I am a marine ecologist with a focus on human impacts in coastal and estuarine ecosystems. My research group investigates drivers of change in marine ecosystems and combines field and laboratory studies to understand how multiple stressors affect food web structure and biogeochemical cycling in coastal ecosystems.
Investigating linkages between land-use changes (in particular intensification of farming practices), in South Island, New Zealand, and ecological and biogeochemical shifts in recipient estuaries.
We have constructed nitrogen loading models for the South Island to estimate nutrient flux to estuaries based on different land use practices in the catchment. Stable isotope ratios in an opportunistic seaweed species reflected these different nitrogen loading regimes, providing a good indicator of local nutrient sources. We also documented shifts in growth rates of select bivalves and fishes and recorded changes in organic matter sources that support secondary consumers in the estuaries with greater nitrogen loads. To groundtruth the field surveys and transplant experiments, we have conducted laboratory experiments to quantify nutrient uptake and tissue turnover rates in select organisms. This research was supported by a Ministry of Fisheries Biodiversity Research grant.
We currently investigate spatial and temporal variation in rates of benthic denitrification in estuaries subject to different nitrogen loading regimes. This research aims to quantify nitrogen removal rates in pristine as well as nutrient enriched estuaries in South Island, New Zealand, and to investigate physicochemical and biological factors that correlate with coupled and direct denitrification. This research is supported by PBRF money made available to C. Savage.
Our research team also conducts work on nutrient fluxes and oxygen dynamics in subtidal sediments impacted by high organic matter loading from mussel farm deposits. In particular, we have a project on the potential of a bioturbator (sea cucumber) for the remediation of mussel impacted sediment. This work forms a component of a larger integrated aquaculture project with NIWA.
In order to understand the influence of humans against a background of natural variability in marine ecosystems, we have employed palaeoecological techniques to reconstruct historical changes in pristine and impacted coastal systems. In Fiordland, we use biomarkers (e.g., stable isotopes, pigments, lignin, BIT index), in water column samples and sedimentary records to reconstruct long-term change in productivity and organic matter sources to the fjords.
Part of this research involves identifying suitable biomarkers as proxies of refractory terrestrial organic matter and marine organic matter. Research is also underway to understand mechanisms that affect these proxies (particularly phytoplankton pigments) as they settle out of the water column and are incorporated into the sedimentary record. This research has been supported by University of Otago Research Grants and PBRF funds.
My research has recently expanded to the tropical Pacific, where I am interested in how multiple stressors affect coral reef ecosystems. In particular, I am interested in how alterations in physicochemical factors (temperature, salinity, light environment), individually and combined, affect carbon cycling and implications of this for climate change.
Thomas, S., Pilditch, C. A., Thrush, S. F., & Savage, C. (2022). Ecosystem function responses to nutrient enrichment mediated by mud content in soft sediment habitats.
New Zealand Journal of Marine & Freshwater Research. Advance online publication.
doi: 10.1080/00288330.2022.2102043
Journal - Research Article
Källberg Normark, L., Liénart, C., Pillay, D., Garbaras, A., Savage, C., & Karlson, A. M. L. (2022). Isotopic niche size variability in an ecosystem engineer along a disturbance gradient in a South African lagoon.
Marine Environmental Research,
173, 105541.
doi: 10.1016/j.marenvres.2021.105541
Journal - Research Article
Robertson, B. P., & Savage, C. (2021). Thresholds in catchment nitrogen load for shifts from seagrass to nuisance macroalgae in shallow intertidal estuaries.
Limnology & Oceanography,
66, 1353-1366.
doi: 10.1002/lno.11689
Journal - Research Article
Thrush, S. F., Hewitt, J. E., Gladstone-Gallagher, R. V., Savage, C., Lundquist, C., O'Meara, T., … Pilditch, C. (2021). Cumulative stressors reduce the self-regulating capacity of coastal ecosystems.
Ecological Applications,
31(1), e02223.
doi: 10.1002/eap.2223
Journal - Research Article
Karlson, A. M. L., Pilditch, C. A., Probert, P. K., Leduc, D., & Savage, C. (2021). Large infaunal bivalves determine community uptake of macroalgal detritus and food web pathways.
