Latham Island lies some 66 kilometers to the east of Dar es Salaam off the Tanzanian coast. It is a flat coral island some 300 meters wide by some 300 meters long. lies some 66 kilometers to the east of Dar es Salaam and it is a flat coral island some 300 meters wide by some 300 meters long. It is named after the East Indiaman Latham which discovered the island in 1758. It was annexed by Zanzibar in 1898 and now forms part of the United Republic of Tanzania.
Depending on which monsoon winds are blowing there is often a sandbank attached to the island which moves around as the wind changes direction. The East African Coastal Current flows past the island from south to north and is gradually eroding it away. Also depending on which monsoon wind is blowing, the current speed varies and is at its highest between July and November and at its lowest in February and March. The current can be quite strong.
When arriving in the vicinity of the island particularly if one is downwind, the first thing that comes to ones attention is the smell. In fact it can make one gasp for breath if one gets a full whiff of the smell. Depending on the tide and the sea state , it can be a bit tricky going ashore on the island as there can be a bit of a shore break if the swell is up.
Due to the islands isolated location it has for centuries been the breeding ground for at least four species of seagulls . The Swift Tern (Sterna bergii thalassina) , the Common Noddy (Anous stolidus plumbeigularis) the Masked booby (Sula dactylatra melanops) and the Sooty Tern (Sterna fuscata nubilosa) are known to breed on the island. The ammonia like smell from the guano is pretty powerful.
The visibility is excellent, as good as the cleanest swimming pool or aquarium one can imagine. Looking over the side of the boat with the bottom at 14 meters one can easily follow individual reef fish. It does not get better than this in salt water. In the image below the depth is about 20 meters. It is very blue.
In late February 2021, we dived the west side of the island , there is little reef on this side of the island just a sand drop off and perhaps because of the excellent visibility , there are grass patches down to 35 meters which one does not usually see. We then tried diving the east side of the island , which on the chart looked encouraging but we found only grass beds on this side of the island.
There were however large numbers of the quite rare Ring-cheek slender wrasse ( Pseudojuloides argyreogaster) present in these grass beds. In every other location I have seen these fishes they are reclusive and hard to approach. On the grass beds on the east side of the island they were in great abundance.
We later learnt that the reef in the area is mainly to the south of the island and unfortunately had to leave this for the next trip to the area !
Aside from the large numbers of Pseudojuloides argyreogaster , we found a pair of Dragonets that appear to be undescribed. These are pictured below.
These specimens found at around 30 meters on rubble bottom. About 6 cm in length. Unfortunately my camera was not set up for macro images on this trip. They appeared to be engaged in mating behavior with the male in foreground below showing off for the female.
The other probably undescribed fish that was found is what appears to be a Pterogogus species which does not resemble any other species known.
This specimen was in the grass beds at around 18 meters and was one of two seen. Approximately 12 cm in length. Very reclusive and very hard to photograph as it hid in the grass if one approached it.
With some luck the next time the weather settles another trip can be planned to dive the South of the Island . Looking forward to it !