Glass Reefs

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:

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

Level 3-4

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

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

California

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

Bacteria

Crustaceans

Crab

Prawn 

Shrimp

Echinoderms

Fish 

Jellyfish

Mammals

Dolphins

Sharks

Shellfish

Worms

Projects & Refuges

North America

Canada

British Columbia

USA

Washington

Maps

Europe

Norway

North America

Canada

British Columbia

USA

California