Experts at the University of Alberta are describing a new sea sponge that is abundant off the coast of British Columbia. The newly discovered sponge makes up nearly 20 percent of the glass sponge reefs in this region, yet is a non-reef forming sponge.
Off the coast of British Columbia, hundreds of kilometers of ocean floor is covered with rare glass sponge reefs. The intricate silica skeletons of the sea sponges are stacked on top of each other to form multi-level habitats for creatures such as rockfish, halibut, and shrimp.
Live glass sponge reefs are unique to Pacific coastal waters, and first appeared during the Jurassic period. According to NOAA, the reefs were thought to have gone extinct about 40 million years ago. The only remains were assumed to be giant fossil cliffs across parts of Spain, France, Germany, and Romania.
But in 1987, Canadian scientists discovered living glass sponge reefs on the northern coast of British Columbia that were thousands of years old.
Containing the only known glass sea sponges, this region – including Hecate Strait and Queen Charlotte Sound – was designated as a marine protected area in 2017.
To effectively preserve the rare, delicate reefs, scientists must develop a better understanding of them.
Graduate student Lauren Law conducted the current study with Professor Sally Leys, a researcher in the Department of Biological Sciences at the University of Alberta. Law is now a biologist with Fisheries and Oceans Canada.
“One of the most important reasons for studying the diversity of sea sponges in our oceans is for conservation management,” said Law. “Many studies in the protected area have focused on describing the crustaceans and fish living in the reefs, but non-reef forming sponges remain overlooked.”
The new species, Desmacella hyalina, was discovered using an underwater robot that was deployed on the ocean floor to survey reefs and collect samples.
“Our findings show Desmacella comprise a surprisingly large amount of live sponge cover in the reefs and can have potential major influence on reef function, recruitment, and overall ecosystem health,” said Law. “While we have discovered a new species, we have yet to determine its relationship with glass sponges in the area.”
The study authors said that further research is needed to better understand the role of Desmacella in the ecosystem, as well as more ecological assessment of glass sponge habitat focused on surveying non-reef forming sponges.
“Properly knowing the components of an environment and the linkages between them here- this new species Desmacella hyalina and the reef sponges it lives on – is a major step forward in understanding the ecosystem services and function of the sponge reefs,” said Leys. “This is the information we need for concrete management strategies.”
The study is published in the journal Marine Biodiversity.