Instruments and MethodsLive capture of megafauna from 2300 m depth, using a newly designed Pressurized Recovery Device
Introduction
The last 30 years have seen the discovery of several deep-sea ecosystems (hydrothermal vents, cold seeps, whale-falls, sunken woods, and seamounts (Tyler, 1995)) which have modified our vision of the deep sea. Once considered as a homogeneous biological desert (Menzies, 1965), it is now seen as a patchwork of habitats where life may show diverse forms, with locally high biomasses (Van Dover et al., 2002). At the same time, the interest for fishing resources in the deep sea has grown to an alarming degree (Devine et al., 2006; Glover and Smith, 2003), pointing to the risk of severe ecosystem perturbation. Several other forms of human activity are threatening the largest habitat of the biosphere, such as CO2 sequestration projects, waste dumping, mineral prospecting, and their impact on deep-sea fauna has barely been evaluated (Glover and Smith, 2005). It is therefore a matter of urgency to learn more about the ecology and the biology of deep-sea species, especially concerning their response to environmental changes. Although in situ experiments have yielded some interesting results (Bailey et al., 2002; Vardaro et al., 2007), laboratory studies of live animals are a precious tool here, since they allow physiological investigation at various levels, from genetic expression to organismal, physiological, and behavioural responses. Unfortunately, while some organisms may be studied in pressurized aquaria (Childress et al., 1993; Shillito et al., 2001; Girguis and Lee, 2006), many deep-living creatures preclude in vivo investigation because of lethal decompression effects upon sampling (MacDonald, 1997). The addressing of these issues requires that target species be (i) captured at depth, (ii) recovered at their natural pressure, and (iii) studied in vivo at the laboratory. In most previous attempts involving pressurized recovery (MacDonald and Gilchrist, 1972; Yayanos, 1978; Drazen et al., 2005; and references herein), a single container fulfilled these three tasks. This may lead to contradicting technical requirements and we believe that experimental possibilities would be greatly expanded by using dedicated cells for each of these tasks. Here we give account of the recovery of live animals from depths exceeding 2000 m, using a new Pressurized Recovery Device (PRD) named PERISCOP (Projet d’Enceinte de Remontée Isobare Servant la Capture d’Organismes Profonds). This prototype aims at making pressurized recovery a more efficient and practical process. Additionally, its present design is adapted to future evolutions: the transfer of freshly caught animals, without decompression, towards larger ship-based pressure aquaria.
Section snippets
General principle
The PERISCOP system is composed of: (1) an in situ sampling cell (Fig. 1) and (2) a PRD, designed to maintain in situ pressure during recovery (Fig. 2). The PRD is installed on a “shuttle” device, which is moored and recovered away from the submersible. Once fauna have been confined inside the sampling cell, the latter is stored inside the PRD, which is then sealed and later recovered after ascent through the water column. In addition, the main aperture of the PRD is designed to permit future
The sampling process (Fig. 4)
During the MOMARETO cruise in August 2006 (Mid-Atlantic Ridge), we made six attempts at recovering hydrothermal vent organisms at their native pressure (Table 1), by using the Remotely Operated Vehicle (R.O.V.) Victor 6000 (Ifremer). Two additional “control” attempts were made using the PRD, but with no pressure retention (i.e. V4 had been left open, see Fig. 2). Three shrimp and one fish species were sampled, at depths of 1700 (Mirocaris fortunata and Chorocaris chacei) and 2300 m (Rimicaris
Sampling efficiency and specificity, normal and safe operation
There have been previous successful attempts to recover deep-sea organisms at their native pressure, despite the difficulties involved in achieving this task (Yayanos, 1978; MacDonald and Gilchrist, 1982; Jannasch et al., 1982; Wilson and Smith, 1985; Bianchi et al., 1999; Koyama et al., 2002; Drazen et al., 2005). With regard to megafauna, the first challenge is to manage efficient capture. Most existing devices act as baited traps. One main drawback here is that the target species must be
Conclusion
The success of the PERISCOP provides a new step towards allowing biologists normal and practical access to live deep-sea megafauna. Three major improvements are proposed, with respect to previous devices. Their aim is to: (i) allow choice of sampling by a submersible, without requiring exclusive dedication of the dive towards this task; (ii) improve safety and simplicity of pressure compensation, as well as recording pressure and temperature history during recovery; and (iii) propose a system
Acknowledgements
We are indebted to Captains and crews of N/O “Pourquoi Pas ?” and ROV “Victor 6000” (Ifremer). This research was funded by the European Community program EXOCET/D (FP6-GOCE-CT-2003-505342). We are also grateful to P. Gavaia, E. Bonnivard, and S. Halary for their help, and to the chief scientists of previous cruises (D. Jollivet for Biospeedo 2004 and A. Godfroy for Exomar 2005), along with the Captains and crews of the manned submersible “Nautile”, and N/O “Atalante” (Ifremer) for participating
References (30)
- et al.
