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Map of Ecuador showing the major drainage basins. 1, Santiago‐Cayapas Drainage; 2, Esmeraldas River; 3, Chone River; 4, Portoviejo River; 5, Daule River; 6, Babahoyo River; 7, Zapotal River; 8, Guayas River; 9, Taura River; 10, Cañar River; 11, Balao River; 12, Jubones River; 13, Aguarico River; 14, Napo River; 15, Curaray River; 16, Pastaza River; 17, Morona River; 18, Santiago River
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Freshwater fish communities in Ecuador exhibit some of the highest levels of diversity and endemism in the Neotropics. Unfortunately, aquatic ecosystems in the country are under serious threat and conditions are deteriorating. In 2018–19, the government of Ecuador sponsored a series of workshops to examine the conservation status of Ecuador's fresh...
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... The majority of the studied species are classified as "least concern," but there is also a significant proportion of species in both habitat categories classified as "data deficient," which have started to be researched in Ecuador. These results reflect the efforts of Ecuadorian scientists to fill the information gap on data-poor species, helping to better understand their status and guide appropriate conservation efforts (Aguirre et al., 2021). However, the "endangered" ...
Bony fishes play a pivotal role in Ecuador's social, economic, and ecological aspects. However, the current state of scientific knowledge on this group remains poorly understood. This study aims to assess the scientific output related to Ecuadorian bony fishes, identifying both well‐researched and understudied areas. A scientometric analysis was conducted using the Scopus database, evaluating 265 peer‐reviewed publications on marine and freshwater bony fishes. The results revealed that 55.5% of studies focused on marine environments, 41.9% on freshwater ecosystems, and 2.6% on mixed environments. The earliest study was published more than 130 years ago, with a marked increase in research output since 2018. Geographic and regional disparities in research efforts were evident, with the Galapagos Islands hosting the highest number of studies at the provincial level and the coastal region leading in regional publications. Additionally, there has been a notable increase in the participation of women in research over time; however, it remains significantly below parity. English was the dominant language in these publications. On average, the delay between data collection and publication was 8.43 years, which may lead to outdated or ineffective management decisions. This underscores the importance of continually updating data to ensure the accuracy of conservation status assessments. Both marine and freshwater species that were endemic have been less studied compared to non‐endemic species. Most of the studied species were categorized as “least concern,” although a significant proportion of species classified as “data deficient” have started to be investigated by Ecuadorian researchers. The categories “endangered” and “near threatened” were the least studied, highlighting the urgent need for conservation initiatives targeting these vulnerable taxa. Biases in the number of studies among families, species, and geographic distribution indicate the need to expand research efforts to underrepresented taxa and regions. This analysis underscores the necessity of diversifying methodologies and broadening the research focus to more comprehensively address the challenges associated with the conservation and management of bony fishes in Ecuador.
... The Santiago and Morona Rivers are located within the maximum precipitation region, where rainfall-based erosivity is also significant (see Figure S3 in Supporting Information S1). The Santiago River is formed in Ecuador by the confluence of the Zamora and Upano Rivers, in a biodiversity hotspot known as the Kutukú-Condor corridor (Aguirre et al., 2021). Along the Peruvian region, the Santiago River runs in a valley confined by the Campanquiz and Huaracayo cordilleras that form the Santiago-Nieva depression which is covered by Tertiary-aged sediments (Parsep, 2001) (see Figure 1b, where sedimentary records from the Jurassic, Cretaceous and Tertiary (Eocene-Pliocene) periods are depicted, Baby et al. (2019) and Gil and Flinch (2022)). ...
The transition from the Andes to the Amazon lowland hosts a high biodiversity and currently is facing several anthropogenic activities, including hydropower infrastructure projects. Little is known about the geomorphology of the Andean gorges, rivers and the interaction with the fish diversity upstream and downstream of gorges. The Marañón River is a major river that connects the Andes to the Amazon lowland and it carries 40% of the sediment load arriving to Brazil. The Santiago River is the last tributary into the Marañón River before the last gorge (Manseriche). Current plans for hydropower reservoirs include the construction of several dams along the Marañón River, being the largest with a 4,500 MW capacity at the Manseriche Gorge (MG). This study seeks to characterize the baseline processes of the hydrogeomorphology and fish diversity. Results show that the Santiago River is under transitional morphodynamic regime while the Marañón River is a fully developed anabranching river. This study reveals a clear difference in fish species richness and abundance between the upstream and downstream regions of the MG, with some species only found in specific regions. The MG acts as a natural boundary condition for the hydrogeomorphology and fish diversity. If the hydropower dam at MG was built, the reservoir in the upstream reach will produce the Santiago River to disappear and sedimentation to occur, consequently modifying sediment transport boundary conditions for the lower Marañón River. Downstream of the potential dam incision will occur, reducing lateral connectivity, particularly at sites where unique species were found.
