December 2007
One of the greatest pleasures we derive from life afloat arises from the sea being our back garden. In the Tropics it is nicely warm, currently our instruments are showing 29.9°C here in Langkawi, Malaysia. We have both been water babies all our lives, starting scuba diving over forty years ago. Di now has problems clearing her ears so is limited to snorkeling which is no problem as Dave only dons full scuba gear for excursions to significant depths at special locations. In fact, much of the most interesting marine life generally resides at depths of less than 10m.
We have a Bauer Junior compressor aboard which means Dave can dive extensively in remote areas, which is often where the best marine life is to be found. This year we have added Indonesia to our list of memorable remote sites like Tobago, Los Roques, Bonaire, San Blas, Galapagos, Tuamotos, Easter Island, Wallis Island, Tonga, Fiji, Vanuatu and the Great Barrier Reef.
This fourth version of our marine page uses images taken from Australia's East Coast and Indonesia, chosen to be examples of a wide range of species, arranged pretty much in alphabetical order.
This large especially large example of algae was seen off Adundara Island, NE of Adun in Indonesia. To left and right it is flanked by the long tentacles of giant sea anemone (Stichodactyla gigantea). We found anemones to be very common in all Indonesian waters and hence saw masses of anemone fish, one of the Damsel family (Nemos).
In May we were lucky enough to spend two days on a dive boat anchored off Australia's Great Barrier Reef so, with other cameras around, Dave managed to get in an underwater picture at last. If you'd like to get a better view of the fish, see Clark's Anemonefish (Amphiprion clarkii), Dusky Anemonefish (Amphiprion melanopus) and(Amphiprion crysoperus) in the earlier Marine pages 2 & 3.
There are no more images featuring fish in this page. This is mainly because in Indonesian waters you don't see that many decent sized (over 10cm) fish, thanks to the incessant efforts of millions of fishermen. This trap is one of a myriad of types we saw across the country. Unfortunately they don't stop at line, net and trap fishing but also use explosives widely. Strictly it is illegal but the rule of law is a little tenuous in remote places. We heard explosions but were never ever close, whereas other friends suffered mild concussion whilst snorkeling.
So, after that introduction to anemones, here is an example of one we believe to be relatively rare, we found it at Batu Boga on the north coast of Flores, Indonesia. The only other thriving colonies we can remember were in Waya Island, Fiji and Lamen Bay on Epi in Vanuatu.
Early in September we spent four magical days anchored off the idyllic islet of Sebayor Kecil in a marine park between the larger islands of Flores and Komodo. The variety of species was almost beyond belief, much greater than any other site we have ever visited. The diving was excellent but even better were the drift snorkels we would do through a 1km long pass each morning. This, again a fairly rare specie of anemone, was one of many on the route through the pass.
Ascidians are efficient filter feeders and usually quite colourful. Never before had we seen such an abundance of them as there were in Indonesian waters. In many places they were in there tens on almost every rock.
Again at our lovely anchorage at Sebayor Kecil we found this compact coral head loose in the bottom, probably dislodged by fishing gear. Just couldn't resist taking aboard for a few minutes to make a photographic record free of the usual underwater limitations.
This sort of close work is much more difficult underwater where Macro camera modes need much more light and camera stability becomes a major factor.
Lizard Island about 150nm north of Cairns is a magic spot, famed as the place where Captain Cook climbed the hill to search for a way through the Great Barrier Reef. The bay on the NW is named after Mrs Watson, who in the early days of the colony, fled from attacking aborigines by taking to the sea with her Chinese servant in a large, cast iron, whale blubber, rendering pan. Escape they did but sadly they landed on a small islet without water and died of thirst. In the marine world Lizard Island is now famed for the large number of huge, giant clam (probably not tautology). Many are close to 2m across with flesh in various colours at patterns.
This is what the innards of a giant clam look like if you are brave enough to stick your arm and camera in close enough. I have had them close up on me but so far it has been a relatively slow business. Still does tend to raise the heartbeat just a little!
