH SURF ADVISORY REMAINS IN EFFECT UNTIL 10 AM AST SATURDAY.
* WAVES AND SURF: NORTH-NORTHWEST TO NORTH SWELLS OF 8 TO 10 FEET WITH PERIOD OF 12 TO 14 SECONDS WILL PRODUCE BREAKING WAVES OF BETWEEN 12 TO 16 FEET.
* TIMING: FROM TONIGHT THROUGH SATURDAY MORNING.
* IMPACTS: LARGE BREAKING WAVES WILL CAUSE DANGEROUS CONDITIONS IN THE SURF ZONE AND STRONG RIP CURRENTS. WAVE ACTION SURGING UPON THE COASTLINE AND HIGHER THAN NORMAL WATER LEVELS MAY POSE A THREAT TO LIFE AND PROPERTY.
Chitons are also known as sea cradles or coat-of-mail shells. On St. John they can often be seen adhering to rocks in shallow water. They survive by grazing the algae that grows on rocks, which is helpful in that a clean substrate can be used as a starting point for corals.
I just found out that one of my favorite hard corals, the Orange Cup Coral (Tubastraea coccinea), is considered an invasive species.
Orange cup corals are beautiful brightly colored orange corals with flower-like yellow tentacles that extend at night or in areas of low light.
Although the orange cup coral is a hard coral, it’s not a reef-building coral. Also, unlike other corals, the cup coral, does not depend on the symbiotic algae, which shares it’s photosynthesis-created food with the coral animal. Because of this, the cup coral can grow in dark places such as shaded walls, caves and underneath overhanging ledges.
I first noticed orange cup corals on the walls of an rocky indentation on the Tektite snorkel and again on the walls of the caves at Norman Island. Now I see them elsewhere even on the Trunk Bay Underwater Trail.
Cup corals do not seem to be a major problem here in the Virgin Islands as they seem to prefer the darker areas that other corals don’t like and I’ve not seen any great proliferation in all the years that I have been snorkeling around the Virgin Islands.
They are, however, a problem in the Gulf of Mexico where they tend to crowd out other native coral and sponge species. They especially like oil rig platforms where hundreds of thousands of colonies may be found attached a platform.
You’ll need to look carefully to see the translucent jellyfish in the above photo, but seeing it in the water is even more difficult. It has a dome shaped head and four tentacles. It’s a sea wasp. It stings hard and it’s hard to avoid. If you are unfortunate enough to get stung, pour vinegar on the the affected area and in severe cases seek medical attention.
I saw quit a few of these strange jellyfish while snorkeling the southwestern side of Maho Bay. They were resting on the bottom in about ten feet of water. While most jelly fish swim around with their head up and tentacles down, the Cassiopea spends most of its time with its’ head down resting on the sea floor and with its tentacles extended upward, hence the name, upsidedown jellyfish.
The upsidedown jellyfish can give divers a mild sting, which can be very itchy. According to Wikipedia: “The stinging cells are excreted in a mucus; swimming over the jellyfish (especially using swim fins) may cause transparent, essentially invisible, sheets of this mucus to be lifted up into the water column, where they are then encountered by unsuspecting swimmers,” but being that these jellies were in fairly deep water, this shouldn’t be a problem for snorkelers observing them.
This creature has always fascinated me. When I first saw one, I thought it was some sort of underwater flower, and I was certainly surprised to find out that it was not only an animal but a worm. What looks like the flower’s petals are tentacles, which filter plankton from the seawater for food and increase the amount of oxygen that the worm can absorb. When hungry fish or a snorkelers finger come too close the tentacles retract to the safety of the tube that gives the species the name, tube worm. If a fish is faster than the worm and bites off some tentacles, the worm will regrow the lost parts. The tube is fashioned from parchment, sand, and bits of shell that is permanently affixed to a rock, coral or some other substrate by a sticky mucus secreted by the worm.
TI photographed this banded coral shrimp along the eastern shoreline of Hawksnest Bay, heading out from Openheimer Beach.
Also known as barber pole shrimp, the banded coral shrimp are cleaning shrimp that eat the parasites off of passing fish, waving their antennae to attract any fish that want to be cleaned.
According to Paul Human’s Reef Creature Identification: “when approached, they retreat into protective recesses. If a bare hand is slowly extended toward the shrimp, it may leave its retreat and even attempt to clean fingers.”
The bearded fireworm is a slow creature, and is not considered a threat to humans unless touched by a careless swimmer. The bristles, when flared, can penetrate human skin, injecting a powerful neurotoxin and producing intense irritation and a painful burning sensation around the area of contact. The sting can also lead to nausea and dizziness. This sensation lasts up to a few hours, but a painful tingling can continue to be felt around the area of contact. In a case of accidental contact, application and removal of adhesive tape will help remove the spines; applying alcohol to the area will also help alleviate the pain. Cold water and ice soothe the pain of the poison that was injected from the bearded fireworm. More information
All about St John in the beautiful US Virgin Islands (USVI) American Paradise