Fibropapillomatosis and the Chelonid Alphaherpesvirus 5 in Green Turtles from West Africa

Monteiro, J. Lemos; Duarte, M. Teresa; Amadou, Kidé; Barbosa, Castro; Bar, Nahi El; Madeira, Fernando Miguel; Regalla, Aissa; Duarte, Ana; Tavares, Luís; Patrício, Ana R.

doi:10.1007/s10393-021-01526-y

Cited by 13 publications

(11 citation statements)

References 54 publications

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“…In the Bijagoś, the majority of turtles foraged outside MPAs (88%, n=12), but within the limits of the UNESCO Bolama-Bijagoś Archipelago Biosphere Reserve (BABR, 98.1%). Notably, the BABR also hosts foraging aggregations of immature green turtles (Monteiro et al, 2021), therefore, creating and implementing relevant regulations within the BABR would greatly enhance the protection of green turtles in West Africa. In this study, our tracking effort was focused during the time of year when the large majority of the Bijagós green turtle population nest, as this is the most relevant period for informing for conservation.…”

Section: Mpa Coverage Of Foraging Grounds and Connectivity Across The...mentioning

confidence: 99%

Green Turtles Highlight Connectivity Across a Regional Marine Protected Area Network in West Africa

Patrício

Beal²,

Barbosa³

et al. 2022

Front. Mar. Sci.

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Networks of marine protected areas (MPAs) are invaluable for the protection of species with high dispersal capacity, yet connectivity within networks is poorly understood. We demonstrate the connectivity within the regional MPA network in West Africa (RAMPAO), mediated by the largest green turtle population in the eastern Atlantic Ocean. We equipped with satellite tags 45 female green turtles nesting in the Bijagós Archipelago, Guinea-Bissau, and tracked them during internesting, migration, and foraging to quantify the degree of coverage the RAMPAO network provides during each of these critical periods. During the internesting period, turtles were largely concentrated around the nesting islands, with a mean of 94.8% (SD 0.1%, range: 46% - 100%, n = 40 turtles) of tracking positions falling within MPA limits. Among the 35 turtles successfully tracked into the foraging period, we identified variable migratory strategies, with 12 turtles remaining near-resident at distances of 40-90 km from breeding sites, 10 turtles migrating 300-400 km to The Gambia and Senegal, and 13 turtles traveling >1000 km to northern Mauritania. Of the 35 foraging turtles, 26 used MPAs, with a mean of 78.0% (SD 34.8%, range: 3.7% - 100%) of their tracking positions falling within the limits of RAMPAO MPAs, across Guinea-Bissau, Senegal and Mauritania. Migration corridors with high concentrations of passing turtles were mostly located nearshore, and 21% of these high passage areas fell within the MPA network. Overall, we found that this population connects five RAMPAO MPAs, yet some foraging sites (e.g., in the Bijagós) and important migration areas (e.g., Cap-Vert peninsula) described here are currently unprotected. These results are relevant to any considerations of MPA extension or establishment within the regional network, which would contribute towards meeting the Convention on Biological Diversity targets for national marine protected area estate coverage. By documenting biological connectivity across RAMPAO, this study represents an important example of the relevance of international protected area networks for green turtle conservation and for wider conservation action at a regional scale.

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Section: Mpa Coverage Of Foraging Grounds and Connectivity Across The...mentioning

confidence: 99%

Green Turtles Highlight Connectivity Across a Regional Marine Protected Area Network in West Africa

Patrício

Beal²,

Barbosa³

et al. 2022

Front. Mar. Sci.

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“…All samples used in this study came from two distinct locations in Guinea-Bissau, West Africa. Esophageal and cloacal swabs were collected from juveniles foraging in coastal waters around the islands of Unhocomo and Unhocomozinho (11°31′ N–16°40′ W, Figure 1 a), in the westernmost limit of the Bijagós Archipelago, Guinea-Bissau, where important foraging grounds for juvenile green turtles exist [ 34 , 42 ]. Intestine and stomach samples were collected from hatchlings found dead at the nesting beach of Poilão Island (10°52′ N–15°43′ W, Figure 1 b), which hosts one of the world’s largest green turtle nesting populations, producing over one million hatchlings every year [ 43 ].…”

Section: Methodsmentioning

confidence: 99%

“…Guinea-Bissau hosts a major green turtle population, with most of the nesting concentrated in the southeast of the Bijagós archipelago, and foraging grounds spreading through this archipelago [ 33 ], with an important one around the westernmost islands [ 34 ]. Two recent studies found that juvenile green sea turtles in this foraging ground feed mostly on red algae [ 35 , 36 ], thus, it is likely that red algae microbiomes are present in the GI tract of these turtles.…”

