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Stressors Increase the Impacts of Coastal Macrofauna Biodiversity Loss on Ecosystem Multifunctionality. Ecosystems 2022. [DOI: 10.1007/s10021-022-00775-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AbstractThere is substantial evidence that biodiversity underpins ecosystem functioning, but it is unclear how these relationships change with multiple stressors in complex real-world settings. Coastal zones are affected by numerous stressors (for example, sediment input and nutrient runoff from land) and the cumulative effects of these stressors may result in pronounced and unexpected changes in the functioning of ecosystems. To investigate the cumulative effects of turbidity and elevated nutrients on coastal biodiversity-ecosystem functioning relationships, we performed a large-scale field experiment manipulating in situ sediment porewater ammonium concentrations and measured multiple ecosystem functions related to carbon fixation and mineralisation in 15 estuaries with varying levels of turbidity. The results indicated that the benthic macrofauna diversity (species richness, abundance, and functional richness) declined with increased porewater ammonium concentrations and there were clear thresholds in light levels at the seafloor in relation to the biodiversity-ecosystem function relationships. Multifunctionality indices (an integrated index of all measured functions) in moderately turbid and turbid estuaries (daily mean seafloor PAR < 420 µmol m−2 s−1) decreased with the loss of macrofauna biodiversity. Functioning in low-turbidity estuaries (daily mean PAR > 420 µmol m−2 s−1) however remained relatively constant, suggesting that they were more resilient against the nutrient-induced biodiversity loss. Our results demonstrate that ecosystems already stressed by stressors that alter functional performance (turbidity) may be more prone to loss of overall functioning if biodiversity is reduced by another stressor (nutrient enrichment), highlighting the potential snowballing effects of cumulative change.
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Hewitt JE, Bulmer RH, Stephenson F, Thrush SF. Sampling frequency, duration and the Southern Oscillation influence the ability of long-term studies to detect sudden change. GLOBAL CHANGE BIOLOGY 2021; 27:2213-2224. [PMID: 33599051 DOI: 10.1111/gcb.15558] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2020] [Accepted: 02/04/2021] [Indexed: 06/12/2023]
Abstract
Ecologists have long acknowledged the importance of context dependency related to position along spatial gradients. It is also acknowledged that broad-scale climate patterns can directly and indirectly alter population dynamics. What is not often addressed is whether climate patterns such as the Southern Oscillation interact with population-level temporal patterns and affect the ability of time-series data, such as long-term state of the environment monitoring programmes, to detect change. Monitoring design criteria generally focus on number of data points, sampling frequency and duration, often derived from previous information on species seasonal and multi-year temporal patterns. Our study questioned whether the timing of any changes relative to Southern Oscillation, interacting with species populations dynamics, would also be important. We imposed a series of simulated reductions on macrofaunal abundance data collected regularly over 29 years from two sites, using species selected for observed differences in temporal dynamics. We hypothesized that (1) high within-year sampling frequency would increase detection ability for species with repeatable seasonality cycles and (2) timing of the reduction in abundance relative to the Southern Oscillation was only likely to affect detection ability for long-lived species with multi-year cyclic patterns in abundance. However, regardless of species population dynamics, we found both within-year sampling frequency and the timing of the imposed reduction relative to the Southern Oscillation Index affected detection ability. The latter result, while apparently demonstrating a confounding influence on monitoring, offers the opportunity to improve our ability to detect and interpret analyses of monitoring data, and thus our ability to make recommendations to managers.
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Affiliation(s)
- Judi E Hewitt
- Marine Ecology Group, National Institute of Water and Atmosphere, Hamilton, New Zealand
- Department of Statistics, University of Auckland, Auckland, New Zealand
| | - Richard H Bulmer
- Marine Ecology Group, National Institute of Water and Atmosphere, Hamilton, New Zealand
| | - Fabrice Stephenson
- Marine Ecology Group, National Institute of Water and Atmosphere, Hamilton, New Zealand
| | - Simon F Thrush
- Institute of Marine Studies, University of Auckland, Auckland, New Zealand
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Thrush SF, Hewitt JE, Gladstone‐Gallagher RV, Savage C, Lundquist C, O’Meara T, Vieillard A, Hillman JR, Mangan S, Douglas EJ, Clark DE, Lohrer AM, Pilditch C. Cumulative stressors reduce the self-regulating capacity of coastal ecosystems. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2021; 31:e02223. [PMID: 32869444 PMCID: PMC7816261 DOI: 10.1002/eap.2223] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/25/2019] [Revised: 06/09/2020] [Accepted: 06/29/2020] [Indexed: 05/11/2023]
Abstract
Marine ecosystems are prone to tipping points, particularly in coastal zones where dramatic changes are associated with interactions between cumulative stressors (e.g., shellfish harvesting, eutrophication and sediment inputs) and ecosystem functions. A common feature of many degraded estuaries is elevated turbidity that reduces incident light to the seafloor, resulting from multiple factors including changes in sediment loading, sea-level rise and increased water column algal biomass. To determine whether cumulative effects of elevated turbidity may result in marked changes in the interactions between ecosystem components driving nutrient processing, we conducted a large-scale experiment manipulating sediment nitrogen concentrations in 15 estuaries across a national-scale gradient in incident light at the seafloor. We identified a threshold in incident light that was related to distinct changes in the ecosystem interaction networks (EIN) that drive nutrient processing. Above this threshold, network connectivity was high with clear mechanistic links to denitrification and the role of large shellfish in nitrogen processing. The EIN analyses revealed interacting stressors resulting in a decoupling of ecosystem processes in turbid estuaries with a lower capacity to denitrify and process nitrogen. This suggests that, as turbidity increases with sediment load, coastal areas can be more vulnerable to eutrophication. The identified interactions between light, nutrient processing and the abundance of large shellfish emphasizes the importance of actions that seek to manage multiple stressors and conserve or enhance shellfish abundance, rather than actions focusing on limiting a single stressor.
