Project Hypoxolith

Tracking effects of sub-lethal hypoxia exposure in fishes with otolith chemistry

Links to publications:

• Altenritter, M.E., Cohuo, A. and Walther, B.D. 2018. Proportions of demersal fish exposed to sublethal hypoxia revealed by otolith chemistry. Marine Ecology Progress Series 589: 93-208.
• Altenritter, M.E. and Walther, B.D. 2019. The legacy of hypoxia: tracking carryover effects of low oxygen exposure in a demersal fish using geochemical tracers. Transactions of the American Fisheries Society 148: 569-583.
• Limburg, K.E., Wuenschel, M.J., Hüssy, K., Heimbrand, Y. and Samson, M. 2018. Making the otolith magnesium chemical calendar-clock tick: plausible mechanism and empirical evidence. Reviews in Fisheries Science & Aquaculture 26: 479-493.
• Limburg, K.E., and Casini, M. 2018. Effect of marine hypoxia on Baltic sea cod Gadus morhua: evidence from otolith chemical proxies. Frontiers in Marine Science 5: 482.
• Limburg, K.E. and Casini, M. 2019. Otolith chemistry indicates recent worsened Baltic cod condition is linked to hypoxia exposure. Biology Letters 15(12): 20190352.

Hypoxia (low oxygen conditions) is a growing global threat that impairs the health and functioning of marine ecosystems. Although the potential impacts of hypoxic exposure are severe, there is little known about the consequences of systemic, sub-lethal exposure to hypoxic events for individuals, populations and communities of fishes. The objective of this NSF-sponsored project was to determine whether sub-lethal exposure to hypoxia during early life stages leads to sub-optimal growth and differential mortality. This project used biogeochemical proxies in fish ear stones (otoliths) retrospectively to identify periods of hypoxia exposure. The geochemical proxies Mn/Ca and I/Ca that are incorporated into otoliths relate to hypoxia (Limburg et al. 2015). We used these to identify patterns of sub-lethal hypoxia exposure and ask whether exposure results in differential growth and survival patterns compared to non-exposed fish. We are making across-system, interspecies comparisons of hypoxia exposure and consequences from the Gulf of Mexico (Atlantic Croaker Micropogonias undulatus), the Baltic Sea (Baltic Cod Gadus morhua and Baltic Flounder Platichthys flesus), and Lake Erie (Yellow Perch Perca flavescens), thus examining the largest anthropogenic hypoxic regions in the world spanning freshwater, estuarine, and marine ecosystems.

Some more background can be found on this web page.

Participants: Ben Walther (Lead PI, Texas A&M Corpus Christi); Karin Limburg (PI, ESF); Zunli Lu (PI, Syracuse University); Matt Altenritter (post-doc with Ben, now at SUNY Brockport); Melvin Samson (PhD student, ESF)