A marine biologist with a focus on tropical coastal management, I have 20 years’ experience of working in integrated coastal zone management with NGOs, public and private agencies in the Caribbean, Eastern Africa and Egypt. I have extensive natural resource management experience as a Manager of a Marine Park and National Park (8 years in the Dutch Caribbean), and project leader for various bilateral research and development projects. Research and monitoring has included environmental, fishery and sea turtle assessments for Protected Areas in the Caribbean, Egypt, Uganda and Nigeria.

As a Researcher and an Environmental Consultant for both the public and private sector, I have produced and coordinated Protected Area Management Plans, targeted Species Monitoring Plans and Environmental Impact Assessments, with an ongoing personal interest in co-management of natural resources, stakeholder engagement within conservation management policies and activities and communication of conservation and research activities to the wider public. My research interests lie in the understanding of spatial and habitat use by marine species, with a focus on sea turtles and reef fisheries, predominantly in the Caribbean and Indian Ocean.

Areas of Expertise

  • Marine biologist with PhD in ecology of sea turtles and MSc in tropical coastal management
  • Coastal zone specific research has focused on Marine Protected Areas in the Chagos Archipelago, Caribbean and Red Sea
  • 15 years working on conservation ecology (from fieldwork to policy writing) around the world including 8 years as the manager of marine and national parks (St Eustatius, Dutch Caribbean)
  • Research on conservation, population size and ecology of hawksbill and green turtles in the Caribbean and British Indian Ocean Territory
  • 20 years’ experience of work in nature conservation and integrated coastal zone management with public and private agencies as well as with NGO’s
  • Development of sustainable management of natural resources on small islands, currently the President of the Council of Advisors of the Dutch Caribbean Nature Alliance (DCNA)


  1. Mortimer, J., Esteban, N., Guzman, A., Hays, G. Estimates of marine turtle nesting populations in the south-west Indian Ocean indicate the importance of the Chagos Archipelago Oryx 1 12
  2. Stokes, H., Mortimer, J., Hays, G., Unsworth, R., Laloë, J., Esteban, N. Green turtle diet is dominated by seagrass in the Western Indian Ocean except amongst gravid females Marine Biology 166 10
  3. Schofield, G., Esteban, N., Katselidis, K., Hays, G. Drones for research on sea turtles and other marine vertebrates – A review Biological Conservation 238 108214
  4. Unsworth, R., Bertelli, C., Cullen-Unsworth, L., Esteban, N., Jones, B., Lilley, R., Lowe, C., Nuuttila, H., Rees, S. Sowing the Seeds of Seagrass Recovery Using Hessian Bags Frontiers in Ecology and Evolution 7
  5. Hays, G., Bailey, H., Bograd, S., Bowen, W., Campagna, C., Carmichael, R., Casale, P., Chiaradia, A., Costa, D., Cuevas, E., Bruyn, P., Dias, M., Duarte, C., Dunn, D., Dutton, P., Esteban, N., Friedlaender, A., Goetz, K., Godley, B., Halpin, P., Hamann, M., Hammerschlag, N., Harcourt, R., Harrison, A., Hazen, E., Heupel, M., Hoyt, E., Humphries, N., Kot, C., Lea, J., Marsh, H., Maxwell, S., McMahon, C., Sciara, G., Palacios, D., Phillips, R., Righton, D., Schofield, G., Seminoff, J., Simpfendorfer, C., Sims, D., Takahashi, A., Tetley, M., Thums, M., Trathan, P., Villegas-Amtmann, S., Wells, R., Whiting, S., Wildermann, N., Sequeira, A. Translating Marine Animal Tracking Data into Conservation Policy and Management Trends in Ecology & Evolution 34 5 459 473
  6. Rivas, M., Esteban, N., Marco, A. Potential male leatherback hatchlings exhibit higher fitness which might balance sea turtle sex ratios in the face of climate change Climatic Change

See more...