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Affiliation(s)
- Simon F. Thrush
- Institute of Marine ScienceThe University of AucklandPrivate Bag 92019Auckland1142New Zealand
| | - Judi E. Hewitt
- Department of StatisticsThe University of AucklandPrivate Bag 92019Auckland1142New Zealand
- National Institute of Water and Atmospheric ResearchPO Box 11‐115Hillcrest Hamilton3251New Zealand
| | - Rebecca V. Gladstone‐Gallagher
- Institute of Marine ScienceThe University of AucklandPrivate Bag 92019Auckland1142New Zealand
- School of ScienceUniversity of WaikatoPrivate Bag 3105Hamilton3240New Zealand
| | - Candida Savage
- Department of Marine ScienceUniversity of OtagoPO Box 56Dunedin9054New Zealand
- Department of Biological SciencesUniversity of Cape TownPrivate BagRondebosch7700South Africa
| | - Carolyn Lundquist
- Institute of Marine ScienceThe University of AucklandPrivate Bag 92019Auckland1142New Zealand
- National Institute of Water and Atmospheric ResearchPO Box 11‐115Hillcrest Hamilton3251New Zealand
| | - Teri O’Meara
- Institute of Marine ScienceThe University of AucklandPrivate Bag 92019Auckland1142New Zealand
- Smithsonian Environmental Research Center647 Contees Wharf RoadEdgewaterMaryland21037‐0028USA
| | - Amanda Vieillard
- Institute of Marine ScienceThe University of AucklandPrivate Bag 92019Auckland1142New Zealand
| | - Jenny R. Hillman
- Institute of Marine ScienceThe University of AucklandPrivate Bag 92019Auckland1142New Zealand
| | - Stephanie Mangan
- School of ScienceUniversity of WaikatoPrivate Bag 3105Hamilton3240New Zealand
| | - Emily J. Douglas
- National Institute of Water and Atmospheric ResearchPO Box 11‐115Hillcrest Hamilton3251New Zealand
- School of ScienceUniversity of WaikatoPrivate Bag 3105Hamilton3240New Zealand
| | - Dana E. Clark
- School of ScienceUniversity of WaikatoPrivate Bag 3105Hamilton3240New Zealand
- Cawthron InstitutePrivate Bag 2Nelson,7042New Zealand
| | - Andrew M. Lohrer
- National Institute of Water and Atmospheric ResearchPO Box 11‐115Hillcrest Hamilton3251New Zealand
| | - Conrad Pilditch
- School of ScienceUniversity of WaikatoPrivate Bag 3105Hamilton3240New Zealand
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Rishworth GM, Adams JB, Bird MS, Carrasco NK, Dänhardt A, Dannheim J, Lemley DA, Pistorius PA, Scheiffarth G, Hillebrand H. Cross-continental analysis of coastal biodiversity change. Philos Trans R Soc Lond B Biol Sci 2020; 375:20190452. [PMID: 33131440 PMCID: PMC7662198 DOI: 10.1098/rstb.2019.0452] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/17/2020] [Indexed: 01/16/2023] Open
Abstract
Whereas the anthropogenic impact on marine biodiversity is undebated, the quantification and prediction of this change are not trivial. Simple traditional measures of biodiversity (e.g. richness, diversity indices) do not capture the magnitude and direction of changes in species or functional composition. In this paper, we apply recently developed methods for measuring biodiversity turnover to time-series data of four broad taxonomic groups from two coastal regions: the southern North Sea (Germany) and the South African coast. Both areas share geomorphological features and ecosystem types, allowing for a critical assessment of the most informative metrics of biodiversity change across organism groups. We found little evidence for directional trends in univariate metrics of diversity for either the effective number of taxa or the amount of richness change. However, turnover in composition was high (on average nearly 30% of identities when addressing presence or absence of species) and even higher when taking the relative dominance of species into account. This turnover accumulated over time at similar rates across regions and organism groups. We conclude that biodiversity metrics responsive to turnover provide a more accurate reflection of community change relative to conventional metrics (absolute richness or relative abundance) and are spatially broadly applicable. This article is part of the theme issue 'Integrative research perspectives on marine conservation'.
