Scientific Publications By ORP’s Researchers & Scientists

Published 2023

Hancock, J.M, Choma, J., Mainye, L., Wambi, P., Stelfox, M., Polyak, M.M.R., Wamuba, S., Kóhnk, S. (2023)

Using Photo-ID to document and monitor the prevalence of fibropapilloma tumours in a foraging aggregation of green turtles‘. Front. Mar. Sci. 10:1217683. doi: 10.3389/fmars.2023.121768

This paper proposes to use Photo-ID as a non-invasive, low-cost, and citizen-science-friendly approach to monitoring sea turtles and their diseases in foraging grounds, where documenting disease incidence is challenging and may be thus under-documented. A 13% prevalence of fibropapillomatosis disease was identified in the local green turtle (Chelonia mydas) population in Diani-Chale National Marine Reserve (DCMR) on Kenya’s South Coast by analysing Photo-ID data collected from 2018. In addition, the temporal progression of external tumours in 47 affected individuals was also monitored, finding evidence of tumour progression and regression.

Hudgins, J.A., Hudgins, E.J., Köhnk, S., Mohamed Ryad, E., Stelfox, M. (2023):

A brighter future? Stable and growing sea turtle populations in the Republic of Maldives‘.
PLoS ONE 18(4): e0283973

In this article a first analysis of a photo ID dataset from selected reefs in the Maldives is presented, discussing abundance and other demographic parameters for green and hawksbill turtles. The article highlights that populations might be stable or increasing at most reefs over the observation period and it shows how valuable and cost effective community generated data is for conservation.

Published 2022

Köhnk, S. and Stelfox, M. (2022):
Still swimming with turtles: tourist-turtle interactions in the Maldives pre- and post-COVID-19‘.
Indian Ocean Sea Turtle Newsletter, June 2022

This article evaluates the impact of tourism on sea turtle behavior pre- and post-COVID19 related reduction in tourism activity in the Maldives.

Köhnk, S. (2022):
Eretmochelys imbricata, Hawksbill sea turtle. The Maldives National Red List of Threatened Species‘.

Köhnk, S. and Stelfox, M. (2022):
Chelonia mydas, Green sea turtle. The Maldives National Red List of Threatened Species‘.

Stelfox, M. and Köhnk, S. (2022):
Lepidochelys olivacea. The Maldives Red List of Threatened Species‘.

Published 2021

Köhnk, S., Brown, R. & Liddell, A. (2021):
Finding of a two-headed green turtle embryo during nest monitoring in Baa Atoll, Maldives‘.
Onderstepoort Journal of Veterinary Research 88(1), a1940,

A detailed account of the discovery of a two-headed, partially developed green sea turtle embryo. The embryo was found while researching the nesting activity of sea turtles on an island in Baa atoll, Maldives. The article shows the importance of monitoring nesting activities as a basis for conservation.

Köhnk, S., Petros, C., Lomas, C., Riyad, E.M., Shameel, I., Hawlitschek, O. & Stelfox, M. (2021):
Stowaways: Marine Leeches Infecting Olive Ridley Sea Turtles Entangled in Ghost Nets in Maldivian Waters’.
Comparative Parasitology 88(2): 169-176.

The article presents the first recorded cases of sea turtles infected with a parasitic leech species, belonging to the Ozobranchidae family, in the Maldives. The possible implications of this leech presence are discussed, with a focus on sea turtles residing in the Indian Ocean.

Stelfox, M., Martin-Cereceda, M., Vahed, K., Hudgins, J., Köhnk, S., Iqbal, U., Shameel, I., Hancock, J.M. and Sweet, M. (2021):
The Olive Ridley Project (ORP): A successful example of how to engage researchers, conservation practitioners and civil society’.
Research for All, 5 (2), 448–73. 

The article explores how the Olive Ridley Project actively engages with various audiences and the process in which it works. Providing reflective insight into the learning, enrichment, and challenges of engaging various stakeholders, the article shows how ORP can be used as a model for further projects, combining scientific knowledge, education, and action.