Acroporidae forms what is probably the largest of all the families of hard corals. Most species tend to be tree-like, unlike this example. It is often important when photographing corals to take a close up of the structural detail to aid identification.
These two pictures taken near Alor in eastern Indonesia illustrate how muh easier identification is with a close-up
The fact that these can clearly be seen to be closed cells is a useful identifying feature.
This form of Fungia, named no doubt after their look-alike land based fungi, are relatively common in all tropical waters. They exist as independent items, not connected to rocks or other coral structures, as are most corals.
This beautifully presented example was seen at Pura Island in the Selat Pantar Strait, just off Alor in Indonesia. The colours often vary according to the locally available minerals.
Feather stars are another of those species we regarded as relatively rare until we swam in Indonesian waters where they are commonplace. This one was at Batu Boga on the northern coast of the island of Flores
We showed one of these in our last Marine page but we couldn't resist this image of three together. Never have we seen so many in one place as we did at Batu Boga on Flores. A count along a strip around 20m by 10m revealed over 40 of the pests. They destroy corals by excreting fluids from their under sides that digest the polyps, the living organism of the reef, then reabsorb them as food. One can normally see where they have been by the lighter colour of the dead coral.
Should you decide to skew natures work by picking some up and casting them ashore, you'll be needing a thick pair of gloves. Penetration of the skin is easily achieved and believe me it is painful for many days!
The corals we have shown you so far have all been what are known as hard corals, the reason being pretty obvious. The next two are subtle variants of the same specie of soft coral and illustrate how nature often creates not a single defined structure but a continuum of forms across a sometimes wide spectrum.
This example is from Watsons Bay on Lizard Island in northern Queensland. The variability along with colour variation often makes for difficulties in classification. We have photograhed 78 examples of sarcophyton which span what might be described as around 12 basic forms.
Now we have reached the S for sponge bit of our story. These are the simple but effective filter feeders, this one pictured at Pura Island in Selat Pantar Strait, close to Alor in Indonesia.
This example is also from Pura Island where the waters are clear and deep. Sponges have the least complex body structure of all multi-celled creatures.
Yet again from Pura Island, yet another variation on the sponge theme. Nothing you want to take into the bath with you though. A typical sponge comprises an outer layer of tissue, the cortex and a fibrous inner layer impregnated with numerous glass-like slivers of silica or calcium carbonate.
This strange looking star was new to us but they are relatively common in shallow waters. We saw this one at Riung in Ende Province on Flores. They come in widely varying colour combinations and remind you of a three dimensional representation of a complex mathematical function.
Holothurians are the sand gobblers of the marine world and though there is no obvious similarity, they are echinoderms like the starfish. They grow up to around 1.5m long and are so soft that they flatten and distort if you attempt to move them. A bit like a slimy, empty sausage skin. They are found widely on sandy surfaces in shallow waters.
These nasty guys are also very common, noctural feeders they are mostly found hiding within rocky crevices during daylight and rarely in the open as these were. Their delicate, venomous spines can easily penetrate a foot and break off within, leading to many days of excruciating pain. Stepping onto a rocky or coral surface without some form of protection is not to be recommended in tropical waters. What is the significance of these rarely seen blue lines, I have no idea. They do have a top mounted anal orifice with a retractable tube but it seems unlikely to be connected to this phenomena.
We never cease to be amazed by the shapes of the structures that the basic polyp elements that form corals organise themselves into. It is truly incredible that these invisibly small polyps join millions upon millions to form a structure such as all the ones above. Some, such as the soft coral Clavularia, look just like the flowers we see in a garden. An individual polyp comprises a fleshy sack topped with a ring of tentacles around a central mouth opening. Members of a colony are linked by living tissue that enables them to share nutrients. The colouration is derived from an algae incorporated in the structure which also assists in process of nutrient conversion to carbon rich organic compounds. When it dies its skeleton contributes to the formation of the solid limestone foundation of the reef.