Galapagos Islands Research Articles

Preliminary insights of the genetic diversity and invasion pathways of Cedrela odorata in the Galapagos Islands, Ecuador.

Cedrela odorata is considered the second most invasive tree species of the Galapagos Islands. Although it is listed in CITES Appendix II and there are population losses in mainland Ecuador, in Galapagos it is paradoxically a species of concern due to its invasive potential. Genetic studies can shed light on the invasion history of introduced species causing effects on unique ecosystems like the Galapagos. We analyzed nine microsatellite markers in C. odorata individuals from Galapagos and mainland Ecuador to describe the genetic diversity and population structure of C. odorata in the Galapagos and to explore the origin and invasion history of this species. The genetic diversity found for C. odorata in Galapagos (H e = 0.55) was lower than reported in the mainland (H e = 0.81), but higher than other invasive insular plant species, which could indicate multiple introductions. Our results suggest that Ecuador's northern Coastal region is the most likely origin of the Galapagos C. odorata, although further genomic studies, like Whole Genome Sequencing, Rad-Seq, and/or Whole Genome SNP analyses, are needed to confirm this finding. Moreover, according to our proposed pathway scenarios, C. odorata was first introduced to San Cristobal and/or Santa Cruz from mainland Ecuador. After these initial introductions, C. odorata appears to have arrived to Isabela and Floreana from either San Cristobal or Santa Cruz. Here, we report the first genetic study of C. odorata in the Galapagos and the first attempt to unravel the invasion history of this species. The information obtained in this research could support management and control strategies to lessen the impact that C. odorata has on the islands' local flora and fauna.

Some Ceratozetoidea species (Acari: Oribatida: Ceratozetidae, Humerobatidae) from the Galapagos Islands

A new species of oribatid mites from the Galapagos Islands, Ceratozetes yupanqui n. sp. is described and illustrated. It is morphologically most similar to two South American species, Ceratozetes platyrhinus and C. platyrhinoides, in having a broadened rostrum without incisions, but the new species exhibits consistent morphological differences in comparison to these species which are discussed. Numerous specimens of Ceratozetes yupanqui n. sp. were found on western islands of the archipelago, in moister habitats at higher altitudes in leaf and grass litter, as well as in arid lowlands in dry leaf and cactus litter. In previous listings of Galapagos species, Humerobates rostrolamellatus was erroneously reported as "Porozetes sp." Additional morphological features of this species are presented, based on the record from the Galapagos Islands. Morphological differences between H. rostrolamellatus and H. flechtmanni from Brazil are highlighted.

The potential of Wave Energy Converters in the Galapagos islands

This study investigates the potential of Wave Energy Converters (WECs) technology in the Galapagos Islands. Despite the region’s high wave energy potential (262 TWh/year of gross potential and 25TWh/year of sustainable potential), the current high cost of WEC technology limits its economic competitiveness compared to mature renewables like solar and wind. Our analysis, using the OSeMOSYS model, reveals that decarbonizing the Galapagos’ power sector with solar and wind is feasible and cost-effective. However, deploying WECs is even more expensive. Initially, WECs have the highest levelized cost of electricity (LCOE) (43 ct.USD/kWh in 2030), but this decreases by 2050, ending up at 26 ct.USD/kWh, a value below the benchmark for fossil thermal power plants without fuel subsidies. Deploying WECs, together with solar and wind technologies may contribute for diversifying the Galapagos’ power system, reducing fossil fuel reliance, and mitigating climate change impacts.

First record of the family Azotidae from Ecuador, with a description of a new species of Ablerus Howard (Hymenoptera: Chalcidoidea: Azotidae) from the Galapagos Islands

Azotidae (Hymenoptera: Chalcidoidea) is a small family (1 genus, 92 species) comprised primarily of hyperparasitoids of species of Hymenoptera that target whiteflies and scale insects. In the present study, we provide the first record of the genus Ablerus Howard, 1898 (=Azotus Howard 1898) from the Galapagos Islands, based on material collected in a survey of Hymenoptera across the archipelago’s main islands. One new species, Ablerus byroni sp. n. is described and illustrated.

"Special Regime - Galapagos islands" analysis of the electricity and public lighting service: Current status

This article presents the impact of applying the electricity sector and public lighting policies in the Galapagos Islands, focused on a framework that addresses six issues: legislation, demand, financial, technologies, environmental, and international commitments. The installed power capacity in 2022 was 31.55 MW, 23.04 % from renewable sources. By 2027, the power generation is expected to be 57.62 MW with 56 % renewable sources, without a short-term plan to comply with the "Zero fossil fuels" policy. The electrical system is isolated from the continent, and some policies analyzed can serve as a reference to implement changes in similar systems.

