|SCOR Working Group 118: New Technologies for Observing Marine Life|
Terms of Reference
Working Group Members
Funding provided by
the SLOAN Foundation's
Census of Marine Life
2002 Working Group Meeting
(28-30 October 2002, Lima, Peru)
Overview of Technologies Discussed
After reminding the group of its Terms of Reference, David Farmer chaired a discussion about the technological needs of the CoML Pilot Projects. This was followed by a discussion of possible synergies between the various technologies.Technical needs of CoML Pilot Projects
NaGISA is likely to have both sorting and archiving problems, given the wide range of material (macrophytes to meiobenthos) that it proposes to collect and the lack of basic facilities (electricity and microscopes) in some areas. A basic data collection protocol based on digital images and sequences from stereoscopy and mosaics (underwater archaeology) offers the prospect of cheap storage in minimal space. Physical samples might perhaps be archived at regional nodes. But, regardless of the location of the archive, sub-samples must be preserved for subsequent genetic analysis. This is a simple process, which entails fixing material quickly in formalin and then transferring it to ethanol. Although it is possible to travel with amplified DNA, local archives will probably increase in importance as it becomes progressively harder to ship samples, because of CITES regulations or security precautions.
Progress with acoustic identification in tropical regions, which would inevitably be slow, if tackled by individual research institutes, would be much faster and better co-ordinated if tackled by regional centres of excellence, which should be favourably regarded by international funding agencies. Molecular biology, optical technology and taxonomy would be other obvious candidates for centres of excellence, each with its own range of expertise and matching technology. Although it would still be necessary to provide technology appropriate to local problems, the South American participants agreed that there was strong support for international collaboration between their countries. They welcomed the proposal for a system of complementary centres of excellence, which they saw as a means of obtaining advanced technology and improving the infrastructure for marine research. At present, whilst some countries (e.g. Mexico) had good research vessels but poor technology, others had neither the vessels nor the technology. Mariano Gutiérrez Torero agreed to set up a sub-group to discuss possibilities for centres of excellence and prepare an agreed statement of needs. In addition to the World Bank, support might be forthcoming from the EU, which had apparently provided resources to single laboratories when arrangements were made to ensure collaboration with institutes in neighbouring countries. Another way of stimulating development would be for SCOR/CoML to bring international meetings to the centres of excellence. For example, Bill Karp suggested that FA,ST would welcome an invitation to hold its 2004 meeting in Peru now that country was an observer at ICES. Sponsorship from FAO might also be possible. Although Venema's retirement had removed FAO's internal driver for acoustics, FAO had recently joined the Fishing Technology and Fish Behaviour (FTFB) working group as a co-sponsor. FTFB and FA,ST both reported to the Fishing Technology Committee (FTC) at ICES.
In response to questions from Carlos Robinson and David Mellinger about possible effects of acoustic signals on other animals, Van Holliday and David Farmer pointed out that small fish tags produce no more noise than snapping shrimps and this will merge with the background noise within a few hundred metres. RAFOS signals are different, being transmitted in code at low power and at a much lower frequency, which changes with time. Neither is likely to have much effect on other animals, however, despite the problems of public perception that there have been with the ATOC experiments.
During further discussion, direct questions from David Farmer established that, although electronic tags are not currently used in South America, there was considerable potential to use them with both fish and marine mammals. Mariano Gutiérrez Torero explained that he wanted to use pop-up satellite-detected tags with tuna and hake and David Farmer drew attention to the opportunity to record oceanographic data from diving mammals at the same time as recording their behaviour. David Mellinger commented that Bruce Mate was keen to train people in South America to use electronic tags with marine mammals. Electronic tags were also highly suitable for benthic organisms as well as fish and mammals. As had been shown in Europe, where electronic tags had been applied to fisheries investigations for several decades, it was necessary to acquire descriptive data with individuals before trying to construct testable models of population behaviour. An automated tagging system allowed large numbers of pelagic fish to be tagged with PIT (passive integrating transponders) tags, which could detected relatively cheaply by scanning the catch on board the purse seine fleet. Data could be sent ashore by radio and the technique could provide a quantitative estimate of the stock, as well as information on its distribution. After discussion, it was the agreed to recommend the uptake of electronic tags in South America.
Landers can be used to estimate the number of species and individuals in an area, using bait, a flash camera and a simple current meter, all relatively cheap and simple technology. More sophisticated systems (e.g. the AUDOS system developed by the University of Aberdeen in Scotland) are available with scanning sonar and other advanced technology. The are many opportunities to develop innovative methods of attraction and repulsion, using light, sound and other factors. For exploited species, landers can be combined with long-lines to obtain much better estimates of fish density than can be provided by the lander itself. Conceptually, too, there is no reason why landers should not be used in midwater as well as on the bottom. Because they are likely to provide new insights and support new research projects at low cost, development and application of landers was recommended as a technical area deserving support.
These new tools would permit accurate descriptions of habitats, of the sort already required by EU governments ahead of the relevant technological developments. Changes in populations of benthos could already be recorded by sequential surveys using a sidescan sonar and good quality GPS, a point illustrated by Van Holliday, who showed tracks of dispersing animals recorded with a 100 kHz sidescan sonar in a patch of the burrowing urchin Brisaster. Emmanuel Boss pointed out that LIDAR and laser line-scan could also be used for habitat mapping and Bill Karp mentioned that scientists at the NMFS laboratory in Seattle are evaluating technologies for characterizing demersal habitat including video, sidescan sonar, multibeam sonar, and laser line-scan. Laser line-scan also holds promise for assessment of crab abundance. It was pointed out that there was a seabed group in Seattle pursuing this subject. Jorge Castillo drew the group's attention to two requirements in South America, the first to survey fish populations around sea mounts using a combination of acoustics and optics, and the second to measure the size of fish with a stereo camera. As Van Holliday pointed out, the second problem could be solved by using the camera in conjunction with two parallel laser beams, separated by a known distance.
Although not of specific relevance to TOPP, there followed a general discussion of ways of transmitting oceanographic data via the IRIDIUM system using Argo floats and gliders, whose characteristics were summarised by Emmanuel Boss. Both platforms offered exciting possibilities for biological oceanography, if the physicists could be persuaded to add the extra sensors. There were many Argo floats in use in the open ocean, costs were coming down and programmes were underway to add optical sensors (e.g. beam transmissometer). Biofouling problems could be solved with copper shutters and floats could remain at 1000 m for 10 days. Gliders contained a bladder and were able to change their buoyancy and centre of gravity with moving internal parts. They had small wings and were designed to make double-oblique dives at speeds of 20-25 cm s-1. On surfacing, they recorded their position by GPS and transferred data by IRIDIUM, or cellular phone link. Gliders could currently carry a CTD sensor and developments were underway to add sensors for measuring oxygen, fluorescence and backscatter (at two frequencies). They could maintain station for up to two weeks in a tidal regime with currents of 2 knots. Gliders were being developed in the USA by three groups, one of which was a commercial company. At present, costs were about $30-40 k.
In discussion, it was concluded that gliders had considerable potential for investigating smaller, coastal ecosystems at a much lower cost than a research vessel. They were non-intrusive, could be used for adaptive sampling and could be launched from a zodiac in shallow water. At present they were power-limited and could probably not carry a sonar. However, as Van Holliday pointed out, the power requirements of electronic devices decreased by an order of magnitude every few years. With appropriate sensor development, there was therefore considerable scope for the use of gliders over the next decade. More information is available from www.webbresearch.com using the link 'The SLOCUM glider' listed under Products and Projects.
Synergies between technologies