Marine Research

Research Focus

As a marine biologist Andrea’s interests largely lie within the field of scientific exploration. She considers herself a conservation biologist, and to that end her team’s research focuses predominately on questions related to the effective management and conservation of marine animals.

To answer these questions Andrea is often required to travel around the world on exploratory missions. On these missions her goal is to examine particular aspects of a species biology or behaviour, to explore new habitats or regions of diversity, or to examine threats or areas faced with particular conservation problems.

Personally Andrea has also always been interested in using technology to push the limits of our knowledge. Over the years in the field she has used everything from advanced or technical diving technology to specialized scientific equipment to explore the environments used by our flagship species. On our expeditions, this technology allows her to go deeper, spend longer periods of time, work in otherwise hazardous conditions and survey remote locations in an effort to gain a better understanding of an animal’s daily habits, a species’ biological constraints, or the threats that a particular population of animals might face.

Andrea is one of the founders of the Marine Megafauna Foundation (MMF), a 501c3 charitable organization in the USA that is developing research branches across the globe. Underway since 2003, MMF’s longest running scientific research center is in Africa. Focused on the Inhambane Province of Mozambique, one of the center’s flagship programs is on manta rays. As its principal scientist, Dr. Andrea Marshall, directs her team’s efforts towards key aspects of the biology and ecology of both species of Manta. Locally in Mozambique, the Foundation’s intention has always been to use their data towards effective management strategies and conservation initiatives. To that end, Andrea continues to work on topics related to the monitoring and management of the local manta ray populations and the development of a marine protected area that would protect the critical habitats that line the Mozambican coast.

A passionate conservation biologist, Dr. Marshall also monitors anthropogenic threats to manta ray populations across the globe from southern Ecuador & the Galapagos Islands, to Myanmar and Indonesia. She is also heavily involved in global conservation initiatives for manta rays and has been actively involved in listing them on the appendices of CMS and CITES. As internationally threatened species, the health of many manta ray populations are now being examined and the sustainability of emerging fisheries questioned. Effective management and sustainable long-term conservation can only be properly actioned once the needs of a species and its biological constraints are properly understood. To that end, Andrea and her team continue to focus their research efforts to best inform on conservation action plans and long-term management strategies in the countries they work using multidisciplinary approaches to define the conservation priorities of the different populations of manta rays.

Andrea’s current projects and interests include:

Global manta ray distribution
Genetic differentiation of manta ray species and populations
Manta ray phylogeography
Reproductive ecology of Manta alfredi and Manta birostris
Migratory patterns and habitat use of manta rays
Economic evaluation of manta ray tourism
Anthropogenic threats to manta ray globally
Population estimation and demographic studies of manta ray populations
Feeding ecology of manta rays
Social networks and behavior of Manta species
Development of ‘Manta Matcher’, the world’s first online global database for manta rays

Peer-Reviewed Scientific Publications

For a copy of any of these publications contact andrea@marinemegafauna.org

Andrea Marshall, Anna Flam, Nakia Cullain, Michelle Carpenter, Janneman Conradie, Stephanie Venables. (2023) Southward range extension and transboundary movements of reef manta rays Mobula alfredi along the east African coastline. Journal of Fish Biology. DOI:10.1111/jfb.15290

Kanina Harty, Michael Guerrero, Anna Knochel, Guy Stevens, Andrea Marshall, Katherine Burgess, Josh Stewart. (2022) Demographics and dynamics of the world’s largest known population of oceanic manta rays Mobula birostris in coastal Ecuador Marine Ecology Progress Series. DOI: 10.3354/meps14189

Michelle Carpenter, Nakia Cullain, Stephanie Venables, Yara Tibiriçá, Charles Griffiths, Andrea Marshall(2022) Evidence of Závora Bay as a critical site for reef manta rays, Mobula alfredi, in southern Mozambique. Journal of Fish Biology. DOI: 10.1111/jfb.15132

Elitza Germanov, Simon Pierce, Andrea Marshall, et al. (2022) Residency, movement patterns, behavior and demographics of reef manta rays in Komodo National Park. PeerJ. DOI:10.7717/peerj.13302

