Oysters are considered a delicacy throughout the world and are consumed with great satisfaction by many, without knowing that these wonderful marine creatures have a much greater purpose than filling one’s belly. Oysters have a big impact on the ecosystem due to their feeding mechanism and they improve the water quality in their habitat. The idea of using bivalves like mussels, oysters and clams to purify waterways has been on the minds of conservationists and scientists for decades.
Being a filter feeder, the oyster has to filter a large quantity of water in order to obtain its nutrients. They are very effective at filtering water since a single oyster can filter up to 2 gallons of water per hour. A group of oysters, which is commonly called an oyster reef, has a huge impact on its habitat and removing them can cause serious problems for all the marine wildlife.
Oysters are considered to filter large amounts of water to feed and breathe (exchange O2 and CO2 with water) but they are not permanently open. They regularly shut their valves to enter a resting state, even when they are permanently submersed. In fact their behavior follows very strict circatidal and circadian rhythms according to the relative moon and sun positions. Oysters consume nitrogen-containing compounds (nitrates and ammonia), phosphates, plankton, detritus, bacteria, and dissolved organic matter, removing them from the water. Oysters also remove other suspended solids from the water column and package them into bundles which they release as pseudofeces. This bundle is then utilized by other organisms on the oyster reef for food.
Several studies have shown that oysters and mussels have the capacity to dramatically alter nitrogen levels in estuaries. So it turns out oyster reefs work like sewage treatment plants, which lure bacteria to convert nitrogen into gas.
Oysters usually reach maturity in one year and as generations of oysters settle on top of each other and grow, they form reefs that provide structured habitat for many fish species and crabs. To get a big picture of how important their role is, just think about this: an oyster reef supports life for 24,000 other organisms per square meter.
And even more, oysters can prevent erosion since they live along the shoreline and form reefs. As damaging waves travel toward the coast, they first hit oyster reefs, which dissipate the wave energy, diminishing its effects on the shore. This decreases the amount of sediment being pulled away from the shoreline, therefore decreasing erosion.
Multiple studies have shown individual oysters are capable of filtering up to 50 gallons of water per day, and thus oyster reefs can significantly improve water quality and clarity, therefore we can call the oyster as one of the best ecosystem engineers of the marine wildlife. Oysters and clams are also used by many people as an effective water filter for their fish tanks as they are cheap and they don’t require a specific maintenance.
So in theory one can build an oyster filtration system to clean dirty water in times of need. What you would need, would be a large tank to host the oysters and a source of filthy water. Depending on the water quantity you will leave the oyster over night to do their job and filter all the water and the next day you will remove the water and boil it for consumption. Of course you will have to leave some water for the oyster and do a cleanup of the tank every four to five days, but if we think about it, this would be a filtration system that doesn’t require too much work and it can be quite efficient in a time of crisis. Here is a video showing how good oysters are at filtering water.
Common oyster predators include above all, humans and after that crabs, seabirds and starfish. Due to human intervention the number of oyster reefs has decreased considerably in the last 50 years and it has a negative impact on the water quality in the states situated on the coastline. However, there is also some good news, since from 2009, there were many programs started in Florida, North Carolina, Georgia and South Carolina, all aiming to restore and preserve the oyster reefs.
In the United States the largest oyster-producing body of water is located in the Chesapeake Bay, although these beds have decreased in number due to overfishing and pollution. Also Willapa Bay in Washington produces more oysters than any other estuary in the US. The other large oyster farms in the US include the bays and estuaries along the coast of the Gulf of Mexico.
Right now researchers are investigating the beneficial effects of raising seaweed and kelp, in conjunction with bivalves, to clean coastal waters. Water filtering is a process that takes time and money, and having a method of doing it naturally is something that we should appreciate and make sure it lasts.
Post ID: 11113