... It varies according to the farming system, whether extensive or intensive. Aquaculture water management is vital for organisms' health and environmental sustainability [5,6]. The monitoring and controlling water quality considers physical, chemical and biological parameters [7]. ...
... Construction period The parameter is the start and end time of the work, established by the schedule. 5 Construction area Location of the construction site. 6 Ease of maintenance The time it takes to put the site back into operation after maintenance. ...
... Fishes: Ecuador has 836 species including 92 (11%) endemics (Barriga 2012). 35% of fresh water fish species are considered threatened in Ecuador; 21 experts collaborated in this work (Aguirre et al. 2021). The IUCN Red List considers only 5% as threatened. ...
Up-to-date and globally available information about the conservation status of biodiversity is of paramount importance, given the accelerating global biodiversity loss. Governments rely on this information for policies on conservation and sustainable use of biodiversity. Ecuador, a neotropical biodiversity hotspot, harbors a significant number of endemic plant, animal, and fungal species and several of these groups have been evaluated in Ecuadorian non-IUCN Red Lists. The IUCN Red List of Threatened Species (IUCN 2024)—which is necessarily incomplete—could be improved with these works. See below for discussions and references for each group. (See also Suppl. material 1 for collaborating institutions and their acronyms)
Plants : Ecuador has ca. 18,800 vascular plant species (Ulloa et al. 2018). Ecuador’s Red List of Plant Endemics (Leon-Yanez et al. 2011) was an effort led by Catholic University's herbarium with the participation of 80 experts from national and international institutions. The work revealed 78% of the 4,500 endemic plant species as threatened, but the IUCN Red List indicates 73% as such.
Fungi : There is no known catalog of native Ecuadorian fungal taxa. Laessoe and Petersen (2008) estimate 100,000 fungi species for Ecuador. Several Ecuadorian species are included in The Global Fungal Red List Initiative (Mueller et al. 2024) and only three are included in the IUCN Red List.
Insects : No catalog of native Ecuadorian insects, nor their conservation status are available. An updated list of Ecuadorian type specimens (Salazar et al. 2023) lists the number of species of the four most diverse insects groups for Ecuador: Coleoptera (6,370), Lepidoptera (6,278), Diptera (2,895), and Hymenoptera (2,467).
Fishes : Ecuador has 836 species including 92 (11%) endemics (Barriga 2012). 35% of fresh water fish species are considered threatened in Ecuador; 21 experts collaborated in this work (Aguirre et al. 2021). The IUCN Red List considers only 5% as threatened.
Amphibia : A recent Ecuadorian Red List assessment found 635 species of native amphibians in Ecuador, 53% of which are categorized as threatened; 33 experts collaborated with the assessments (Ortega et al. 2021). 43% of Ecuadorian taxa are threatened according to the IUCN Red List.
Reptiles : Ecuador has 401 reptile species, 27% of them are threatened; 15 collaborators participated in the report (Carrillo et al. 2005). In the IUCN Red List, 26% are threatened.
Birds : There are 1,582 native species in Ecuador with 39 (2.5 %) endemic (Remsen et al. 2024). The last Ecuadorian non-IUCN Red List, prepared by 77 collaborators from three institutions (Freile et al. 2019) revealed 10% of the taxa as threatened. The IUCN Red List indicates only 5% as threatened.
Mammals : There are 471 native species, including 62 (13%) endemics (Tirira et al. 2024). The latest Ecuadorian non IUCN-Red List assessment, evaluated by 124 collaborators from at least three museums, mentions that 29% are threatened (Tirira 2021). The IUCN Red List indicates only 12% as such.
There is an urgent need to create an efficient workflow for conservation assessments made by local taxonomists, including training in the IUCN Red List process (IUCN 2016). With these actions, large disparities, as those observed in fishes, amphibians and mammals, could be fixed.
... The region features distinct white-water (e.g., Napo, Putumayo) and sub-Andean or Piedmont (e.g., Tiputini, Curaray) rivers with high suspended sediments and nutrient concentrations, fostering high fish diversity and productivity (Freitas et al., 2010). In contrast, lowland black-water rivers (e.g., Cuyabeno, Yasuní), while less productive, maintain equivalent fish species richness with a lighter sediment load and higher acidity (Aguirre et al., 2021). ...
