Particle Size Analysis and organic carbon content data from marine sediment samples within the Trevose Box, off southwest England, April 2023 (DEFRA funded FISP project)

Particle Size Analysis (PSA) and organic carbon content data from marine sediment sampling of two plots within the Trevose Box off south-west England between 14 - 18 April 2023 before and after fishing. This DEFRA funded FISP (Fisheries Industry Science Partnerships scheme) project aimed to understand the acute effects of scallop dredging and beam trawling on seabed carbon. The project was led by Bangor University in collaboration with Imperial College London, CEFAS, Western Fish Producers Organisation and the South Western Fish Producer Organisation. The study was conducted in two areas offshore south-west England, UK. The areas were within the Trevose box, which is a management area closed to bottom fishing for the months of January, February and March each year. This allowed us to sample areas which had not been exposed to fishing immediately before our sampling which would reduce the chance of seeing any effect from our experimental fishing. One plot was designated an area that would be experimentally fished by a beam trawler, and another by a scallop dredger (Figure 1). The plots were chosen to minimise differences in depth, seabed habitat, sediment type, wave energy and tidal currents within and between them. Both were chosen where their respective types of fishing gear had been used previously, although scallop dredging has been less common in this area in recent years. The sampling from the RV Prince Madog and experimental fishing from the fishing vessels took place between 14 – 18th April 2023. Before any fishing activity took place, grab sampling was conducted in the dredge plot and in the beam trawl plot that would be later fished to varying amounts, which will be referred to as ‘Times fished’ or ‘fishing intensity’. A 0.1 m2 Day grab was used. When the day grab was onboard two cores were used to subsample the grab sample as deep as possible, these were then sliced in 1 cm intervals and frozen onboard for later carbon analysis. A homogenised sample from the day grab was also taken for Particle Size Analysis. After the ‘Before’ grab samples were taken, a beam trawler and scallop dredger towed their gear along the sampled lanes in each respective plot. The 'After’ samples were taken after that fishing activity. Please see report for full details on how the PSA and organic content values were determined. Whitton, T.A., Austin, M., Newbould, A., Kennedy, H., Allender, S., Cavan, E., Parker, R., North, C., Hatchman, J., Hiddink, J.G. (2024) The impact of mobile demersal fishing on blue carbon in seabed sediments. Report to DEFRA. https://research.bangor.ac.uk/portal/en/researchoutputs/the-impact-of-mobile-demersal-fishing-on-blue-carbon-in-seabed-sediments(1fa1845a-6669-4b5b-83e1-234a6eafc75c).html

Date (Creation): 2024-11-20

Citation identifier: http://data.bgs.ac.uk/id/dataHolding/13608317

Point of contact

Organisation name	Individual name	Electronic mail address	Role
Bangor University	Tim Whitton	not available	Originator
Bangor University	Jan Geert Hiddink	not available	Originator
Bangor University	Alice Newbould	not available	Originator
Bangor University	Susan Allender	not available	Originator
British Geological Survey	Enquiries	not available	Custodian
British Geological Survey	Enquiries	not available	Distributor
British Geological Survey	Enquiries	not available	Point of contact

Maintenance and update frequency: notApplicable

GEMET - INSPIRE themes, version 1.0

Geology

BGS Thesaurus of Geosciences

Grab samples
TOC
Particle size distribution
NGDC Deposited Data
Citable Data
Marine surveys
MEDIN
Marine sediments

dataCentre

Keywords

NERC_DDC

Access constraints: Other restrictions

Other constraints: no limitations

Other constraints: The dataset is made freely available for access, e.g. via the Internet. Either no third party data / information is contained in the dataset or BGS has secured written permission from the owner(s) of any third party data / information contained in the dataset to make the dataset freely accessible.

Use constraints: Other restrictions

Other constraints: The copyright of materials derived from the British Geological Survey's work is vested in the Natural Environment Research Council [NERC]. No part of this work may be reproduced or transmitted in any form or by any means, or stored in a retrieval system of any nature, without the prior permission of the copyright holder, via the BGS Intellectual Property Rights Manager. Use by customers of information provided by the BGS, is at the customer's own risk. In view of the disparate sources of information at BGS's disposal, including such material donated to BGS, that BGS accepts in good faith as being accurate, the Natural Environment Research Council (NERC) gives no warranty, expressed or implied, as to the quality or accuracy of the information supplied, or to the information's suitability for any use. NERC/BGS accepts no liability whatever in respect of loss, damage, injury or other occurence however caused.

Other constraints: There are no restrictions on the use that may be made of the dataset, although an appropriate copyright acknowledgement must be made when any part of the dataset is reproduced. Either no third party data / information is contained in the dataset or BGS has secured written permission from the owner of any third party data / information contained in the dataset to make the dataset freely available without any use constraints - inclusion of any third party data / information will affect the copyright acknowledgement that needs to be made.

Spatial representation type: Vector

Language: English

Topic category

Geoscientific information

Geographic identifier: BRISTOL CHANNEL [id=2001350]
British Geological Survey Gazetteer: Gazetteer of sea areas 2010 revision

Geographic identifier: CELTIC SEA [id=2001353]
British Geological Survey Gazetteer: Gazetteer of sea areas 2010 revision

Begin date: 2023-04-14

End date: 2023-04-18

Unique resource identifier: WGS 84 (EPSG::4326)

Distribution format

Name	Version
.xlsx

Distributor contact

Organisation name	Individual name	Electronic mail address	Role
British Geological Survey	Enquiries	not available	Distributor

OnLine resource

Protocol	Linkage	Name
	https://webapps.bgs.ac.uk/services/ngdc/accessions/index.html#item186571	Data

OnLine resource

Protocol	Linkage	Name
	https://doi.org/10.5285/6d342aad-6b68-4345-beee-3cee4cb516c9	Digital Object Identifier (DOI)

Hierarchy level: Dataset

Other: dataset

Conformance result

Title: INSPIRE Implementing rules laying down technical arrangements for the interoperability and harmonisation of Geology

Date (Publication): 2011

Explanation: See the referenced specification

Pass: No

Conformance result

Title: Commission Regulation (EU) No 1089/2010 of 23 November 2010 implementing Directive 2007/2/EC of the European Parliament and of the Council as regards interoperability of spatial data sets and services

Date (Publication): 2010-12-08

Explanation: See http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2010:323:0011:0102:EN:PDF

Pass: No

Statement: Each 1 cm sediment slice for carbon analysis dried at 60 °C and fractioned with a 2 mm sieve. Any fresh calcium carbonate from fauna that was retained on the 2 mm was added to the < 2 mm fraction, then the whole <2 mm fraction weighed then homogenised. Samples were acidified in 1N HCl to remove inorganic carbon. Pure CaCO3 powder were also acidified to make sure full inorganic carbon digestion occurred. Acidified samples were then rinsed and dried for CHN analysis to determine the organic carbon and nitrogen content as a % of the >2mm fraction for each slice down to 5 cm (5 slices of 0-1,1-2,3,4 and 5-6 cm intervals from the sediment surface). Sediment PSA broadly followed the procedures in Mason (2022) where the fraction > 1mm was analysed using dry sieving and those <1 mm using laser diffraction. This data in half phi size classes was then merged and analysed in GRADISTAT.