Daniel Nyqvist

Daniel Nyqvist
Politecnico di Torino | polito · DIATI - Department of Environment, Land and Infrastructure Engineering

PhD

About

23
Publications
7,118
Reads
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275
Citations
Introduction
My current research focus is on fish behavior in regulated rivers. I'm also interested in movement ecology, fish behavior in relation to anthropogenic noise and electromagnetism, and the connections between ecology and people.

Publications

Publications (23)
Article
Repeat salmonid spawners may make large contributions to total recruitment and long term population stability. Despite their potential importance, relatively little is known about this phase of the life history for anadromous populations, and nothing has been reported for landlocked populations. Here, we studied post-spawning behaviour and survival...
Article
Passage of fish through hydropower dams is associated with mortality, delay, increased energy expenditure and migratory failure for migrating fish and the need for remedial measures for both upstream and downstream migration is widely recognised. A functional fish passage must ensure safe and timely passage routes that a substantial portion of migr...
Article
The purpose of this study was to investigate behavior and survival of radio-tagged wild- and hatchery-reared landlocked Atlantic salmon smolts as they migrated past three hydropower dams equipped with fish bypass solutions in the Winooski River, Vermont, USA. Among hatchery-released smolts, those released early were more likely to initiate migratio...
Article
Full-text available
Interspecific competition among terrestrial gastropods has previously been considered to have little effect on population dynamics and local distribution. Recent studies, however, demonstrate several cases in which interspecific competition plays a major role in structuring terrestrial gastropod communities. To explore the general importance of int...
Article
Full-text available
The loss of longitudinal connectivity in regulated rivers, both up- and downstream, has been detrimental for biodiversity worldwide. While progress has been made regarding upstream fish passage solutions, many questions remain unanswered regarding downstream passage alternatives. To address these knowledge gaps, we used Atlantic salmon (S. salar) s...
Article
The European eel population is critically endangered due to a multitude of human-induced factors such as habitat fragmentation, parasites, fishing, and climate change. In freshwater, downstream migrating silver eels encountering hydroelectric plants often suffer substantial delays and increased mortality from trash-rack impingement and turbine-indu...
Article
Full-text available
Anguillid eels grow in freshwater but spawn in the open ocean. The cues that guide eels over long distances to the spawning area are unknown. The Earth's magnetic field can provide directional and positional information and is likely used by catadromous eels during their spawning migration; as magnetosensitivity and compass orientation have been re...
Article
Full-text available
To predict the effects of habitat alterations on animal populations we need insight into how the habitat configuration influences local scale movements. This relationship may be particularly important for effective management of pest species. We tracked 80 PIT-tagged Spanish slugs (Arion vulgaris) in 16 × 16 m arenas with manipulated habitat fragme...
Article
Full-text available
Arionid slugs can be serious pests on horticultural and agricultural crops. Using slug movement barriers is a potentially effective method to control slug damage. We evaluated the performance of waterglass (sodium silicate) and copper foil as barriers against Arion vulgaris movement both in a controlled experiment and in a semi-field validation und...
Article
Full-text available
Where migrating fish have to pass multiple dams, very high passage performance is required at the series of obstacles to avoid accumulated negative effects of multiple dam passage. In some rivers, migrating fish are trapped, transported past several obstacles, and released to continue their migration. Such trap-and-transport solutions, however, hav...
Article
• Habitat structural complexity affects the behaviour and physiology of individuals, and responses to the environment can be immediate or influence performance later in life through delayed effects. • Here, we investigated how structural enrichment, both pre‐release in the hatchery rearing environment and post‐release in the wild, influenced winter...
Article
Hydropower dams disrupt longitudinal connectivity and cause fragmentation of river systems, which has led to declines in migratory fish species. Atlantic salmon smolts rely on intact longitudinal connectivity to move downstream from rearing habitats in freshwater to feeding grounds at sea. Smolts often suffer increased mortality and delays when the...
Article
Studying fish behaviour at hydropower dams is needed to facilitate the design and improvement of fish passage solutions, but few studies have focused on Atlantic salmon kelts. Here, we used radio telemetry (n = 40, size range = 50–81 cm) and acoustic sonar to study kelt movements in the forebay as well as their dam passage survival and subsequent m...
Thesis
Hydropower dams block migration routes and disrupt longitudinal connectivity in rivers, thereby posing a threat to migratory fish species. Various fish passage solutions have been implemented to improve connectivity, but with varying success. A well-functioning passage solution must ensure safe and timely passage for a substantial portion of the mi...
Article
Predicting growth is critical in aquaculture, but models of growth are largely missing for mud crab species. Here, we present the first model of natural growth in juvenile and adult mud crabs Scylla serrata from East Africa using a stepwise growth function based on data on intermoult periods and growth at moult from field mark-recapture, pond and l...
Article
Full-text available
Surface ice in rivers and lakes buffers the thermal environment and provides overhead cover, protecting aquatic animals from terrestrial predators. We tested if surface ice influenced the behavior (swimming activity, aggressive encounters, and number of food items eaten) and stress level (coloration of eyes and body) of stream-living brown trout Sa...
Technical Report
Full-text available
Forskargruppen Naturresurs Rinnande Vatten på ämnet biologi vid Karlstads universitet medverkar i det Interregfinansierade projektet Vänerlaxens fria gång. Under två år har vi genomfört projekt i Klarälven i syfte att lära oss mer om laxens biologi i Klarälven. För att kunna genomföra en god förvaltning av ett ekosystem måste man ha goda kunskaper...
Thesis
The mud crab (Scylla serrata) is a big portunid crab that lives on soft muddy bottoms, often associated with mangroves, in the Indo-West Pacific. It is fished and cultured across its area of distribution. Small-scale, community-based aquaculture of mud crabs may have the potential to develop into an important alternative income for resource poor co...

Questions

Questions (5)
Question
We would like to film and record fish behavior in relatively small (5m*5m*5m) net pens at day time through variable ocean conditions, likely with multiple synchronized cameras. Any experience of a well-functioning and affordable camera system would be appreciated.
Question
Atlantic salmon has been extirpated from many rivers. It seems reintroduction projects progress relatively slowly in Rivers Elbe and Rhine, and a long-running reintroduction program was recently abandoned in Connecticut River. I’m looking for rivers where Atlantic salmon has been successfully reintroduced.
Question
If a tagged fish is predated by another fish, for how long time is the tag retained in the stomach of the predator? Are there any published studies? Anything on salmon smolts and in-river predation?
Question
Does anyone have experience with fish tags (acustic or radio) that detect predation events? Anything published?
Question
I'm looking for studies that compare behavior and survival of fry released salmon with that of wild fish (and/or with hatchery released smolt/parr), especially during the smolt stage. 

Network

Cited By

Projects

Project (1)
Project
RIBES (River flow regulation, fish BEhaviour and Status) European Training Network (ETN) will train 15 ESRs in the interdisciplinary field of Ecohydraulics to find innovative solutions for freshwater fish protection and river continuity restoration in anthropogenically altered rivers. More information: www.msca-ribes.eu