Measurement of in situ oxygen consumption of deep-sea fish using an autonomous lander vehicle
Deep-Sea Research I
(2002) - et al.
A high-pressure sampler to measure microbial activity in the deep sea
Deep-Sea Research I
(1999) - et al.
Thermally protecting cod-ends for the recovery of living deep-sea animals
Deep-Sea Research
(1978) - et al.
Pressure-stat aquarium system designed for capturing and maintaining deep-sea organisms
Deep-Sea Research
(2002) Hydrostatic pressure as an environmental factor in life processes
Comparative Biochemistry and Physiology
(1997)- et al.
The pressure tolerance of deep-sea amphipods collected at their ambient pressure
Comparative Biochemistry and Physiology
(1982) Fish at high pressure: a hundred year history
Comparative Biochemistry and Physiology
(2002)- et al.
A study of possible “reef effects” caused by a long-term time-lapse camera in the deep North Pacific
Deep-Sea Research
(2007) - et al.
Live capture maintenance and partial decompression of a deep-sea grenadier fish (C. acrolepis) in a hyperbaric trap-aquarium
Deep-Sea Research
(1985) - et al.
New species of Pachycara Zugmayer (Pisces: Zoarcides) from the Rainbow Hydrothermal Vent Field (Mid-Atlantic Ridge)
Copeia
(2005)
Worms bask in extreme temperatures
Nature
Thermotolerance and the ‘pompeii worms’
Marine Ecology Progress Series
Inorganic carbon uptake in hydrothermal vent tubeworms facilitated by high environmental pCO2
Nature
Fisheries: deep-sea fishes qualify as endangered
Nature
Cited by (40)
Update of the PERISCOP system for isobaric sampling of deep-sea fauna
2023, Deep-Sea Research Part I: Oceanographic Research PapersCitation Excerpt :The PERISCOP system is attached to a shuttle device, which allows mooring and recovery of various instruments and tools related to the submersible's activity during scientific dives. The shuttle presented in Fig. 4 belongs to the Nautile team (Ifremer's manned submersible, so-called Human Occupied Vehicle, or H.O.V.), however the PERISCOP has also been successfully used with two other shuttle devices belonging to the Victor 6000 team (Ifremer's Remotely Operated Vehicle, or R.O.V., see Shillito et al., 2008). As described in Shillito et al., 2008, the PERISCOP system allows active sampling of fauna by means of a deep submersible, i.e. it allows choosing for samples, as opposed to most other PRDs which rely on attraction of fauna to bait.
Capturing amphipods in the Mariana Trench with a novel pressure retaining sampler
2022, Deep-Sea Research Part I: Oceanographic Research PapersActive temperature-preserving deep-sea water sampler configured with a pressure-adaptive thermoelectric cooler module
2022, Deep-Sea Research Part I: Oceanographic Research PapersCitation Excerpt :The autonomous microbial sampler keeps the sample in a thick-walled insulation chamber made of high-density polyethylene (HDPE) material which has low thermal conductivity; the temperature inside increases by 3°C in 0.5 h and 7°C in 1 h (Taylor et al., 2006). A sampling system named PERISCOP can recover deep-sea animals and maintain the in situ pressure and temperature by putting the entire pressurized device into a box made of heat-insulating material such as syntactic foam; the internal temperature increased about 6°C after about 40 min’ recovery operation, the seafloor temperature was 4–5°C and the surface water temperature was 23–25°C range throughout the cruise (Shillito et al., 2008). All the samplers mentioned above used passive temperature preservation to maintain the sample at a low temperature.
Baited camera survey of deep-sea demersal fishes of the West African oil provinces off Angola: 1200–2500m depth, East Atlantic Ocean
2017, Marine Environmental ResearchCitation Excerpt :In our study there is little evidence to suggest that the zoarcids were consuming bait and their posture and distribution around the bait favours a grazing predatory strategy. Zoarcid fishes are commonly found in sulfide-rich habitats such as mud volcanoes (Milkov et al., 1999), hydrothermal vents and cold seeps (Rosenblatt and Cohen, 1986; Sibuet and Olu, 1998; Biscoito et al., 2001, 2002; Shillito et al., 2008) and are even thought to play a significant role in determining the biological structure of vent habitats (Sancho et al., 2005). Dense populations of benthic zoarcids are known to occur around pockmarks (Hovland et al., 2005) which, are common to this study site (Olu-Le Roy et al., 2007; Savoye et al., 2009).
Long-term maintenance and public exhibition of deep-sea hydrothermal fauna: The AbyssBox project
2015, Deep-Sea Research Part II: Topical Studies in Oceanography