Per-length biomass estimates of Antarctic krill (Euphausia superba)
Total biomass and areal biomass density are often necessary to establish ecological relationships and enable informed management decisions, in particular setting fisheries catch limits. Further refining these estimates to sub-population biomass based on length informs ecological models of predator-p...
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ftdoajarticles:oai:doaj.org/article:1f71bb3c20a9422db59d3f443046268d 2023-06-18T03:38:13+02:00 Per-length biomass estimates of Antarctic krill (Euphausia superba) Abigail J. R. Smith Simon J. Wotherspoon Martin J. Cox 2023-05-01T00:00:00Z https://doi.org/10.3389/fmars.2023.1107567 https://doaj.org/article/1f71bb3c20a9422db59d3f443046268d EN eng Frontiers Media S.A. https://www.frontiersin.org/articles/10.3389/fmars.2023.1107567/full https://doaj.org/toc/2296-7745 2296-7745 doi:10.3389/fmars.2023.1107567 https://doaj.org/article/1f71bb3c20a9422db59d3f443046268d Frontiers in Marine Science, Vol 10 (2023) conversion factor length-wetmass relationship length-frequency size distribution net sampling Science Q General. Including nature conservation geographical distribution QH1-199.5 article 2023 ftdoajarticles https://doi.org/10.3389/fmars.2023.1107567 2023-06-04T00:37:34Z Total biomass and areal biomass density are often necessary to establish ecological relationships and enable informed management decisions, in particular setting fisheries catch limits. Further refining these estimates to sub-population biomass based on length informs ecological models of predator-prey dynamics, ecosystem energy transfer and biogeochemical cycles; however, measures of uncertainty in these per-length biomass estimates are needed. We present a statistical method to calculate the per-length biomass of Antarctic krill (Euphausia superba) from conversion factors using acoustic and net sample data. Variability in krill length-frequency, and wetmass introduced by net sampling is also explored through non-parametric bootstrapping. We applied this method on a 1 mm length window to active acoustic and net sample data collected during an Antarctic krill biomass survey in CCAMLR Division 58.4.2 (62 – 67°S; 55 – 80°E, with a survey area of 775,732 km2) performed between February – March 2021. We found that 77% of the total estimated biomass was attributable to krill of length 14 – 49 mm. The largest biomass of krill in a single length bin was estimated as 340,000 t (95% CI: 148,000 - 408,000 t) and was found in the 49 mm length bin (i.e., 48.5 to 49.5 mm). This method will allow future surveys (with sufficient data) to estimate biomass of krill on a per-length basis along with associated uncertainty (confidence intervals) derived from net sampling and so may be used to provision size-based ecosystem models with krill biomass. Article in Journal/Newspaper Antarc* Antarctic Antarctic Krill Euphausia superba Directory of Open Access Journals: DOAJ Articles Antarctic Frontiers in Marine Science 10 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
conversion factor length-wetmass relationship length-frequency size distribution net sampling Science Q General. Including nature conservation geographical distribution QH1-199.5 |
spellingShingle |
conversion factor length-wetmass relationship length-frequency size distribution net sampling Science Q General. Including nature conservation geographical distribution QH1-199.5 Abigail J. R. Smith Simon J. Wotherspoon Martin J. Cox Per-length biomass estimates of Antarctic krill (Euphausia superba) |
topic_facet |
conversion factor length-wetmass relationship length-frequency size distribution net sampling Science Q General. Including nature conservation geographical distribution QH1-199.5 |
description |
Total biomass and areal biomass density are often necessary to establish ecological relationships and enable informed management decisions, in particular setting fisheries catch limits. Further refining these estimates to sub-population biomass based on length informs ecological models of predator-prey dynamics, ecosystem energy transfer and biogeochemical cycles; however, measures of uncertainty in these per-length biomass estimates are needed. We present a statistical method to calculate the per-length biomass of Antarctic krill (Euphausia superba) from conversion factors using acoustic and net sample data. Variability in krill length-frequency, and wetmass introduced by net sampling is also explored through non-parametric bootstrapping. We applied this method on a 1 mm length window to active acoustic and net sample data collected during an Antarctic krill biomass survey in CCAMLR Division 58.4.2 (62 – 67°S; 55 – 80°E, with a survey area of 775,732 km2) performed between February – March 2021. We found that 77% of the total estimated biomass was attributable to krill of length 14 – 49 mm. The largest biomass of krill in a single length bin was estimated as 340,000 t (95% CI: 148,000 - 408,000 t) and was found in the 49 mm length bin (i.e., 48.5 to 49.5 mm). This method will allow future surveys (with sufficient data) to estimate biomass of krill on a per-length basis along with associated uncertainty (confidence intervals) derived from net sampling and so may be used to provision size-based ecosystem models with krill biomass. |
format |
Article in Journal/Newspaper |
author |
Abigail J. R. Smith Simon J. Wotherspoon Martin J. Cox |
author_facet |
Abigail J. R. Smith Simon J. Wotherspoon Martin J. Cox |
author_sort |
Abigail J. R. Smith |
title |
Per-length biomass estimates of Antarctic krill (Euphausia superba) |
title_short |
Per-length biomass estimates of Antarctic krill (Euphausia superba) |
title_full |
Per-length biomass estimates of Antarctic krill (Euphausia superba) |
title_fullStr |
Per-length biomass estimates of Antarctic krill (Euphausia superba) |
title_full_unstemmed |
Per-length biomass estimates of Antarctic krill (Euphausia superba) |
title_sort |
per-length biomass estimates of antarctic krill (euphausia superba) |
publisher |
Frontiers Media S.A. |
publishDate |
2023 |
url |
https://doi.org/10.3389/fmars.2023.1107567 https://doaj.org/article/1f71bb3c20a9422db59d3f443046268d |
geographic |
Antarctic |
geographic_facet |
Antarctic |
genre |
Antarc* Antarctic Antarctic Krill Euphausia superba |
genre_facet |
Antarc* Antarctic Antarctic Krill Euphausia superba |
op_source |
Frontiers in Marine Science, Vol 10 (2023) |
op_relation |
https://www.frontiersin.org/articles/10.3389/fmars.2023.1107567/full https://doaj.org/toc/2296-7745 2296-7745 doi:10.3389/fmars.2023.1107567 https://doaj.org/article/1f71bb3c20a9422db59d3f443046268d |
op_doi |
https://doi.org/10.3389/fmars.2023.1107567 |
container_title |
Frontiers in Marine Science |
container_volume |
10 |
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1769003118512570368 |