Partial Recovery of Macro-Epibenthic Assemblages on the North-West Shelf of the Black Sea
The north-west shelf of the Black Sea has suffered well-documented declines in biodiversity since the 1960s, and by the 1990s was considered a dead zone with virtually no sign of macroscopic epibenthic life. It was characterised by high levels of anthropogenic input, massive phytoplankton blooms, an...
| প্রধান লেখক: | , , , , |
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| বিন্যাস: | প্রবন্ধ |
| ভাষা: | English |
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Frontiers Media S.A.
2019-07-01
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| মালা: | Frontiers in Marine Science |
| বিষয়গুলি: | |
| অনলাইন ব্যবহার করুন: | https://www.frontiersin.org/article/10.3389/fmars.2019.00474/full |
| _version_ | 1828404343646191616 |
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| author | Tim Stevens Tim Stevens Laurence Mee Laurence Mee Jana Friedrich Jana Friedrich Dmitry Aleynik Galina Minicheva |
| author_facet | Tim Stevens Tim Stevens Laurence Mee Laurence Mee Jana Friedrich Jana Friedrich Dmitry Aleynik Galina Minicheva |
| author_sort | Tim Stevens |
| collection | DOAJ |
| description | The north-west shelf of the Black Sea has suffered well-documented declines in biodiversity since the 1960s, and by the 1990s was considered a dead zone with virtually no sign of macroscopic epibenthic life. It was characterised by high levels of anthropogenic input, massive phytoplankton blooms, and periodically hypoxic to anoxic bottom waters. An important contributor to primary production on the northwest shelf is the red alga Phyllophora spp. growing in waters to 70 m depth. Phyllophora is a habitat forming taxon supporting complex assemblages of bivalves, sponges, and ascidians, with an associated rich fish fauna. From 1990 on, nutrient loads entering the system plummeted and the severity of algal blooms decreased. Changes to benthic communities, however, were far less rapid, and the trajectory and rate of any recovery of the dead zone, in particular Zernov’s Phyllophora Field, is far from certain. This study used towed underwater video imagery from research cruises in summer 2006 and spring 2008 to classify and map macro-epibenthic assemblage structure, and related this to putative physical, chemical and spatial drivers. Distinct and relatively stable benthic communities were in evidence across the northwest shelf at that time. These communities were largely structured by substrate type and depth, but there is some evidence that nutrients continued to play a role. Phyllophora spp. was present across much, but not all, of its former range, but at far lower percent cover than previously. The pattern of abundance of Phyllophora in 2006–2008 did not correlate with the documented pre-eutrophication pattern from 1966. There is some evidence that faster-growing opportunistic species have hindered recovery. We conclude that while there was evidence of sustained recovery, by 2008 the macro-epibenthic communities of the northwest shelf of the Black Sea were far from their pre-eutrophication state. |
| first_indexed | 2024-12-10T10:34:43Z |
| format | Article |
| id | doaj.art-4b625a61c1d9456ca2865641aa641369 |
| institution | Directory Open Access Journal |
| issn | 2296-7745 |
| language | English |
| last_indexed | 2024-12-10T10:34:43Z |
| publishDate | 2019-07-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Marine Science |
| spelling | doaj.art-4b625a61c1d9456ca2865641aa6413692022-12-22T01:52:28ZengFrontiers Media S.A.Frontiers in Marine Science2296-77452019-07-01610.3389/fmars.2019.00474471042Partial Recovery of Macro-Epibenthic Assemblages on the North-West Shelf of the Black SeaTim Stevens0Tim Stevens1Laurence Mee2Laurence Mee3Jana Friedrich4Jana Friedrich5Dmitry Aleynik6Galina Minicheva7School of Environment and Science, Griffith University, Brisbane, QLD, AustraliaMarine Institute, University of Plymouth, Plymouth, United KingdomMarine Institute, University of Plymouth, Plymouth, United KingdomThe Scottish Association for Marine Science, Oban, United KingdomHelmholtz Center for Polar and Marine Research, Alfred Wegener Institute, Bremerhaven, GermanyCenter for Materials and Coastal Research, Helmholtz-Zentrum Geesthacht, Geesthacht, GermanyThe Scottish Association for Marine Science, Oban, United KingdomInstitute of Marine Biology, The National Academy of Sciences of Ukraine, Odessa, UkraineThe north-west shelf of the Black Sea has suffered well-documented declines in biodiversity since the 1960s, and by the 1990s was considered a dead zone with virtually no sign of macroscopic epibenthic life. It was characterised by high levels of anthropogenic input, massive phytoplankton blooms, and periodically hypoxic to anoxic bottom waters. An important contributor to primary production on the northwest shelf is the red alga Phyllophora spp. growing in waters to 70 m depth. Phyllophora is a habitat forming taxon supporting complex assemblages of bivalves, sponges, and ascidians, with an associated rich fish fauna. From 1990 on, nutrient loads entering the system plummeted and the severity of algal blooms decreased. Changes to benthic communities, however, were far less rapid, and the trajectory and rate of any recovery of the dead zone, in particular Zernov’s Phyllophora Field, is far from certain. This study used towed underwater video imagery from research cruises in summer 2006 and spring 2008 to classify and map macro-epibenthic assemblage structure, and related this to putative physical, chemical and spatial drivers. Distinct and relatively stable benthic communities were in evidence across the northwest shelf at that time. These communities were largely structured by substrate type and depth, but there is some evidence that nutrients continued to play a role. Phyllophora spp. was present across much, but not all, of its former range, but at far lower percent cover than previously. The pattern of abundance of Phyllophora in 2006–2008 did not correlate with the documented pre-eutrophication pattern from 1966. There is some evidence that faster-growing opportunistic species have hindered recovery. We conclude that while there was evidence of sustained recovery, by 2008 the macro-epibenthic communities of the northwest shelf of the Black Sea were far from their pre-eutrophication state.https://www.frontiersin.org/article/10.3389/fmars.2019.00474/fullmacro-epibenthosBlack SeaPhyllophoratowed videodead zoneecosystem recovery |
| spellingShingle | Tim Stevens Tim Stevens Laurence Mee Laurence Mee Jana Friedrich Jana Friedrich Dmitry Aleynik Galina Minicheva Partial Recovery of Macro-Epibenthic Assemblages on the North-West Shelf of the Black Sea Frontiers in Marine Science macro-epibenthos Black Sea Phyllophora towed video dead zone ecosystem recovery |
| title | Partial Recovery of Macro-Epibenthic Assemblages on the North-West Shelf of the Black Sea |
| title_full | Partial Recovery of Macro-Epibenthic Assemblages on the North-West Shelf of the Black Sea |
| title_fullStr | Partial Recovery of Macro-Epibenthic Assemblages on the North-West Shelf of the Black Sea |
| title_full_unstemmed | Partial Recovery of Macro-Epibenthic Assemblages on the North-West Shelf of the Black Sea |
| title_short | Partial Recovery of Macro-Epibenthic Assemblages on the North-West Shelf of the Black Sea |
| title_sort | partial recovery of macro epibenthic assemblages on the north west shelf of the black sea |
| topic | macro-epibenthos Black Sea Phyllophora towed video dead zone ecosystem recovery |
| url | https://www.frontiersin.org/article/10.3389/fmars.2019.00474/full |
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