A Busy Summer…

Where did it go? It seems only yesterday that classes were finishing, exams were being graded, and the weather was starting to warm up after a long Ithaca winter… now it has been 5 weeks since students returned to classes, leaves are changing color and dropping, and we find ourselves preparing for the next winter… did anything happen since those early days of summer? Of course they did, and at a crazy pace as well!! Its been a highly productive and insightful summer for the team as we make serious inroads into the various projects underway in the lab. While several of the team were away from the lab performing internships at other institutions, Ashley, Ian and Chris were very hard at work in Ithaca, with a few field expeditions along the way!

In June, our efforts focused on understanding Diadema antillarum mortality, while also completing some biochemical analyses of sea cucumber tissues, which were a follow up to our experiments in Sitka late 2021. The results of the latter work have proven very interesting indeed – not only have we been able to resolve the flavivirus first observed in viral metagenomes from specimens collected in 2016, but we have also been able to associate these – sometimes unexpectedly – with ecosystem productivity and animal health. This project continues to surprise us with unexpected, often completely opposite, results from what we had hypothesized.

On the Diadema front, the lab cultured some very interesting microorganisms from sick urchins collected in Florida. While we still do not yet know the cause of the condition, we are honing our efforts on a few candidate microbes which seem to be associated with mass mortality in the field. In late June, Ian traveled to St Petersburg, FL, to work will colleagues Mya Breitbart (University of South Florida) and Chris Kellogg (USGS) and trainees Bella Ritchie and Jim Evans on Diadema mass mortality.

After much workup of specimens collected during these experiments back in the lab in Ithaca, the team then focused on further experiments to examine how microorganisms may interact with Diadema antillarum, and further our work to look at viruses in sea cucumbers.

August arrived and came with a surprise: despite the Diadema condition waning in the previous 2 months with no reports from any islands of the Caribbean, the conditions suddenly appeared again in Aruba mid-August. Hence, this afforded another opportunity to sample microorganisms in an active disease setting. Ian traveled to Aruba to work with collaborators Don Behringer and Liz Duermit (University of Florida), who were on the island during a wider survey of Diadema demography. We were also joined by Sietske van der Wal from the Aruba National Parks foundation. Snorkeling at 5 locations during the 48 hour visit, we observed active Diadema mortality at all sites, and collected a variety of specimens to aide in understanding microbes associated with the condition.

Further to our work in Aruba, we sought an opportunity to perform wider sampling of seawater and biofilms on the surfaces of sympatric (co-occurring) plants and animals at a site which was previously affected by the condition. To achieve this, Ian and Chris returned to St Thomas and St John, where we collected over 100 swab specimens from a variety of surfaces, in collaboration with Marilyn Brandt and Moriah Sevier (University of Virgin Islands). Specimens were collected from sites sampled in April 2022, as well as a further 9 sites on St John, and at Flat Key and Brewer’s Bay, St Thomas.

After a brief time back in the lab to process results of our surveys, Hurricane Fiona affected the US Virgin Islands and led to considerable rainfall and runoff. This afforded us the opportunity to gauge the impacts of large terrestrial-marine transfer of suspended materials and its impacts on potentially pathogenic microbial associates to Diadema mass mortality. Ian and rotation graduate student, Brayan Vilanova-Cuevas, again traveled to St Thomas, this time to survey a site adjacent to our August sampling on St John, as well as additional sites around St Thomas.

A productive summer! With so many samples in hand – many of which have already been analyzed – we are now well placed to perform analyses through the winter!

I’ve put together a short video to summarize our work, which can be accessed here… please check it out!

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