Comparing Seamounts and Coral Reefs with eDNA and BRUVS Reveals Oases and Refuges on Shallow Seamounts
Seamounts are the least known ocean biome. Considered biodiversity hotspots, biomass oases, and refuges for megafauna, large gaps exist in their real diversity relative to other ecosystems like coral reefs. Using environmental DNA metabarcoding (eDNA) and baited video (BRUVS), we compared fish assem...
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| Format: | Article |
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MDPI AG
2023-11-01
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| Online Access: | https://www.mdpi.com/2079-7737/12/11/1446 |
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| author | Florian Baletaud Gaël Lecellier Antoine Gilbert Laëtitia Mathon Jean-Marie Côme Tony Dejean Mahé Dumas Sylvie Fiat Laurent Vigliola |
| author_facet | Florian Baletaud Gaël Lecellier Antoine Gilbert Laëtitia Mathon Jean-Marie Côme Tony Dejean Mahé Dumas Sylvie Fiat Laurent Vigliola |
| author_sort | Florian Baletaud |
| collection | DOAJ |
| description | Seamounts are the least known ocean biome. Considered biodiversity hotspots, biomass oases, and refuges for megafauna, large gaps exist in their real diversity relative to other ecosystems like coral reefs. Using environmental DNA metabarcoding (eDNA) and baited video (BRUVS), we compared fish assemblages across five environments of different depths: coral reefs (15 m), shallow seamounts (50 m), continental slopes (150 m), intermediate seamounts (250 m), and deep seamounts (500 m). We modeled assemblages using 12 environmental variables and found depth to be the main driver of fish diversity and biomass, although other variables like human accessibility were important. Boosted Regression Trees (BRT) revealed a strong negative effect of depth on species richness, segregating coral reefs from deep-sea environments. Surprisingly, BRT showed a hump-shaped effect of depth on fish biomass, with significantly lower biomass on coral reefs than in shallowest deep-sea environments. Biomass of large predators like sharks was three times higher on shallow seamounts (50 m) than on coral reefs. The five studied environments showed quite distinct assemblages. However, species shared between coral reefs and deeper-sea environments were dominated by highly mobile large predators. Our results suggest that seamounts are no diversity hotspots for fish. However, we show that shallower seamounts form biomass oases and refuges for threatened megafauna, suggesting that priority should be given to their protection. |
| first_indexed | 2024-03-09T17:00:58Z |
| format | Article |
| id | doaj.art-caafa9f1add3453c9c65dc679c2377a3 |
| institution | Directory Open Access Journal |
| issn | 2079-7737 |
| language | English |
| last_indexed | 2024-03-09T17:00:58Z |
| publishDate | 2023-11-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Biology |
| spelling | doaj.art-caafa9f1add3453c9c65dc679c2377a32023-11-24T14:30:29ZengMDPI AGBiology2079-77372023-11-011211144610.3390/biology12111446Comparing Seamounts and Coral Reefs with eDNA and BRUVS Reveals Oases and Refuges on Shallow SeamountsFlorian Baletaud0Gaël Lecellier1Antoine Gilbert2Laëtitia Mathon3Jean-Marie Côme4Tony Dejean5Mahé Dumas6Sylvie Fiat7Laurent Vigliola8ENTROPIE, Institut de Recherche pour le Développement (IRD), UR, UNC, IFREMER, CNRS, Centre IRD de Nouméa, 98848 Noumea, New Caledonia, FranceENTROPIE, Institut de Recherche pour le Développement (IRD), UR, UNC, IFREMER, CNRS, Centre IRD de Nouméa, 98848 Noumea, New Caledonia, FranceGINGER SOPRONER, 98000 Noumea, New Caledonia, FranceENTROPIE, Institut de Recherche pour le Développement (IRD), UR, UNC, IFREMER, CNRS, Centre IRD de Nouméa, 98848 Noumea, New Caledonia, FranceGINGER BURGEAP, 69000 Lyon, FranceSPYGEN, 73370 Le Bourget-du-lac, FranceENTROPIE, Institut de Recherche pour le Développement (IRD), UR, UNC, IFREMER, CNRS, Centre IRD de Nouméa, 98848 Noumea, New Caledonia, FranceENTROPIE, Institut de Recherche pour le Développement (IRD), UR, UNC, IFREMER, CNRS, Centre IRD de Nouméa, 98848 Noumea, New Caledonia, FranceENTROPIE, Institut de Recherche pour le Développement (IRD), UR, UNC, IFREMER, CNRS, Centre IRD de Nouméa, 98848 Noumea, New Caledonia, FranceSeamounts are the least known ocean biome. Considered biodiversity hotspots, biomass oases, and refuges for megafauna, large gaps exist in their real diversity relative to other ecosystems like coral reefs. Using environmental DNA metabarcoding (eDNA) and baited video (BRUVS), we compared fish assemblages across five environments of different depths: coral reefs (15 m), shallow seamounts (50 m), continental slopes (150 m), intermediate seamounts (250 m), and deep seamounts (500 m). We modeled assemblages using 12 environmental variables and found depth to be the main driver of fish diversity and biomass, although other variables like human accessibility were important. Boosted Regression Trees (BRT) revealed a strong negative effect of depth on species richness, segregating coral reefs from deep-sea environments. Surprisingly, BRT showed a hump-shaped effect of depth on fish biomass, with significantly lower biomass on coral reefs than in shallowest deep-sea environments. Biomass of large predators like sharks was three times higher on shallow seamounts (50 m) than on coral reefs. The five studied environments showed quite distinct assemblages. However, species shared between coral reefs and deeper-sea environments were dominated by highly mobile large predators. Our results suggest that seamounts are no diversity hotspots for fish. However, we show that shallower seamounts form biomass oases and refuges for threatened megafauna, suggesting that priority should be given to their protection.https://www.mdpi.com/2079-7737/12/11/1446conservationbiomassbiodiversityhotspotcoral reefsmesophotic slope |
| spellingShingle | Florian Baletaud Gaël Lecellier Antoine Gilbert Laëtitia Mathon Jean-Marie Côme Tony Dejean Mahé Dumas Sylvie Fiat Laurent Vigliola Comparing Seamounts and Coral Reefs with eDNA and BRUVS Reveals Oases and Refuges on Shallow Seamounts Biology conservation biomass biodiversity hotspot coral reefs mesophotic slope |
| title | Comparing Seamounts and Coral Reefs with eDNA and BRUVS Reveals Oases and Refuges on Shallow Seamounts |
| title_full | Comparing Seamounts and Coral Reefs with eDNA and BRUVS Reveals Oases and Refuges on Shallow Seamounts |
| title_fullStr | Comparing Seamounts and Coral Reefs with eDNA and BRUVS Reveals Oases and Refuges on Shallow Seamounts |
| title_full_unstemmed | Comparing Seamounts and Coral Reefs with eDNA and BRUVS Reveals Oases and Refuges on Shallow Seamounts |
| title_short | Comparing Seamounts and Coral Reefs with eDNA and BRUVS Reveals Oases and Refuges on Shallow Seamounts |
| title_sort | comparing seamounts and coral reefs with edna and bruvs reveals oases and refuges on shallow seamounts |
| topic | conservation biomass biodiversity hotspot coral reefs mesophotic slope |
| url | https://www.mdpi.com/2079-7737/12/11/1446 |
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