Drivers of Spatial Distributions of Basking Shark (Cetorhinus maximus) in the Southwest Pacific
Basking sharks (Cetorhinus maximus) were widely reported throughout New Zealand waters. Once commonly observed, and sometimes in large numbers, basking sharks are now infrequently reported. Basking shark observations are known to be highly variable across years, and their distribution and occurrence...
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ftdoajarticles:oai:doaj.org/article:ab0d69c95bb846099953ce22cfe8fbbb 2023-05-15T15:33:37+02:00 Drivers of Spatial Distributions of Basking Shark (Cetorhinus maximus) in the Southwest Pacific Brittany Finucci Clinton A. J. Duffy Tom Brough Malcolm P. Francis Marco Milardi Matthew H. Pinkerton Grady Petersen Fabrice Stephenson 2021-04-01T00:00:00Z https://doi.org/10.3389/fmars.2021.665337 https://doaj.org/article/ab0d69c95bb846099953ce22cfe8fbbb EN eng Frontiers Media S.A. https://www.frontiersin.org/articles/10.3389/fmars.2021.665337/full https://doaj.org/toc/2296-7745 2296-7745 doi:10.3389/fmars.2021.665337 https://doaj.org/article/ab0d69c95bb846099953ce22cfe8fbbb Frontiers in Marine Science, Vol 8 (2021) New Zealand species distribution models boosted regression tree models threatened species elasmobranch Science Q General. Including nature conservation geographical distribution QH1-199.5 article 2021 ftdoajarticles https://doi.org/10.3389/fmars.2021.665337 2022-12-31T06:43:05Z Basking sharks (Cetorhinus maximus) were widely reported throughout New Zealand waters. Once commonly observed, and sometimes in large numbers, basking sharks are now infrequently reported. Basking shark observations are known to be highly variable across years, and their distribution and occurrence have been shown to be influenced by environmental predictors such as thermal fronts, chl-a concentration, and the abundance of prey (zooplankton). Little is known of basking sharks in the South Pacific and more information on distribution, habitat use, and migratory patterns is required to better understand the species’ regional ecology. Here, we used bootstrapped Habitat Suitability Models [HSM, ensembled from Boosted Regression Tree (BRT) and Random Forest (RF) models] to determine the drivers of basking shark distribution, predict habitat suitability and estimated uncertainty in the South Pacific for the first time. High−resolution environmental (1 km2 grid resolution) and biotic data, including inferred prey species, and all available basking shark records across New Zealand’s Exclusive Economic Zone (EEZ) were included in the ensemble HSMs. The most influential driver of modeled basking shark distribution was vertical flux of particulate organic matter at the seabed, which may indicate higher levels of primary production in the surface ocean and higher prey density in the mesopelagic zone and at the seafloor. The BRT and RF models had good predictive power (AUC and TSS > 0.7) and both models performed similarly with low variability in the model fit metrics. Areas of high basking shark habitat suitability included the east and west coasts of the South Island, Puysegur Ridge, and Auckland Island slope. The outputs produced here could be incorporated into future management framework for assessing threat and conservation needs (e.g., spatially explicit risk assessment) for this regionally protected species, as well as providing guidance for future research efforts (e.g., areas of interest for sampling). Article in Journal/Newspaper Auckland Island Cetorhinus maximus Directory of Open Access Journals: DOAJ Articles New Zealand Pacific Frontiers in Marine Science 8 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
New Zealand species distribution models boosted regression tree models threatened species elasmobranch Science Q General. Including nature conservation geographical distribution QH1-199.5 |
spellingShingle |
New Zealand species distribution models boosted regression tree models threatened species elasmobranch Science Q General. Including nature conservation geographical distribution QH1-199.5 Brittany Finucci Clinton A. J. Duffy Tom Brough Malcolm P. Francis Marco Milardi Matthew H. Pinkerton Grady Petersen Fabrice Stephenson Drivers of Spatial Distributions of Basking Shark (Cetorhinus maximus) in the Southwest Pacific |