The cognitive and conative image in insular marine protected areas: A study from Galapagos, Ecuador

The present study aimed to identify the factors related to cognitive and conative image attributes in an insular marine protected area and determine which factors explain tourist satisfaction and behavioral loyalty. The research was conducted in the Galapagos Islands, a marine protected area in Ecuador, South America. A total of 407 tourist questionnaires were collected on-site, including national and foreign visitors, and factor analysis and ordinal logistical regression techniques were applied. The findings reveal four factors in the image attributes of insular marine protected areas: Staff Attention, Tourist Facilities, Nature, and Cultural Activities. Among the factors explaining satisfaction with the tourist destination, as well as the intention to recommend it and provide positive feedback, Nature and Staff Attention at the destination stand out. Meanwhile, the cultural activities factor best explains the intention to return to the destination.These findings enhance the academic understanding of the factors influencing the image of coastal and marine destinations, particularly in insular marine protected areas. They also offer valuable insights for destination managers, providing practical guidelines to improve destination images, thereby boosting tourist satisfaction and loyalty.

Undetection of vector-borne viruses in equids of Galapagos Islands.

Domestic species, including equids, were introduced in the Galapagos Islands in the XIX century. Equine vector-borne diseases are circulating in South America but their occurrence in the Galapagos Island was unknown. The objective of this study was to detect the occurrence of West Nile virus (WNV), Usutu virus (USUV) and equine infectious anemia virus (EIAV) in the four Galapagos Islands raising equids if they were present at a prevalence >1%. Serum samples were collected from 411 equids belonging to 124 owners from April to July 2019. All the results were negative to the ELISA tests used suggesting that WNV, USUV and EIAV are not circulating in the equine population of the Galapagos Islands.

Influence of larval and adult diets on the maturation of male and female reproductive organs of the avian vampire fly, Philornis downsi (Diptera: Muscidae)

AbstractThe invasive avian vampire fly, Philornis downsi, Dodge and Aitken (Diptera: Muscidae) is a threat to the long‐term conservation of Darwin's finches and other landbirds in the Galapagos Islands. Adult flies feed on fermented fruit, but their larvae are obligate parasites that feed on, and often cause the mortality of, the developing nestlings. Various techniques for the control of this parasite are currently under study, but the inability to rear flies in captivity has slowed progress. To help understand the reproductive behaviour of P. downsi, in this study, we measured the reproductive organs of male and female flies to determine the age flies mature physiologically, as well as the influence of the larval and adult diets on this process. Both females and males reared from larvae that had developed in the wild on live birds reached physiological maturity at 6 days; in the males, this was associated with increased pigmentation of the testes and the presence of free sperm, and in the females, mature eggs. Females reared in the laboratory on an artificial diet produced mature eggs at 6 days. However, the ovaries of laboratory‐reared females were statistically smaller than those of wild females, suggesting that egg production was affected by larval diet. Physiological maturity was delayed in laboratory‐reared males, taking twice as long. The testes of these males had more unpigmented areas and deformities indicating that the artificial larval diet was insufficient. Enrichment of the adult diet could help compensate for this. The addition of methoprene (M) to the diet was found to have a positive effect on the sexual development of the flies. In females, a diet of sugar + yeast hydrolysate (YH) in a 3:1 ratio combined with M favoured the development of larger ovaries and the production of mature eggs at an earlier age (3 days). In the case of males, a diet with YH increased testis size and M accelerated the growth of testis length even when males were fed only with sugar and without YH. Additional studies are recommended for improving the diets for mass‐rearing this highly harmful fly.

