Lander techniques for deep-ocean biological research

Photographic landers have proved to be a useful tool for deep-ocean biological research. This paper presents a calculation to define the niche landers have when compared to wire gears used on research vessels, and then describes how landers have developed to enable experiments previously only possible in shallow water or in the laboratory to be transported to the deep ocean at depths to 6000m. A number of diverse case studies using the authors' landers are described to illustrate these developments. These studies include fish tracking experiments using the AUDOS (Aberdeen University Deep Ocean Submersible) Lander to study deep-ocean fish movements. Two experiments designed to investigate deep-ocean fish physiology are presented; the first investigated muscle performance of fish in-situ using an electrical stimulator aboard the 'Sprint' Lander; and the second describes a lander capable of trapping and measuring the in-situ oxygen consumption of deep-ocean fish. A further case study to investigate bioluminescence in both the water column and on the sea floor to abyssal depths using the SIT (Intensified Silicon Intensified Tube) lander is described. Finally, to investigate the effects of time signals on deep-ocean animals a case study using the DOBO (Deep Ocean Benthic Observer) lander is detailed.