PT  - JOURNAL ARTICLE
AU  - Robert Nikolaus
AU  - Malwina Schafft
AU  - Andreas Maday
AU  - Christian Wolter
AU  - Robert Arlinghaus
TI  - Impact of recreational fisheries on aquatic and riparian biodiversity in artificial lake ecosystems: implications for conservation
AID  - 10.1101/667493
DP  - 2019 Jan 01
TA  - bioRxiv
PG  - 667493
4099  - http://biorxiv.org/content/early/2019/06/11/667493.short
4100  - http://biorxiv.org/content/early/2019/06/11/667493.full
AB  - There is consensus that humanity is facing a global biodiversity crisis, with freshwater-associated biodiversity being reported to be in particularly dire state. Novel ecosystems created through human use of littoral resources (e.g., sand, gravel), i.e., gravel pit lakes, can provide substitute habitats of importance to conservation of freshwater biodiversity. However, we can expect these lakes, which are often managed for and by recreational fisheries, to also exhibit generally high recreational use intensity, which may negatively impact aquatic biodiversity. Our objective was to evaluate the species inventory and conservation value of a range of aquatic and riparian taxa (plants, amphibians, dragonflies, damselflies, waterfowl, songbirds) within and associated with artificially created lake ecosystems managed by recreational fisheries. To examine the specific impact of recreational fisheries we compared the biodiversity in N = 16 gravel pits managed by recreational fisheries with N = 10 lakes that were not experiencing recreational fisheries, while controlling for a set of environmental variables. Managed and unmanaged gravel pit lakes were similar in regards to morphological and productivity-related lake variables, while differing in littoral and riparian habitat structure and recreational use intensity by anglers and other recreationists. Despite these differences, the average species richness and conservation value of all the examined taxa was similar among both lake types, with the exception of amphibians whose conservation value was found to be larger in unmanaged lakes. With the exception of submerged macrophytes – a taxon found to be particularly species rich and extensively developed in managed lakes – no faunal breaks in any of the taxa were revealed when examining the pooled species inventory of managed and unmanaged lakes. Variation in species richness and conservation value among lakes was strongly driven by available vegetated and woody habitat, lake morphology and location in the landscape, rather than being related to the presence of recreational fisheries or recreational use intensity. Collectively, we found no evidence that anglers and recreational-fisheries management constitute a relevant stressor to aquatic and riparian biodiversity.