Potential of restored gravel pits to provide suitable habitats for Eurasian otters in anthropogenic landscapes

Abstract

In anthropogenic landscapes, which are usually characterized by the existence of highly heterogeneous patchworks of habitats with different conservation status, restored gravel pits have the potential to play a conservation role for semiaquatic species such as Eurasian otters (Lutra lutra). Here, we report an otter habitat suitability analysis on a complex fluvial system in an anthropogenic landscape to understand the role of different artificial water bodies (i.e. irrigation channels and ditches) and natural water bodies (i.e. rivers) related to a restored gravel pit lagoon system as providers of suitable habitats for otters. We implemented seven sampling campaigns during 2016 and 2017 consisting of 19 transects across all existing types of water bodies. We integrated 34 environmental variables with otter habitat use, measured by three spraint marking intensity indicators. We found that otter use of water bodies was not related to the natural or artificial origin of the water. Three key factors influenced habitat suitability: riparian vegetation tree cover, forestland use (either natural or planted) within 100 m from the banks, and the level of human disturbance. Our results suggest that otters' tolerance of human activities might be lower in key areas of their territory compared to areas they pass through or explore. We argue that restored gravel pit lagoon systems can potentially play a role in providing suitable habitats for otters in anthropogenic landscapes.

Habitat selection of Eurasian otters (Lutra lutra) in urban rivers: the effects of urbanization, water quality, and river structure

“…According to our SOM results, areas with higher spraint intensities had higher human populations and lower riparian vegetation; however, these locations displayed a high number of arti cial structures, a wide distribution of gravel pits, and numerous covered areas. Although the importance of riparian vegetation in promoting optimal otter habitats has been emphasized by numerous scholars, heterogeneous habitat compositions in urban rivers may enable exible habitat use for otters, even in low-riparian vegetation areas(Remonti et al 2011;Weinberger et al 2019;Martin-Collado et al 2020). In this context, our results implied that the frequent occurrence of otters in highly urbanized areas could likely be attributed to the suitability of river habitats in these environments.Arti cial structures provide otters with opportunities to inhabit urban rivers.…”

“…In particular, riparian vegetation plays a key role in the selection of resting sites by otters in landscapes that are predominantly in uenced by human activities (Weinberger et al 2019). Additionally, the implementation of alternative habitats aimed at mitigating the adverse effects of frequent river construction, such as habitat destruction and fragmentation, can assist in facilitating the adaptation of otters to urban environments (Pedroso et al 2014;Van Looy et al 2014;Martin-Collado et al 2020). The ndings of this study highlight both the positive habitat potential of otters in landscapes greatly impacted by human activities and the crucial importance of maintaining secure habitats in order to ensure their persistence.…”

Comprehensive evaluation of coal mine pit lake hydrological connectivity in South Kalimantan, Indonesia

“…Another important point was, as in previous studies, the potential for water strati cation and, therefore, the potential for water quality variation along the depth of the pit lake [82]. [90,92,93]. In each catchment area, hydrological connectivity can be analyzed through the linkage between natural and arti cial compartments within the landscape that form a particular river system using Remote Sensing (RS) and Geographic Information System (GIS) [43].…”

Review of global trends in meeting the ecological challenges of the mining industry. Part I: International research

“…The required habitation conditions include water body bank vegetation and afforestation, and no people presence nearby. The mined-out gravel quarries are assumed to be suitable for living of this mammal [19].…”