Sustainable Tourism in Galapagos: The Perception of the Stakeholders

Summary The Galapagos Islands (Ecuador) are a living laboratory and a sensitive area where, among other activities, tourism is performed. The unique flora, fauna, and landscapes motivate thousands of people to visit the islands every year, generating economic benefits and various considerations regarding environmental issues. Information © The Authors 2024

Climate projections of oceanographic variables in the Exclusive Economic Zone of Ecuador: A 21st century perspective to inform impact and adaptation assessment

Climate projections of ocean variables are essential to inform adaptation strategies and plans involving open and coastal oceanic regions. Assessment of baseline and projections of sea surface temperature (SST), pH, dissolved oxygen (DO), mean sea level (MSL), waves coastal flooding within Ecuador’s Exclusive Economic Zone, including Galapagos Islands are reported herein. With different magnitudes of change, both near-future (2021–2050) and far-future projections (2051–2080) show a statistically robust increase in SST, MSL rise and a reduction in pH, a proxy for acidification. In contrast, DO decrease is only observed in surface (0–100 m) but not in subsurface waters (100–400 m). The likelihood of extreme sea level events in the coastal cities of La Libertad, Manta and Esmeraldas would remain almost unchanged for near-future projections (2026–2045) whereas, for end-of-century projections (2081–2100), historical 1 in a 100-year extreme flooding events would become yearly occurrences. The generated data product offers a state-of-the-art research and management tool for the 21st century under the combined stressors of global climate change. Since the eastern Tropical Pacific Ocean is one of the most productive and biodiverse worldwide due to the equatorial upwelling system, possible impacts on marine biodiversity, social, and economic systems are discussed.

Water Quality from Natural Sources for Sustainable Agricultural Development Strategies: Galapagos, Ecuador

Water is an essential element for agricultural sustainability. In volcanic islands, freshwater sources are limited, challenging the local farming water supply. Rainfall dependence in the Galapagos Islands limits continuous agriculture, and despite using natural water sources, their irrigation quality is little known. This study aimed to carry out a control–diagnosis of irrigation water quality of the natural sources of the four agrarian islands of the Galapagos, considering water quality parameters for the proposal of sustainability strategies in the water and agricultural context. The workflow included (i) freshwater supply situation diagnosis, (ii) physicochemical parameters measurement and hydrochemical characterisation, and (iii) irrigation analysis and sustainability strategies configuration. Results indicated that of the 34 sources analysed, 55.88% are suitable for irrigation and are located in San Cristobal and Santa Cruz. The remaining 44.12% showed problems with parameters such as faecal coliforms, salinity, metals, carbonates, BOD5, and COD above the national permitted limits. Six strategies for water and agricultural sustainability are proposed, including periodic water monitoring, academy–government–community projects, community water board creation, water sowing and harvesting systems, effective management of effluent, and agricultural strengthening. The study guides comprehensive hydric management initiatives to benefit agrarian development and food security, aligning with SDGs 2 and 6.

Longest recorded migration of a silky shark (Carcharhinus falciformis) reveals extensive use of international waters of the Tropical Eastern Pacific.

Despite being a heavily fished species, little is known about the movements of silky sharks (Carcharhinus falciformis). In this study, we report the longest (in duration and distance traveled) and most spatially extensive recorded migration for a silky shark. This shark, tagged with a fin-mount satellite transmitter at the Galapagos Islands, traveled >27,666 km over 546 days, making two westerly migrations into international waters as far as 4755 km from the tagging location. These extensive movements in an area with high international fishing effort highlights the importance of understanding silky shark migrations to inform management practices.

Defining large‐scale arid island vegetation recovery targets through evaluating a reference ecosystem within an archipelago extent

Island ecological restoration presents challenges in establishing historical frames and reference ecosystems. Our study takes place in the Galapagos Islands and focuses on North Seymour (NS), recognized as a reference ecosystem for Baltra Island, which has suffered significant degradation. We assessed NS's arid plant community, comparing it with early twentieth‐century records. A first survey identified that dominant woody species on NS include native Bursera graveolens, Cordia lutea, Castela galapageia, Parkinsonia aculeata, and Opuntia echios, while Cleome viscosa is the only exotic species registered. A second survey divided both islands into evenly distributed plots, recording adults and juveniles of the five dominant species from the first survey. NS showed a structured community with higher species richness and density compared to Baltra. Castela galapageia prevailed in disturbed areas on Baltra. Juvenile regeneration was scarce on both islands. NS exhibited high species richness throughout, while Baltra had only two areas with similar high richness. Co‐occurrence analysis revealed significant associations between P. aculeata and B. graveolens on both islands. However, Baltra's network displayed missing links, indicating the need for restoration efforts. In conclusion, the structured plant community of NS can serve as one of the reference ecosystems needed for framing a restoration model for Baltra.

Genome Assembly of Pyrocephalus nanus: A Step Toward the Genetic Conservation of the Endangered Little Vermilion Flycatcher of the Galapagos Islands.