Abdul Rahman, R. et al. (2021):
First Record of a Stranded Loggerhead Turtle (Caretta caretta) in a Ghost Net off Penang, Malaysia‘.
Marine Turtle Newsletter, Issue 162, January 2021, pg 22–24

A loggerhead sea turtle was found in Malaysia for the first time. While the incident is important, it was tempered by the fact that the loggerhead turtle was found in a ghost net. This paper describes the rescue, rehabilitation, and release of the loggerhead, as well as implications for a foraging population in Malaysia and the threat of ghost nets in the Indian Ocean.

published 2020

Hancock, J., Choma, J., Mainye, L., Stelfox, M., & Hudgins, J. (2020):
Photo Identification as a Tool to Study Sea Turtle Populations in Kenyan Marine Protected Areas‘.
Society for Conservation Biology, October 2020

The article shows the use of photo ID as a means to identify individual sea turtles in the Diani-Chale Management Area in Kenya. The method of data collection offers a non-invasive, cost-effective way to monitor local sea turtle populations, which can later be used for spatial planning and conservation management.

Lomas, C., British Cheolina Group (2020):
Conservation and rehabilitation of sea turtles in the Maldives‘.
Testudo Vol. 9 No. 2, October 2020

An article describing the work of the Marine Turtle Rescue Centre in the Maldives, highlighting most prevalent causes for patient admittance and commonly encountered symptoms. Of the 125 turtles treated at the veterinary clinic until the time of publication, the vast majority were olive ridley turtles.

Stelfox, M., Burian, A., Shanker, K., Rees, A. F., Jean, C., Willson, M. S., Manik, N. A., Sweet, M. (2020):
Tracing the origin of olive ridley turtles entangled in ghost nets in the Maldives: A phylogeographic assessment of populations at risk‘.
Biological Conservation, Volume 245, May 2020, 108499

This study explores the likely origin of entangled olive ridley sea turtles recovered from ghost nets in the Maldives through the use of ghost net analysis, genetic samples from entangled individuals and previous genetic research on olive ridley populations. The potential impact of ghost net entanglements is also evaluate.

Stelfox, M., Lett, C., Reid, G., Souch, G., Sweet, M. (2020):
Minimum drift times infer trajectories of ghost nets found in the Maldives‘.
Marine Pollution Bulletin, Volume 154, May 2020, 111037

This article highlights the possible fisheries responsible for ghost gear found in The Maldives. The research involved assessing the percentage cover and length of the gooseneck barnacle (found attached to ghost nets) in order to estimate the age of the nets and to eventually model where these nets have likely drifted from and which fisheries are responsible.

Veríssimo, D., Vieira, S., Monteiro, D., Hancock, J., Nuno, A. (2020):
Audience research as a cornerstone of demand management interventions for illegal wildlife products: Demarketing sea turtle meat and eggs‘.
Conservation Science and Practice, 16 January 2020

The article explores the profiles, motivations and preferences of individuals that consume sea turtle meat and eggs in São Tomé, West Africa in order to inform interventions aimed at reducing the demand of sea turtle products in the region. The article also explores the most trusted channels for communicating the importance of sea turtle conservation, providing insights into how best to go about educating the local community and guiding behavioural change.

Published 2019

Stelfox, M. (2019):
The cryptic and transboundary nature of ghost gear in the Maldivian archipelago‘.
PhD Thesis, University of Derby (2019)

Abandoned, lost or discarded fishing gear (ALDFG), more commonly referred to as ghost gear, is a global issue that impacts many marine organisms worldwide. In the Maldivian archipelago a large number of olive ridley sea turtles (Lepidochelys olivacea) are found entangled in these nets (more commonly referred to as ghost nets) each year. However, the origin of these nets or turtles are unknown considering fishing with the use of nets is restricted to the bait fisheries within the exclusive economic zone of the Maldives. Therefore, ghost gear has a transboundary and cryptic nature, making it difficult to assess the environmental impact and origin of the gear. This thesis aimed to develop new tools and techniques which could be utilised to examine these unknowns.

Stelfox, M., Bulling, M., Sweet, M. (2019):
Untangling the origin of ghost gear within the Maldivian archipelago and its impact on olive ridley (Lepidochelys olivacea) populations‘.
Endangered Species Research. 10.3354/esr00990. (2019)

The data collected during a 5 year period was utilised to find out the net characteristics and fishing practices associated with sea turtle entanglements. 11 net types were found in the study area, with the combined capacity to have entangled anywhere between 3,400 and 1,2200 turtles before detection. The analyses highlight the need for continued research on ghost gear in order to reduce the frequency of entanglements as well as the importance of gear marking in order to improve the traceability of ghost nets.

