Analyzing the Effects of Hypoxia on the Microbiome of Atlantic Brief Squid: The Model Organism for Future Global Regime Shifts Due to Expansion of Hypoxic Environments

Principal Investigator:

Leone Yisrael

Start/End Year:

2022 - 2024


Johns Hopkins University

Strategic focus area:

Healthy coastal ecosystems


Globally, there has been a consistent increase in the volume of hypoxic waters along coasts. Hypoxia can have numerous negative impacts on ecosystems such as modifying nitrogen and phosphorus cycling, altering food webs, degrading fisheries, and making coastal habitats uninhabitable to many economically and ecologically important fish species. Yet, hypoxia is not universally harming marine organisms. Rather some have benefitted from the effects of hypoxia since it can generate regime shifts, where certain species leave habitats since they can no longer tolerate the environmental conditions, leading to other tolerant organisms moving into those oxygen-limiting waters. The Atlantic Brief Squid, Loliguncula brevis, is one such organism. Although, this species resides in Chesapeake Bay, a nutrient-rich, temporally hypoxic brackish system, the adaptations that permit it to do so are not understood. A common mechanism for marine invertebrates to survive extreme habitats is through symbiotic relationships with microbes. We propose to examine the Atlantic Brief Squids’ microbiome to determine the presence and potential influence of endosymbionts in increasing the squids’ ability to tolerate hypoxic waters. In this study, I propose the Atlantic Brief Squid have endosymbiotic microorganisms, which utilize nitrogenous and sulfidic material. The breakdown and production of such compounds allow the species to live in hypoxic eutrophic areas. I will use metagenomic methods to identify bacterial richness and composition and analyze the functional genes present in the bacterial microbiome of the Atlantic Brief Squid in hypoxic and oxic areas. Subsequentially, I will compare what is found in the squid to the bacteria living in the water column, then compare those to microbes living in the water column. This study will create a novel model system to explore the importance of symbiotic interactions in increasing survivability and habitat range in multi-stressor environments.

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