Stephanie Venables, Janneman Conradie, Andrea Marshall (2022) First records of the ornate eagle ray Aetomylaeus vespertilio from the Inhambane Province, Mozambique. Journal of the Marine Biological Association of the United Kingdom. DOI: 10.1017/S0025315422000054

Nathan Pacoureau, Cassandra Rigby, Peter Kyne, Richard Sherley, [others], Andrea Marshall, [others], Nicholas Dulvy (2021) Half a century of global decline in oceanic sharks and rays. NatureDOI:10.1038/s41586-020-03173-9

Robert Perryman, Michelle Carpenter, Eric Lie, Georgy Sofronov, Andrea Marshall, Culum Brown (2021) Reef manta ray cephalic lobe movements are modulated during social interactions. Behavioural Ecology and Sociobiology DOI:10.1007/s00265-021-02973-X

Stephanie Venables, Andrea Marshall, Amelia Armstrong, Joseph Tomkins, Jason Kennington (2020) Fine-scale population structure and effective population size of reef manta rays Mobula alfredi in southern Mozambique using genome-wide SNPs. Heredity DOI:10.1038/s41437-020-00373

Jessica Pate, Andrea Marshall (2020) Urban Manta Rays: Juvenile manta ray habitat along a highly developed Florida coastline. Endangered Species Research DOI:10.3354/esr01054

M Aaron MacNeil, [others], Anna Flam, Andrea Marshall, Alexandra M Watts, [others] (2020). Global Status and Conservation Potential of Tropical Reef Sharks. Nature DOI:10.1038/s41586-020-2519-y

Stephanie Venables, Daniel Van Duinkerken, Christopher Rohner, Andrea Marshall (2020) Habitat use and movements patterns of reef manta rays Mobula alfredi in southern Mozambique. Marine Ecology Progress Series DOI:10.3354/meps13178

Elitza Gemanov, Andrea Marshall, I. Gede Hendrawan, Ryan Admiraal, Christoph Rohner, Janis Argeswara, Raka Wulandari, Mahardika Himawan, Neil Loneragan (2019) Microplastics on the Menu: Plastics pollute Indoneisan manta ray and whale shark feeding grounds. Frontiers in Marine ScienceDOI:10.3389/fmars.2019.00679

Stephanie Venables, Andrea Marshall, Elitza Gemanov, Robert Perryman, Ricardo Tapilatu, Gede Hendrawan, Anna Flam, Mike van Keulen, Joseph Tomkins, Jason Kennington (2019) It is not all black and white: investigating colour polymorphism in manta rays across Indo-Pacific populations. Proceedings of the Royal Society B DOI:10.1098/rspb.2019.1879

Robert Perryman, Stephanie Venables, Ricardo Tapilatu, Andrea Marshall, Culum Brown, Daniel Franks (2019) Social preferences and network structure in a population of reef manta rays. Behavioural Ecology and Sociobiology DOI:10.1007/s00265-019-2771-x

Atlantine Boggio- Pasqua, Anna Flam, Andrea Marshall (2019) Spotting the ‘small eyes”: using photo-ID methodology to study a wild population of smalleye stingray (Megatrygon microps) in southern Mozambique. Peer J DOI:10.7717/peerj.7110

Elitza Gemanov, Lars Bejder, Delphine B.H. Chabanne, Dharmadi Dharmadi, I. Gede Hendrawan, Andrea D. Marshall, Simon J. Pierce, Mike van Keulen, Neil Loneragan (2019) Contrasting Habitats Use and Population Dynamics of Reef Manta Rays Within the Nusa Penida Marine Protected Area, Indonesia. Frontiers in Marine Science DOI:10.3389/fmars.2019.00215

Randall Arauz, Elpis J. Chavez, E. Mauricio Hoyos-Padilla, Andrea Marshall (2019) First record of the reef manta ray, Mobula alfredi, from the eastern Pacific. Marine Biodiversity Records DOI:10.1186/s41200-019-0162-9

Josh Stewart, [others], Andrea Marshall, [others] (2018) Research priorities to support effective manta and devil ray conservation. Frontiers in Marine Science DOI:10.3389/fmars.2018.00314

