Tipping points in ecosystem structure, function and services
We are investigating how marine ecosystems respond to change, and identifying tipping points, risks and ways of managing them.
Project leader: Simon Thrush, University of Auckland
Duration: April 2016 – June 2019
We are investigating the effects of multiple stressors and cumulative impacts on marine ecosystems. Stressors can be caused by unexpected events (such as earthquakes) or impacts of human activities (such as increased sediment, nutrients or contaminants in the water), or climate change. These stressors can lead to ‘tipping points’ when rapid transformations occur, and an ecosystem loses its capacity to cope with change. Tipping points often involve the loss of valuable marine resources, or ecosystem services.
This is the first nationwide assessment of how estuaries and harbours in Aotearoa New Zealand respond to change. Our results show that as coastal waters become more turbid and nutrient levels increase biodiversity and ecosystem function decline. Rocky shores and kelp forests are also affected, with elevated turbidity decreasing the ability of these systems to respond to change and recover from disturbance.
Coastal and marine ecosystems deliver multiple benefits and services, so it is important to deal with the cumulative impacts of stressors and develop management strategies to reduce their impact. Our research suggests there is a growing need to apply an ecosystem-based management framework to manage risk and sustain New Zealand’s coastal ecosystems. This is even more important given the ongoing impacts of climate change.
In the media
- Commercial fishing shake-up, what's in store? 2 June 2019 Nine to Noon, RNZ. Interview with Jeremy Helson, Fisheries Inshore NZ Chief Executive and Professor Simon Thrush, University of Auckland
- Tipping Points and the health of estuaries, 8 March 2018, Our Changing World, RNZ
An in-depth piece that gets into the detail of what the Tipping points project is investigating, and why.
- 50 questions about the environment: Our oceans, NZ Herald, Jan 2018
Simon Thrush, leader of the Tipping Points project, was interviewed about key issues facing ocean and coastal ecosystems, including threats and pressures like ocean acidification, tipping points, and considerations for marine management.
- Allison AEF, Dickson ME, Fisher KT and Thrush SF (2018) Dilemmas of modelling and decision-making in environmental research. Environmental Modelling & Software 99(Supplement C):147 DOI: 10.1016/j.envsoft.2017.09.015
- Anderson A, Azhar M, Cooper J, James J, Debes J, Azhar D, Vandermark W, Leung KC, Yang K, Hilman J, Schenone S, Strozzi AG, Gee T, Friedrich H, Thrush S & Delmas P (2018). A multi-scale framework for the automated surveying of the Whangateau estuary using off-the-shelf equipment. International Conference Image and Vision Computing New Zealand. 1-6. DOI: 10.1109/IVCNZ.2017.8402506
- Blain CO & Shears NT (2019) Seasonal and spatial variation in photosynthetic response of the kelp Ecklonia radiata across a turbidity gradient. Photosynthesis Research 140 (1): 21-38. DOI: 10.1007/s11120-019-00636-7
- Chiantore M, Thrush SF, Asnaghi V & Hewitt JE (2018). The multiple roles of β-diversity help untangle community assembly processes affecting recovery of temperate rocky shores. Royal Society Open Science 5: 171700 DOI: 10.1098/rsos.171700
- de Juan S, Hewitt J, Subida MD & Thrush S (2018). Translating Ecological Integrity terms into operational language to inform societies. Journal of Environmental Management 228: 319-327 DOI: 10.1016/j.jenvman.2018.09.034
- Douglas EJ, Pilditch CA, Lohrer AM, Savage C, Schipper LA & Thrush SF (2018). Sedimentary environment influences ecosystem response to nutrient enrichment. Estuaries and Coasts 41: 1994 DOI: 10.1007/s12237-018-0416-5
- Ellingsen KE, Yoccoz NG, Tveraa T, Hewitt J & Thrush SF (2017). Long-term environmental monitoring for assessment of change: measurement inconsistencies over time and potential solutions. Environmental Monitoring and Assessment 189(11):595 DOI: 10.1007/s10661-017-6317-4
- Gladstone-Gallagher RV, Hughes RW, Douglas EJ & Pilditch CA (2018). Biomass-dependent seagrass resilience to sediment eutrophication. Journal of Experimental Marine Biology and Ecology 501: 54-64 DOI: 10.1016/j.jembe.2018.01.002
- Hewitt JE & Thrush SF (2019) Monitoring for tipping points in the marine environment. Journal of Environmental Management 234: 131-137 DOI: 10.1016/j.jenvman.2018.12.092
- Jones HFE, Pilditch CA, Hamilton DP and Bryan KR (2017) Impacts of a bivalve mass mortality event on an estuarine food web and bivalve grazing pressure. New Zealand Journal of Marine and Freshwater Research 51(3):370 DOI: 10.1080/00288330.2016.1245200
- Kakeh N, Coco G and Marani M (2016) On the morphodynamic stability of intertidal environments and the role of vegetation. Advances in Water Resources 93(B), 303-314 DOI: 10.1016/j.advwatres.2015.11.003
- McCartain LD, Townsend M, Thrush SF, Wethey DS, Woodin SA, Volkenborn N & Pilditch CA (2017). The effects of thin mud deposits on the behaviour of a deposit-feeding tellinid bivalve: implications for ecosystem functioning. Marine and Freshwater Behaviour and Physiology 50(4):239 DOI: 10.1080/10236244.2017.1364123
- O'Meara T, Gibbs E & Thrush SF (2017). Rapid organic matter assay of organic matter degradation across depth gradients within marine sediments. Methods in Ecology and Evolution 9(2) DOI: 10.1111/2041-210X.12894
- O'Meara T, Hillman J & Thrush S (2017). Rising tides, cumulative impacts and cascading changes to estuarine ecosystem functions. Scientific Reports 7 DOI: 10.1038/s41598-017-11058-7
- Schiel DR (2019) Experimental analyses of diversity partitioning in southern hemisphere algal communities. Oecologia, 190(1):179-193. DOI: 10.1007/s00442-019-04375-3.
