Explore the Deep Sea
Expeditions
Expedition 4: Deep-sea creatures
The fourth of five expeditions to the Lau Basin (in May 2005) picked up where the third expedition left off. The main focus was on deep-sea biology, especially on:
- Genetic analysis. Researchers are examining vent animals' genetic material (DNA), to investigate how individuals at different vent sites are related to each other, and how genetically diverse they are (a high degree of genetic diversity can be a good thing if the environment changes, because in a diverse population there are more likely to be individuals which can survive in new conditions). This will help answer the puzzle of how populations of animals develop at vent sites, and how and when dispersal between vent sites might take place.
- Mussel ecology. Mussel beds found in the Lau Basin are being compared with those found elsewhere in the world, to understand more about how and when creatures in the Lau Basin evolved.
The right tools for the job
Researchers are sending the remotely-operated submarine vehicle Jason II down to the seafloor, thousands of meters below the ship. Jason can collect samples from the seafloor and the water column using specialized equipment. For instance:
- Sediment scoops are canvas bags. Jason grasps the bag's T-shaped handle with its manipulator arm, and drags the bag along the seafloor.
- A suction sampler can be used to “vacuum” up animals. The samples are deposited in mesh-lined canisters for their journey to the surface. Crab traps (left) and mussel pots are also used to collect live specimens.




