It’s been a couple of months since the last post on the team’s progress. This isn’t because we haven’t been working hard towards the two projects in the lab – far from it – but rather we’ve been inundated with super cool results that have not only given us new insight into the role of viruses in host ecology, but also have opened some new doors and generated new ideas. This is especially interesting since we now head into our first field season, which is timed around the normal timeframe in which echinoderm wasting is seen (late summer, early fall), and also the timing of the annual sea cucumber fishery in SE Alaska. So while the weather cools off, the research ramps up.
In mid-August, the team was notified (through social media… of course! how else?!) of a sea cucumber mortality event around Nanoose, British Columbia, Canada. Sea cucumbers bore epidermal lesions, leading to mortality in some cases, and affected a large number of individuals at specific sites. Through some very outstanding detective work and citizen science data collection by Em Lim (Simon Fraser University), the mortality event was delineated in time and space, and they very rapidly organized further monitoring, coordination with Fisheries & Oceans Canada. They also collected specimens for investigation of the flavivirus we investigate, which is currently underway. We hope to have this work completed – along with surveying the prevalence of flaviviruses in SE Alaska from specimens collected in June, completed very shortly, but already two patterns have emerged: the aiFVs have ~20% prevalence in at least two species, and we have identified the tropism of these viruses to surfaces with greatest contact with sediments and water. Jay and Ashley have done some incredible work to survey the aiFVs in tissue samples, generate new hypotheses about their role(s) in host ecology, and are currently working on a field-deployable kit for fishers, Alaska Native, and citizen science groups to monitor aiFVs in this or next season.
In early November, Ian and Chris will travel gea cucumber microbiome structure, abundance and activity, host gene expression, and aiFV abundance and replication. The idea here is to see if processes similar to those influencing sea star wasting disease (i.e. micro-scale hypoxia generated from microbial respiration) influence viral replication and host hypoxic response. These experiments will generate thousands of samples and produce much fodder for future projects.
On the seagrass front, Jordan’s working through sea grass viromes and come up with some really astonishing results, notably the presence of certain viruses that are protozoan transmitted and cause significant mortality of grasses in agricultural settings. This work is part of our global seagrass virome study, which so far has shown mostly viruses that are apathogenic or persistent, but with ephemeral putatively pathogenic RNA viruses which warrant further attention in directed study. We will shortly extend the virome study to samples from the Baltic and Australia.
Meanwhile, Jordan has also been working with Ricardo to prepare microbiome amplicon libraries from seagrasses collected over a summer time series to examine root- and shoot-associated microbiomes as they progress under organic matter enrichment during the season. Working with sediment-bound root-associated microbiomes requires meticulous attention, especially how best to dislodge sediment particles (and their billions of associated microorganisms) away from root structures (and their far fewer microorganisms).
Finally, Ian’s had the good fortune to be able to return to Australia to visit family, which has been challenging since the onset of the COVID-19 pandemic. Whilst there, he observed seagrasses in Moreton Bay and looked for characteristic wasting lesions. This region is interesting since some sediment types impart near-constant hypoxia when immersed, but fully oxic conditions when emmersed.
And so the field season – and progress on our two research axes (with common hypotheses) accelerates!