- Schiel DR, Alestra T, Gerrity S, Orchard S, Dunmore R, Pirker J, Lilley S, Tait L, Hickford M & Thomsen M (2019) The Kaikōura earthquake in southern New Zealand: Loss of connectivity of marine communities and the necessity of a cross‐ecosystem perspective. Aquatic Conservation: Marine and Freshwater Ecosystems. 2019: 1-15 https://doi.org/10.1002/aqc.3122
- Schiel DR & Gunn TD (2019) Effects of sediment on early life history stages of habitat-dominating fucoid algae. Journal of Experimental Marine Biology and Ecology, 516, pp.44-50 DOI: 10.1016/j.jembe.2019.04.005
- Shen H, Thrush SF, Wan X et al (2016) Optimization of hard clams, polychaetes, physical disturbance and denitrifying bacteria of removing nutrients in marine sediment. Marine Pollution Bulletin 110(1): 86–92 DOI: 10.1016/j.marpolbul.2016.06.081
- Shen H, Jiang G, Wan X, Li H, Qiao Y, Thrush S & He P (2017). Response of the microbial community to bioturbation by benthic macrofauna on intertidal flats. Journal of Experimental Marine Biology and Ecology 488:44 DOI: 10.1016/j.jembe.2016.12.010
- Tait LW (2019) Giant kelp forests at critical light thresholds show compromised ecological resilience to environmental and biological drivers. Estuarine, Coastal and Shelf Science, 219, 231-241. DOI: 10.1016/j.ecss.2019.02.026
- Tait LW & Schiel DR (2018) Ecophysiology of layered macroalgal assemblages: importance of subcanopy species biodiversity in buffering primary production. Frontiers in Marine Science, 5, p.444. DOI: doi.org/10.3389/fmars.2018.00444
- Thrush SF, Hewitt JE, Kraan C, Lohrer AM, Pilditch CA & Douglas E (2017) Changes in the location of biodiversity–ecosystem function hot spots across the seafloor landscape with increasing sediment nutrient loading. Proceedings of the Royal Society B: Biological Sciences 284(1852) DOI: 10.1098/rspb.2016.2861
- Thomsen MS, Mondardini L, Alestra T, Gerrity S, Tait L, South P, Lilley S and Schiel D (2019) Local extinction of bull kelp (Durvillaea spp.) due to a marine heatwave. Frontiers in Marine Science, 6, p.84. DOI: 10.3389/fmars.2019.00084
- Thrush SF, Lewis N, Le Heron R et al (2016) Addressing surprise and uncertain futures in marine science, marine governance, and society. Ecology and Society 21(2) 44 DOI: 10.5751/ES-08574-210244
- Tinoco RO and Coco G (2016) A laboratory study on sediment resuspension within arrays of rigid cylinders. Advances in Water Resources 92(Supplement C):1–9 DOI: 10.1016/j.advwatres.2016.04.003
- Urlich S, Thrush S, Hewitt J & E Jorgensen E (2018). The Earth Summit 25 Years on: Why is biodiversity continuing to decline? The Resource Management Journal pp19-21
- Urlich S, Thrush S, Hewitt J & E Jorgensen E (2018). What it Means to “Maintain” Biodiversity in our Coastal Marine Environment. The Resource Management Journal pp25-30
- Zhou Z, Ye Q and Coco G (2016). A one-dimensional biomorphodynamic model of tidal flats: Sediment sorting, marsh distribution, and carbon accumulation under sea level rise. Advances in Water Resources 93(B), 288-302 DOI: 10.1016/j.advwatres.2015.10.011
Latest news and updates
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