https://ipt.sanbi.org.za/resource?r=demersal_research_trawl_invertebrate_saeon Dr Lara Atkinson South African Environmental Observation Network Offshore Marine Scientist

Cape Town Western Cape 8001 ZA

0214023489 lj.atkinson@saeon.ac.za https://egagasini.saeon.ac.za/ Dr Lara Atkinson South African Environmental Observation Network Offshore Marine Scientist

5th Floor, Foretrust Building, Martin Hammerschlag Way, Cape Town Western Cape 8001 ZA

0214023489 lj.atkinson@saeon.ac.za https://egagasini.saeon.ac.za/ 2024-03-26 eng 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. Porifera Cnidaria Annelida Arthropoda Bryozoa Branchiopoda Mollusca Echinodermata Chordata Hemichordata. Demersal offshore marine epifauna Invertebrates research Trawl. GBIF Dataset Type Vocabulary: http://rs.gbif.org/vocabulary/gbif/dataset_type_2015-07-10.xml Observation GBIF Dataset Subtype Vocabulary: http://rs.gbif.org/vocabulary/gbif/dataset_subtype.xml Acknowledgement required by Egagasini Node, South African Environmental Observation Network. This work is licensed under a Creative Commons Attribution (CC-BY) 4.0 License. West and South coasts of South Africa, extending from the border with Namibia at the Orange River Mouth to Port Alfred 14.6 26.9 -28.75 -36.75 2011-01-05 2022-02-08 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). genus Psilaster Total of 316 species belonging to 10 marine Phyla genus Haliporoides unkown Dr Lara Atkinson South African Environmental Observation Network Offshore Marine Scientist

5th Floor, Foretrust Building, Martin Hammerschlag Way, Cape Town Western Cape 8001 ZA

0214023489 lj.atkinson@saeon.ac.za https://egagasini.saeon.ac.za/ N/A 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 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. 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. 2024-02-28T14:58:26.761+02:00 dataset Atkinson LJ SAEON Offshore invertebrate research trawl programme.