| 1. |
- Chapman, Ben B, et al.
(författare)
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Patterns of Animal Migration
- 2014
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Ingår i: Animal movement across scales. - : Oxford University Press. - 9780199677184 ; , s. 11-35
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Bokkapitel (refereegranskat)
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| 2. |
- Mattsson, Karin, et al.
(författare)
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Brain damage and behavioural disorders in fish induced by plastic nanoparticles delivered through the food chain
- 2017
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- The tremendous increases in production of plastic materials has led to an accumulation of plastic pollution worldwide. Many studies have addressed the physical effects of large-sized plastics on organisms, whereas few have focused on plastic nanoparticles, despite their distinct chemical, physical and mechanical properties. Hence our understanding of their effects on ecosystem function, behaviour and metabolism of organisms remains elusive. Here we demonstrate that plastic nanoparticles reduce survival of aquatic zooplankton and penetrate the blood-to-brain barrier in fish and cause behavioural disorders. Hence, for the first time, we uncover direct interactions between plastic nanoparticles and brain tissue, which is the likely mechanism behind the observed behavioural disorders in the top consumer. In a broader perspective, our findings demonstrate that plastic nanoparticles are transferred up through a food chain, enter the brain of the top consumer and affect its behaviour, thereby severely disrupting the function of natural ecosystems.
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| 3. |
- Lard, Mercy, et al.
(författare)
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Tracking the small with the smallest--using nanotechnology in tracking zooplankton.
- 2010
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 5:10
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Tidskriftsartikel (refereegranskat)abstract
- A major problem when studying behavior and migration of small organisms is that many of the questions addressed for larger animals are not possible to formulate due to constraints on tracking smaller animals. In aquatic ecosystems, this problem is particularly problematic for zoo- and phytoplankton, since tracking devices are too heavy to allow the organism to act naturally. However, recent advances in nanotechnology have made it possible to track individual animals and thereby to focus on important and urgent questions which previously have not been possible to address. Here we report on a novel approach to track movement and migratory behavior of millimeter sized aquatic animals, particularly Daphnia magna, using the commercially available nanometer sized fluorescent probes known as quantum dots. Experimental trials with and without quantum dots showed that they did not affect behavior, reproduction or mortality of the tested animals. Compared to previously used methods to label small animals, the nano-labeling method presented here offers considerable improvements including: 24 h fluorescence, studies in both light and darkness, much improved optical properties, potential to study large volumes and even track animals in semi-natural conditions. Hence, the suggested method, developed in close cooperation between biologists, chemists and physicists, offers new opportunities to routinely study zooplankton responses to light, food and predation, opening up advancements within research areas such as diel vertical/horizontal migration, partial migration and other differences in intra- and interspecific movements and migration.
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| 4. |
- Cornwallis, Charlie K, et al.
(författare)
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Single-cell adaptations shape evolutionary transitions to multicellularity in green algae
- 2023
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Ingår i: Nature Ecology and Evolution. - 2397-334X. ; 7:6, s. 889-902
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Tidskriftsartikel (refereegranskat)abstract
- The evolution of multicellular life has played a pivotal role in shaping biological diversity. However, we know surprisingly little about the natural environmental conditions that favour the formation of multicellular groups. Here we experimentally examine how key environmental factors (predation, nitrogen and water turbulence) combine to influence multicellular group formation in 35 wild unicellular green algae strains (19 Chlorophyta species). All environmental factors induced the formation of multicellular groups (more than four cells), but there was no evidence this was adaptive, as multicellularity (% cells in groups) was not related to population growth rate under any condition. Instead, population growth was related to extracellular matrix (ECM) around single cells and palmelloid formation, a unicellular life-cycle stage where two to four cells are retained within a mother-cell wall after mitosis. ECM production increased with nitrogen levels resulting in more cells being in palmelloids and higher rates of multicellular group formation. Examining the distribution of 332 algae species across 478 lakes monitored over 55 years, showed that ECM and nitrogen availability also predicted patterns of obligate multicellularity in nature. Our results highlight that adaptations of unicellular organisms to cope with environmental challenges may be key to understanding evolutionary routes to multicellular life.
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| 5. |
- Hansson, Lars-Anders, et al.
