Fate and effects of Nodularia spumigena and its toxin, nodularin,

0,36

MB

in Baltic Sea planktonic food webs

34

stron

3692

ID

Finnish Institute of Marine Research

2006

rok

CONTENTS

List of original articles 7

Contributions .. 7

Abstract .. 9

1. Introduction.. 11

1.1 Cyanobacteria in the Baltic Sea – an ancient phenomenon.. 11

1.2 Why do cyanobacteria form blooms in the Baltic Sea? . 11

1.3 Harmfulness of Nodularia spumigena 12

1.4 Properties of nodularin.. 14

1.5 Interactions of zooplankton and N. spumigena in the Baltic Sea – what is known so far? 15

1.6 Transfer of nodularin and effects on zooplanktivores. 15

2. Objectives of the study 16

3. Methods .. 16

3.1 Dissolved toxin uptake experiments 16

3.2 Toxin fate experiments .. 16

3.3 Feeding and reproduction experiments .. 17

3.4 Toxin disappearance experiments. 17

3.5 Zooplankton sampling in the field for toxin analyses – Field measurements . 17

3.6 Trophic transfer experiments on planktivores. 17

3.7 Toxin analyses .. 18

4. Results and discussion . 18

4.1 Toxin uptake in zooplankton .. 18

4.2 Toxin concentrations in the field .. 21

4.3 Nodularin transfer via zooplankton to planktivores. 21

4.4 Effects on zooplankton and planktivores .. 22

4.5 Possible ecosystem consequences. 23

5. Conclusions 24

Acknowledgements 25

References 26