Littoral meiofauna community structure in San Julián bay, Santa Cruz province, Argentina
For the first time, standing stocks and community structure have been reported in San Julián Bay, located in the Santa Cruz province, toward the southern tip of South America, within the sub-Antarctic region. The mean density of the meiofauna found was 6724 individuals/10 cm2, with a high dominance...
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| Format: | Article |
| Language: | English |
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Asociación Argentina de Ecología
2023-11-01
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| Series: | Ecología Austral |
| Subjects: | |
| Online Access: | https://ojs.ecologiaaustral.com.ar/index.php/Ecologia_Austral/article/view/2117 |
| _version_ | 1797393090680455168 |
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| author | Virginia Lo Russo Catalina T. Pastor de Ward Héctor Zaixso |
| author_facet | Virginia Lo Russo Catalina T. Pastor de Ward Héctor Zaixso |
| author_sort | Virginia Lo Russo |
| collection | DOAJ |
| description |
For the first time, standing stocks and community structure have been reported in San Julián Bay, located in the Santa Cruz province, toward the southern tip of South America, within the sub-Antarctic region. The mean density of the meiofauna found was 6724 individuals/10 cm2, with a high dominance of nematodes (97.69%). Multivariate studies (PERMANOVA) revealed two distinct meiofauna assemblages: one, in an upper littoral salt marsh habitat and other, in a medium to low soft bare sediment. In the middle of the bay —in front of San Julián city— salt marsh habitats had the highest meiofaunal density, while bare sediments (medium-low levels) were the lowest. The mean average in the salt marsh area was 12246 individuals/10 cm2, with nematodes being dominant followed by oligochaetes as the subdominant taxa. The mean average in bare sediments (medium to low levels) was 3962 individuals/10 cm2, with nematodes as dominant and turbellarians, mastigophorans and maxillopodos (harpacticoid copepods) as subdominant taxa. Bare sediments related to Patagonian mussel’s populations presented the lowest meiofauna densities. Diversity showed an opposite trend, with a maximum in medium-low levels and a minimum in salt-marshes habitat. Richness in number of taxa ranged from 8 to 12, with a total number of 18 taxa. Despite dominance of nematodes in meiofauna assemblages is known, maximum density found in San Julián bay is much higher than previously found for estuaries from north and mid-latitudes littoral sandy beaches and in the nearby region of the Straits of Magellan and Beagle Channel and other sub-Antarctic and Antarctic sites. On the other hand, the number of meiofauna taxa (no nematodes) is low, and its community structure differs from what has been reported in previous studies. The meiofauna taxa assemblages provide evidence that, in salt-marsh habitats, they have the highest densities, but the lowest diversity when compared with lower levels. This is likely due to adaptation problems of meiofauna communities to a semi-terrestrial habitat.
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| first_indexed | 2024-03-08T23:58:07Z |
| format | Article |
| id | doaj.art-c72d02506bdd4de38b7de4694026e786 |
| institution | Directory Open Access Journal |
| issn | 0327-5477 1667-782X |
| language | English |
| last_indexed | 2024-03-08T23:58:07Z |
| publishDate | 2023-11-01 |
| publisher | Asociación Argentina de Ecología |
| record_format | Article |
| series | Ecología Austral |
| spelling | doaj.art-c72d02506bdd4de38b7de4694026e7862023-12-13T00:27:44ZengAsociación Argentina de EcologíaEcología Austral0327-54771667-782X2023-11-0133310.25260/EA.23.33.3.0.2117Littoral meiofauna community structure in San Julián bay, Santa Cruz province, ArgentinaVirginia Lo Russo0Catalina T. Pastor de Ward1Héctor Zaixso2Laboratorio de Meiofauna Marina (LAMEIMA). Instituto de Diversidad y Evolución Austral (IDEAus-CONICET)Laboratorio de Meiofauna Marina (LAMEIMA). Instituto de Diversidad y Evolución Austral (IDEAus-CONICET)Laboratorio de Meiofauna Marina (LAMEIMA). Instituto de Diversidad y Evolución Austral (IDEAus-CONICET) For the first time, standing stocks and community structure have been reported in San Julián Bay, located in the Santa Cruz province, toward the southern tip of South America, within the sub-Antarctic region. The mean density of the meiofauna found was 6724 individuals/10 cm2, with a high dominance of nematodes (97.69%). Multivariate studies (PERMANOVA) revealed two distinct meiofauna assemblages: one, in an upper littoral salt marsh habitat and other, in a medium to low soft bare sediment. In the middle of the bay —in front of San Julián city— salt marsh habitats had the highest meiofaunal density, while bare sediments (medium-low levels) were the lowest. The mean average in the salt marsh area was 12246 individuals/10 cm2, with nematodes being dominant followed by oligochaetes as the subdominant taxa. The mean average in bare sediments (medium to low levels) was 3962 individuals/10 cm2, with nematodes as dominant and turbellarians, mastigophorans and maxillopodos (harpacticoid copepods) as subdominant taxa. Bare sediments related to Patagonian mussel’s populations presented the lowest meiofauna densities. Diversity showed an opposite trend, with a maximum in medium-low levels and a minimum in salt-marshes habitat. Richness in number of taxa ranged from 8 to 12, with a total number of 18 taxa. Despite dominance of nematodes in meiofauna assemblages is known, maximum density found in San Julián bay is much higher than previously found for estuaries from north and mid-latitudes littoral sandy beaches and in the nearby region of the Straits of Magellan and Beagle Channel and other sub-Antarctic and Antarctic sites. On the other hand, the number of meiofauna taxa (no nematodes) is low, and its community structure differs from what has been reported in previous studies. The meiofauna taxa assemblages provide evidence that, in salt-marsh habitats, they have the highest densities, but the lowest diversity when compared with lower levels. This is likely due to adaptation problems of meiofauna communities to a semi-terrestrial habitat. https://ojs.ecologiaaustral.com.ar/index.php/Ecologia_Austral/article/view/2117salt marshesbare-sedimentsnematodessub-Antarcticcoastal area |
| spellingShingle | Virginia Lo Russo Catalina T. Pastor de Ward Héctor Zaixso Littoral meiofauna community structure in San Julián bay, Santa Cruz province, Argentina Ecología Austral salt marshes bare-sediments nematodes sub-Antarctic coastal area |
| title | Littoral meiofauna community structure in San Julián bay, Santa Cruz province, Argentina |
| title_full | Littoral meiofauna community structure in San Julián bay, Santa Cruz province, Argentina |
| title_fullStr | Littoral meiofauna community structure in San Julián bay, Santa Cruz province, Argentina |
| title_full_unstemmed | Littoral meiofauna community structure in San Julián bay, Santa Cruz province, Argentina |
| title_short | Littoral meiofauna community structure in San Julián bay, Santa Cruz province, Argentina |
| title_sort | littoral meiofauna community structure in san julian bay santa cruz province argentina |
| topic | salt marshes bare-sediments nematodes sub-Antarctic coastal area |
| url | https://ojs.ecologiaaustral.com.ar/index.php/Ecologia_Austral/article/view/2117 |
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