Incredibly powerful whole genome studies of conservation genetics, evolution, and biogeography become possible for non-model organisms when reference genomes are available. Here, we report the sequence and assembly of the whole genome of the little vermilion flycatcher (Pyrocephalus nanus; family Tyrannidae), which is an endemic, endangered, and declining species of the Galapagos Islands. Using PacBio HiFi reads to assemble long contigs and Hi-C reads for scaffolding, we assembled a genome of 1.07 Gb comprising 267 contigs in 152 scaffolds, scaffold N50 74 M, contig N50 17.8 M, with 98.9% assigned to candidate chromosomal sequences and 99.72% of the BUSCO passeriformes 10,844 single-copy orthologs present. In addition, we used the novel HiFiMiTie pipeline to fully assemble and verify all portions of the mitochondrial genome from HiFi reads, obtaining a mitogenome of 17,151 bases, containing 13 protein-coding genes, 22 tRNAs, 2 rRNAs, two control regions, and a unique structure of control region duplication and repeats. These genomes will be a critical tool for much-needed studies of phylogenetics, population genetics, biogeography, and conservation genetics of Pyrocephalus and related genera. This genome and other studies that use it will be able to provide recommendations for conservation management, taxonomic improvement, and to understand the evolution and diversification of this genus within the Galapagos Islands.

Optimal Design of a Hybrid Solar–Battery–Diesel System: A Case Study of Galapagos Islands

In this study, the sizing problem of hybrid diesel–photovoltaic–battery systems was determined using a particle swarm optimization approach. The goal was to optimize the number of solar panels and batteries that could be installed to reduce the overall cost of an isolated grid system, originally powered by diesel generators, located on Isabela Island in the Galapagos, Ecuador. In this study, real solar radiation and temperature profiles were used, as well as the load demand and electrical distribution system relative to this island. The results reveal that the total cost for the proposed approach is lower as it reaches the global optimal solution. It also highlights the advantage of a hybrid diesel–photovoltaic–battery (DG-PV-BAT) system compared to conventional systems operated exclusively by diesel generators (DGs) and systems made up of DGs and PV panels; compared to them, a reduction in diesel consumption and total cost (71% and 56%, respectively) is achieved. The DG-PV-BAT system also considerably improves environmental factors and the quality of the power line. This study demonstrates the advantages of hybridizing systems isolated from the network through the proposed approach.

Using modified trapping regimes to understand the behavioral and spatial ecology of Philornis downsi (Diptera: Muscidae).

The avian vampire fly Philornis downsi (Dodge & Aitken) (Diptera: Muscidae) is native to continental South America and the Caribbean, but invasive in the Galapagos Archipelago. The larvae of P. downsi feed on the blood and tissues of the nestlings of 75% of the small land bird species that are endemic or native to Galapagos, causing high in-nest mortality and severe population declines in some species. Efficient trapping techniques are vital to safeguarding these birds in the short term as well as for monitoring fly populations, but basic information about the ecology of the fly is still needed to help develop a species-appropriate trapping method. In this study, we used a novel trapping regime with a vertical distribution to make inferences about P. downsi's behavioral and spatial ecology and to optimize trap catch. Our results showed that male and female P. downsi were trapped in greater numbers below the canopy (3.1-7.5 m), lower down than other commonly caught insect species (5.1-11.5 m). Notably, the effect of trap height remained consistent across seasons and different weather conditions. These findings suggest that P. downsi tend to move at heights where their hosts nest (at or below the canopy) and do not spend time above the canopy. This also makes it unlikely that strategies such as hill-topping or aerial swarming are being used to locate mates. As such, trapping and control efforts should be focused below the canopy in forests with similar canopy heights to effectively capture P. downsi and reduce bycatch of other insects.

Understanding the sources of marine litter in remote islands: The Galapagos islands as a case study

Determining the sources of marine litter is necessary to mitigate this increasing global problem. Plastic bottles are useful tracers of marine litter and constitute the main item (24%) stranding on remote beaches in the Galapagos Islands. The aim of this study was to estimate the abundance of plastic bottles in remote beaches and inferred their sources. To do so, we collected plastic bottles at 60 remote Galapagos Island beaches from 2018 to 2022. 76% of beaches were qualified as badly polluted, with >34 bottles·100 m−1. Most identified bottles came from Peru (71%), followed by China (17%) and Ecuador (9%). Although most locally-sold products are made in Ecuador, they contribute little to beach litter loads. Polyethylene terephthalate bottles with lid (necessary for litter dispersal) represented 88% of all bottles, demonstrating that most of the litter reaching the Galapagos comes from distant sources, mainly from South America. However, bottle ages indicate that at least 10% of Peruvian, 26% of Ecuadorian, and all Chinese bottles likely were dumped from ships. Reducing marine litter reaching the Galapagos Islands requires tackling litter leakage from land-based sources in South America and better compliance with regulations banning the dumping of plastics and other persistent wastes from ships.

