Associate Professor Mary Sewell

Associate Professor

Ecology, Evolution and Behaviour

Phone: +64 9 3737599 ext 83758
Thomas Building, Rm 130
Email: m.sewell@auckland.ac.nz

Research Interests

Research in this laboratory focuses on the reproduction and development of marine invertebrates, with a special focus on echinoderms. We are located in the Basement of the Thomas Building (Level 1), though considerable research takes place outside Auckland – from the Leigh Marine Laboratory, to sites within the Hauraki Gulf, and as far afield as Antarctica.

Teaching

I contribute to teaching in the following courses:

• BIOSCI 206 Principles of Ecology
• BIOSCI 208 Invertebrate Diversity
• BIOSCI 724 Marine Ecology

Post-graduate Research

Students interested in aspects of this research are encouraged to contact Dr. Mary Sewell for further information.

 

A spawning female Odontaster validus

Leptosynapta clarki with young

A Hawaiian fashion shop

Evechinus chloroticus (kina)

Echinoderm Reproduction and Development

Echinoderms have been the focus of my research since I was a graduate student - with both my Masters and PhD research on reproduction in a broadcast spawning (Australostichopus mollis) and a brooding species (Leptosynapta clarki) respectively. As a post-doctoral researcher I began to study starfish and sea urchins and now work broadly on reproduction in echinoderms.

A particular focus of my recent research has been on maternal investment in echinoderm eggs, and in particular in the protein and lipid content of species with both planktotrophic (feeding) and lecithotrophic development (non-feeding). In collaborative research with Prof. Maria Byrne (University of Sydney) and students (Inke Falkner, Thomas Prowse) we have been using the School of Biological Sciences Iatroscan TLC/FID system to examine the evolution of maternal provisioning in congeneric asteroids and ophiuroids from New Zealand and Australia. This has shown that there are clear differences in the lipid classes and amounts of lipid in planktotrophs versus lecithotrophs, and we are now expanding our studies to include echinoids and holothuroids to understand patterns of maternal provisioning in echinoderm evolution.

We have also applied our research expertise on lipid and protein in sea urchin gonads to development of aquaculture feeds. In collaborative research with Prof. Phil Bremer and Assoc-Prof. Mike Barker (University of Otago) we have used both proteomics and lipid content as a measure of “quality” in sea urchin gonads intended for the export market.

Recent Publications

• Mercier, A., Sewell, M.A., Hamel, J-F. (2012).  Pelagic propagule duration and developmental mode: reassessment of a fading link.  Global Ecol. Biogeogr. doi: 10.1111/geb_12018.
• Verachia, W.,  Sewell, M.A., Niven, B., Barker, M., Bremer, P. (2012). Seasonal changes in the biochemical properties of Evechinus chloroticus gonads (Echinodermata: Echinoidea).  New Zealand Journal of Marine and Freshwater Research DOI:10.1080/00288330.2012.697070.
• Adams, D.K., Sewell, M.A., Angerer, R.C., Angerer, L.M. (2011). Rapid adaptation to food availability by a dopamine-mediated morphogenetic response.  Nature Communications, 2 DOI: 10.1038/ncomms1603.
• Phillips, K., Hamid, N., Silcock, P., Sewell, M.A., Barker, M., Weaver, A., Then, S., Delahunty, C., Bremer, P. (2010). Effect of manufactured diets on the yield, biochemical composition and sensory quality of Evechinus chloroticus sea urchin gonads. Aquaculture, doi:10.1016/j.aquaculture.2010.07.030.
• Phillips, K., Hamid, N., Silcock, P., Delahunty, C., Barker, M., Sewell, M.A., Bremer, P. (2010). Sensory and volatile analysis of sea urchin roe from Northern and Southern regions in New Zealand. LWT - Food Science and Technology 43: 202-213.
• Prowse, T.A.A., Falkner, I., Sewell, M.A., Byrne, M. (2009). Long-term storage lipids and developmental evolution in echinoderms. Evolutionary Ecology Research 11: 1069-1083.
• Byrne, M., Prowse, T.A.A., Sewell, M.A., Dworjanyn, S., Williamson,J.E, Vaïtilingon, D. (2008). Maternal provisioning for larvae and larval provisioning for juveniles in the toxopneustid sea urchin Tripneustes gratilla. Mar. Biol. 155: 473-482.
• Byrne, M., Sewell, M.A., Prowse, T.A.A. (2008). Nutritional ecology of sea urchin larvae: influence of endogenous and exogenous nutrition on echinopluteal growth and phenotypic plasticity in Tripneustes gratilla. Functional Ecology 22: 643-648.
• Sewell, M.A., Eriksen, S., Middleditch, M.J. (2008). Identification of protein components from the mature ovary of the sea urchin Evechinus chloroticus (Echinodermata: Echinoidea). Proteomics 8: 2531-2542.
• Prowse, T.A.A., Sewell, M.A., Byrne, M. (2008). Fuels for development: evolution of maternal provisioning in asterinid sea stars. Mar. Biol. 153: 337-349.