... This concern may intensify within floodplain lakes and pools, losing connectivity to main channels since heavy metal concentrations in fish tend to decrease during the flooded period. Additionally, several of these water bodies are key to the artisanal fisheries of the Amazon, facing threats from overfishing, urban development, and dams (Aguirre et al., 2021). Consequently, decreased connectivity between the Napo and its main tributaries and floodplains could result in a cascade of effects, including flooded forest degradation, fish diversity loss, and reduced food security for the Western Amazonian population. ...
The Amazon River Basin's fish diversity is shaped by its dynamic flood-pulse system, critical for hydrological and ecological connectivity. This study examines the Napo Moist Forest (NMF) ecoregion, mapping permanent and seasonally flooded areas from 2018 to 2021 using remote sensing and deep learning models. We aimed to map these areas at a high spatial resolution (10-m pixels) and analyse their role in maintaining lateral connectivity essential for fish diversity. Using synthetic aperture radar data from Sentinel-1 combined with deep learning algorithms, we produced high-accuracy flood maps to assess landscape connectivity between rivers and floodplains. Our methodology included creating a ground truth dataset with the Normalized Difference Water Index and integrating high-resolution optical data for model training, overcoming challenges of cloud coverage and dense vegetation. Our predictive model achieved high accuracy (mean pixel accuracy = 97 %) and consistently predicted 4801 km² of surface water, with only 3 % (130 km²) being seasonally flooded areas over four years. The Caquetá, Bajo Marañón, Napo, and Pastaza watersheds accounted for nearly 60 % of the flooded areas, highlighting their ecological importance. Connectivity analysis in three areas of interest within the NMF ecoregion revealed important seasonal and interannual fluctuations in hydrological connectivity due to changes in flooded patch characteristics. Reductions in the number and flooded patch area during low water seasons increased the distance between patches, leading to a disconnection between flooded areas, channels and rivers. Despite hydrological fluctuations, certain patches maintained consistent flooding, critical for lateral connectivity and sustaining aquatic biodiversity. These seasonally flooded areas act as connectors, influencing patch dynamics and connectivity with tributaries. Seasonal and interannual variations in hydrological connectivity are crucial for sustaining fish diversity. Conserving dynamic floodplains supports migratory fish life cycles and biodiversity. This study underscores the importance of high-resolution temporal and spatial data in conservation planning for aquatic ecosystems.
... This is causing the fragmentation of ecosystems, which directly affects the distribution of plants and the change in climatic conditions (Bruijnzeel et al., 2010(Bruijnzeel et al., , 2011. Although cloud forests continue to be an area of great biodiversity (Kessler, 2022), their area is designated as a hot spot (Aguirre et al., 2021). Podocarpus sp. is one of the indicators or pioneer species for natural capital restoration and biodiversity conservation programs in the study area (Villamarín et al., 2009;Gardner, 2013;Bremer et al., 2019). ...
Several samples of fossilized wood (charcoal) were collected in the Papayita archaeological site, in coastal Ecuador. This carbonized material was encountered inside a layer of volcanic ash that sealed the site. The ash-sized tephra was produced by a sub-Plinian eruption from the Guagua Pichincha volcano contempora-neous with the late Valdivia phases during the Formative Period. Each of the samples was sectioned into 10 to 15 subsamples and examined under a Scanning Electron Microscope (SEM), producing high-resolution images with a large depth of field where the anatomical structures and their geochemical composition were vividly discernible. Each sample corresponds to organic matter of vegetable origin, that is, carbonized wood in the form of small rocks, whose appearance is that of carbonized woody tree trunks and or branches. We were able to observe vascular structures, specifically bundles of xylem. It was possible to conclude that these tracheids underwent a physicochemical transformation typical of petrification processes, leaving the molds intact. This allowed us to determine structural elements that support the identification of the group of plants to which these samples belong, through the methodology of comparison of the anatomical components of current species. The fossilized wood structures are three-dimensional and present characteristics that correspond to the group of higher plants, Gymnosperms, of the Podocarpaceae group. Among them, quadrangular tracheids, circular hole-shaped pits in the vascular system, and absent resin canals stand out. Central to the analysis is the presence of transverse parenchyma, which can be ascertained to correspond to vegetation from climates that are temperate or cold.
