Andrea Denise Marshall

Andrea Denise Marshall
Marine Megafauna Foundation · Manta Ray Research Program

PhD

About

140
Publications
56,112
Reads
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3,178
Citations
Citations since 2016
67 Research Items
2471 Citations
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20162017201820192020202120220100200300400500
20162017201820192020202120220100200300400500
Introduction
I am a principal scientist for the Marine Megafauna Foundation and director of it's global manta ray research program. As a conservation biologist I focus my team’s efforts towards key aspects of the biology and ecology of both species of manta ray in aggregation sites across the globe. I have or currently work in areas like Mozambique, Ecuador, Indonesia, Myanmar and Florida. Through my Foundation I also work to develop science based managements strategies for manta rays and work with stakeholders, investors and government to develop practical solutions for their conservation in key areas, particularly the development of protected areas and eco-tourism. I am also scientific advisor for Manta Matcher, a global online automated database for manta rays which is open sourced resource for all.
Additional affiliations
January 2003 - present
Marine Megafauna Foundation
Position
  • Managing Director
Description
  • The Marine Megafauna Foundation is a global not-for-profit organization dedicated to the preservation of the world largest and most threatened marine species and their wild habitats.
January 2002 - December 2008
The University of Queensland
Position
  • PhD Student

Publications

Publications (140)
Article
Full-text available
Background The reef manta ray ( Mobula alfredi ) is a globally threatened species and an iconic tourist attraction for visitors to Indonesia’s Komodo National Park (NP). In 2013, manta ray fishing was banned in Komodo NP and its surroundings, preceding the nationwide manta ray protection in 2014. Over a decade ago, a previous acoustic telemetry stu...
Article
We report two separate sightings of the ornate eagle ray Aetomylaeus vespertilio (Bleeker, 1852) in the Bazaruto Seascape of southern Mozambique. In May 2021, a single individual was encountered at a depth of 30 m during an in-water survey in the Bazaruto Archipelago National Park. Another solitary individual was documented ~55 km away during an ae...
Article
Full-text available
Despite substantial progress in mobulid research over the past decade, knowledge gaps in manta ray ecology and behaviour remain, particularly in the South Atlantic Ocean. Opportunistic photographic and video records of manta rays collected between 2002 and 2019 at Fernando de Noronha Archipelago ( FNA ) in northeast Brazil provide evidence to suppo...
Article
Full-text available
Reef manta rays (Mobula alfredi) are social elasmobranchs that have structured societies and actively interact with preferred social partners. Being able to detect cues and signals produced by conspecifics is vital in enabling social behavior. Many elasmobranch species communicate via body and fin postures, but it is not yet known if or how mobulid...
Article
Full-text available
Overfishing is the primary cause of marine defaunation, yet declines in and increasing extinction risks of individual species are difficult to measure, particularly for the largest predators found in the high seas. Here we calculate two well-established indicators to track progress towards Aichi Biodiversity Targets and Sustainable Development Goal...
Article
Little is known about the extent of genetic connectivity along continuous coastlines in manta rays, or whether site visitation is influenced by relatedness. Such information is pertinent to defining population boundaries and understanding localized dispersal patterns and behaviour. Here, we use 3057 genome-wide single-nucleotide polymorphisms (SNPs...
Article
Full-text available
The giant oceanic manta ray Mobula birostris was listed in the US Endangered Spe- cies Act as a threatened species in 2018, yet insufficient data exist on manta populations through- out US waters to designate critical habitat. Taxonomic and genetic evidence suggests that manta rays in the Western Atlantic are a separate species (M. cf. birostris) a...
Article
Site-specific knowledge of spatial ecology is essential for the implementation of effective conservation measures for wide-ranging marine species. We used passive acoustic telemetry to examine the movements and site usage of reef manta rays Mobula alfredi in the Inhambane Province of Mozambique. Acoustic receivers were installed at 14 sites spannin...
Article
Full-text available
