Glass Reefs
Table of Contents
Introduction
"Sponge reefs are reefs produced by sea sponges. All modern sponge reefs are formed by hexactinellid sponges, which have a skeleton made of silica, and are often referred to as glass sponges. Such reefs are now very rare, and found only in waters off the coast of British Columbia, Washington and southern Alaska. Recently sponge reefs were identified within the strait of Georgia and Howe sound close to Vancouver.[1] Although common in the late Jurassic period, reef-building sponges were believed to have gone extinct during or shortly after the Cretaceous period, until the existing reefs were discovered in Queen Charlotte sound in 1987–1988[2] – hence these sometimes being dubbed living fossils." - Wikipedia: Sponge Reef
"Glass sponge reefs are incredibly rare, so rare and so hard to find, in fact, that they were thought to have gone extinct 40 million years ago until 1987 when they were found by accident. The reefs in the Hecate Strait and Charlotte Sounds are the most pristine and the largest. They are 9000 years old and over 1,000 sq km (620 sq miles). Others have been found in the Strait of Georgia, Howe Sound and Chatham Sound." - Northwest Wildlife Preservation Society
Glass Sponges
"Glass sponges are some of the oldest and simplest animals on earth. They don’t have eyes or even a stomach, yet they do some amazing things. Glass sponges build intricate skeletons out of silica (glass) that provide many other animals with a home, and they filter vast quantities of bacteria from seawater." - Glass Sponge Reefs
Where
Most glass sponges live in depths greater than 500 meters.
Off the coast of British Colombia, in the North Pacific, vast reefs spanning hundreds of square kilometers live in shallower depths of approximately 200 meters.
It is believes that these depths are favorable to sponge reefs because of high silica content, high water flow, and high food content and cold temperatures which are reminiscent of the deep sea.
3 Types Form Reefs
Only three species are known to form reefs:
Cloud Sponge (Aphrocallistes vastus)
These are all found growing as individuals throughout the Pacific Ocean, but are only known to form reefs in the Northeast Pacific.
Lifespan
An individual sponge grow at a rate of 0-7cm/year and can live to be at least 220 years old. - Wikipedia: Sponge Reef
Benefits of Glass Reefs
Acidification and Climate Change
While these reefs are under threat from climate change and acidification, it's important to note than "the glass sponge reefs help counteract global climate change, because they feed on small bacteria and trap carbon and nitrogen, preventing them from escaping into the atmosphere. ... this can also reduce ocean acidification." - Protecting Rare Ancient Glass Sponge Reefs
Environmental Cleaners
Glass sponges help filter bacteria and other pollutants from ocean waters.
"The 19 known reefs in the Salish Sea between Vancouver Island and B.C.'s mainland can filter about 100 billion litres of water each day, removing 75 to 90 per cent of microbes..." - National Observer
Threats to Glass Reefs
Aquaculture
Very little is known about these rare reefs, but divers have discovered them, only to seem them smothered shortly after by aquaculture farms. The food waste and feces fell down until the entire ecosystem became "a wasteland, covered in brown sediment."
Click the Aquaculture button to learn more about how this industry harms the environment.
Fishing Industry
Off the Coast of British Columbia "over half of the large reefs in Hecate Strait were destroyed by trawlers before fishing closures were put in place by the federal government in 2002." - IUCN
According to Yale, "a moment’s work by a ground-trawling fishing net can destroy hundreds of years’ worth of growth . The sponges can build at 3 to 7centimeters per year, says Leys, but meanwhile the bottom gets buried in sediment and the whole structure compacts, slowing down the overall growth. Sonar scans from the early 2000s showed “abundant” trawl marks, and submersible dives have spotted stumps and ridges where whole sections of sponge were plowed off by fishing gear."
Climate Change & Ocean Acidification
"Researchers found ocean acidification and warming, both alone and in combination, rapidly reduced the sponges' filtration capacity, which could starve the creatures.
The sponges also became weaker and more elastic, said Stevenson, meaning reefs could become brittle and collapse under the weight of newer generations of living sponges, which grow around seven centimetres a year." - Climate Change Threatens Glass Sponge Reefs: Study
Vibrations
Vibrations, larger particles, and impacts can arrest filter feeding, negatively affecting glass reefs. These can be caused by the shipping industry, tourism, the fishing industry, aquaculture.
Fishing Industry
When the fishing industry rips up the ocean floor with drag nets and dredging equipment, it creates both noise and particle pollution which disrupts entire ecosystems. Dragnet fishing has only recently been banned in and around glass reefs, but many corals that were 500+ years old have already been destroyed in mere minutes, from direct contact, and nearby reefs were impacted by the noise and debris.
Energy & Military
Both the military and fossil fuel industries use seismic testing to explore our oceans. Mobile species such as whales have been known to risk their own lives beaching themselves to get away from the agonizing experience, but smaller species including plankton (a vital food source for glass reefs and whales) has demonstrated negative effects after seismic blasting.
Transportation
In some areas ferries pass over these reefs. There is a possibility that the vibrations from their engines are also problematic.
Ocean Acidification
Rising acidification is harming our remaining glass reefs.