topic_facet |
New Zealand species distribution models boosted regression tree models threatened species elasmobranch Science Q General. Including nature conservation geographical distribution QH1-199.5 |
description |
Basking sharks (Cetorhinus maximus) were widely reported throughout New Zealand waters. Once commonly observed, and sometimes in large numbers, basking sharks are now infrequently reported. Basking shark observations are known to be highly variable across years, and their distribution and occurrence have been shown to be influenced by environmental predictors such as thermal fronts, chl-a concentration, and the abundance of prey (zooplankton). Little is known of basking sharks in the South Pacific and more information on distribution, habitat use, and migratory patterns is required to better understand the species’ regional ecology. Here, we used bootstrapped Habitat Suitability Models [HSM, ensembled from Boosted Regression Tree (BRT) and Random Forest (RF) models] to determine the drivers of basking shark distribution, predict habitat suitability and estimated uncertainty in the South Pacific for the first time. High−resolution environmental (1 km2 grid resolution) and biotic data, including inferred prey species, and all available basking shark records across New Zealand’s Exclusive Economic Zone (EEZ) were included in the ensemble HSMs. The most influential driver of modeled basking shark distribution was vertical flux of particulate organic matter at the seabed, which may indicate higher levels of primary production in the surface ocean and higher prey density in the mesopelagic zone and at the seafloor. The BRT and RF models had good predictive power (AUC and TSS > 0.7) and both models performed similarly with low variability in the model fit metrics. Areas of high basking shark habitat suitability included the east and west coasts of the South Island, Puysegur Ridge, and Auckland Island slope. The outputs produced here could be incorporated into future management framework for assessing threat and conservation needs (e.g., spatially explicit risk assessment) for this regionally protected species, as well as providing guidance for future research efforts (e.g., areas of interest for sampling). |
format |
Article in Journal/Newspaper |
author |
Brittany Finucci Clinton A. J. Duffy Tom Brough Malcolm P. Francis Marco Milardi Matthew H. Pinkerton Grady Petersen Fabrice Stephenson |
author_facet |
Brittany Finucci Clinton A. J. Duffy Tom Brough Malcolm P. Francis Marco Milardi Matthew H. Pinkerton Grady Petersen Fabrice Stephenson |
author_sort |
Brittany Finucci |
title |
Drivers of Spatial Distributions of Basking Shark (Cetorhinus maximus) in the Southwest Pacific |
title_short |
Drivers of Spatial Distributions of Basking Shark (Cetorhinus maximus) in the Southwest Pacific |
title_full |
Drivers of Spatial Distributions of Basking Shark (Cetorhinus maximus) in the Southwest Pacific |
title_fullStr |
Drivers of Spatial Distributions of Basking Shark (Cetorhinus maximus) in the Southwest Pacific |
title_full_unstemmed |
Drivers of Spatial Distributions of Basking Shark (Cetorhinus maximus) in the Southwest Pacific |
title_sort |
drivers of spatial distributions of basking shark (cetorhinus maximus) in the southwest pacific |
publisher |
Frontiers Media S.A. |
publishDate |
2021 |
url |
https://doi.org/10.3389/fmars.2021.665337 https://doaj.org/article/ab0d69c95bb846099953ce22cfe8fbbb |
geographic |
New Zealand Pacific |
geographic_facet |
New Zealand Pacific |
genre |
Auckland Island Cetorhinus maximus |
genre_facet |
Auckland Island Cetorhinus maximus |
op_source |
Frontiers in Marine Science, Vol 8 (2021) |
op_relation |
https://www.frontiersin.org/articles/10.3389/fmars.2021.665337/full https://doaj.org/toc/2296-7745 2296-7745 doi:10.3389/fmars.2021.665337 https://doaj.org/article/ab0d69c95bb846099953ce22cfe8fbbb |
op_doi |
https://doi.org/10.3389/fmars.2021.665337 |
container_title |
Frontiers in Marine Science |
container_volume |
8 |
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1766364139938119680 |