First-Ever Submarine Dive on Vancouver’s “Living Fossils”: Glass Sponge Reefs
Researchers discover a seafloor oasis made of hundreds of glass sponges.
by Anne Casselman
Howe Sound, British Columbia—Through the submersible’s acrylic viewport, a large patch of glass sponges looms up from the seafloor of Howe Sound (map), a network of fjords located on Vancouver’s doorstep. The sponges glow creamy white and orange under the sub’s high-intensity lamps and extend across a 40-foot-high (12.2-meter-high) mound.
"Topside, topside, be advised we have sponge at this location," senior pilot Jeff Heaton says into his communication system from a depth of 135 ft (41.1 m).
"This is a sponge reef," says Heaton from inside the inch-thick (2.5-centimeter-thick) steel hull of the Aquarius submersible, a three-person vehicle owned and operated by Nuytco Research. “No doubt about it.”
This week, the Canadian Parks and Wilderness Society (CPAWS) and Nuytco Research mounted the first submarine expedition to the glass sponge reefs found in Georgia Strait off of Vancouver.
The expedition aims to check on the status of these sponge reefs, which currently have no protection from damage by fishing activities, and to raise awareness of their existence…
…a species of pyurid ascidian (sea squirt) that occurs off the coasts of New South Wales and Victoria, Australia. Like most tunicates P. spinifera is a filter feeder, filtering the water around it for nutrients and expelling out excess. P. spinifera ‘comes’ in a wide range of colors, ranging from white, pink, yellow, orange, and purple. The color is determined by the symbiotic sponge that covers the ascidian’s surface.
Most animals, when chased by a predator, can run away. Not so for many coral reef animals, such as sponges and corals, that are attached to a surface and can’t move away. Instead, these sessile critters (such as the liver sponge shown here) must have other types of defenses that protect them from predators. These could include structural defenses, such as hard shells or prickly spines, or chemical defenses that make them taste bad.
Studying these defense mechanisms could lead to the discovery of new medicines, tools for increasing seafood supply and safety, and new resources and industrial processes.
This white sponge (in the family Euplectellidae) is anchored to the seafloor with very long spicules. These spicules create microhabitat for very small crustaceans and worms. It is fastened to angular pillow-lava talus near the bottom of the steep talus slope flanking the cone of Axial Seamount. The amount of sediment that has accumulated suggests the cone is fairly old, and the presence of a large, long-lived, sessile organisms such as this sponge suggests the talus slope is stable.
Read about what researchers on the WesternFlyer are learning about volcanic eruptions at the deep sea Axial Seamount:
During Sunday’s dive in Hydrographer Canyon, a deep sea canyon off the NE coast of the United States, amongst the diverse coral community, our remotely operated vehicle observed a glass sponge containing cephalopod eggs. If you look closely you can see what looks to be a recent hatchling!
Another Look at the Changes on the Antarctic Sea Floor
What scientists thought would take centuries to occur is taking place in just a matter of years. “…populations of glass sponges have tripled between 2007 and 2011, allowing them to completely take over the seafloor.”
In the frigid, inky ocean depths beneath permanent ice shelves, life tends to move pretty slowly. But a recent expedition to the seafloor under a newly thawed Antarctic ice sheet has revealed an unexpected invertebrate invasion. Some of Earth’s strangest species, a group of ghostly pale sponges made of glass, have set up shop there in a hurry, upending much of what scientists know about these exotic creatures.
Thanks to changes in this ecosystem brought on by a warming climate, these gardens of glass sponges have sprouted up in only a few years, a veritable population explosion for species once thought to take decades or centuries to spread. It suggests that glass sponges could find themselves squarely on the winner’s podium when it comes to climate change.
In 2011, a team led by researchers from the Alfred Wegener Institute for Polar and Marine Research completed a new census of glass sponge growth on the seafloor underneath the Larsen Ice Shelf in Antarctica’s Weddell Sea, following up on a similar survey done in 2007. Their surprising results were published today in Current Biology…
…is a species of glass sponge found throughout the northern Pacific Ocean. Cloud sponges are one of the few species of glass sponges that are able to form slow growing reefs. They provide a substrate that a community of invertebrates and other animals can thrive on. Like all glass sponges the cloud sponge’s body wall is made of silicaceous material which makes it unattractive as a meal to most predators, however a few species of sea stars are know to prey on it.
Also known as the Scroll Sponge or the Paper Sponge, the elephant ear sponge is a species of demosponge found throughout the Indo-pacific and is most common in Indonesia and on the Great Barrier Reef. Like most sponges the elephant ear sponge makes its living by filtering the water around it and extracting any nutrients in it. It also is a host for a number of animals like crustaceans and a sea cucumber that make use of the nutrients that are exuded by the sponge.
…is a species of calcareous sponge found throughout the shallow waters of the Mediterranean sea and western Atlantic Ocean. C.clanthrus is made up of a tangled system of tubes, and unlike other calcareous sponges these tubes have an osculum ( a sponge structure which water flows through). This species is also an asconoid which means its choano and pinacocytes are primitive and the sponge has to manage more water. It is also made up of exclusively three-pointed spicules (a structural support element in sponges) which are called triactines.
Antarctica’s Bizarre Creatures Come to Life Online
by Megan Gannon
The strange creatures that thrive on the bottom of the chilly ocean surrounding Antarctica have been revealed in a comprehensive collection of snapshots and datasets now available online.
The database, published as part of a paper in the journal Nature Conservation, covers the frozen continent’s macrobenthic organisms, creatures that live on the seafloor and are big enough to be seen by the naked eye.
This community includes spiny echinoderms, sponges, crustaceans as well as some bottom-dwelling fish that are uniquely adapted to the region’s ice-laden waters — for instance, icefish (Notothenioidei), which have a natural antifreeze chemical in their blood and body fluids that allow them to survive in frigid temperatures…
These changes won’t necessarily be for the good of the shell and skeleton builders. New research published in Marine Biology shows that boring sponges eroded scallop shells twice as fast under the more acidic conditions projected for the year 2100. This makes bad news for the scallops even worse: not only will they have to cope with weakened shells from acidification alone, but their shells will crumble even more quickly after their cohabiters move in.
Boring sponges aren’t named thus because they’re mundane; rather, they make their homes by boring holes into the calcium carbonate shells and skeletons of animals like scallops, oysters and corals. Using chemicals, they etch into the shell and then mechanically wash away the tiny shell chips, slowly spreading holes within the skeleton or shell and sometimes across its surface. Eventually, these holes and tunnels can kill their host, but the sponge will continue to live there until the entire shell has eroded away…
is a species of freshwater sponge that can be found in North America, Europe and Asia. They can usually be found lodged under logs and rocks in clean freshwater lakes and slow flowing streams. To deal with the harsh winters that come with living in freshwater the sponge becomes dormant during winter months. During the summer the sponges reproduce either by budding asexually or sexually by giving birth to larvae.