... All captured species occur in the Ecuadorian Amazon (Barriga 2012), where at least 36 species are known to be exploited for commercial fisheries (Burgos 2019). In addition, the most abundant families captured in our sampling (i.e., Characidae, Loricariidae, Pimelodidae) are also families with high species diversity in the Amazonian slope of Ecuador (Aguirre et al. 2021). Based on our observations during field trips and previous experiences in other localities, indigenous communities would eat any fish species regardless of size or flavor. ...
Mercury is a highly toxic element present in water, soil, air, and biota. Anthropogenic activities, such as burning fossil fuels, mining, and deforestation, contribute to the presence and mobilization of mercury between environmental compartments. Although current research on mercury pathways has advanced our understanding of the risks associated with human exposure, limited information exists for remote areas with high diversity of fauna, flora, and indigenous communities. This study aims to deepen our understanding of the presence of total mercury in water, sediments, and fish, within aquatic ecosystems of two indigenous territories: Gomataon (Waorani Nationality) and Sinangoé (Ai´Cofán Nationality) in the Ecuadorian Amazon. Our findings indicate that, for most fish (91.5%), sediment (100%) and water (95.3%) samples, mercury levels fall under international limits. For fish, no significant differences in mercury levels were detected between the two communities. However, eight species exceeded recommended global limits, and one surpassed the threshold according to Ecuadorian legislation. Piscivore and omnivore fish exhibited the highest concentrations of total mercury among trophic guilds. Only one water sample from each community’s territory exceeded these limits. Total mercury in sediments exhibited greater concentrations in Gomataon than Sinangoé. Greater levels of mercury in sediments were associated with the occurrence of total organic carbon. Considering that members of the communities consume the analyzed fish, an interdisciplinary approach, including isotopic analysis, methylmercury sampling in humans, and mercury monitoring over time, is imperative for a detailed risk assessment of mercury exposure in Amazonian communities.
... The ichthyofauna of Western Ecuador is characterized by its isolation, high levels of endemism and relatively low richness when compared to the Ecuadorian Amazon (113 spp Western Slope vs 744 spp Napo basin alone) [13,14]. Approximately 38% of freshwater fishes of the Ecuadorian CGE are endemic [15]. Fish studies in the CGE have characterized its diversity patterns, richness, adaptations and ecology [8,[16][17][18][19]. ...
... A total of 26 freshwater fish species, 23 genera, 17 families from 7 orders were collected and analyzed in this study from 20 sampling sites along the Cube basin (Fig 2 and S2 and S7 Tables in S1 File). Three species are introduced while the remaining 23 constitute 20% of the fish reported for Western Ecuador [15] and 42.8% are endemic. Four species are amphidromous (Awaous transandeanus, Sicydium salvini, Gobiomorus maculatus and Agonostomus monticola) and records of three native species were unique to one sampling site (Synbranchus marmoratus and Pseudocurimata boehlkei, Astroblepus cyclopus; sites 10, 13 and 10 respectively (S1 Table in S1 File)). ...
... Our study aligns itself in barcoding efforts by improving our understanding of Ecuadorian species. Many CGE species are endemic and endangered [15], and some were sequenced for the first time, contributing to the current and future knowledge and conservation value of freshwater fishes in Ecuador. Although COI is the most used gene in barcoding for freshwater fish, we also used 16S rRNA as a complementary gene marker in case COI-sequences of analyzed species were absent in GenBank or if species were not successfully barcoded with COI marker. ...
DNA barcoding, based on mitochondrial markers, is widely applied in species identification and biodiversity studies. The aim of this study was to establish a barcoding reference database of fishes inhabiting the Cube River from Western Ecuador in the Chocó-Darien Global Ecoregion (CGE), a threatened ecoregion with high diversity and endemism, and evaluate the applicability of using barcoding for the identification of fish species. Barcode sequences were obtained from seven orders, 17 families, 23 genera and 26 species, which were validated through phylogenetic analysis, morphological measurements, and literature review. Our results showed that 43% of fish species in this region are endemic, confirmed the presence of known species in the area, and included the addition of three new records of native (Hoplias microlepis, Rhamdia guatemalensis and Sicydium salvini) and an introduced species (Xiphophorus maculatus) to Ecuador. In addition, eight species were barcoded for the first time. Species identification based on barcoding and morphology showed discrepancy with species lists from previous studies in the CGE, suggesting that the current baseline of western fishes of Ecuador is still incomplete. Because this study analyzed fishes from a relatively small basin (165 km²), more molecular-based studies focusing on fish are needed to achieve a robust sequence reference library of species inhabiting Western Ecuador. The new sequences of this study will be useful for future comparisons and biodiversity monitoring, supporting the application of barcoding tools for studying fish diversity in genetically unexplored regions and to develop well-informed conservation programs.
