Baseline and Environmental Monitoring in Deep Water - A New Approach (original) (raw)
Related papers
2008
The survey was carried out in the same three areas as 2006 and 2007, reflecting fishing areas covered during the Irish deepwater survey programme in the 1990s. Two areas were located on the western continental slope (FRS regions 2&4) and one area on the northern slope of the Porcupine Bank (FRS region 5). The overall sampling area, with fishing tows, is shown in figure 1. The survey was coordinated with the Scottish deepwater survey that covers the slope in area IVa from 55º to 58.5ºN and comparative tows were carried out in Areas 2 and 4. Sampling procedures Fish tows In each area trawl hauls were made at four depths, 500m, 1000m, 1500m and 1800 meters, along the slope, Table 1. The plan was to conduct two hauls at each depth in each area. Effective fishing time, when the net settled on the bottom, was set at two hours. The tows were the same as last year. A new 1800m tow had to be scouted in both Areas 2 and 4, as we only had one tow at this depth last year. Similarly we had to find two new tows at 500m in Area 5. We had suffered gear damage on all tows at this depth in previous years. Hauls were carried out along the slope. Comparative Tows Comparative tows were carried out with the RV Scotia in Areas 2 and 4. For the first time both ships were in the same areas at the same time. In previous years the Explorer tended to fish sites a week ahead of the Scotia. CTD transects CTD transects were carried out in the same locations as last year, Table 3, Figure 1. Like last year it was occasionally necessary to collect the data over two nights. Plankton samples were collected at each station. A Bongo net was hauled vertically from 200m. Fish sampling At each station the entire catch was sorted to species level and weighed. Full biological sampling, length, weight, sex, maturity and age, was carried out on all commercial species. Additional biological sampling, without ageing, was carried out on all elasmobranchs and chimareids. For each species a random sample of the entire catch was taken for these measurements. Where fish were difficult to identify samples were preserved for further identification ashore. Samples of unusual or rare fish were also preserved. Length measurements for various fish species were agreed on; Sharks total length Skates total length Chimaeras pre supra caudal fin Rhinochimaerids second dorsal fin Grenadiers snout to base of anal fin Bony fish total length Orange Roughy total length Black Scabbard total length. Smoothhead standard length Black Scabbard: As well as samples for our own programme Black Scabbard samples were collected for a Ph. D. student in UCC. Lengths, weights, otoliths, gonads and genetic samples were taken.
New techniques in sediment core analysis: an introduction
Geological Society, London, Special Publications, 2006
Marine sediment cores are the fundamental data source for information on seabed character, depositional history and environmental change. They provide raw data for a wide range of research including studies of global climate change, palaeoceanography, slope stability, oil exploration, pollution assessment and control, and sea-floor surveys for laying cables, pipelines and siting of sea-floor structures. During the last three decades, a varied suite of new technologies have been developed to analyse cores, often non-destructively, to produce high-quality, closely spaced, co-located downcore measurements, characterizing sediment physical properties, geochemistry and composition in unprecedented detail. Distributions of a variety of palaeoenvironmentally significant proxies can now be logged at decadal and, in some cases, even annual or subannual scales, allowing detailed insights into the history of climate and associated environmental change. These advances have had a profound effect on many aspects of the Earth Sciences, particularly palaeoceanography. In this paper, we review recent advances in analytical and logging technology, and their application to the analysis of sediment cores. Developments in providing access to core data and associated datasets, and data-mining technology, in order to integrate and interpret new and legacy datasets within the wider context of sea-floor studies, are also discussed. Despite the great advances in this field, however, challenges remain, particularly in the development of standard measurement and calibration methodologies and in the development of data analysis methods. New data visualization tools and techniques need to be developed to optimize the interpretation process and maximize scientific value. Amplified collaboration environments and tools are needed in order to capitalize on our analysis and interpretation capability of large, multi-parameter datasets. Sophisticated, yet simple to use, searchable Internet databases, with universal access and secure long-term funding, and data products resulting in user-defined data-mining query and display, so far pioneered in the USA and Australia, provide robust models for efficient and effective core data stewardship.