The implications of plastic pollution, including microplastics, on marine ecosystems and species are increasingly seen as an environmental disaster. Yet few reports focus on filter-feeding megafauna in regions heavily impacted by plastic pollution, such as Indonesia in the Coral Triangle, a global marine biodiversity hotspot. Here, we evaluate plas...
Article
Intraspecific colour polymorphisms have been the focus of numerous studies, yet processes affecting melanism in the marine environment remain poorly understood. Arguably, the most prominent example of melanism in marine species occurs in manta rays (Mobula birostris and Mobula alfredi). Here, we use long-term photo identification catalogues to docu...
Article
Full-text available
Understanding how individual behavior shapes the structure and ecology of populations is key to species conservation and management. Like many elasmobranchs, manta rays are highly mobile and wide-ranging species threatened by anthropogenic impacts. In shallow water environments, these pelagic rays often form groups and perform several apparently so...
Article
Full-text available
Background: The smalleye stingray (Megatrygon microps) is a large and rare dasyatid ray, patchily distributed across the Indo-West Pacific. Free-swimming individuals have regularly been recorded in Southern Mozambican coastal waters utilizing different inshore environments. Distinctive features of the species include latitudinal rows of white spot...
Article
Full-text available
Manta rays (Mobula spp.) are highly valued in nature-based tourism globally. In Indonesia, although manta rays are protected, critical information is lacking on their habitat use, population dynamics and movements. We investigate the population structure and residency patterns of reef manta rays (Mobula alfredi) in the Nusa Penida Marine Protected...
Article
Full-text available
An opportunistic sighting of a reef manta ray (Mobula alfredi) along the northeastern corner of Cocos Island, Costa Rica, represents the first sighting of this species nearly 6000 km from the nearest confirmed sighting location in the Marquesas Islands and the first record of this species on either side of the American continent. Cocos Island is si...
Article
Full-text available
Manta and devil rays are filter-feeding elasmobranchs that are found circumglobally in tropical and subtropical waters. Although relatively understudied for most of the Twentieth century, public awareness and scientific research on these species has increased dramatically in recent years. Much of this attention has been in response to targeted fish...
Conference Paper
Full-text available
Despite their iconic megafauna status and importance to the global tourism economy, both species of manta ray (Mobula birostris, Mobula alfredi) are considered internationally threatened (Lewis et al., 2015, Anderson et al., 2011, Cisneros-Montemayor et al., 2013), primarily due to the high demand for their gill rakers in traditional medicine marke...
Article
Microplastic pollution can impact filter-feeding marine megafauna, namely mobulid rays, filter-feeding sharks, and baleen whales. Emerging research on these flagship species highlights potential exposure to microplastic contamination and plastic-associated toxins. Research and its wide communication are needed to understand the magnitude of the iss...
Article
Full-text available
Traditionally, large planktivorous elasmobranchs have been thought to predominantly feed on surface zooplankton during daytime hours. However, the recent application of molecular methods to examine long-term assimilated diets, has revealed that these species likely gain the majority from deeper or demersal sources. Signature fatty acid analysis (FA...
Data
Comparison of surface zooplankton signature fatty acid (FA) profiles among sampling months with 95% ellipses. Non-metric multi-dimensional scaling ordination of surface zooplankton FA profiles sampled at Isla de la Plata, Ecuador, from August 2013 to October 2013, and August 2014 to September 2014. There was a significant difference among samples (...
Data
Signature fatty acid (FA) profiles (% of total FA ± s.d.) of surface zooplankton collected from Isla de la Plata, Ecuador among sampling months and temperature groupings. Here, the FA profiles of surface zooplankton were significantly different among sampling months and temperature groupings (SIMPER, p <0.05). (DOCX)
Data
Individual Mobula birostris and surface zooplankton fatty acid profiles, along with sampling date and location. (XLSX)
Data
Comparison of surface zooplankton signature fatty acid (FA) profiles between different in situ temperature groupings at time of collection. Non-metric multi-dimensional scaling ordination of surface zooplankton FA profiles sampled at Isla de la Plata, Ecuador, from August—October 2013, and August—September 2014. There was a significant difference i...
Data