Collaborators and Links

Professor Maria Byrne, University of Sydney
Professor Phil Bremer, University of Otago

Associate Professor Mike Barker, University of Otago

Evechinus chloroticus ovary (whole)

Evechinus chloroticus ovary (histological section)

Chromarods in the Iatroscan TLC/FID

2D gel from Evechinus chloroticus ovary

Antarctic Larvae

The pelagic community of the Ross Sea consists of a permanent component (= holoplankton) and a temporary component which is primarily made up from the larval stages of benthic marine invertebrates and fish (= the meroplankton). To date little attention has been paid to the distribution and abundance patterns of the meroplankton in the Ross Sea in part because of the difficulty in identifying the larvae of marine invertebrates and fish to the species-level.

Traditionally identification of larvae to the species-level has relied on the time consuming and labour-intensive process of fertilizing eggs and culturing the larvae through to metamorphosis. In Antarctica, the low seawater temperatures and long developmental times make this procedure even more problematic than in temperate environments. With my collaborator Dr. Shane Lavery (SBS, University of Auckland) we have been using a molecular-based approach to match DNA sequences of the meroplankton with adult benthic marine invertebrates (Sewell et al. 2006).

My Antarctic research has recently fallen under the umbrella of the Latitudinal Gradient Project (LGP) where we have worked at three sites along the Victoria Land Coast (Cape Hallett, Terra Nova Bay, Granite Harbour) to examine how the meroplankton community changes with the latitudinal gradient of solar radiation, temperature and sea ice cover. We are also examining the coastal versus oceanic gradient using samples collected on New Zealand’s International Polar Year-Census of Antarctic Marine Life (IPY-CAML) Cruise.

Recent publications

• Sewell, M.A., Jury, J.A. (2011). Seasonal patterns in diversity and abundance of the High Antarctic meroplankton: Plankton sampling using a Ross Sea desalination plant.  Limnology and Oceanography 56: 1667-1681.
• Heimeier, D., Lavery, S., Sewell, M.A. (2010). Using DNA barcoding and phylogenetics to identify Antarctic invertebrate larvae: lessons from a large scale study. Marine Genomics 3: 165-177.
• Heimeier, D, Lavery S., Sewell M.A. (2010). Molecular species identification of Astrotoma agassizii from planktonic embryos: further evidence for a cryptic species complex. Journal of Heredity 101: 775-779 doi: 10.1093/jhered/esq074
• Sewell, M.A., Jury, J.A. (2009). Desalination plants as plankton sampling devices in temporal studies: proof-of-concept and suggestions for the future. Limnol. Oceanogr.: Methods 7: 363-370.
• Sewell, M.A., van Dijken, S.G., Suberg, S. (2008). The cryopelagic meroplankton community in the shallow waters of Gerlache Inlet, Terra Nova Bay, Antarctica. Antarctic Science 20: 53-59.
• Sewell, M.A., Lavery, S., Baker, C.S. (2006) Whose larvae is that? Molecular identification of planktonic larvae of the Ross Sea. New Zealand Aquatic Environment and Biodiversity Report No. 3. 57 pp.
• Sewell, M.A. (2005). Examination of the meroplankton community in the south-western Ross Sea, Antarctica, using a collapsible plankton net. Polar Biology 28: 119-131.

Collaborators and Links

Antarctica New Zealand
Latitudinal Gradient Project
Census of Antarctic Marine Life

Collapsible plankton net in “open” position

Gastrula

Starfish bipinnaria

Nemertean pilidia

Ocean Acidification

Ocean acidification (OA) has been described as “the other CO₂ problem”, “global warming’s evil twin” and “a meltdown tinged with acid”. Given that one third of humanity’s emissions of carbon dioxide are absorbed by the world’s oceans, OA will be one of the most important stressors facing marine ecosystems of the future. . Under the OA conditions predicted by the Intergovernmental Panel on Climate Change (IPCC 2007), organisms with calcium carbonate skeletons (e.g. coccoliths, corals, molluscs, sea urchins) will suffer significantly from increased costs to the growth and maintenance of skeletal structures, and/or the dissolution of their skeletons.