Section: Introductionmentioning

confidence: 99%

Red, Gold and Green: Microbial Contribution of Rhodophyta and Other Algae to Green Turtle (Chelonia mydas) Gut Microbiome

et al. 2022

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The fitness of the endangered green sea turtle (Chelonia mydas) may be strongly affected by its gut microbiome, as microbes play important roles in host nutrition and health. This study aimed at establishing environmental microbial baselines that can be used to assess turtle health under altered future conditions. We characterized the microbiome associated with the gastrointestinal tract of green turtles from Guinea Bissau in different life stages and associated with their food items, using 16S rRNA metabarcoding. We found that the most abundant (% relative abundance) bacterial phyla across the gastrointestinal sections were Proteobacteria (68.1 ± 13.9% “amplicon sequence variants”, ASVs), Bacteroidetes (15.1 ± 10.1%) and Firmicutes (14.7 ± 21.7%). Additionally, we found the presence of two red algae bacterial indicator ASVs (the Alphaproteobacteria Brucella pinnipedialis with 75 ± 0% and a Gammaproteobacteria identified as methanotrophic endosymbiont of Bathymodiolus, with <1%) in cloacal compartments, along with six bacterial ASVs shared only between cloacal and local environmental red algae samples. We corroborate previous results demonstrating that green turtles fed on red algae (but, to a lower extent, also seagrass and brown algae), thus, acquiring microbial components that potentially aid them digest these food items. This study is a foundation for better understanding the microbial composition of sea turtle digestive tracts.

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“…The FP epizootic has been identified as one of the five major threats to sea turtles, which has been reflected in the renewed scientific interest in this disease in the last decade [5,7,11,13,[18][19][20][21][22][23][24][25][26]. Prevalence statistics reveal the rapid establishment of FP among many sea turtle populations, with reported increases from 13.3 to 42% in Florida, USA (2005-2016), 13.2 to 35.3% in northeastern Brazil (2012)(2013)(2014)(2015), 0% to 33% in Guinea-Bissau (2009-2019) and 0.6% to 35.2% in Texas, USA (2010)(2011)(2012)(2013)(2014)(2015)(2016)(2017)(2018) [7,17,[27][28][29][30][31]. The disease also continues to be reported in previously unaffected populations [32][33][34][35].…”

Section: Introductionmentioning

confidence: 99%

Evolutionary Comparisons of Chelonid Alphaherpesvirus 5 (ChHV5) Genomes from Fibropapillomatosis-Afflicted Green (Chelonia mydas), Olive Ridley (Lepidochelys olivacea) and Kemp’s Ridley (Lepidochelys kempii) Sea Turtles

Whitmore

Yetsko

Farrell

et al. 2021

Animals

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The spreading global sea turtle fibropapillomatosis (FP) epizootic is threatening some of Earth’s ancient reptiles, adding to the plethora of threats faced by these keystone species. Understanding this neoplastic disease and its likely aetiological pathogen, chelonid alphaherpesvirus 5 (ChHV5), is crucial to understand how the disease impacts sea turtle populations and species and the future trajectory of disease incidence. We generated 20 ChHV5 genomes, from three sea turtle species, to better understand the viral variant diversity and gene evolution of this oncogenic virus. We revealed previously underappreciated genetic diversity within this virus (with an average of 2035 single nucleotide polymorphisms (SNPs), 1.54% of the ChHV5 genome) and identified genes under the strongest evolutionary pressure. Furthermore, we investigated the phylogeny of ChHV5 at both genome and gene level, confirming the propensity of the virus to be interspecific, with related variants able to infect multiple sea turtle species. Finally, we revealed unexpected intra-host diversity, with up to 0.15% of the viral genome varying between ChHV5 genomes isolated from different tumours concurrently arising within the same individual. These findings offer important insights into ChHV5 biology and provide genomic resources for this oncogenic virus.

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Fibropapillomatosis and the Chelonid Alphaherpesvirus 5 in Green Turtles from West Africa

Cited by 13 publications

References 54 publications

Green Turtles Highlight Connectivity Across a Regional Marine Protected Area Network in West Africa

Green Turtles Highlight Connectivity Across a Regional Marine Protected Area Network in West Africa

Red, Gold and Green: Microbial Contribution of Rhodophyta and Other Algae to Green Turtle (Chelonia mydas) Gut Microbiome

Evolutionary Comparisons of Chelonid Alphaherpesvirus 5 (ChHV5) Genomes from Fibropapillomatosis-Afflicted Green (Chelonia mydas), Olive Ridley (Lepidochelys olivacea) and Kemp’s Ridley (Lepidochelys kempii) Sea Turtles

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