Studying the globally unique glass sponge reefs

By Amanda Kahn

[Cross-posted on the Students Ensuring our Oceans’ Future blog.]

One month ago, we were busy in the lab at the University of Alberta preparing and calibrating instruments, gathering GPS waypoints, and preparing dive plans. Three weeks ago, we drove and flew to Vancouver Island with our equipment and plans. Two weeks ago, we boarded a ship to study the glass sponge reefs in the Strait of Georgia in B.C.

CCGS Vector

Heading out on CCGS Vector, our home away from home. Credit: A Kahn 2013

The main reef we were studying on this trip was on Fraser Ridge. If you drained the water from the SoG, you’d be able to see the ridge and the reef about 14 km away from Vancouver. Fraser Ridge reef is too deep for us to study directly by scuba (150 to 180 meters deep), so instead we study it with the help of the remotely operated vehicle (ROV) ROPOS. ROPOS is piloted and run by the Canadian Scientific Submersible Facility (CSSF) and functions as our eyes and hands underwater.


ROPOS, our eyes and hands underwater. Credit: A Kahn 2013

With those eyes and hands, we studied the energy use and water pumping capacity of the glass sponges that build the reef. Glass sponges are really amazing animals—they can move huge amounts of water through their bodies, which are basically modified to be amazing filters. 9,000 liters of water can pass through a single sponge osculum (the “chimney” that water is released from by the sponge) each day! And from that, the glass sponges can feed on tiny particles, especially bacteria. This is pretty unique among animals—most other animals that feed on particles suspended in the water (called “suspension feeders”) can only capture particles that are larger by 10 times or more.  We did a lot of great science while on board the ship, and I’m now at the field station in Bamfield, British Columbia, to work with other sponges.  We will all spend the winter back in Edmonton working up the samples and data collected from this trip.

Glass sponge reef

Glass sponges in a reef–check out all of those oscula! Credit: CSSF 2011

I’m happy to be a part of SEOF because I can feel connected to other folks who are near the ocean full-time, can ask questions about logistics before I arrive, etc.  I’m the regional representative for Alberta and in this post wanted to show that being far from the ocean does not mean that we cannot have access to marine animals or study ocean-related issues.  Logistics may be more tricky than driving down to beach for the weekend to do some intertidal sampling, but it’s definitely doable and totally worthwhile.  Contact me if you have questions about the reefs or if you’re in Alberta and have questions about how you can get involved in the marine science community across Canada.

To learn more about the reefs, check out these videos, compiled by Sameena Sherman, a student from our lab:

Glass sponge videos: Animals of the reefs

by Amanda Kahn

Did you know that glass sponges form reefs the size of cities here in BC?  If we were to drain the water from the Strait of Georgia (between the mainland and Vancouver Island, where Bamfield sits), you’d be able to see huge structures built by generations of glass sponges as they grew higher and higher to get into strong water flow.  Among other things, the Leys lab–headed by Dr. Sally Leys at the University of Alberta–studies the glass sponge reefs.  Student Sameena Sherman put together two videos to introduce the reefs and the animals that live in them.  If you haven’t seen the first video, you can find it here.  Check out the latest video, Animals of the Reefs, below!

Land-locked scientists, getting their gills wet…for science!

by Amanda Kahn

As discussed in the previous post, my labmate Rachel and I traveled to the coast to collect more samples for our research on the reef-forming glass sponge, Aphrocallistes vastus.  We drove to Brentwood Bay the morning of our collection dive and went out to our dive site with the help of Pinnacle Scuba Adventures.  Everyone was in good spirits–it wasn’t raining yet, the water was calm, and we were going diving!  While I started talking about our most recent adventure (a.k.a. field collecting trip) in yesterday’s post on the blog, I have now continued the updates on the Leys Lab website.  Check it out to see how we fared during the dive and to learn more about why Rachel and I are studying the glass sponges, and what we’re hoping to learn about them.

Dive site

At our dive site. Credit: R Brown 2013

The hunt for glass sponge larvae

Amanda loves tide poolsby Amanda Kahn

This past week, I left frozen Edmonton, Alberta for some field work on the coast.  My supervisor (Sally Leys) and I went on the hunt for larvae of glass sponges.  Several years ago, a single larva was spotted in a sponge collected in November or December.  We then found sperm and eggs in sponges this past year, so we decided to go investigate.  This is important because this species of glass sponges forms the foundation of the sponge reefs that populate the straits of western Canada (and so far, form reefs nowhere else in the world), so learning about how and when they reproduce will help us determine what factors might positively or negatively affect their breeding success, and therefore the successful growth of the reefs.

Check out the post documenting our trip at the Leys lab website.

Credit: A Kahn 2012

Also, to see what the reefs look like that these sponges form,  check out the video at this link, compiled by Sameena Sherman of the Leys lab, showing reefs in Hecate Strait.