about south river federation

Everyone loves to see oyster restoration in the South River, millions of spat on shell being poured into the river is a beloved sight -- but where does this process start?

Believe it or not, in a way, this fascinating process starts with YOU! When you go to a restaurant or eat oysters at home, you can make sure leftover shell gets recycled for use in oyster restoration projects. Find resturants that recycle their shell and public shell drop offs here. Once these shells have been collected (usually by our larger partners, like the Chesapeake Bay Foundation and Oyster Recovery Partnership) they are aged for at least a year. The aged shell then goes through a process called "shaking" to remove large debris (dirt, decaying lemon juice and cocktail sauce, etc.). They are cleaned once more before being placed in large setting tanks, at which point they are ready for some oyster larvae!

IMG 7787Oyster larvae is produced by one place in Maryland, the Horn Point Laboratory on the Eastern Shore. Oysters are broadcast spawners, meaning they release their eggs and sperm into the water, where fertilization occurs externally. This whole process is triggered by water temperature, usually between April and August (part of the reason for the common lore that you should old eat oysters in months with the letter 'R'). Horn Point Lab is able to start heating the water they keep their oysters in earlier in the season, tricking the oysters into spawning as early as February. 

When larvae is received from Horn Point, it looks more like a ball of mud than anything else. However, this small "ball of mud" can contain millions of oyster larvae -- the ball of oyster larvae shown right contains 3.5 million oyster larvae!. The larvae are then diluted in a bucket and poured over the oyster shell in the setting tanks. See a video of free swimming oyster larvae here. After two weeks of letting the spat set on the shells, they are ready to be released into the River!

IMG 7934The cages of oysters are loaded up onto Chesapeake Bay Foundation's oyster restoration vessel the Patricia Campbell. This 60-foot boat was designed specifically for deploying oyster spat-on-shell, as well as reef balls. While some use the crane to move the large cages of oysters onto the boat, others peer through microscopes to count the spat that has attached itself to the oyster shells, on the left is a view of what spat look like under the microscope! A sample of shells is taken from each cage, counted for spat set, and averaged per tank. This number is then multiplied by the average number of shells per tank to get the spat set per tank. This is how we know we dropped 3.7 million spat on shell into the South River in September 2017!

Once all the spat has been counted and all the oyster shell has been loaded onto the boat, it is time for deployment! The oyster shell will sit in a large pile in the center of the boat and get transported little by little to the front by a conveyor belt. This shell will then get fed into what can only be described as a "spat flinger" that helps spread the shell over the reef. This is the part people love to see! The Patricia Cambell is guided carefully around the targeted restoration area, spreading spat on shell efficiently throughout the water. Check out a video of the Patricia Campbell delpoying oyster spat on shell here.

Once the shells have settled onto the bottom, the spat is ready to start filtering and growing! The spat will put all its energy into growing its shell, and after a year it will become a juvenile. At three years of age, oysters are officially classified as adults. Oysters typically grow around 1 inch per year, although this can change depending on the salinity and water quality of the water. Learn more about what South River Federation is doing to restore oyster populations here.   

 

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