The Diving: Map and explanations

Click on the map to enlarge it

Diving in Laamu Atoll differs from the other atolls to the north. The atoll has relatively few channels allowing water to enter and escape the atoll, meaning there is less plankton inside the atoll, which reduces current and improves visibility. The reduced flow of water inside the atoll is both good and bad for divers. The bad news is that on a given dive site, bio-diversity is reduced. Plankton is made up of millions of organisms and pelagic (blue water) larvae and eggs. The upside is that you can still find a variety of different animals from Ghost Pipefish, tuna, through to sharks, schooling mobulas and mantas…… but probably not on the same site. Coral formations are also quite different in this atoll with massive structures of both hard and soft corals which thrive in certain conditions like ours.
For photographers, visibility and current are often critical factors for increasing the amount of ‘keepers’. Great visibility means improved light at depth which is very important to retain colours in underwater photos. Little current means it is much easier to take more time in setting up your shot, allowing for easier buoyancy control to avoid scaring the subject, and to avoid damage to the fragile reef.
The two channels (kandu) which lie approximately 45mins to the north of the Diving Center are a hotspot for pelagics such as sharks- grey reef, whitetip reef, silky, nurse, leopard (zebra), thresher and hammerheads can be seen here when the conditions are right. Usually those conditions mean a medium to strong incoming current where water flows from east to west. Some species such as hammerhead and thresher sharks are found in deep water, especially if there is a thermocline at about the 30m/100ft mark. Sharks are opportunistic feeders for the most part and like to hang about reefs where there is a sudden upwelling of water. What happens is a classic food-chain starting from the basic organisms like plankton to apex predators like tuna, sailfish…. and sharks.
It works a bit like this: Plankton is made up of algae (phytoplankton) and microscopic animals and fish larvae (zooplankton) which feeds on the algae which, like all plants need sunlight to grow, so phytoplankton is found mainly at the surface. Zooplankton feeds on the algae during the night when they’re relatively free of predation from fishes. At sunset the zooplankton moves up to the surface and at sunrise they swim back down to depths of around 100m/300ft. Currents hit the reef wall and flow through the channels and the zooplankton is swept along in to the waiting mouths of thousands of plankton eating fishes and corals. These plankton eaters make up the majority of biomass of coral reefs….but waiting for them are predators like tuna, barracuda and jacks or trevally. They are some of the fastest swimming fishes and strike at incredible speeds- sometimes scoring a direct hit and sometimes injuring themselves os other fishes in their attempts. Sharks are attracted to these strikes and have keen senses to distinguish injured fish which they will attempt to take. At night sharks also come in to their own as powerful predators.
To give you some kind of idea about the depths around the Maldives, have a look at this depth chart showing depths in meters around these two kandu, and the northern point Isdhoo Muli. When you can measure depth in kilometers, that means seriously deep water and you can throw in terms like ‘The Abyssal Plain’ which sound really cool. The Isdhoo peninsular in particular has incredible dropoffs only a stonethrow from the outer reef. Divers have reported seeing ‘mola mola’ or sunfish can be found around here at certain times of the year. These massive and mysterious fish are not normally seen near reefs, but perhaps the proximity to deep deep water means we can see deep water fishes like mola mola, thresher sharks and hammerheads.

Click on the map to enlarge it

Imagine a mountain range stretching from the north to the south where all but the very tops of the mountains are visible above the clouds, and this gives you an idea of how the Maldives would look like without the water. Just as wind blows in through mountain valleys, water flows in and out of the atolls through the channels or kandu. The two kandu to the north are very narrow and shallow, and so a terrific volume of water passes through this with the turning tides. Oceanic currents also play a major part in dictating the direction of the current. Generally speaking the currents follow the wind patterns in the Indian ocean so that starting in December, the current flows from east to west pushing water in to the atoll (incoming current) and exiting on the western kandu. The wind direction reverses in April and so the two kandu to the north have more ‘outgoing’ currents with water flowing from west to east. In practice however, predicting currents drives even the most experienced guides and boat captains insane. Different water temperatures, salinity (salt) levels and densities cause different layers of water, and can mean water moving at different speeds and directions on any given dive, but especially when the currents are usually the strongest which is during spring tides in the months of January and May.
Directly inside these two kandus (Fushi and Maabaidhoo) there are a few pinnacles of coral growth which occur regularly in the Maldives. They’re a bit like irritations causing pearl growth in some oysters- a lot bigger but just as pretty. These pinnacles are called ‘thila’ in the Maldives and for some reason, they’re called ‘Haa’ down here in Laamu. These Thilas or Haa have a lot of variety in coral and fish species as they get good flow of nutrients from different directions as well as sunlight and shadows which offer ‘niche organisms’ to grow. Thilas (or Haa) are a bit like oasis in a desert- they have a lot of schooling fish like snapper, fusiliers and jacks as well as soft coral growth. The current is usually not very strong on these reefs in Laamu but there is usually a dominant side where the fast swimming, plankton-eating fish (and their predators) will be found, and a quieter side where the slower moving fishes hang out.
Then there are the inside reefs of Laamu which can hold many surprises. One dive site that we have found has a lot of pinnacles (or mini-thila) in a fairly small area. We first thought there was only a couple but have since found about 20 of them in one area. These are a unique feature in the Maldives in my experience- the coral formations are random and bizarre. Each mini thila has sections of overhangs and soft coral and then blue water surprises like reef sharks and schooling mobula rays (think mini mantas). By rights, these plankton feeders shouldn’t be found inside the atoll but we did, and this proves that even when you think you know something, nature shows you that you actually know very very little. The visibility is excellent inside the atoll allowing light to penetrate deeper than usual, and coral to grow at much greater depths than in other atolls in the Maldives. This and Laamu’s lack of tourism pressure may be a reason why the coral is in such excellent condition and seems to have been little affected by the bleaching epidemic of the mid-nineties.
The inside walls of Laamu offer very easy diving with a relatively shallow bottom of around 25m/80ft and little current. We have found ghost-pipefishes (ornate and robust) as well as lots of different stingrays and the occasional manta. The plankton is often thickest on the inside reefs due to the availability of plenty of food (in this case plenty of flotsam, and harbours which pool water) and this means that biodiversity increases…. at the expense of visibility. Seagrasses grows in the shallows which is a favourite food of green turtles.
One exciting new prospect for us is exploring the areas between the islands on the eastern edge of the atoll. These small shallow passes also have a lot of current flow and may prove to be excellent habitats for juvenile fishes and macro-lovers.

One thought on “The Diving: Map and explanations

  1. Pingback: Dive Sites Complete - Maldives Complete Blog

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s