For the love of sponges

Dive into the world of freshwater sponges with Ella, a passionate master's student from the University of Otago, New Zealand.  
 
Little is known about Aotearoa New Zealand’s freshwater sponges. To date, only one species has been studied, yet there is a high likelihood that many other exist without us knowing. For my master’s project, I am investigating the diversity of species within New Zealand, how these sponges have been adapting to their different environments through microbiome modifications, and what are the constraints for where they are able to live. This can include things such as water quality and presence of other species (who may be eating them).  

After an initial struggle to find information about where these sponges might be (as nearly all records of previously found New Zealand sponges are from about 100 years ago or are hundreds of meters deep – of which we do not have the resources to reach) I stumbled across an article in Stuff.  

This article mentioned their presence here in Zealandia. Absolutely ecstatic, my supervisors , and I emailed the Zealandia conservation team arrange a meeting.  

We quickly came to realise Zealandia was inundated with these creatures and swiftly booked our flights from Dunedin. At Zealandia we collected a couple of sponge samples that we have brought back to our lab in Otago as well as environmental DNA (eDNA) samples from around the reserve.   

In addition to cataloguing freshwater sponge species here in New Zealand, we are trying to understand what bacteria live inside them – these bacteria commonly live alongside sponges in vast populations and help the sponges to adapt to their niches. We are also curious to see how these bacterial populations change throughout the year, which means coming back to Zealandia in different seasons and taking more sponge samples. To find out what bacteria live inside these sponges we will extract their DNA and sequence it.  

We will be using eDNA information to help us understand why sponges are only found in particular ecosystems like here at Zealandia. eDNA should show us which species are living alongside the sponges. We think that the presence of particular species or river conditions might be impacting their ability to survive.   

We are hoping that through this research we can gain a greater understanding of freshwater sponge populations and how they have adapted to living within their niches here in New Zealand, and whether they can be a good indicator species for overall river health.   

You can spot freshwater sponges along Te Māhanga track living on the rocks.