  • BIO238 Marine Ecosystems: Threats and Conservation

    This module introduces the students to various marine ecosystems and the broad ecological concepts that underpin marine community structure. The first block of lectures will present processes that are common across many marine ecosystems. Subsequent lectures will go into detail on types of marine ecosystems, with specific examples in tropical, temperate, and polar regions. Within these lectures we will focus on some of the threats faced by these ecosystems, ranging from climate change and marine plastics to illegal fishing and tourism. The module will also introduce conservation efforts in the marine ecosystems presented over the semester. There will be two fieldtrips that will exemplify some of the processes and challenges faced by biota found in some of the ecosystems covered in the lectures. One will be to the Crymlyn Burrows saltmarsh/estuary to assess the adaptations of estuarine organisms to salinity variability and the other will be carried out on the RV Mary Anning investigating how primary and secondary production can influence marine community structure. There are three pieces of coursework associated with the module. Two of these will be based around the field trips. These assignments will rely on observations and data, with emphasis placed on teamwork and group cooperation both in the field and when preparing and presenting your findings. The third will be a computer-based practical using ecosystem modelling software to look at how different threats (e.g. ocean warming, overfishing) might impact a virtual marine ecosystem.

  • BIO327 Tropical marine ecology field course

    This field based module will provide students with an introduction to the ecology of tropical marine systems and teach students the key practical skills required by tropical marine biologists. Students will obtain training in how to design, implement and report scientifically robust marine research. The module will complement the level three marine field course and help develop key skills in field based marine biology. Students will learn skills in marine ecology and taxonomy, in-water marine sampling and surveys, and impact assessment. This module will be mostly practical based but will also include theory lectures, workshops and feedback sessions. It would be structured around seven days of directed practical activities and a three day small group based mini-project. The field course will utilise snorkeling and intertidal walking as the major means of sampling throughout directed practical¿s.

  • BIO329 Climate Change Biology

    The module examines the intricate connections between air, land and water in regulating the global climate system, and how that in turn affects planetary scale biology and ecology. Major past and present climate events and projected climate change, and their global ecological and environmental consequences will also be covered.

  • BIO330 Tropical marine ecology and conservation

    This module will provide a holistic overview of the ecology and conservation of important marine ecosystems, and will place this information within the context of ecosystem services, and their value to humanity. This module will consist of up to 12 lectures/seminars on the following topics: ¿ Diversity and biology of coral reef communities ¿ Structure and function of seagrass meadows (temperate and tropical) ¿ Mangrove forest ecology ¿ Connectivity across the tropical marine seascape ¿ The ecosystem services of tropical marine systems ¿ Response of coral reef systems to climate change and ocean acidification ¿ Degradation of tropical marine systems ¿ Resilience thinking and the management of tropical marine systems The module also contains a workshop session and additional direct contact with the module lead lecturer.

  • BIO346 Professional Skills in Marine Biology

    This field-based module will introduce students to the professional techniques utilised to monitor and study marine life in a variety of marine and coastal habitats and in relation to conservation management and biodiversity monitoring in the United Kingdom. The course places a strong emphasis on marine ecological census techniques. Students will learn key skills relevant to the marine ecology sector including protected and economically-important species (especially marine mammals, fish, shellfish, coastal birds), Phase 1 habitat surveys and water quality surveys. Students will also learn about the biotic and abiotic factors that define different UK habitats and relevant regulations that protect them. The module provides an introduction to the Environmental Impact Assessment (EIA) process and a range of impacts on the marine environment including energy generation and pollution. Participants in this module will work in groups acting as a marine environmental consultancy and the class will be responsible for producing key survey results for an Environmental Impact Assessment (EIA) and public engagement presentation for a proposed commercial development in Carmarthen Bay. Students will gain insider experience about professional techniques in marine (and freshwater) biology through a series of lectures delivered by marine environmental practitioners from environmental consultancies and regulatory organisations in the UK. The course includes a five-day residential field course in September/October which provides the students with the opportunity to practice the key technical skills in a real-world setting


  • Increasing understanding of habitat use by foraging sea turtles in Statia National Marine Park, Dutch Caribbean (current)

    Other supervisor: Dr Richard Unsworth
  • Investigating variations in inter-nesting movement of hawksbill and green turtles in the Lesser Antilles (current)

    Other supervisor: Dr Richard Unsworth
  • Untitled (current)

    Other supervisor: Prof Luca Borger