Elitza Gemanov, Andrea Marshall, Lars Bejder, Marina Cristina Fossi, Neil Loneragan (2018) Microplastics: No Small Problem for Filter-Feeding Megafauna. Trends in Ecology & EvolutionDOI:10.1016/j.tree.2018.01.005

Kathrine Burgess, Michel Guerrero, Anthony Richardson, Mike Bennett, Andrea Marshall (2017) Use of epidermal mucus in elasmobranch stable isotope studies: a pilot study using the giant manta ray (Manta birostris). Marine and Freshwater Research DOI:10.1071/MF16355

Steph Venables, Giles Winstanley, Libby Bowles & Andrea Marshall (2016) A Giant Opportunity: The Economic Impact of Manta Rays on the Mozambican Tourism Industry – An Incentive for Increased Management and Protection. Tourism in Marine Environments. DOI:10.3727/154427316X693225

Katherine Burgess, Lydie Couturier, Andrea Marshall, Anthony Richardson, Scarla Weeks & Mike Bennett (2016) Manta birostris, predator of the deep? Insight into the diet of the giant manta ray through stable isotope analysis. Royal Society Open Science DOI:10.1098/rsos.160717

Donald Croll, [others], Andrea Marshall, [others] (2015) Vulnerabilities and Fisheries Impacts: The Uncertain Future of Manta and Devil Rays. Aquatic Conservation: Marine and Freshwater EcosystemsDOI:10.1002/aqc.2591

Tom Kashiwagi, E Maxwell, Andrea Marshall & A Christensen (2015) Evaluating manta ray mucus as an alternative DNA source for population genetics study: underwater-sampling, dry-storage, and PCR success. PeerJ DOI:10.7717/peerj.1188

Chris Rohner, Anthony Richardson, Clare Prebble, Andrea Marshall, Mike Bennett, Scarla Weeks, Geremy Cliff, Sabine Wintner & Simon Pierce (2015) Laser photogrammetry improves size and demographic estimates for whale sharks. Peer J DOI:10.7717/peerj.886.

Craig McClain, [others], Andrea Marshall, [others] (2015) Sizing ocean giants: patterns of intraspecific size variation in marine megafauna. PeerJ DOI:10.7717/peerj.715

Elitza Germanov & Andrea Marshall (2014) Running the Gauntlet: Regional Movement Patterns of Manta alfredi through a complex of parks and fisheries. PloS One DOI:10.1371/journal.pone.0110071

Peter Haskell, Andrew McGowan, Anna Westling, Adriana Mendex-Jimenez, Chris Rohner, Kym Collins, Marcela Rosero-Caicedo, Jodi Salmond, Ara Monadjem, Andrea Marshall & Simon Pierce (2014) Monitoring the effects of tourism on whale shark Rhincodon typus behaviour in Mozambique. Oryx. DOI:10.1017/S0030605313001257

Lydie Couturier, Chris Rohner, Anthony Richardson, Andrea Marshall, Fabrice Jaine, Mike Bennett, Kathy Townsend, Scarla Weeks & Peter Nichols (2013) Stable isotope and signature fatty acid analyses suggest reef manta rays feed on demersal zooplankton. PLoS ONE DOI: 10.1371/journal.pone.0077152

Lydie Couturier, Chris Rohner, Anthony Richardson, Simon Pierce, Andrea Marshall, Fabrice Jaine, Kathy Townsend, Mike Bennett, Scarla Weeks & Peter Nichols (2013) Unusually high levels of n-6 polyunsaturated fatty acids in whale sharks and reef manta rays, Lipids. DOI:10.1007/s11745-013-3829-8

Chris Town, Andrea Marshall & Nutthaporn Sethasathien (2013) Manta Matcher: Automated Photographic Identification of Manta Rays using Keypoint Features. Journal of Applied Ecology DOI:10.1002/ece3.587.

