How a coastal megacity affects marine biodiversity and ecosystem function: Impacts of reduced water quality and other anthropogenic stressors
Coastal marine ecosystems are integral in providing numerous ecosystem functions and services. However, intense and chronic anthropogenic stressors often impact marine ecosystems surrounding highly urbanized, densely populated coastal megacities. The associated reduction of water quality and biodive...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Elsevier
2024-03-01
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| Series: | Ecological Indicators |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S1470160X24001407 |
| _version_ | 1827287444607729664 |
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| author | Rinaldi Gotama David M. Baker Isis Guibert Shelby E. McIlroy Bayden D. Russell |
| author_facet | Rinaldi Gotama David M. Baker Isis Guibert Shelby E. McIlroy Bayden D. Russell |
| author_sort | Rinaldi Gotama |
| collection | DOAJ |
| description | Coastal marine ecosystems are integral in providing numerous ecosystem functions and services. However, intense and chronic anthropogenic stressors often impact marine ecosystems surrounding highly urbanized, densely populated coastal megacities. The associated reduction of water quality and biodiversity of these ecosystems potentially erodes ecosystem functions and provision of services. While there is general consensus that greater biodiversity supports a multitude of ecosystem functions, evidence from marine ecosystems in real-world settings is lacking. In this study, we evaluated the influence of water quality on benthic and fish assemblages, as well as quantified six key ecosystem functions in coastal waters of Hong Kong. Hong Kong’s marine ecosystems are marred with long-term damage that is directly linked with rapid economic growth and anthropogenic activities. We found that water quality significantly affected community composition and clustered assemblages into separate groups related to strength of impact: high impact sites were generally dominated by bivalves and small, opportunistic organisms such as damselfish (Pomacentrinae) and cardinalfish (Apogonidae); low impact sites were dominated by macroalgae, bryozoa, and commercially important piscivores such as groupers (Epinephelinae) and seabreams (Sparidae). Ecosystem function tests showed that low impact sites were much more productive than high impact sites, with 15-times greater macroalgal cover and 5-times higher fish biomass. On the other hand, herbivory and predation rates were context-dependent due to underlying biodiversity effects such as selection, complementarity, and competition. Eutrophication increased decomposition and reduced carbon sequestration, but excessive nutrient input could have suppressed decomposer activities via hypoxia. Therefore, we show that in high impact sites where top-down control is removed, resilient and opportunistic organisms such as cardinalfishes and sea urchins may expand to fulfill functional roles, effectively maintaining ecosystem functions such as predation and herbivory in degraded habitats. Contrary to general consensus, this study demonstrates the merit in conserving even highly impacted marine habitats due to their persistent ecosystem functionality despite chronic water quality issues and shifts in benthic and fish assemblages. |
| first_indexed | 2024-03-07T19:10:11Z |
| format | Article |
| id | doaj.art-3aa1d849cb9843659cdb5c80bda5524e |
| institution | Directory Open Access Journal |
| issn | 1470-160X |
| language | English |
| last_indexed | 2024-04-24T10:58:20Z |
| publishDate | 2024-03-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Ecological Indicators |
| spelling | doaj.art-3aa1d849cb9843659cdb5c80bda5524e2024-04-12T04:44:28ZengElsevierEcological Indicators1470-160X2024-03-01160111683How a coastal megacity affects marine biodiversity and ecosystem function: Impacts of reduced water quality and other anthropogenic stressorsRinaldi Gotama0David M. Baker1Isis Guibert2Shelby E. McIlroy3Bayden D. Russell4Swire Institute of Marine Science and Area of Ecology and Biodiversity, School of Biological Sciences, The University of Hong Kong, Pok Fu Lam, Hong Kong SAR, China; Indo Ocean Project, Banjar Adegan Kawan, Desa Ped, Nusa Penida, Klungkung, Bali, 80771, IndonesiaSwire Institute of Marine Science and Area of Ecology and Biodiversity, School of Biological Sciences, The University of Hong Kong, Pok Fu Lam, Hong Kong SAR, ChinaSwire Institute of Marine Science and Area of Ecology and Biodiversity, School of Biological Sciences, The University of Hong Kong, Pok Fu Lam, Hong Kong SAR, ChinaSwire Institute of Marine Science and Area of Ecology and Biodiversity, School of Biological Sciences, The University of Hong Kong, Pok Fu Lam, Hong Kong SAR, China; School