Recovery of Deep Seawater at Constant Pressure

Abstract

WE wish to report here a significant stage in the development of equipment which will recover deep sea animals at constant pressure and temperature. Organisms in the deep sea live at hydrostatic pressures which are lethal to ordinary surface living forms. Pressure increases by 1 atmosphere (14.7 pounds/inch²) for each 10 m depth and rises to 1,000 atmospheres in the deep trenches. Pressures in the range 0–1,000 atmospheres affect the dissociation and hydration of ions^1,2, and alter the colloidal structure of cytoplasm, inhibiting cell division and similar phenomena^3–5. Pressure may accelerate or retard the rates of many biological reactions^6–8, and affect the normal functioning of muscle and nerve^9,10 and various complex cellular structures^11,12. The variety of organisms found at depth¹³ shows that pressure adaptation is common, but there have been all too few experiments carried out on deep sea organisms¹⁴. We are proposing to filter planktonic animals at various depths and recover them without loss of pressure in a pressure vessel fitted to the cod end of a plankton net. On recovery the plankton suspension will be transferred to an experimental pressure vessel without serious pressure fluctuation. Optical and polarographic techniques are already available for the measurement of respiration, activity and survival of plankton suspensions at pressure.