Seasonality and aquatic metacommunity assemblage in three abandoned gold mining ponds in the southwestern Amazon, Madre de Dios (Peru)

• Published in: Ecological indicators 2021-06, Vol.125, p.107455, Article 107455
• Main Authors: Araújo-Flores, Julio M., Garate-Quispe, Jorge, García Molinos, Jorge, Pillaca-Ortiz, Jorge M., Caballero-Espejo, Jorge, Ascorra, Cesar, Silman, Miles, Fernandez, Luis E.
• Format: Article
• Language: English
• Subjects: Aquatic metacommunity ecology; ASGM; Community assembly; Flood legacy; Neotropical fishes; Species richness
• ISSN: 1470-160X; 1872-7034
• DOI: 10.1016/j.ecolind.2021.107455

•Artisanal Gold Mining transforms forest into novel wetlands in the Peruvian Amazon.•Abandoned AGM ponds contain high species richness of fish, invertebrate and plankton.•Their community structure is widely regulated by flood pulse activity and seasonality.•These remnant surface ponds are located in a hotspot at the Andean-Amazon rim.•Our results can help conservation policies and management of aquatic resources. Worldwide demand for gold has caused increased extractive activities in the Western Amazon, resulting in a wide-scale transformation of the Madre de Dios river basin (Peru) due to Artisanal and Small-scale Gold Mining (ASGM). These impactful activities profoundly affect the natural landscape and hydroscape as terra firme forest and floodplain habitats are deforested leaving a vast landscape of abandoned ponds that are subsequently colonized from surrounding water bodies. However, the metacommunity dynamics of these emergent networks of connected wetlands and their environmental drivers remain virtually unknown. Here, we present a one-year (May 2017–May 2018) study conducted to assess the composition, abundance and trophic structure of fish assemblages in three abandoned ASGM ponds and their interactions in relation to those of other freshwater groups (macroinvertebrates, phytoplankton and zooplankton). We aimed to determine the influence of environmental parameters on community composition, focused on flood pulse influence (FPI), seasonality, and to identify indicators for predicting aquatic communities’ assemblages. A remarkably abundance and diversity were found totaling 4601 sampled fish from 6 orders, 27 families, 68 genera and 103 species, as well as 87 macoinvertebrate, 71 phytoplankton and 44 zooplankton taxa. The two FPI ponds showed a more stable fish trophic structure throughout the year than the unique non-FPI, probably due to the floods provision of buffer against the lack of resources that occurs during the dry season. Conversely, fish of higher trophic levels were not detected during the dry and transition-to-wet seasons in the non-FPI pond surveyed. Community trajectory analysis showed greater stability of fish assemblages in the non-FPI pond compared to the FPI ponds, which experienced larger disturbance of environmental parameters and biotic inputs during flooding events. Detrended correspondence analysis showed floods as the key factor influencing aquatic communities and species accumulation. However, whereas floods had a large i