Arlinghaus, Robert
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Item-typ:Veröffentlichung, Lake depth alters the trajectory of ontogenetic niche shifts in Eurasian perch (Perca fluviatilis) in small lakesThe trophic niche of aquatic generalist predators is influenced by ontogeny, habitat characteristics, availability and type of prey, and competitive interactions. Many interrelated lake characteristics influence the availability of prey and may thereby impact foraging niches and the trajectory of ontogenetic niche shifts. Our work uses Eurasian perch (Perca fluviatilis) as a model species to examine the correlation of multiple lake and fish community characteristics with the size-dependency of perch populations' realised trophic niche. We used carbon and nitrogen stable isotopes to correlate the changes in perch trophic position across a gradient of total lengths in seven gravel pit lakes that differed in lake morphology, habitat heterogeneity, productivity, structural complexity, and fish community composition. Perch populations in lakes with more shallow-water habitat reached a higher trophic position at smaller sizes than perch in deeper lakes. However, the changes in trophic position with increasing size were less pronounced compared to perch from deeper lakes. Large individuals from the latter perch populations ultimately achieved higher mean trophic positions compared to fish from shallow lakes. Perch in lakes with more shallow-water habitat may, therefore, achieve lower rates of piscivory because of higher relative availability of macroinvertebrates or greater competition with zooplanktivores. Our results suggest that large, piscivorous perch are more likely to develop in deeper lakes, and that these changes in perch trophic position across ontogeny are more strongly related to the depth of lakes than to the type of structured habitat in the littoral zone.Wissenschaftlicher ArtikelHeft:3364 - Some of the metrics are blocked by yourconsent settings
Item-typ:Veröffentlichung, 107 - Some of the metrics are blocked by yourconsent settings
Item-typ:Veröffentlichung, The battle between harvest and natural selection creates small and shy fish(NAS, 2021-03-02); ; ; ; Harvest of fish and wildlife, both commercial and recreational, is a selective force that can induce evolutionary changes to life history and behavior. Naturally selective forces may create countering selection pressures. Assessing natural fitness represents a considerable challenge in broadcast spawners. Thus, our understanding about the relative strength of natural and fisheries selection is slim. In the field, we compared the strength and shape of harvest selection to natural selection on body size over four years and behavior over one year in a natural population of a freshwater top predator, the northern pike (Esox lucius). Natural selection was approximated by relative reproductive success via parent-offspring genetic assignments over four years. Harvest selection was measured by comparing individuals susceptible to recreational angling with individuals never captured by this gear type. Individual behavior was measured by high-resolution acoustic telemetry. Harvest and natural size selection operated with equal strength but opposing directions, and harvest size selection was consistently negative in all study years. Harvest selection also had a substantial behavioral component independent of body length, while natural behavioral selection was not documented, suggesting the potential for directional harvest selection favoring inactive, timid fish. Simulations of the outcomes of different fishing regulations showed that traditional minimum size-based harvest limits are unlikely to counteract harvest selection without being completely restrictive. Our study suggests harvest selection may be inevitable and recreational fisheries may thus favor small, inactive, shy, and difficult-to-capture fish. Increasing fractions of shy fish in angling-exploited stocks would have consequences for stock assessment and all fisheries operating with hook and line.Wissenschaftlicher ArtikelBand:118Heft:967 - Some of the metrics are blocked by yourconsent settings
Item-typ:Veröffentlichung, Impact of water-based recreation on aquatic and riparian biodiversity of small lakesWissenschaftlicher ArtikelBand:7825 - Some of the metrics are blocked by yourconsent settings
Item-typ:Veröffentlichung, Influence of protected riparian areas on habitat structure and biodiversity in and at small lakes managed by recreational fisheriesProtected areas are a common management tool to conserve habitats and species by controlling access and disturbances by humans. Whenever protected areas result in restricting access to riparian zones in lakes, they may have positive effects on habitats and taxa beyond fish by lowering influences of trampling or boating on plants, by reducing the degree of human-induced disturbances to sensitive taxa such as birds, and by reducing fishing effort. However, especially in small freshwater systems knowledge about the functioning of protected areas that cover only parts of the lake shorelines is limited. We studied small gravel pit lakes in Germany where recreational fishing clubs have voluntarily assigned no-access riparian protected areas on parts of the lake shorelines and examined outcomes for habitat quality, plants, fish and bird populations. A total of 15 lakes were sampled, and we assessed habitat structure and abundance of plants, and fish within and outside protected areas and bird abundance at the lake scale, relying on standardized sampling methods. After controlling for confounding environmental factors related to lake morphology, age, nutrients, and land use, we detected positive contributions of small-scale riparian protected areas on habitat structure, riparian vegetation, local fish abundance and abundance of sensitive songbirds at the lake-scale, but we found no effects on aquatic vegetation and on disturbance-sensitive waterfowl species. Scale-restricted riparian protected areas voluntarily assigned by recreational fishing clubs can have positive outcomes for habitat quality and biodiversity, particularly by reducing trampling and access to anglers and other recreationists. Moreover, through provision of key habitat for young fish, small-scale riparian protected areas can also benefit fish abundance and in turn recreational fisheries.Wissenschaftlicher ArtikelHeft:25679 - Some of the metrics are blocked by yourconsent settings