Solutions
Level 1-3
Avoid Seafood including farmed. Instead try plant-based alternatives. We've gathered some seafood alternatives that we've enjoyed.
Level 3-4
Expand Marine Protected Zones
Fishery Area Closures
Strait of Georgia and Howe Sound Glass Sponge Reef (17 fisheries area closures) Related poster with map and photos here.
Protect Water Quality
This can be done a few ways from changing the way we farm and garden, to how we eat and what we use to clean.
Reducing road emissions, and borrowing or renting things instead of buying new.
Ocean-Friendly Gardens
These may feature rain gardens or other water-wise designs. They avoid pesticide use, and prevent erosions which can impact waterways and ocean waters.
Rain Gardens
12,000 Rain Gardens of Puget Sound is a group in the Washington State area of "neighbors dedicated to cleaning up Puget Sound". These thoughtfully designed gardens can help protect waterways from common landscape pollutants, which in turn helps protect our oceans too.
Locations
Europe
Norway
North America
Canada
British Columbia’s Sea of Glass "In 1987 a remarkable discovery was made just off the BC coast. 200 metres below the surface, in the inky blackness of the deep sea, Canadian scientists found an underwater oasis exploding with life: gigantic reefs built by fragile glass sponges. The reefs cover hundreds of square kilometers of sea floor and in some places reach the height of an eight story building. British Columbia’s Sea of Glass is a Canadian national treasure."
British Columbia
Chatham Sound
Galiano Reef
Gambier Island the reef is southeast.
Hecate Strait "over half of the large reefs in Hecate Strait were destroyed by trawlers before fishing closures were put in place by the federal government in 2002." - IUCN
Howe Sound There are Glass Sponge Reef Marine Preserves and closures are in or next to the following locations:
Alberta Bay
Anvil Island
Bowyer Island
Brunswick Point
Carmelo Point
Collingwood Channel
Defence Islands
Dorman Point
East Defence Islands
Halkett Point / Halkett Bay Marine Park
Howe Sound - Queen Charlotte Channel
Langdale
Lions Bay and Kelvin Grove
Lost Reef
Mariners Rest
Queen Charlotte Sound
Strait of Georgia A new glass reef has been found at the mouth of the Fraser River, and there are Glass Sponge Reef Marine Preserves in or next to the following locations:
East of Hornby Island
Foreslope Hills
Gabriola Island
Halibut Bank
Outer Gulf Islands
Parksville
Sechelt
Galiano Ridge Glass Sponge Reef | Nautilus Live
1:55minute video showing the various species living in and around these rare glass reefs.
Hecate Strait and Queen Charlotte Sound Glass Sponge Reefs Marine Protected Area
2 minute video
USA
Alaska
So far these reefs have only been found off the coast of southern Alaska.
California
"The massive glass sponge patch was found off of California (upper right) in the Channel Islands National Marine Sanctuary between two of the region’s most well-surveyed and explored sites: Footprint Ridge (The Footprint) and Piggy Bank." - NOAA
Washington State
Native Species
The following species were mentioned while reading about these ecosystems and their communities.
The location tag in parenthesis indicates where these species were mentioned for, but doesn't indicate if they do or don't exist in or around other glass reefs.
Algae
Plankton these are a major food source for glass reef sponges (Canada & USA)
Bacteria
Bacteria are a primary food source for glass reef sponges (Canada & USA)
Crustaceans
Crab
(Canada)
Prawn
Spot Prawns (Canada & Alaska)
Shrimp
(Canada)
Echinoderms
Sea stars (Canada)
Fish
Halibut (Canada & Alaska)
Herring (Canada & Alaska)
Rockfish Glass reefs are believed to act as a nursery for rockfish (Canada)
Salmon (Canada)
Jellyfish
Lion's Mane Jelly
Mammals
Dolphins
Killer Whales (Canada)
Sharks
(Canada & Alaska)
Shellfish
Worms
Projects & Refuges
North America
Canada
British Columbia
Strait of Georgia and Howe Sound Glass Sponge Reef Conservation Initiative "British Columbia's ancient glass sponge reefs are a globally unique ecosystem that are areas of high biodiversity and provide important habitat for many marine animals including salmon, spot prawns, rockfish, herring, halibut and sharks. Through the Strait of Georgia and Howe Sound Conservation Initiative, we have put in place measures to protect and conserve glass sponge reefs on British Columbia's south coast." Includes maps of the marine refuges.
Maps
Europe
Norway
Sensitive Habitats in the MAREANO Mapping Area shows small areas of glass sponges along the northern coast of Norway.
North America
Canada
British Columbia
Glass Sponges Bioherms in Howe Sound (PDF) also includes other maps including one of the Strait of Georgia
Glass Sponge Reefs in Northern British Columbia scroll down to see the map.
Strait of Georgia and Howe Sound Glass Sponge Reef Conservation Initiative "British Columbia's ancient glass sponge reefs are a globally unique ecosystem that are areas of high biodiversity and provide important habitat for many marine animals including salmon, spot prawns, rockfish, herring, halibut and sharks. Through the Strait of Georgia and Howe Sound Conservation Initiative, we have put in place measures to protect and conserve glass sponge reefs on British Columbia's south coast." Includes maps of the marine refuges.
USA
California