Biogeographic classification of the Caspian Sea
Like other inland seas, the Caspian Sea (CS) has been influenced by climate change and anthropogenic disturbance during recent decades, yet the scientific understanding of this water body remains poor. In this study, an eco-geographical classification of the CS based on physical information derived...
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ftdoajarticles:oai:doaj.org/article:9defb3c1f0dd4b00be0da576180fe064 2023-05-15T18:18:47+02:00 Biogeographic classification of the Caspian Sea F. Fendereski M. Vogt M. R. Payne Z. Lachkar N. Gruber A. Salmanmahiny S. A. Hosseini 2014-11-01T00:00:00Z https://doi.org/10.5194/bg-11-6451-2014 https://doaj.org/article/9defb3c1f0dd4b00be0da576180fe064 EN eng Copernicus Publications http://www.biogeosciences.net/11/6451/2014/bg-11-6451-2014.pdf https://doaj.org/toc/1726-4170 https://doaj.org/toc/1726-4189 1726-4170 1726-4189 doi:10.5194/bg-11-6451-2014 https://doaj.org/article/9defb3c1f0dd4b00be0da576180fe064 Biogeosciences, Vol 11, Iss 22, Pp 6451-6470 (2014) Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 article 2014 ftdoajarticles https://doi.org/10.5194/bg-11-6451-2014 2022-12-31T12:44:08Z Like other inland seas, the Caspian Sea (CS) has been influenced by climate change and anthropogenic disturbance during recent decades, yet the scientific understanding of this water body remains poor. In this study, an eco-geographical classification of the CS based on physical information derived from space and in situ data is developed and tested against a set of biological observations. We used a two-step classification procedure, consisting of (i) a data reduction with self-organizing maps (SOMs) and (ii) a synthesis of the most relevant features into a reduced number of marine ecoregions using the hierarchical agglomerative clustering (HAC) method. From an initial set of 12 potential physical variables, 6 independent variables were selected for the classification algorithm, i.e., sea surface temperature (SST), bathymetry, sea ice, seasonal variation of sea surface salinity (DSSS), total suspended matter (TSM) and its seasonal variation (DTSM). The classification results reveal a robust separation between the northern and the middle/southern basins as well as a separation of the shallow nearshore waters from those offshore. The observed patterns in ecoregions can be attributed to differences in climate and geochemical factors such as distance from river, water depth and currents. A comparison of the annual and monthly mean Chl a concentrations between the different ecoregions shows significant differences (one-way ANOVA, P < 0.05). In particular, we found differences in phytoplankton phenology, with differences in the date of bloom initiation, its duration and amplitude between ecoregions. A first qualitative evaluation of differences in community composition based on recorded presence–absence patterns of 25 different species of plankton, fish and benthic invertebrate also confirms the relevance of the ecoregions as proxies for habitats with common biological characteristics. Article in Journal/Newspaper Sea ice Directory of Open Access Journals: DOAJ Articles Biogeosciences 11 22 6451 6470 |
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Open Polar |
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Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 |
spellingShingle |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 F. Fendereski M. Vogt M. R. Payne Z. Lachkar N. Gruber A. Salmanmahiny S. A. Hosseini Biogeographic classification of the Caspian Sea |
topic_facet |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 |
description |
Like other inland seas, the Caspian Sea (CS) has been influenced by climate change and anthropogenic disturbance during recent decades, yet the scientific understanding of this water body remains poor. In this study, an eco-geographical classification of the CS based on physical information derived from space and in situ data is developed and tested against a set of biological observations. We used a two-step classification procedure, consisting of (i) a data reduction with self-organizing maps (SOMs) and (ii) a synthesis of the most relevant features into a reduced number of marine ecoregions using the hierarchical agglomerative clustering (HAC) method. From an initial set of 12 potential physical variables, 6 independent variables were selected for the classification algorithm, i.e., sea surface temperature (SST), bathymetry, sea ice, seasonal variation of sea surface salinity (DSSS), total suspended matter (TSM) and its seasonal variation (DTSM). The classification results reveal a robust separation between the northern and the middle/southern basins as well as a separation of the shallow nearshore waters from those offshore. The observed patterns in ecoregions can be attributed to differences in climate and geochemical factors such as distance from river, water depth and currents. A comparison of the annual and monthly mean Chl a concentrations between the different ecoregions shows significant differences (one-way ANOVA, P < 0.05). In particular, we found differences in phytoplankton phenology, with differences in the date of bloom initiation, its duration and amplitude between ecoregions. A first qualitative evaluation of differences in community composition based on recorded presence–absence patterns of 25 different species of plankton, fish and benthic invertebrate also confirms the relevance of the ecoregions as proxies for habitats with common biological characteristics. |
format |
Article in Journal/Newspaper |
author |
F. Fendereski M. Vogt M. R. Payne Z. Lachkar N. Gruber A. Salmanmahiny S. A. Hosseini |
author_facet |
F. Fendereski M. Vogt M. R. Payne Z. Lachkar N. Gruber A. Salmanmahiny S. A. Hosseini |
author_sort |
F. Fendereski |
title |
Biogeographic classification of the Caspian Sea |
title_short |
Biogeographic classification of the Caspian Sea |
title_full |
Biogeographic classification of the Caspian Sea |
title_fullStr |
Biogeographic classification of the Caspian Sea |
title_full_unstemmed |
Biogeographic classification of the Caspian Sea |
title_sort |
biogeographic classification of the caspian sea |
publisher |
Copernicus Publications |
publishDate |
2014 |
url |
https://doi.org/10.5194/bg-11-6451-2014 https://doaj.org/article/9defb3c1f0dd4b00be0da576180fe064 |
genre |
Sea ice |
genre_facet |
Sea ice |
op_source |
Biogeosciences, Vol 11, Iss 22, Pp 6451-6470 (2014) |
op_relation |
http://www.biogeosciences.net/11/6451/2014/bg-11-6451-2014.pdf https://doaj.org/toc/1726-4170 https://doaj.org/toc/1726-4189 1726-4170 1726-4189 doi:10.5194/bg-11-6451-2014 https://doaj.org/article/9defb3c1f0dd4b00be0da576180fe064 |
op_doi |
https://doi.org/10.5194/bg-11-6451-2014 |
container_title |
Biogeosciences |
container_volume |
11 |
container_issue |
22 |
container_start_page |
6451 |
op_container_end_page |
6470 |
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1766195479428726784 |