Signature fatty acid (FA) profiles (% of total FA ± s.d.) of Mobula birostris among sample collection years. The FA profiles of M. birostris were not significantly different among years (ANOSIM, R = 0.04753, p = 0.27). (PDF)
Data
Similarity percentage analysis (SIMPER) of surface zooplankton fatty acid profiles among cluster groups 1 and 2 (80% similarity). Fatty acids with an average contribution >5% are included and data was not transformed prior to analysis. (PDF)
Data
Similarity percentage analysis (SIMPER) results of Mobula birostris fatty acid profiles for cluster groups A and B (70% similarity). Fatty acids with an average contribution >5% are included and data was not transformed prior to analysis. (PDF)
Data
Detailed methodology for lipid extraction and signature fatty acid analysis. (DOCX)
Preprint
Full-text available
Mobulid rays are one of the most vulnerable chondrichthyan groups due to their low population growth rates and high susceptibility to fisheries. While estimates of human-induced mortality are lacking, sighting trend data can provide an index of their status. We recorded underwater sightings data of Mobula alfredi , M. birostris and M. kuhlii over a...
Preprint
Full-text available
Mobulid rays are one of the most vulnerable chondrichthyan groups due to their low population growth rates and high susceptibility to fisheries. While estimates of human-induced mortality are lacking, sighting trend data can provide an index of their status. We recorded underwater sightings data of Mobula alfredi , M. birostris and M. kuhlii over a...
Article
Stable isotope analysis of tissues with different turnover rates allows for a broader temporal view of a species' feeding habits. Epidermal mucus is a rapid to medium turnover 'tissue' in teleost fish, but its use in elasmobranch dietary studies is unknown. In the present study, we conducted stable isotope analysis on mucus and muscle from the gian...
Article
Manta rays are internationally threatened species and population declines have been reported in various locations worldwide. As iconic megafauna species, they are also major drawcards for wildlife tourism industries. Economic valuation of these industries can provide an incentive for the protection of species and natural habitats through the creati...
Data
Supplementary information for sample collection, isotope values for individual Manta birostris and surface zooplankton tows, and mixing model summary statistics.Included here is a detailed sample collection protocol for obtaining M. birostris muscle tissue samples from free swimming animals. Additionally, the CN isotope values for individual Manta...
Article
Full-text available
The characterization of diet for the giant manta ray Manta birostris has been problematic given their large-scale movement patterns and the difficulty in obtaining stomach contents from this species. The large majority of existing information is based on observational data limited to feeding events at the sea surface during daylight. Recently disco...
Article
Full-text available
1. Manta and devil rays of the subfamily Mobulinae (mobulids) are rarely studied, large, pelagic elasmobranchs, with all eight of well-evaluated species listed on the IUCN Red List as threatened or near threatened. 2. Mobulids have life history characteristics (matrotrophic reproduction, extremely low fecundity, and delayed age of first reproductio...
Article
Full-text available
Cleaning interactions between the short fin devil ray, Mobula kuhlii, and the blue streaked cleaner wrasse, Labroides dimidiatus, were observed at two sites on a single reef in southern Mozambique. Cleaning interactions were filmed and described, with the number and location of interactions recorded and subsequently binned into six distinct body pa...
Article
Full-text available
Cleaning interactions between the short fin devil ray, Mobula kuhlii, and the blue streaked cleaner wrasse, Labroides dimidiatus, were observed at two sites on a single reef in southern Mozambique. Cleaning interactions were filmed and described, with the number and location of interactions recorded and subsequently binned into six distinct body pa...
Method
Included here is a detailed sample collection protocol for obtaining M. birostris muscle tissue samples from free swimming animals. Additionally, the CN isotope values for individual Manta birostris and surface zooplankton tows are presented, along with mixing model summary statistics for the mean credible interval source contributions of surface z...
Method
Included here is a detailed sample collection protocol for obtaining M. birostris muscle tissue samples from free swimming animals. Additionally, the CN isotope values for individual Manta birostris and surface zooplankton tows are presented, along with mixing model summary statistics for the mean credible interval source contributions of surface z...