Development of a hyperbaric trap-respirometer for the capture and maintenance of live deep-sea organisms

Abstract

A major obstacle to the investigation of deep-sea biology is the lack of instrumentation to retrieve deep-sea organisms from their habitat alive, particularly fishes with physoclistous swimbladders. To perform physiological experiments on deep-sea fishes under in situ but controlled conditions, we constructed a high-pressure fish trap-respirometer to capture deep-water fishes at depth and return them to the surface alive at in situ pressure and temperature. Pumps and instrumentation connected aboard ship or in the laboratory are used for maintenance of the animal and experimentation. The trap was designed so that respiration rates, pressure tolerance, and metabolic responses to various gas concentrations (CO 2 and O 2 ) could be examined in a controlled environment. The trap is deployed as an autonomous lander or free vehicle to depths of 4000 m. Once on the seafloor, a fish is captured on a baited hook that triggers the reeling of the fish into the pressure vessel and closure of its sealing door. Two fish, Coryphaenoides acrolepis, have been recovered live from 1450 m and maintained in the laboratory. Both fish were retrieved at ~95% of their in situ pressure and at temperatures of ~6°C. Oxygen consumption rates of these fish were 54.99 µmol O 2 kg -1 h -1 (1.158 kg, 65.0 cm total length, 23.5 cm pre-anal fin length) and 79.43 µmol O 2 kg -1 h -1 (1.305 kg, 66.5 cm total length, 24.5 cm pre-anal fin length). The latter fish was maintained for 3.5 d, and it survived gradual decompression to 76% of the pressure at its capture depth.

Precise continuous measurements of pelagic respiration in coastal waters with Oxygen Optodes

“…comm.). In other systems with Optodes, such as bottomlanders, neither Drazen et al (2005) nor Sommer et al (2008) reported any significant Optode drift over more than 9 h. Signs of system drift of other sensors during the first 10 h can, however, be seen in control samples, although drift rates were not estimated or discussed by the authors (Griffith 1988;Briand et al 2004). …”

“…The same system was used to estimate copepod respiration in small glass vessels (Koster et al 2008). Drazen et al (2005) presented a novel technique with an Optode to measure respiration rates of deep sea fish, and Sommer et al (2008) described an automatic system to regulate oxygen levels and measure sedimentwater fluxes during in situ sediment incubation at vent sites. Additionally, Pakhomova et al (2007), Almroth et al (2009), and Almroth-Rosell et al (2012) used the same type of Optodes with autonomous landers to perform sediment-water incubation studies.…”

The rate of metabolism in marine animals: environmental constraints, ecological demands and energetic opportunities

“…The state of our knowledge remains technology and resource limited, but steady advances (Childress et al 1978;Childress 1985;Robison 2000;Koyama et al 2002;Drazen et al 2005) have allowed the live capture, surface maintenance and measurement of a surprisingly large number of deep-sea animals. A necessarily smaller number of oxygen consumption measurements have been made in situ on the deep-sea floor but techniques for these types of investigations have also seen many advances in recent years (Smith 1978;Smith & Baldwin 1997;Priede & Bagley 2000;Bailey et al 2002).…”

Chasing the Future: How Will Ocean Change Affect Marine Life?

“…What are the natural metabolic rates of active deepsea fishes, and how will they respond to changing CO 2 and O 2 levels? To address this question, MBARI scientists and engineers fabricated a hyperbaric fish trap ( Figure 4) capable of capturing deep-sea fishes (to 4,000 m) and returning them to the laboratory for physiological studies under the pressure, oxygen, and temperature conditions of their capture depth (Drazen et al, 2005).…”