Ryan Gasbarro, MSc Candidate

University of Victoria

Bio: I hail from the lovely Sonoran Desert of Arizona, where I pursued a broad background in environmental science and biology that, through curiosity and some good fortune, eventually led me to ocean science. My main scientific interests lie in the field of marine ecology and exploring the “where and why?” questions of oceanic animals. When I’m not “sciencing” you’re likely to find me indulging my passions for running/hiking, basketball, or music composition.

Supervisor: Verena Tunnicliffe

Institution: University of Victoria, Department of Earth & Ocean Sciences

Start to Finish: 9/2015 to 9/2017

CHONe Project: 2.1.3 Hypoxia and cumulative impacts on seafloor ecosystem function

Project Title: “A time-series of epibenthic community structure along a dissolved oxygen gradient”

Project Description:

             The dissolved oxygen content of the world’s oceans is declining. Due to the heterogeneity of the oceanic environment and the organisms that inhabit it, the effects of dissolved oxygen loss on marine ecosystems remains an active field of research. Saanich Inlet, a seasonally hypoxic fjord, is a rare and intriguing model system for such studies due to the presence of a strong seasonal oxygen gradient and a wealth of continuous data coming from a cabled array of instruments on the seafloor. A ten-year (2006-2016) time-series of repeat (n=13) remotely operated vehicle (ROV) transects along this oxygen gradient with counts of epibenthic macrofauna and their in situ oxygen levels has been completed. With this data, I aim to:

1.) Determine where the critical transitions, or ‘tipping points’ in benthic community structure are along the oxygen gradient using a novel adaptation of Fisher’s Information (FI) statistic.

2.) Assess whether the 2016 benthic communities, in which anomalous oxygen and animal distributions were seen, were structured differently along the oxygen gradient and thus had different tipping points.

3.) Determine the relationship between bottom pH and dissolved oxygen, and use this relationship to hindcast pH for previous transects; this would then allow for an analysis on community structure from a multiple stressors perspective.

This project links with broader CHONe goals in that it will determine the critical transitions in community structure, how these tipping points change over time, and the effect of multiple stressors on the benthos. This links with other CHONe projects that aim to find “labile tipping points” and assess the effects of multiple stressors in other marine systems, and hopefully use this information to better inform future analyses and management.