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Affiliation(s)
- Gavin M. Rishworth
- Institute for Coastal and Marine Research, Department of Botany, Nelson Mandela University, Port Elizabeth 6031, South Africa
- Department of Zoology, Nelson Mandela University, Port Elizabeth 6031, South Africa
| | - Janine B. Adams
- Institute for Coastal and Marine Research, Department of Botany, Nelson Mandela University, Port Elizabeth 6031, South Africa
| | - Matthew S. Bird
- Department of Zoology, University of Johannesburg, Auckland Park, Johannesburg 2006, South Africa
| | - Nicola K. Carrasco
- School of Life Sciences, University of KwaZulu-Natal, Durban 4000, South Africa
| | - Andreas Dänhardt
- Lower Saxon Wadden Sea National Park Authority, Virchowstr. 1 26382 Wilhelmshaven, Germany
| | - Jennifer Dannheim
- Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12 D-27570 Bremerhaven, Germany
- Helmholtz-Institute for Functional Marine Biodiversity at the University of Oldenburg [HIFMB], Ammerländer Heerstrasse 231 26129 Oldenbburg, Germany
| | - Daniel A. Lemley
- Institute for Coastal and Marine Research, Department of Botany, Nelson Mandela University, Port Elizabeth 6031, South Africa
| | - Pierre A. Pistorius
- Department of Zoology, Nelson Mandela University, Port Elizabeth 6031, South Africa
| | - Gregor Scheiffarth
- Institute for Chemistry and Biology of Marine Environments [ICBM], Carl-von-Ossietzky University Oldenburg, Schleusenstrasse 1 D-26382 Wilhelmshaven, Germany
| | - Helmut Hillebrand
- Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12 D-27570 Bremerhaven, Germany
- Helmholtz-Institute for Functional Marine Biodiversity at the University of Oldenburg [HIFMB], Ammerländer Heerstrasse 231 26129 Oldenbburg, Germany
- Institute for Chemistry and Biology of Marine Environments [ICBM], Carl-von-Ossietzky University Oldenburg, Schleusenstrasse 1 D-26382 Wilhelmshaven, Germany
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Handley SJ, Morrisey D, Depree C, Carter M, Mejía Torres LA. Relative macrofaunal biomass reduced under an enriched salmon farm, Pelorus Sound, Aotearoa-New Zealand. MARINE POLLUTION BULLETIN 2020; 157:111303. [PMID: 32658671 DOI: 10.1016/j.marpolbul.2020.111303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Revised: 05/20/2020] [Accepted: 05/20/2020] [Indexed: 06/11/2023]
Abstract
We compared changes in the benthos associated with discharges from a salmon farm at a low-flow location in Pelorus Sound, Aotearoa-New Zealand to the Pearson and Rosenberg model (PRM). As predicted by PRM, benthic enrichment resulted in significant increases in abundance of small, opportunistic macrofauna beneath salmon farm cages. In contrast, at reference sites we found fewer but larger, rare species. When estimates for biomass were calculated from macrofaunal size-classes, reference sites averaged 4.86 times more biomass and 4.35 times greater diversity than farm sites - results also consistent with the PRM. Farm sites favoured deposit feeders at the expense of suspension feeders and grazers. We discuss the significance of large rare species that contributed most to reference biomass estimates that appear under threat from multiple anthropogenic stressors.
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Affiliation(s)
- Sean J Handley
- National Institute of Water & Atmospheric Research (NIWA), PB 893, Nelson 7001, New Zealand.
| | - Don Morrisey
- Cawthron Institute, Private Bag 2, Nelson 7042, New Zealand
| | - Craig Depree
- DairyNZ, Private Bag 3221, Hamilton 3240, New Zealand
| | - Megan Carter
- National Institute of Water & Atmospheric Research (NIWA), PB 893, Nelson 7001, New Zealand
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Using Artificial-Reef Knowledge to Enhance the Ecological Function of Offshore Wind Turbine Foundations: Implications for Fish Abundance and Diversity. JOURNAL OF MARINE SCIENCE AND ENGINEERING 2020. [DOI: 10.3390/jmse8050332] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
As the development of large-scale offshore wind farms (OWFs) amplifies due to technological progress and a growing demand for renewable energy, associated footprints on the seabed are becoming increasingly common within soft-bottom environments. A large part of the footprint is the scour protection, often consisting of rocks that are positioned on the seabed to prevent erosion. As such, scour protection may resemble a marine rocky reef and could have important ecosystem functions. While acknowledging that OWFs disrupt the marine environment, the aim of this systematic review was to examine the effects of scour protection on fish assemblages, relate them to the effects of designated artificial reefs (ARs) and, ultimately, reveal how future scour protection may be tailored to support abundance and diversity of marine species. The results revealed frequent increases in abundances of species associated with hard substrata after the establishment of artificial structures (i.e., both OWFs and ARs) in the marine environment. Literature indicated that scour protection meets the requirements to function as an AR, often providing shelter, nursery, reproduction, and/or feeding opportunities. Using knowledge from AR models, this review suggests methodology for ecological improvements of future scour protections, aiming towards a more successful integration into the marine environment.
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