Chris Rohner, Simon Pierce, Andrea Marshall, Scarla Weeks, Mike Bennett & Anthony Richardson (2013) Trends in sightings and environmental influences on a coastal aggregation of manta rays and whale sharks. Marine Ecology Progress Series DOI:10.3354/meps10290

Tom Kashawagi, Andrea Marshall, Mike Bennett & Jennifer Ovenden (2012) The genetic signature of recent speciation in manta rays (Manta alfredi and M. birostris). Molecular Phylogenetics and EvolutionDOI:10.1016/j.ympev.2012.03.020

Andrea Marshall & Simon Pierce (2012) The use and abuse of photographic identification in sharks and rays. Journal of Fish Biology DOI:10.1111/j.1095-8649.2012.03244.x

Lydie Couturier, Andrea Marshall, Fabrice Jaine, Tom Kashiwagi, Simon Pierce, Anthony Richardson, Kathy Townsend, Scarla Weeks & Mike Bennett. Biology, ecology and conservation of the Mobulidae. Journal of Fish Biology DOI:10.1111/j.1095-8649.2012.03264.x

Andrea Marshall, Christine Dudgeon & Mike Bennett (2011) Size and structure of a photographically identified population of manta rays Manta alfredi in southern Mozambique. Marine BiologyDOI:10.1007/s00227-011-1634-6

Tom Kashiwagi, Andrea Marshall, Mike Bennett & Jennifer Ovenden (2011) Habitat segregation and mosaic sympatry of the two species of manta ray in the Indian and Pacific Oceans: Manta alfredi and M. birostris. Marine Biodiversity Records DOI:10.1017/S1755267211000479

Chris Rohner, Anthony Richardson, Andrea Marshall, Scarla Weeks & Simon Pierce (2011) How large is the world’s largest fish Measuring whale sharks Rhincodon typus with laser photogrammetry, Journal of Fish BiologyDOI:10.1111/j.1095-8649.2010.02861.x

Andrea Marshall & Mike Bennett (2010) Reproductive ecology of the reef manta ray (Manta alfredi) in southern Mozambique. Journal of Fish Biology DOI:10.1111/j.1095-8649.2010.02669.x

Andrea Marshall & Mike Bennett MB (2010) Investigation of shark predation on Manta alfredi off the coast of Mozambique using bite mark analysis. South African Journal of Marine ScienceDOI:10.2989/1814232X.2010.538152

Andrea Marshall, Leonard Compagno & Mike Bennett (2009) Redescription of genus Manta with resurrection of Manta alfredi (Krefft,1868) (Chondrichthyes; Myliobatoidei; Mobulidae). Zootaxa 2301: 1–28.

Andrea Marshall, Simon Pierce & Mike Bennett (2008) Morphological measurements of manta rays (Manta birostris) with a description of a foetus from the east coast of Southern Africa. Zootaxa 1717: 24-30.

Simon Pierce, Will White & Andrea Marshall (2008) New record of the smalleye stingray, Dasyatis microps (Myliobatiformes: Dasyatidae), from the western Indian Ocean. Zootaxa 1734: 65-68.

Conrad Speed, Mark Meekan, David Rowat, Simon Pierce, Andrea Marshall & Corey Bradshaw (2008) Scarring patterns and relative mortality rates of Indian Ocean whale sharks. Journal of Fish BiologyDOI:10.1111/j.1095-8649.2008.01810.x

Andrea Marshall, Peter Kyne, Michael Bennett (2008). Comparing the diet of two sympatric urolophid elasmobranches (Trygonoptera testacea Müller & Henle and Urolophus kapalensis Yearsley & Last): evidence of ontogenetic shifts and possible resource partitioning. Journal of Fish Biology 72: 883-898.

Peer Reviewed Journal Reviews

Lydie Couturier, Andrea Marshall, Fabrice Jaine, Tom Kashiwagi, Simon Pierce, Anthony Richardson, Kathy Townsend, Scarla Weeks, Michael Bennett (2012) Biology, ecology and conservation of mobulid rays, Mobulidae (Gill, 1893) Journal of Fish Biology 80: 1075-1119.

Andrea Marshall, Simon Pierce (2012) The uses and abuses of photographic identification in sharks and rays. Journal of Fish Biology 80: 1361-1379.