Ecosystems,
24(2), 384-402.
doi: 10.1007/s10021-020-00524-5
Journal - Research Article
Snowball, I., Lehoux, A. P., Crawshaw, J., Savage, C., Hipsey, M. R., Ghadouani, A., … Oldham, C. E. (2019). Pollution from land-based sources. In E. J. Techera & G. Winter (Eds.),
Marine extremes: Ocean safety, marine health and the blue economy. (pp. 106-122). Abingdon, Oxon: Routledge.
Chapter in Book - Research
Savage, C. (2009). Marine sources of Omega-3: Is their future in aquaculture? In T. K. Nakamura (Ed.),
Aquaculture research progress. (pp. 169-197). New York: Nova Science.
Chapter in Book - Research
Ballagh, R. J., & Savage, C. M. (2000). The theory of atom lasers. In C. M. Savage & M. P. Das (Eds.),
Proceedings of the Thirteenth Physics Summer School: Bose-Einstein Condensation: Atomic Physics to Quantum Fluids. (pp. 153-188). Singapore: World Scientific.
Chapter in Book - Research
Källberg Normark, L., Liénart, C., Pillay, D., Garbaras, A., Savage, C., & Karlson, A. M. L. (2022). Isotopic niche size variability in an ecosystem engineer along a disturbance gradient in a South African lagoon.
Marine Environmental Research,
173, 105541.
doi: 10.1016/j.marenvres.2021.105541
Journal - Research Article
Thomas, S., Pilditch, C. A., Thrush, S. F., & Savage, C. (2022). Ecosystem function responses to nutrient enrichment mediated by mud content in soft sediment habitats.
New Zealand Journal of Marine & Freshwater Research. Advance online publication.
doi: 10.1080/00288330.2022.2102043
Journal - Research Article
Karlson, A. M. L., Pilditch, C. A., Probert, P. K., Leduc, D., & Savage, C. (2021). Large infaunal bivalves determine community uptake of macroalgal detritus and food web pathways.
Ecosystems,
24(2), 384-402.
doi: 10.1007/s10021-020-00524-5
Journal - Research Article
Robertson, B. P., & Savage, C. (2021). Thresholds in catchment nitrogen load for shifts from seagrass to nuisance macroalgae in shallow intertidal estuaries.
Limnology & Oceanography,
66, 1353-1366.
doi: 10.1002/lno.11689
Journal - Research Article
Thomas, S., Pilditch, C. A., Thrush, S. F., Baltar, F., Crawshaw, J. A., Thomson, B., & Savage, C. (2021). Does the size structure of venerid clam populations affect ecosystem functions on intertidal sandflats?
Estuaries & Coasts,
44(1), 242-252.
doi: 10.1007/s12237-020-00774-5
Journal - Research Article
Thrush, S. F., Hewitt, J. E., Gladstone-Gallagher, R. V., Savage, C., Lundquist, C., O'Meara, T., … Pilditch, C. (2021). Cumulative stressors reduce the self-regulating capacity of coastal ecosystems.
Ecological Applications,
31(1), e02223.
doi: 10.1002/eap.2223
Journal - Research Article
Hope, J. A., Hewitt, J., Pilditch, C. A., Savage, C., & Thrush, S. F. (2020). Effect of nutrient enrichment and turbidity on interactions between microphytobenthos and a key bivalve: Implications for higher trophic levels.
Frontiers in Marine Science,
7, 695.
doi: 10.3389/fmars.2020.00695
Journal - Research Article
Crawshaw, J. A., Schallenberg, M., & Savage, C. (2019). Physical and biological drivers of sediment oxygenation and denitrification in a New Zealand intermittently closed and open lake lagoon.
New Zealand Journal of Marine & Freshwater Research,
53(1), 33-59.
doi: 10.1080/00288330.2018.1476388
Journal - Research Article
Crawshaw, J. A., Schallenberg, M., Savage, C., & Van Hale, R. (2019). Hierarchy of factors controls denitrification rates in temperate intermittently closed and open coastal lakes/lagoons (ICOLLS).