Sweet, M; Stelfox, M. Lamb,J. (2019):
Plastics and shallow coral reefs. Synthesis of the science for policy-makers‘.
United Nations Environment Program (2019)

By using current scientific knowledge, the article aims to provide policy and management recommendations for addressing and reducing the impacts of plastic on shallow-water coral reefs. This contributes to national and international sustainable development goals,promotes planning and management and raises awareness to improve the monitoring of plastics on reefs.

Published 2018

Stelfox, M. (2018):
Ghost Gear, The Silent Killers in Our Oceans‘.
Current Conservation Magazine Vol. 12 Issue 2, 2018:1 8-19

The article highlights what ghost gear is, how ghost fishing occurs and how the cycle will continue unless the gear is removed. The article shows the impact of ghost gear on fishers’ livelihood, the burdens resultant from ghost gear and the work done by the Olive Ridley Project in combating the issues presented.

Published 2017

Hudgins, J., Ali, and Mancini (2017):
Marine Turtles of the Maldives: A field identification and conduct guide‘.
An IUCN Publication funded by USAID. (2017)

This guide to marine turtles in the Maldives introduces the basics of sea turtle biology, species profiling, ecological importance, and global and local (Maldivian archipelago) threats to sea turtles. Aspects of sea turtle conservation were also discussed as well as sea turtle protocol when encountered.

Hudgins, J., Hudgins, E., Ali, K., and Mancini, A. (2017):
Citizen Science Surveys Elucidate Key Foraging and Nesting Habitat for Two Endangered Marine Turtle Species Within the Republic of Maldives‘.
Herpetology Notes, volume 10: 463-471 (2017)

Citizen science-based data collection method was used to find the foraging and commonly sighted areas of sea turtles in the Maldives. Recommendations were given for future protected areas, and the results of the study were used by the government for policy making regarding the protection of sea turtles in the country.

Published 2016

Stelfox, M., Hudgins, J., & Sweet, M. (2016):
A review of ghost gear entanglement amongst marine mammals, reptiles and elasmobranchs.’
Marine Pollution Bulletin 1.111 (2016): 6-17

The article focuses on the impact of ghost gear entanglements on large marine organisms such as marine mammals, reptiles, and elasmobranchs(sharks and rays). Recommendations were made to improve research in the Indian, Southern, and Arctic Oceans and for underrepresented species such as elasmobranchs, manatees, and dugongs.

Dunbar, S. G., Hudgins, J., & Jean, C. (2016):
Meeting Report for the 1st Photo ID Workshop, 36th Annual Symposium on Sea Turtle Biology and Conservation, Lima, Peru, 29 February 2016.’
Marine Turtle Newsletter 151 (2016): 32.

This report is from the first sea turtle photo-ID (PID) workshop at the International Sea Turtle Symposium (ISTS). Sea turtle researchers and conservationists exchanged ideas and methods on current PID platforms, uses, and provided feedback to programmers who are developing sea turtle PID platforms.

Published 2015

Stelfox, M. (2015):
Ghost nets of the Indian Ocean – Olive Ridley Project‘.
IUCN Maldives Marine Newsletter Issue 2 August 2015: 18

The article discusses the origin of the Olive Ridley Project. How it started, how it got its name, and how data was collected using citizen science. It introduces the aims and objectives of ORP with its new partners to expand their reach to India and Sri Lanka.

Stelfox, M. (2015):
The impact of ghost nets on marine species in the Maldives‘.
IUCN Maldives Marine Newsletter Issue 3 January 2015: 13-14

Establishing the effects of ghost nets in the Maldives and why olive ridleys are the most affected species. Results from the research indicated the origin and the make of nets found in the Maldives. Plans and aims of ORP were then discussed to work with other NGOs and governments to combat the issue.

Stelfox, M., Hudgins, J., Ali, K., Anderson R.C. (2015):
High mortality of Olive Ridley Turtles (Lepidochelys olivacea) in ghost nets in the central Indian Ocean.’
BOBLME-2015-Ecology-14 (2015): 1-23.

74 separate ghost nets were examined to find their origin. The results suggest that the nets were from India and Thailand and the fish aggregating devices were from the western Indian ocean. Recommendations were made to reduce ghost nets in the area and to use the non-entangling gear.