Books (Contributing Author)

Fishes of the Western Indian Ocean (In press), Mobulidae Chapter.

Simon Pierce, Jason Holmberg, Alison Kock, Andrea Marshall (2018) Photographic identification of sharks. In: Shark research: emerging technologies and applications for the field and laboratory. Carrier JC, Heithaus MR, Simpfendorfer CA (eds.). CRC Press, Boca Raton. pp 219-234

“The Galapagos Marine Reserve: a Dynamic Socio-Ecological System,” of the Galapagos Book Series, “Social and Ecological Interactions in the Galapagos Islands,” edited by Stephen J. Walsh & Carlos F. Mena. Springer Science & Business Media (2014).

IUCN Red List Assessments

Marshall, A., Barreto, R., Carlson, J., Fernando, D., Fordham, S., Francis, M.P., Herman, K., Jabado, R.W., Liu, K.M., Pacoureau, N., Rigby, C.L., Romanov, E. & Sherley, R.B. 2019. Mobula alfredi . The IUCN Red List of Threatened Species 2019: e.T195459A68632178. https://dx.doi.org/10.2305/IUCN.UK.2019-3.RLTS.T195459A68632178.en. Downloaded on 14 January 2020.

Marshall, A., Bennett, M.B., Kodja, G., Hinojosa-Alvarez, S., Galvan-Magana, F., Harding, M., Stevens, G. & Kashiwagi, T. 2018. Mobula birostris (amended version of 2011 assessment). The IUCN Red List of Threatened Species 2018: e.T198921A126669349. https://dx.doi.org/10.2305/IUCN.UK.2018-1.RLTS.T198921A126669349.en. Downloaded on 14 January 2020.

Marshall, A., Barreto, R., Carlson, J., Fernando, D., Fordham, S., Francis, M.P., Herman, K., Jabado, R.W., Liu, K.M., Rigby, C.L. & Romanov, E. 2019. Mobula mobular . The IUCN Red List of Threatened Species 2019: e.T110847130A110847142. https://dx.doi.org/10.2305/IUCN.UK.2019-3.RLTS.T110847130A110847142.en. Downloaded on 14 January 2020.

Marshall, A., Barreto, R., Carlson, J., Fernando, D., Fordham, S., Francis, M.P., Herman, K., Jabado, R.W., Liu, K.M., Rigby, C.L. & Romanov, E. 2019. Mobula hypostoma . The IUCN Red List of Threatened Species 2019: e.T126710128A896599. https://dx.doi.org/10.2305/IUCN.UK.2019-3.RLTS.T126710128A896599.en. Downloaded on 14 January 2020.

Marshall, A., Barreto, R., Bigman, J.S., Carlson, J., Fernando, D., Fordham, S., Francis, M.P., Herman, K., Jabado, R.W., Liu, K.M., Pardo, S.A., Rigby, C.L., Romanov, E. & Walls, R.H.L. 2019. Mobula tarapacana . The IUCN Red List of Threatened Species 2019: e.T60199A124451161. https://dx.doi.org/10.2305/IUCN.UK.2019-3.RLTS.T60199A124451161.en. Downloaded on 14 January 2020.

Marshall, A., Barreto, R., Bigman, J.S., Carlson, J., Fernando, D., Fordham, S., Francis, M.P., Herman, K., Jabado, R.W., Liu, K.M., Pardo, S.A., Rigby, C.L., Romanov, E., Smith, W.D. & Walls, R.H.L. 2019. Mobula thurstoni . The IUCN Red List of Threatened Species 2019: e.T60200A124451622. https://dx.doi.org/10.2305/IUCN.UK.2019-3.RLTS.T60200A124451622.en. Downloaded on 14 January 2020.

Marshall, A., Barreto, R., Carlson, J., Fernando, D., Fordham, S., Francis, M.P., Herman, K., Jabado, R.W., Liu, K.M., Rigby, C.L. & Romanov, E. 2019. Mobula munkiana . The IUCN Red List of Threatened Species 2019: e.T60198A124450956. https://dx.doi.org/10.2305/IUCN.UK.2019-3.RLTS.T60198A124450956.en. Downloaded on 14 January 2020.