Aquatic Ecology,
53, 719-744.
doi: 10.1007/s10452-019-09721-4
Journal - Research Article
Crawshaw, J., O'Meara, T., Savage, C., Thomson, B., Baltar, F., & Thrush, S. F. (2019). Source of organic detritus and bivalve biomass influences nitrogen cycling and extracellular enzyme activity in estuary sediments.
Biogeochemistry,
145, 315-335.
doi: 10.1007/s10533-019-00608-y
Journal - Research Article
Savage, C. (2019). Seabird nutrients are assimilated by corals and enhance coral growth rates.
Scientific Reports,
9, 4284.
doi: 10.1038/s41598-019-41030-6
Journal - Research Article
Douglas, E. J., Pilditch, C. A., Lohrer, A. M., Savage, C., Schipper, L. A., & Thrush, S. F. (2018). Sedimentary environment influences ecosystem response to nutrient enrichment.
Estuaries & Coasts,
41(7), 1994-2008.
doi: 10.1007/s12237-018-0416-5
Journal - Research Article
Robertson, B. P., & Savage, C. (2018). Mud-entrained macroalgae utilise porewater and overlying water column nutrients to grow in a eutrophic intertidal estuary.
Biogeochemistry,
139, 53-68.
doi: 10.1007/s10533-018-0454-x
Journal - Research Article
Robinson, G., MacTavish, T., Savage, C., Caldwell, G. S., Jones, C. L. W., Probyn, T., … Stead, S. M. (2018). Carbon amendment stimulates benthic nitrogen cycling during the bioremediation of particulate aquaculture waste.
Biogeosciences,
15(6), 1863-1878.
doi: 10.5194/bg-15-1863-2018
Journal - Research Article
Savage, C., Thrush, S. F., & Pilditch, C. A. (2018). Tipping points in coastal ecosystems.
Junctures,
2018(19), 12-14.
Journal - Research Article
Bierschenk, A. M., Savage, C., & Matthaei, C. D. (2017). Intensity of catchment land use influences biological traits of benthic invertebrates along a freshwater-marine continuum.
Limnology & Oceanography,
62(S1), S292-S308.
doi: 10.1002/lno.10584
Journal - Research Article
Cui, X., Bianchi, T. S., & Savage, C. (2017). Erosion of modern terrestrial organic matter as a major component of sediments in fjords.
Geophysical Research Letters,
44(3), 1457-1465.
doi: 10.1002/2016GL072260
Journal - Research Article
Cui, X., Bianchi, T. S., Kenney, W. F., Wang, J., Curtis, J. H., Xue, K., & Savage, C. (2017). Carbon dynamics along a temperate fjord-head delta: Linkages with carbon burial in fjords.
Journal of Geophysical Research: Biogeosciences,
122(12), 3419-3430.
doi: 10.1002/2017JG003891
Journal - Research Article
Cui, X., Bianchi, T. S., Hutchings, J. A., Savage, C., & Curtis, J. H. (2016). Partitioning of organic carbon among density fractions in surface sediments of Fiordland, New Zealand.
Journal of Geophysical Research: Biogeosciences,
121(3), 1016-1031.
doi: 10.1002/2015JG003225
Journal - Research Article
Cui, X., Bianchi, T. S., Savage, C., & Smith, R. W. (2016). Organic carbon burial in fjords: Terrestrial versus marine inputs.
Earth & Planetary Science Letters,
451, 41-50.
doi: 10.1016/j.epsl.2016.07.003
Journal - Research Article
Gongol, C., & Savage, C. (2016). Spatial variation in rates of benthic denitrification and environmental controls in four New Zealand
estuaries.
Marine Ecology Progress Series,
556, 59-77.
doi: 10.3354/meps11865
Journal - Research Article
Karlson, A. M. L., Niemand, C., Savage, C., & Pilditch, C. A. (2016). Density of key-species determines efficiency of macroalgae detritus uptake by intertidal benthic communities.
PLoS ONE,
11(7), e0158785.
doi: 10.1371/journal.pone.0158785
Journal - Research Article