Diving in the “Muck Diving” Capital of the World- The Lembeh Straits

Image: Veronica and Dom rinsing the SVII camera


The team has just completed its first day of survey from the Ocean Rover boat, currently moored in the middle of the Lembeh Strait off the coast of Bitung. The Lembeh Strait is a very unique place, known by underwater photographers as the “muck diving” capital of the world.



What is muck diving?


Muck diving is a form of scuba diving activity that takes place in areas with darker sediments on the substrate referred to as “muck”.  In Lembeh this is created by volcanic black sand from the 11 volcanoes within a few kilometers of area. This provides a perfect contrast for macro-photographers to shoot pictures of all sorts of critters including octopus, dragonets, and ghost pipefish with the colours standing out against the black sand.



Bottlenecks and speciation


What really sets Lembeh Strait apart from other muck diving destinations is its location. The Lembeh Strait is a very narrow passage between mainland North Sulawesi and Lembeh Island. The area is already one of the world’s hotspots for global marine biodiversity, but the narrow passage and currents passing through the straits causes a bottleneck of zooplankton and other juveniles which cannot escape into the open ocean.  This bottleneck leads to increased evolution of new species known as speciation, caused by the constant mixing of new organisms getting isolated in the strait for millions of years.



Transects in the muck


We managed to complete two scientific transects in the muck with one starting in front of Critters Lembeh Resort. The SVII camera was driven at a slower speed than usual to ensure the orb (carrying the three cameras) did not bump into any corals, rocks or marine life due to the lowered visibility.


Despite the low visibility the dive was very interesting and I could see images of the colours popping out of the various coral and sponges on the tablet straight away! The SVII camera managed to get interesting shots of some unusual fish species, including bangai cardinal fish (Pterpogon kaudemi), a large school of convict blennies (Pholidichthys leucotaenia), ridged shrimpfish (Centricus scutatus), and a couple of barramundi cod (Cromileptes altives) amongst many more. Despite seeing these unusual special critters, I was really keen to sight the elusive wunderpus (Wunderpus photogenicus) or mimic octopus (Thaunoctopus mimicus). I am looking forward to the images being loaded to the Catlin Global Reef Record so I can inspect them and see what other weird and fun animals I can find.