of Life Sciences, Simon F. S. Li Marine Science Laboratory, The Chinese University of Hong Kong, Hong Kong SAR, ChinaSwire Institute of Marine Science and Area of Ecology and Biodiversity, School of Biological Sciences, The University of Hong Kong, Pok Fu Lam, Hong Kong SAR, China; The Joint Laboratory for Marine Ecology and Environmental Sciences (JLMEES), The Swire Institute of Marine Science, The University of Hong Kong, Hong Kong SAR, China; Institute for Climate and Carbon Neutrality, The University of Hong Kong, Hong Kong SAR, China; Corresponding author at: Swire Institute of Marine Science and Area of Ecology and Biodiversity, School of Biological Sciences, The University of Hong Kong, Pok Fu Lam, Hong Kong SAR, China.Coastal marine ecosystems are integral in providing numerous ecosystem functions and services. However, intense and chronic anthropogenic stressors often impact marine ecosystems surrounding highly urbanized, densely populated coastal megacities. The associated reduction of water quality and biodiversity of these ecosystems potentially erodes ecosystem functions and provision of services. While there is general consensus that greater biodiversity supports a multitude of ecosystem functions, evidence from marine ecosystems in real-world settings is lacking. In this study, we evaluated the influence of water quality on benthic and fish assemblages, as well as quantified six key ecosystem functions in coastal waters of Hong Kong. Hong Kong’s marine ecosystems are marred with long-term damage that is directly linked with rapid economic growth and anthropogenic activities. We found that water quality significantly affected community composition and clustered assemblages into separate groups related to strength of impact: high impact sites were generally dominated by bivalves and small, opportunistic organisms such as damselfish (Pomacentrinae) and cardinalfish (Apogonidae); low impact sites were dominated by macroalgae, bryozoa, and commercially important piscivores such as groupers (Epinephelinae) and seabreams (Sparidae). Ecosystem function tests showed that low impact sites were much more productive than high impact sites, with 15-times greater macroalgal cover and 5-times higher fish biomass. On the other hand, herbivory and predation rates were context-dependent due to underlying biodiversity effects such as selection, complementarity, and competition. Eutrophication increased decomposition and reduced carbon sequestration, but excessive nutrient input could have suppressed decomposer activities via hypoxia. Therefore, we show that in high impact sites where top-down control is removed, resilient and opportunistic organisms such as cardinalfishes and sea urchins may expand to fulfill functional roles, effectively maintaining ecosystem functions such as predation and herbivory in degraded habitats. Contrary to general consensus, this study demonstrates the merit in conserving even highly impacted marine habitats due to their persistent ecosystem functionality despite chronic water quality issues and shifts in benthic and fish assemblages.http://www.sciencedirect.com/science/article/pii/S1470160X24001407Benthic communityDegraded habitatsEcosystem functionEutrophicationMarine biodiversityTrophic structure |
| spellingShingle | Rinaldi Gotama David M. Baker Isis Guibert Shelby E. McIlroy Bayden D. Russell How a coastal megacity affects marine biodiversity and ecosystem function: Impacts of reduced water quality and other anthropogenic stressors Ecological Indicators Benthic community Degraded habitats Ecosystem function Eutrophication Marine biodiversity Trophic structure |
| title | How a coastal megacity affects marine biodiversity and ecosystem function: Impacts of reduced water quality and other anthropogenic stressors |
| title_full | How a coastal megacity affects marine biodiversity and ecosystem function: Impacts of reduced water quality and other anthropogenic stressors |
| title_fullStr | How a coastal megacity affects marine biodiversity and ecosystem function: Impacts of reduced water quality and other anthropogenic stressors |
| title_full_unstemmed | How a coastal megacity affects marine biodiversity and ecosystem function: Impacts of reduced water quality and other anthropogenic stressors |
| title_short | How a coastal megacity affects marine biodiversity and ecosystem function: Impacts of reduced water quality and other anthropogenic stressors |
| title_sort | how a coastal megacity affects marine biodiversity and ecosystem function impacts of reduced water quality and other anthropogenic stressors |
| topic | Benthic community Degraded habitats Ecosystem function Eutrophication Marine biodiversity Trophic structure |
| url | http://www.sciencedirect.com/science/article/pii/S1470160X24001407 |
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