Restoring the threatened Scalesia forest: insights from a decade of invasive plant management in Galapagos

Island forests are becoming increasingly fragmented and colonized by invasive species, which can eventually lead to local species extinctions. In the Galapagos Islands, invasive species pose a serious extinction threat to the endemic daisy tree Scalesia pedunculata, formerly the dominant habitat-forming species of the unique Scalesia forest. This forest has been reduced to fragments due to land use changes in the past and is now increasingly invaded by introduced plants. We conducted a field experiment on Santa Cruz Island to assess the impacts of blackberry (Rubus niveus) and two other invasive plant species, Cestrum auriculatum and Tradescantia fluminensis, as well as the effects of the removal of two of these (R. niveus and C. auriculatum) on cover, composition and diversity of the resident plant communities. Particular attention was paid to effects of the invasive species on the S. pedunculata population. Annual vegetation monitoring was carried out in a total of 34 permanent plots (10 m × 10 m) over 10 years (2014–2023), using the line-intercept method. Seventeen of these plots were established in an invaded area and 17 plots in an area with continuous invasive plant removal since 2014. Results indicated that there were significant changes in both the species composition of the plant communities and average percent cover of species over time, comparing removal plots with invaded plots. Species composition in removal plots changed significantly more than in invaded plots, towards a plant community with greater percent cover of endemic species. A significant negative relationship between the three invasive species and cover of S. pedunculata suggested that multiple invader species may have additive negative impacts. Natural recruitment of S. pedunculata by seeds was observed in the removal but not in the invaded plots. These results, as well as the striking decrease of 71% in cover of adult S. pedunculata in the invaded plots indicate that this threatened species will be driven to local extinction on Santa Cruz Island, Galapagos, in less than 20 years if invasive plant species are not removed on a large scale.

Thriving in dry conditions: on the Neotropical spider genus Galapa (Araneae: Pholcidae).

The genus Galapa Huber, 2000 includes tiny spiders (body length <1.5 mm) restricted to semi-arid habitats. It has long been thought to be endemic to the Galapagos Islands until G. spiniphila Huber, 2020 was described from the Venezuelan Paraguan Peninsula. Here, we support this generic assignment with molecular (CO1) data and describe two new species from Colombia (G. gabito Huber sp. n.) and Costa Rica (G. murphyi Huber sp. n.), showing that the genus is actually widely distributed. Distribution modelling identifies several high suitability areas for Galapa, all of which are poorly sampled with respect to Pholcidae (ranging from Nicaragua to northern Peru and Guiana). Our results suggest a strong sampling bias against spiders restricted to dry tropical regions and habitats.

Sea surface microplastics in the Galapagos: Grab samples reveal high concentrations of particles

Plastic pollution in the oceans is increasing, yet most global sea surface data is collected using plankton nets which limits our knowledge of the smaller and more bioaccessible size fraction of microplastics (<5 mm). We sampled the biodiverse coastal waters of the Galapagos Island of San Cristobal, comparing two different microplastic sampling methodologies; 1 l whole seawater grab samples filtered to 1.2 μm and sea surface plankton tows with a net mesh size of 200 μm. Our data reveal high concentrations of microplastics in Galapagos coastal waters surrounding the urban area, averaging 11.5 ± 1.48 particles l−1, with a four-order of magnitude increase in microplastic abundance observed using grab sampling compared with 200 μm plankton nets. This increase was greater when including anthropogenic cellulose particles, averaging 19.8 ± 1.86 particles l−1. Microplastic and anthropogenic cellulose particles smaller than 200 μm comprised 44 % of the particles from grab samples, suggesting previous estimates of microplastic pollution based on plankton nets likely miss and therefore underestimate these smaller particles. The particle characteristics and distribution of these smaller particles points strongly to a local input of cellulosic fibres in addition to the microplastic particles transported longer distances via the Humbolt current found across the surface seawater of the Galapagos. Improving our understanding of particle characteristics and distributions to highlight likely local sources will facilitate the development of local mitigation and management plans to reduce the input and impacts of microplastics to marine species, not just in the Galapagos but globally.