South African Environmental Observation Network Offshore Demersal Invertebrate Monitoring Part 1

Dr Lara Atkinson1, Dr Lara Atkinson2

1 South African Environmental Observation Network, 8001, Cape Town, South Africa; 2 South African Environmental Observation Network, 5th Floor, Foretrust Building, Martin Hammerschlag Way,, 8001, Cape Town, South Africa

Corresponding author(s): Dr Lara Atkinson (lj.atkinson@saeon.ac.za), Dr Lara Atkinson (lj.atkinson@saeon.ac.za)

Received {date}; Revised {date}; Accepted {date}; Published {date}

Citation: Combination of authors, year of data paper publication (in parentheses), Title, Journal Name, Volume, Issue number (in parentheses), and doi of the data paper.

Resource Citation

Atkinson LJ SAEON Offshore invertebrate research trawl programme.

Abstract

9793 Benthic marine invertebrate records sampled using a research demersal trawl net off the west and south coasts of South Africa during the years 2011 to 2022.

Keywords: Porifera, Cnidaria, Annelida, Arthropoda, Bryozoa, Branchiopoda, Mollusca, Echinodermata, Chordata, Hemichordata. Demersal, offshore marine epifauna, Invertebrates, research Trawl., Observation

General description

Additional information: Acknowledgement required by Egagasini Node, South African Environmental Observation Network.

Data published through GBIF: https://ipt.sanbi.org.za/resource?r=demersal_research_trawl_invertebrate_saeon

Taxonomic coverage

General taxonomic coverage description: All marine invertebrates that are retained in the research trawl net from each trawl deployed are identified and recorded. These surveys take place in collaboration with the annual demersal research surveys conducted by the Fisheries Department, currently under the Department of Forestry, Fisheries and Environment (DFFE).
Taxonomic ranks
Genus: Psilaster

Taxonomic coverage

General taxonomic coverage description: Total of 316 species belonging to 10 marine Phyla
Taxonomic ranks
Genus: Haliporoides

Spatial coverage

General spatial coverage: West and South coasts of South Africa, extending from the border with Namibia at the Orange River Mouth to Port Alfred
Coordinates: 36°45'0''S and 28°45'0''S Latitude; 14°35'60''E and 26°53'60''E Longitude 

Temporal coverage: January 5, 2011 - February 8, 2022

Methods

Method step description: N/A
Study extent description: Demersal research trawl gear are used to collect invertebrates as bycatch during fish surveys. The trawl gear used is German Otter trawl with otter trawl boards and a footrope rope-wrapped chain. The mesh size of the codend liner was 40 mm stretched mesh. See Atkinson et al 2011 doi: 10.2989/1814232X.2011.572378 and Axelsen and Johnsen 2015 doi:10.1111/fog.12079
Sampling description: Samples were collected using a research demersal trawl net towed for 30 minutes per trawl, unless hard ground was encountered or net was damaged in which case shorter tow durations are noted. Sampling unit is nautical miles squared.
Quality control description: Data were validated by engaging with experts where necessary and using various field guides. Coordinates of the start position of the trawl are provided and due to the depths at which the trawls operate and the uncertainty of where the vessel is in relation to the trawl net on the seafloor, no further useful co-ordinate uncertainty can be provided.

Datasets

Dataset description
Object name: Darwin Core Archive South African Environmental Observation Network Offshore Demersal Invertebrate Monitoring Part 1
Character encoding: UTF-8
Format name: Darwin Core Archive format
Format version: 1.0
Distribution: https://ipt.sanbi.org.za/archive.do?r=demersal_research_trawl_invertebrate_saeon
Publication date of data: 2024-03-26
Language: English
Licences of use: Creative Commons Attribution (CC-BY) 4.0 License

Metadata language: English
Date of metadata creation: 2024-02-28
Hierarchy level: Dataset