(författare)
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Experimental evidence for a mismatch between insect emergence and waterfowl hatching under increased spring temperatures
- 2014
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Ingår i: Ecosphere. - : Wiley-Blackwell. - 2150-8925. ; 5:9, s. 1-9
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Tidskriftsartikel (refereegranskat)abstract
- By combining a large-scale experimental assessment on timing of insect emergence with long-term monitoring of waterfowl hatching date, we here show that insect emergence is mainly driven by temperature, whereas there is only a weak effect of increasing spring temperatures on inter-annual variability in observations of waterfowl chicks. Hence, a change in timing of the mass-emergence of insects from lakes and wetlands, which is the crucial food source for waterfowl chicks, will likely result in a consumer/resource mismatch in a future climate change perspective. Specifically, we experimentally show that a moderate increase in temperature of 3 degrees C above ambient, expected to occur within 25-75 years, leads to a considerably (2 weeks) earlier, and more pronounced, peak in insect emergence (Chironomus sp). Moreover, by utilizing long-term Citizen Science databases, ranging over several decades, we also show that common waterfowl species are unable to significantly adjust their reproduction to fit future temperature increase. Hence, based on our data we predict a future mismatch between insect emergence and waterfowl species basing their reproduction on temperature. This will have a profound impact on reproductive success and population dynamics of many aquatic birds, as well as on freshwater biodiversity.
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| 6. |
- Björnerås, Caroline, et al.
(författare)
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Inland blue holes of The Bahamas - chemistry and biology in a unique aquatic environment
- 2020
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Ingår i: Fundamental and Applied Limnology. - : Schweizerbart science publishers. - 1863-9135. ; 194:2, s. 95-106
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Tidskriftsartikel (refereegranskat)abstract
- While lake systems in temperate regions have been extensively studied, tropical and subtropical systems have received less attention. Here, we describe the water chemistry and biota of ten inland blue holes on Andros Island, The Bahamas, representative of the morphological, abiotic, and biotic variation among Androsian inland blue holes. The majority of the studied blue holes were vertically stratified with oxic freshwater overlying anoxic saline groundwater of marine origin. Water chemistry (e.g. total phosphorus and nitrogen) in shallow waters was similar among blue holes, while turbidity and water color varied. Presence of hydrogen sulfide and reduced iron in and below the halocline indicate reducing conditions in all stratified blue holes. The biota above the halocline was also similar among blue holes with a few taxa dominating the phytoplankton community, and the zooplankton community consisting of copepods and rotifers. The Bahamas mosquitofish (Gambusia hubbsi) was present in all investigated blue holes, often accompanied by other small planktivorous fish, while the piscivorous bigmouth sleeper (Gobiomorus donnitor) was only present in some of the blue holes. Our field study reinforces that inland blue holes are highly interesting for biogeochemical research, and provide naturally replicated systems for evolutionary studies.
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| 7. |
- Brodersen, Jakob, et al.
(författare)
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Condition-dependent individual decision-making determines cyprinid partial migration
- 2008
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Ingår i: Ecology. - : Wiley. - 0012-9658 .- 1939-9170. ; 89:5, s. 1195-1200
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Tidskriftsartikel (refereegranskat)abstract
- Partial migration is a common phenomenon among many animals and occurs in many types of ecosystems. Understanding the mechanisms behind partial migration is of major importance for the understanding of population dynamics and, eventually, ecosystem processes. We studied the effects of food availability on the seasonal partial migration of cyprinid fish from a lake to connected streams during winter by the use of passive telemetry. Fish with increased access to food were found to migrate in higher proportion, earlier in the season, and to reside in the streams for a longer period compared to fish with decreased access to food. Furthermore, fewer unfed migrants returned to the lake, indicating higher overwinter mortality. Our results suggest that individual fish trade off safety from predation and access to food differently depending on their body condition, which results in a condition-dependent partial migration. Hence, our main conclusion is that individual decision-making is based on assessment of own condition which offers a mechanistic explanation to partial migration. Moreover, this may be of high importance for understanding population responses to environmental variation as well as ecosystem dynamics and stability. Read More: http://www.esajournals.org/doi/abs/10.1890/07-1318.1
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| 8. |
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| 9. |
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| 10. |
- Brodersen, Jakob, et al.
(författare)
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Variable individual consistency in timing and destination of winter migrating fish
- 2012
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Ingår i: Biology Letters. - : The Royal Society. - 1744-9561 .- 1744-957X. ; 8, s. 21-23
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Tidskriftsartikel (refereegranskat)abstract
- Migration is an important event in the life history of many animals, but there is considerable variation within populations in the timing and final destination. Such differential migration at the population level can be strongly determined by individuals showing different consistencies in migratory traits. By tagging individual cyprinid fish with uniquely coded electronic tags, and recording their winter migrations from lakes to streams for 6 consecutive years, we obtained highly detailed long-term information on the differential migration patterns of individuals. We found that individual migrants showed consistent site fidelities for over-wintering streams over multiple migratory seasons and that they were also consistent in their seasonal timing of migration. Our data also suggest that consistency itself can be considered as an individual trait, with migrants that exhibit consistent site fidelity also showing consistency in migratory timing. The finding of a mixture of both consistent and inconsistent individuals within a population furthers our understanding of intrapopulation variability in migration strategies, and we hypothesize that environmental variation can maintain such different strategies.
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