While this year marked the smallest amount of oysters that we’ve planted in the last 8 years, we are still very proud of every single oyster we did plant. The 2019/2020 growing season was completely out of the ordinary and it was the first year we have ever run this program with oysters that we produced in-house.
For those who don’t know, 2019 was an abnormal year in terms of the salinity and precipitation levels in the Chesapeake Bay. Oysters do best in water that has a salinity of at least 10 parts per thousand (ppt) and oyster larvae will not settle and become spat in water with a salinity less than 6 ppt. In 2019, many parts of the Chesapeake Bay were seeing abnormally low salinity levels, so oyster reproduction did not go well. Because of this, the Horn Point Oyster Hatchery in Cambridge, MD, struggled to produce oyster spat on shell, which is used for oyster restoration throughout the Chesapeake Bay. If you are interested, you can read more about this issue in the 2019 Baltimore Sun article Maryland oysters are having a bad year, and here's why.
This shortage of spat on shell led to the suspension of the Marylanders Grow Oysters program for the 2019/2020. This program distributes spat on shell for volunteer oyster growers throughout the state, and with very little spat available, they were forced to put the program on hold for a year.
It was only because of our own oyster nursery that Philips Wharf was able to produce a small amount of oyster spat for our Tilghman Islanders Grow Oysters (TIGO) growers. Even so, we were not expecting to produce the spat for our TIGO program, since we are normally provided spat through the Marylanders Grow Oysters program. This meant we had to drastically reduce the number of cages and the number of growers for the 2019/2020 season. The fact that this program continued at all is a huge accomplishment and shows how committed Phillips Wharf is to oyster restoration. It also shows how amazing our TIGO growers and supporters are because during the 2019/2020 growing season, this program was completely funded by private donations.
So let’s take a look at what we accomplished during the 2019/2020 TIGO growing season:
In 2019, 68 cages were placed with 27 growers. In July 2020, we collected these cages and produced 23 bushels of oysters, all of which have been planted on oyster bars in Harris Creek. Based on our calculations, that’s over 11,000 oysters (an estimated 11,155 oysters total)!
While these oysters ranged in size from 20 mm to 90 mm, the average size was 53.5 mm, which is 2.1 inches. The general rule of thumb for oysters is that they grow approximately 1 inch per year, but they can grow faster in higher salinity and with abundant food. This suggests we produced some happy, well fed oysters over the last year!
While 27 growers sounds like a small number, each grower hosts multiple cages. Each cage holds over 100 oysters (this year, we estimate about 160 oysters per cage) and every single oyster has the capacity to filter a huge amount of water over the course of its life.
Estimates suggest that an adult oyster can filter up to 50 gallons of water in a single day, so the number of oysters we planted this year can filter as much as 557,750 gallons of water in a single day. That’s the work of just 27 growers.
Imagine what we can do with more: more cages, more oysters, more growers.
If you are interested in joining this program, we are currently accepting applications for volunteer growers for the 2020/2021 season. Renewal forms and new volunteer forms are available on our website. They can be emailed to [email protected] or mailed to the address on the bottom of the form. Since we plan to distribute cages in mid to late September, we are hoping to receive renewal forms no later than August 31st, 2020.
If you aren’t able to grow oysters with us but want to support the program, we are always accepting donations. These donations allow us to produce our own spat in house, purchase new oyster cages or replace old cages, monitor the growth of TIGO oysters, communicate with growers, and pay staff to manage this program. Donations can made online or mailed to:
Phillips Wharf Environmental Center
P.O. Box C
Tilghman, MD 21671