Adverse impacts of hypoxia on aquatic invertebrates: A meta-analysis

Galic, N. and Hawkins, T. and Forbes, V. E.

Sci Total Environ (2019) 652: 736–743

DOI: 10.1016/j.scitotenv.2018.10.225

Abstract

Hypoxia in aquatic ecosystems is often a result of anthropogenic activities, such as increased nutrient loading, originating from agriculture or urbanization, as well as global warming. Aquatic invertebrates are especially important in ecosystems due to their central role in secondary production and in dynamics of food webs. To better understand impacts of oxygen availability on key physiological processes in invertebrates, we conducted a literature search and synthesized the findings of published studies. We found 55 studies that quantified impacts of hypoxia on feeding, growth, reproduction and respiration rates in 54 different aquatic invertebrate species. We applied non-linear regression models which took into account phylogenetic correlation in the data set. Fitting Michaelis-Menten models, we found that there were differences in how different processes responded to a decline in oxygen availability. Respiration rates were halved at highest oxygen concentration (6.44 mg O(2)/L), followed by reproductive (3.66 mg O(2)/L), growth (1.77 mg O(2)/L) and, finally, feeding rates (0.77 mg O(2)/L). Our findings confirm observations that reproduction is highly sensitive as organisms quickly reduce their reproductive output when exposed to stressful conditions. As long as they have sufficient reserves, organisms continue growing even under stressful conditions, and we confirmed that growth was not very sensitive to a decline in oxygen availability. We discuss potential impacts of global warming on oxygen availability and demand for aquatic macroinvertebrates. Given that oxygen availability is declining in many ecosystems, we can expect that organismal responses will be increasingly compromised with potential consequences for ecosystems and the services they deliver.

Citation

Galic, N., Hawkins, T., & Forbes, V. E. (2019). Adverse impacts of hypoxia on aquatic invertebrates: A meta-analysis. Sci Total Environ, 652, 736–743. https://doi.org/10.1016/j.scitotenv.2018.10.225 Animals, Reproduction, Respiration, Ecosystem, Food Chain, Hypoxia, *Environmental Monitoring, *Eutrophication, Aquatic macroinvertebrates, Aquatic Organisms/*physiology, Feeding, Global Warming, Growth, Invertebrates/*physiology, Michaelis-Menten model

Keywords

• Animals
• Reproduction
• Respiration
• Ecosystem
• Food Chain
• Hypoxia
• *Environmental Monitoring
• *Eutrophication
• Aquatic macroinvertebrates
• Aquatic Organisms/*physiology
• Feeding
• Global Warming
• Growth
• Invertebrates/*physiology
• Michaelis-Menten model