... The government was sponsoring in 2018-19 a series of workshops to examine the conservation status of Ecuador's freshwater fish. Concerns were identified for 35 species, most of which are native to the Amazon region, and overfishing of Amazonian pimelodid catfishes emerged as a major issue [89]. Besides overfishing other important reasons affecting freshwater fishes in Ecuador are the physical alteration of rivers, deforestation, wetland and floodplain degradation, agricultural and urban water pollution, mining, oil extraction, dams, introduced species and climate change [89]. ...
... Concerns were identified for 35 species, most of which are native to the Amazon region, and overfishing of Amazonian pimelodid catfishes emerged as a major issue [89]. Besides overfishing other important reasons affecting freshwater fishes in Ecuador are the physical alteration of rivers, deforestation, wetland and floodplain degradation, agricultural and urban water pollution, mining, oil extraction, dams, introduced species and climate change [89]. ...
This is a review of the importance of inland water fisheries and fish farming as a food source in the Amazon basin. Small-scale fisheries resources have been depleted and climate change poses a growing threat, failure to address the issues confronting the sector places the food safety and livelihoods of millions of people at risk. The governments should form partnerships with the communities for them to assist in managing the resources. The fishers would gain in this co-management but also have to assume responsibility for their decisions and actions. Co-management is always far better than no-management. From the landings, trade, and consumption of fish, it has been estimated that the total fish catch in the Amazon basin is above half a million tonnes/year in live weight. However, this figure is very rough given that 75 per cent of represented landings come from Brazil with no updated official statistics after 2010 on commercial landings. Aquaculture offers the largest potential to increase fish supplies in the long term but the rapid growth is unevenly distributed among countries. Three major aquaculture producers are Ecuador, Brazil and Colombia but Amazon basin aquaculture has some importance also in Peru. Aquaculture development in the region is facing many challenges including to combat against diseases and epizootics, the need for better hatchery and grow-out technology, brood stock improvement, appropriate and most economic feed production and water-quality management. This paper pays also attention to the unwanted spread of alien fish species often as escapees from aquaculture. Annual per capita fish consumption in kg/capita in the Amazon basin countries varies between 2.6-25.3 kg/year, the three leading countries being Guyana, Peru and Suriname. The consumption is fairly low compared to the European Union and the global averages which are around 27 and 22 kg/capita/year, respectively. However, in all Amazonian countries, 50 up to almost 100 per cent of artisanal freshwater fishing takes place for personal consumption, implying that it may not be fully recorded in official consumption statistics. Ornamental fish culture and trade have had an important role in the Amazon basin countries, the three biggest producers and exporters of aquarium fish being Brazil, Colombia and Peru. In 2008 economic crisis hit Brazil and started the decline of the ornamental fish trade. One reason for the decrease in the trade was the competition with neighbouring Colombia and Peru with less bureaucratic systems and fewer restrictions on which species can be exported. International pressure to stop the commerce of wild-caught fish intensified and the increase of husbandry practices and reproduction in Southeast Asia caused the downturn of the Brazilian Amazonian market. Thousands of families lost their livelihoods and many fishermen were forced to start working in sport fishing and commercial fisheries. Sport fishing is a hobby for those to whom money or fish food is not the main object but more important is to get a good photo together with a big fish. Sport fishers are all practising the catch and release system so fish is not away from nature and the activity is an important income source in tourism and benefits the local fishers often in remote rural areas. Free-time fishing may not be so significant for the national economy but it has high value in social and recreational terms for many people from all walks of life. Citation: Mikkola H (2024) Aquaculture and Fisheries as a Food Source in the Amazon Region-A Review. Food Nutr J 9: 286.
... So these fish are often exploited by local communities to catch them because of the high selling price, the female lempuk fish that are laying eggs are more expensive and are currently threatened with a population decline due to continuous fishing activities, which could have an impact on population decline and even threaten its sustainability. Several factors that can pose a threat to fish diversity and cause extinction include overfishing, species introduction, pollution, habitat changes and even disappearance [Aguirre et al., 2021]. The first step that can prevent this from happening is by carrying out environmental and biological characterization efforts related to conservation and domestication efforts in the next step. ...
