| 1. |
|
|
| 2. |
- Brannas, E., et al.
(författare)
-
Use of the passive integrated transponder (PIT) in a fish identification and monitoring system for fish behavioral studies
- 1994
-
Ingår i: Transactions of the American Fisheries Society. - 0002-8487 .- 1548-8659. ; 123:3, s. 395-401
-
Tidskriftsartikel (refereegranskat)abstract
- Using Arctic charr Salvelinus alpinus, the system was developed in order to track individual differences. The authors demonstrate some of the applications in behavioral research, such as individual, general, and diet locomotor activity patterns, rheotactic behavior, and sociograms showing activity relationships among individuals within a group. -from Authors
|
|
| 3. |
- Brännäs, E., et al.
(författare)
-
A model of patch visit behaviour in fish
- 1998
-
Ingår i: Biometrical Journal. - 0323-3847 .- 1521-4036. ; 40:6, s. 717-724
-
Tidskriftsartikel (refereegranskat)abstract
- The patch visit or sampling behaviour of fish is studied over a 15 day period. The experimental setup consists of three connected patches between which movement is automatically registered. Using an integer-valued time series model we find a diel effect on the probability to stay in one of the patches.
|
|
| 4. |
- Brännäs, Eva, et al.
(författare)
-
Potential toxic effect on aquatic fauna by the dwarf shrub : Empetrum hermaphroditum
- 2004
-
Ingår i: Journal of Chemical Ecology. - 0098-0331 .- 1573-1561. ; 30:1, s. 215-227
-
Tidskriftsartikel (refereegranskat)abstract
- The common evergreen dwarf shrub Empetrum hormaphroditum has influence on the functioning of boreal terrestrial ecosystems in northern Sweden. The negative effects of E. hermaphroditum are partly attributed to the production of the dihydrostilbene, batatasin-III, which is released from leaves and litter by rain and snowmelt. In this study, we investigated whether batatasin-III is carried by runoff into streams and lakes during the snowmelt period and whether it is also potentially hazardous to aquatic fauna. Sampling of water from streams and a lake for which the surrounding terrestrial vegetation is dominated by E. hermaphroditum was done during the snowmelt period in May 1993 and in 1998, and analyzed for batatasin-III. Using 24- and 48-hr standard toxicity tests, we analyzed toxicity to brown trout (Salmo trutta) alevins and juvenile water fleas (Daphnia magna). Toxicity (proportion of dead individuals) to trout was tested at pH 6.5 and compared with that of a phenol within a range of concentrations. In the toxicity (proportion of immobilized indivuals) test on D. magna, the interactive effect of pH (pH 5.5-7.0) was included. Concentration of batatasin-III was generally higher in 1998 than in 1993 and showed peak levels during snowmelt. Concentration in ephemeral runnels > the lake > streams running through clear-cuts dominated by E. hermaphroditum > control streams lacking adjacent E. hermaphroditum vegetation. The maximum concentration of batatasin-III found was 1.06 mg l-1. The proportion of dead yolk sac alevins increased significantly (P < 0.001) with increasing concentrations of batatasin-III and time of exposure. After 24 hr, EC 50 was 10 mg l-1. It was 2 mg l-1 after 48 hr. The effect of phenol was negligible, indicating a specific phytotoxic effect of the bibenzyl structure of batatasin-III. The proportion of mobile D. magna became significantly smaller (P < 0.001) with increasing concentrations of batatasin-III, with decreasing pH, and with increasing exposure time. EC 50 varied between 7 and 17 mg l-1 at pH 5.5 and 7.0, respectively. After 24 hr EC50 decreased and was 2.5 at pH 5.5 and 12 mg l-1 at pH 7.0. The levels of batatasin-III found in the field samples were below the lowest EC50 in acute toxicity tests. However, in view of the interactive effect of pH and exposure time, this study suggests that this stable plant metabolite may impose a lethal effect on the aquatic fauna in small streams.
|
|
| 5. |
- Brännäs, E, et al.
(författare)
-
Behaviour and welfare in farmed fish
- 2008
-
Ingår i: Fish behaviour. (Eds. C. Magnhagen, V. Braithwaite, E. Forsgren, and B. Kapoor.). - Enfield N.H : Science Publishers (USA). - 9781578084357 ; , s. 593-627
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)
|
|
| 6. |
|
|
| 7. |
- Serrano, Ignacio, et al.
(författare)
-
Thresholds for survival of brown trout during the spring flood acid pulse in streams high in dissolved organic carbon
- 2008
-
Ingår i: Transactions of the American Fisheries Society. ; 137, s. 1363-1377
-
Tidskriftsartikel (refereegranskat)abstract
- The survival of brown trout Salmo trutta embryos and first-year juveniles was studied using in situ bioassays during the snowmelt-driven spring flood in 12 streams in northern Sweden. Unlike in most previous studies on the impact of acidity on brown trout, the streams in this study were high in dissolved organic carbon (DOC), and as a result organic acids play a primary role in controlling pH. During the spring flood period DOC concentrations increased strongly in most streams and, in combination with dilution of acid-neutralizing capacity, resulted in a decrease in pH and an increase in total and inorganic monomeric aluminum. High mortality of brown trout juveniles occurred during the spring flood and was best correlated to the high H+ concentration. No toxic effect could be directly attributed to measured inorganic aluminum concentrations. An empirical model to predict juvenile brown trout mortality in DOC-rich streams was developed, and based on these predictions a critical chemical threshold of pH 4.8–5.4 is proposed for first-year juveniles. There was high embryo and yolk sac fry survival during the spring flood, even at sites with pH as low as 4.0, suggesting that the pH threshold in DOC-rich waters is lower than the previously established threshold for low-DOC systems. We discuss the complex role that DOC has in humic-rich surface waters, where it both causes a pH decrease and protects against aluminum toxicity in fish. The results suggest that first-year juveniles are likely to be the stage most vulnerable to the effects of episodic pH depression associated with the snowmelt period in northern boreal systems. This results from asynchrony in the seasonality of the spring flood acid pulse and the seasonality of trout embryo development, which is slow in cold northern waters.
|
|