In recent work we have shown that OA has immediate impacts on both the morphology and gene expression patterns in temperate sea urchin larvae, most of which indicate a depressed metabolism (O’Donnell et al. 2010). In Marsden-funded research we are conducting similar experiments on the New Zealand sea urchin Evechinus chloroticus to understand the mechanisms by which OA impacts fertilization, early development and metabolic rate, at the biochemical, cellular and whole-organism levels.  This involves taking a systems biology approach, incorporating studies of the transcriptome, proteome and metabolome.

The recent "Interdisciplinary Symposium on Ocean Acidification and Climate Change" held at the University of Hong Kong (http://www.biosch.hku.hk/ecology/isoacc/index.htm) brought together international and regional marine scientists to discuss the problem and explore potential solutions.  As a participant it is clear that OA is a significant problem for coastal marine ecosystems and that future research requires an interdisciplinary approach - involving marine biologists, oceanographers, ecologists and biomaterial scientists.

Collaborators and Links

Prof. Gretchen Hofmann, UC Santa Barbara

Dr. V. Thiyagarajan, University of Hong Kong

Recent publications

Sewell, M.A., Hofmann, G.E. (2013).  Ocean acidification and echinoderms: how bad will it be for our favourite phylum?  In C. Johnson (Ed.), Echinoderms in a Changing World, pp. 3-10, Taylor and Francis Group, London. 

Yu, P.C., Sewell, M.A., Matson, P.C., Rivest, E.B., Kapsenberg L, Hofmann G.E. (2012).  Growth attenuation with developmental schedule progression in embryos and early larvae of Sterechinus neumayeri raised under elevated CO₂.  PLoS ONE 8 (1) e52448. doi: 10.1371/journal.pone.0052448.

Matson P.G., Yu, P.C., Sewell, M.A., Hofmann, G.E.  (2012).  Development under elevated pCO₂ conditions does not affect lipid utilization and protein content in early life-history stages of the purple sea urchin, Strongylocentrotus purpuratus.  Biological Bulletin 223: 312–327.

Sewell, M.A., Hofmann G.E. (2011).  Antarctic echnoids and climate change: a major impact on the brooding forms. Global Change Biol. 17: 734-744.

• Fangue, N.A., O’Donnell, M.J., Sewell, M.A., Matson, P.G., MacPherson, A.C., Hofmann, G.E. (2010). A laboratory-based experimental system for the study of ocean acidification effects on marine invertebrate larvae. Limnology and Oceanography Methods doi:10:4319/lom.2010.8.xxx
• Hofmann, G.E., Barry, J.P, Edmunds, P.J., Gates, R.D., Hutchins, D.A, Klinger, T., Sewell, M.A. (2010). The effect of ocean acidification on polar, tropical and temperate marine calcifying organisms: an organism to ecosystem perspective. Annual Review Ecology Evolution and Systematics 41: 127-147; doi: 10.1146/annurev.ecolsys.110308.120227.
• O’Donnell, M.J., Todgham, A.E., Sewell, M.A., Hammond, L.T., Ruggiero, K., Fangue, N.A., Zippay, M.L., Hofmann, G.E. (2010). Ocean acidification alters skeleton formation of larvae of the sea urchin Lytechinus pictus: evidence from morphometrics and microarray data. Mar. Ecol. Prog. Ser. 398: 157-171.

Multivariate analysis of Lytechinus pictus larvae raised in OA conditions

Evechinus in their natural environment

Evechinus chloroticus(kina); our focus species

Temperature block with fertilization experiments at differing pH

Microplastics

Did you know that you might be contributing to marine pollution simply by washing your face? In recent research we have shown that the plastic particles in facial cleansers are so small that they have a good likelihood of travelling from your bathroom sink and into the ocean.  This research was highlighted in an episode of “What’s Really In Our ....” (TV3) in the episode on soaps and cleansers (see link below - starts 18:20 min).

Recent publications

• Fendall, L.S., Sewell, M.A. (2009). Contributing to marine pollution by washing your face: microplastics in facial cleansers. Mar. Poll. Bull. 58: 1225-1228.

Selected Recent Publications