An Anchor-box dredge for deep-sea sampling

Carey, Andrew G.; Hancock, Danil R.

doi:10.1016/0011-7471(65)90816-8

Cited by 4 publications

(4 citation statements)

References 2 publications

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“…In deep water, neither gear has much drag on descent in relation to that of the wire and the empirical curve provided by Carey and Hancock (1965) for dredging, and may be used to approximate the final payout necessary in relation to depth. The mouth of the trawl should be rigged with chain links lashed along the mouth edges to ensure the leading edge will run over the sediment surface and take up animals.…”

Section: Trawlsmentioning

confidence: 99%

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Deep‐Sea Benthic Sampling

Gage¹,

Bett²

2005

Methods for the Study of Marine Benthos

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Section: Trawlsmentioning

confidence: 99%

“…7.10d). In the Anchor Box Dredge of Carey and Hancock (1965), the canvas collecting bag is replaced by a 57 cm wide steel box equipped with removable hardened steel cutting teeth ( Fig. 7.10e).…”

Section: Anchor Dredgesmentioning

confidence: 99%

Deep‐Sea Benthic Sampling

Gage¹,

Bett²

2005

Methods for the Study of Marine Benthos

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“…A modified version of the Sanders' anchor-dredge (the Anchor-Box Dredge) was developed by Carey and Hancock (1965). This samples an area of 1.3 m 2 , to a depth of 10 cm, and has been successfully used to depths of 2800 m, where it was worked with a warp to depth ratio of 1.39:1.…”

Section: Fig 58mentioning

confidence: 99%

Macrofauna Techniques

and¹,

Moore²

2005

Methods for the Study of Marine Benthos

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“…This mechanism allows the suprabenthic-and epibenthic net to immediately close once the EBS has left the bottom . Compared to other devices such as the anchor-box dredge or box dredge (Macintyre 1964;Carey and Hancock 1965), the EBS has good hydrodynamic properties, maintaining a stable position in the water column. Its robust construction and steel frame minimise mechanical damage during sampling, allowing to sample on hard substrates among rocks and slopes .…”

Section: Sampling Effort In the Somentioning

confidence: 99%

Diversity and biogeography of southern ocean peracarid crustaceans in a changing environment

Franco¹

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The Southern Ocean (SO) is one of the most pristine regions of our Planet, characterised by high levels of biodiversity (5% of the global diversity) (David and Saucède 2015) and hosting a unique fauna (up to 90% of SO species are endemic) (De Broyer and Danis 2011; Chown et al. 2015). Yet, the knowledge on SO biodiversity is still far from being completed. In addition, the knowledge on the impact that changing environments have on SO species-richness is very little and for some groups, it is still totally unknown. For instance, most of studies generally focus on one single species such as Antarctic krill (Kawaguchi et al. 2011), Clio pyramidata Linnaeus, 1767 (Orr et al. 2005), Globigerina bulloides d'Orbigny, 1826 (Moy et al. 2009), or only on a high taxonomic level (e.g. phylum, class): Echinodermata, Crustacea, Mollusca, Porifera, Bryozoa, Brachiopoda, Hydrozoa, Ascidiacea, Holoturoidea (Barnes 1999; Rowden et al. 2015; Post et al. 2017; Gutt et al. 2019; Vause et al. 2019; Pineda-Metz et al. 2020). Ultimately, the influence of sea-ice coverage on benthic species diversity was totally unknown prior to this study. In light of this, the objectives of the thesis are: 1. To expand the knowledge on shelf and deep-sea peracarid assemblage structure and abundance on a small regional (Weddell Sea) and on a large regional (Atlantic sector of the SO and South Atlantic Ocean) geographic scale. 2. To assess the environmental variables driving peracarid assemblage structure and abundance from the above mentioned areas. 3. To investigate SO benthic isopod species diversity from the Atlantic sector of the SO and assess the influence of environmental variables on their species-richness and composition. 4. To describe new possible peracarid species by means of integrative taxonomy, using morphological descriptions and whole genome sequencing analyses to support the species identification. Objective outcomes: The present thesis provides new information on the abundance and assemblage structure based on 64766 peracarid crustaceans from different 28 locations within the Atlantic sector of the SO continental shelf and deep sea (Chapters I-II). These locations are characterised by different environmental conditions, for instance different sea-ice concentrations. Results from Chapters I-II confirmed the dominance of peracarid assemblages in the benthos, with amphipods being the most abundant group, followed by isopods. Sea ice was identified as the main driver shaping benthic peracarid assemblage structure (Chapter I). On a larger geographic scale and wider bathymetric range (e.g. including sampling locations from previous studies performed in the South Atlantic Ocean and at a depth range from 160 to ~6000 m), depth was the main physical variable driving peracarid assemblage structure (Chapter III). In addition, 16157 isopod specimens from the Atlantic sector of the SO were identified to species level at a smaller scale (Chapter IV). In this case, sea ice was identified as the main physical driver affecting isopod diversity and composition among sampling locations (Chapter IV). Reduced concentration of sea ice causes a decrease in isopod biodiversity, thus climate change was identified as a huge threat for this taxon and for SO benthos in general. During the identification process, two new isopod species were discovered (Chapter V). The two new species (Notopais sp.1 n. sp. and Notopais sp.2 n. sp.) were accurately described and identified by means of integrative taxonomy. This provided the first whole genome sequencing of benthic isopods from the SO and the first complete mitochondrial genome of the genus Notopais (Chapter V). Thanks to the collaboration with the University of Genoa (Dipartimento di Scienze della Terra dell'Ambiente e della Vita, DISTAV, Italy) and the National Antarctic Museum (MNA) in Genoa, two new SO species of the suborder Valvifera G. O. Sars, 1883 were described by means of classical taxonomy. In this case, a molecular approach could not be used because both new species were represented by a single specimen, therefore it was important to preserve the integrity of the holotypes (Chapters VI-VII).

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An Anchor-box dredge for deep-sea sampling

Cited by 4 publications

References 2 publications

Deep‐Sea Benthic Sampling

Deep‐Sea Benthic Sampling

Macrofauna Techniques

Diversity and biogeography of southern ocean peracarid crustaceans in a changing environment

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