Effect of low dissolved oxygen on the viability of juvenile Margaritifera margaritifera : Hypoxia tolerance ex situ
Year of publication
2022
Authors
Hyvärinen, Heini S.H.; Sjönberg, Tuomo; Marjomäki, Timo J.; Taskinen, Jouni
Abstract
The decline of endangered freshwater pearl mussel (FPM, Margaritifera margaritifera) has been attributed to juvenile mortality caused by low concentrations of dissolved oxygen in the stream substrate resulting from fine sediments (siltation) that impede water exchange in the interstitial microhabitat of juveniles. If low oxygen concentration causes recruitment failure of FPMs, knowledge on the oxygen tolerance of juvenile FPMs is essential for the conservation of the species, as it will justify conservation efforts improving water exchange in the bottom gravel. However, the tolerance of low oxygen of FPM juveniles has not been directly studied. Juvenile FPMs (9–11 months old) were exposed in individual chambers equipped with optical oxygen measurement spots to different levels of dissolved oxygen at 19 °C and their viability was monitored for 10 days to assess the acute oxygen tolerance of juvenile FPMs. Oxygen concentration ranged between 8.8 and 6.2 mg L−1 in the high oxygen treatment (control), 5.0–0.4 mg L−1 in the medium treatment, and 1.3–0.04 mg L−1 in the low oxygen treatment (near-anoxic conditions). Viability of juvenile FPMs depended on the concentration of available dissolved oxygen, such that all juveniles exposed to near-anoxic conditions were classified as non-viable, whereas all mussels exposed to high and medium concentrations were viable at the end of the 10 day experiment. Juveniles differed in their ability to tolerate near-anoxic conditions, so that some individuals survived only 1 day and others survived up to 9 days. This study provides the first direct experimental evidence on the oxygen sensitivity of FPM juveniles and suggests that >10-day events of very low dissolved oxygen at summer temperatures are fatal to juvenile FPMs, supporting the view that actions preventing low oxygen episodes in the substrate are essential for recruitment, and conservation, of FPMs.
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Publication type
Publication format
Article
Parent publication type
Journal
Article type
Original article
Audience
ScientificPeer-reviewed
Peer-ReviewedMINEDU's publication type classification code
A1 Journal article (refereed), original researchPublication channel information
Publisher
Volume
32
Issue
8
Pages
1393-1400
ISSN
Publication forum
Publication forum level
1
Open access
Open access in the publisher’s service
Yes
Open access of publication channel
Partially open publication channel
Self-archived
Yes
Other information
Fields of science
Ecology, evolutionary biology
Keywords
[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]
Publication country
United Kingdom
Internationality of the publisher
International
Language
English
International co-publication
No
Co-publication with a company
No
DOI
10.1002/aqc.3859
The publication is included in the Ministry of Education and Culture’s Publication data collection
Yes