Item-typ:Veröffentlichung, Status of aquatic and riparian biodiversity in artificial lake ecosystems with and without management for recreational fisheries: Implications for conservation(1052-7613, 2020); ; ; ; 1. Humanity is facing a biodiversity crisis, with freshwater-associated biodiversity in a particularly dire state. Novel ecosystems created through human use of mineral resources, such as gravel pit lakes, can provide substitute habitats for the conservation of freshwater and riparian biodiversity. Many of these artificial ecosystems are subject to a high intensity of recreational use, however, which may limit their biodiversity potential. 2. The species richness of several taxa (plants, amphibians, dragonflies, damselflies, waterfowl, and songbirds) was assessed and a range of taxonomic biodiversity metrics were compared between gravel pit lakes managed for recreational fisheries (n = 16) and unmanaged reference lakes (n = 10), controlling for non-fishing-related environmental variation. 3. The average species richness of all the taxa examined was similar among lakes in both lake types and no substantial differences in species composition were found when examining the pooled species inventory. Similarly, there were no differences between lake types in the presence of rare species and in the Simpson diversity index across all of the taxa assessed. 4. Variation in species richness among lakes was correlated with woody habitat, lake morphology (surface area and steepness), and land use, but was not correlated with the presence of recreational fisheries. Thus, non-fishing-related environmental variables had stronger effects on local species presence than recreational fisheries management or the presence of recreational anglers. 5. Collectively, no evidence was found that anglers and recreational fisheries management constrain the development of aquatic and riparian biodiversity in gravel pit lakes in the study region; however, the conservation of species diversity in gravel pit lakes could benefit from an increasing reliance on habitat enhancement activities.Wissenschaftlicher ArtikelBand:31Heft:191 - Some of the metrics are blocked by yourconsent settings
Item-typ:Veröffentlichung, Positioning aquatic animals with acoustic transmitters1. Geolocating aquatic animals with acoustic tags has been ongoing for decades, relying on the detection of acoustic signals at multiple receivers with known positions to calculate a 2D or 3D position, and ultimately recreate the path of an aquatic animal from detections at fixed stations. 2. This method of underwater geolocation is evolving with new software and hardware options available to help investigators design studies and calculate positions using solvers based predominantly on time-difference-of-arrival and time-of-arrival. 3. We provide an overview of the considerations necessary to implement positioning in aquatic acoustic telemetry studies, including how to design arrays of receivers, test performance, synchronize receiver clocks and calculate positions from the detection data. We additionally present some common positioning algorithms, including both the free open-source solvers and the ‘black-box’ methods provided by some manufacturers for calculating positions. 4. This paper is the first to provide a comprehensive overview of methods and considerations for designing and implementing better positioning studies that will support users, and encourage further knowledge advances in aquatic systems.Wissenschaftlicher ArtikelBand:14Heft:10133 - Some of the metrics are blocked by yourconsent settings
Item-typ:Veröffentlichung, Aufwertung von Uferstrukturen an Baggerseen(Alfred Toepfer Akademie für Naturschutz, 2023); ; ; ; Wissenschaftlicher ArtikelBand:32/33/34Heft:169 - Some of the metrics are blocked by yourconsent settings
Item-typ:Veröffentlichung, Do anglers and managers think similarly about stocking, habitat management and harvest regulations? Implications for the management of community-governed recreational fisheriesPerceptions about suitable fisheries management directions can differ between anglers and fisheries managers. Opposing beliefs, attitudes and norms about how to manage a local fishery can in turn create conflict. Within a system of community-held local fishing rights, typical for central Europe, the interaction of anglers and local-level fisheries managers is particularly strong and direct because the managers are typically elected members of the local angling communities that are organized in clubs. In this role local fisheries managers are responsible for decisions about management measures, such as stocking or harvest regulations. Our objectives were to assess the perceived objectives, beliefs and attitudes towards a range of management-relevant issues, while contrasting anglers and elected fisheries managers in the context of German fishing clubs. Based on three large mail surveys conducted between 2010 and 2018 and including a total of 3112 anglers and 314 elected fisheries managers from the Federal State of Lower Saxony (north-western Germany) we found that anglers and fisheries managers both supported conservation objectives and held strong pro-stocking beliefs, which was particularly pronounced among anglers. Both groups significantly differed in their pro-ecological beliefs and the perceived functionality of habitat management and harvest regulations relative to fish stocking. Fisheries managers considered habitat enhancement and harvest regulations to deliver greater benefits than stocking compared to anglers. Both groups also differed in their behavioural intention to alter stocking practices, particularly with respect to the stocking of large and adult fish, which was desired by anglers, but on average rejected by fisheries managers in favour of the release of smaller fish. Our work shows that even within the traditional practice of fish stocking, anglers and fisheries managers differ in their perceptions. Engaging in decisions that deviate from the perception of anglers is prone to create conflicts. Harmonization of perspectives maybe possible through joint experiments in fisheries management at the club level, aiming to collectively learn about successes and risks of traditional and novel management approaches.Wissenschaftlicher ArtikelHeft:26061 - Some of the metrics are blocked by yourconsent settings
Item-typ:Veröffentlichung, Biodiversität, Angeln und Gesellschaft(Leibniz-Institut für Gewässerökologie und Binnenfischerei (IGB), 2023); ; ; ; BuchBand:3266