Final Report for FNE10-682
The Great Eastern Shellfish Company farm raises premium quality salt oysters from spat to market size on Maryland’s Eastern Shore. We raise and harvest up to 250,000 quality salt oysters every 1-2 years, through modern float off-bottom aquaculture. Currently our oysters are raised in off-the-bottom floats consisting of flat mesh bags on rectangular PVC floats. It seemed to be the state of the art for off bottom culturing of oysters for the half shell market. It does well, but there is a problem. The oyster floats we currently use produce excessive fouling, are wasteful, and are cumbersome to harvest. Fouling is labor and time intensive to remove, prohibits oyster growth, and reduces water quality. We have analyzed or tried every system out there. After having made many improvements to our floats over the years, we now have developed a new float that combines the best features of the best containment systems in use. It’s called a “Big Flip Float”. It’s for commercial oyster farmers. It grows oysters off the bottom. It is easy to load, easy to keep clean and easy to harvest from. With a SARE grant, we implemented the new Big Flip Float (BFF) containment system, and compared the performance of the new system against current practices.
With the new BFF containment system, we have significantly reduced fouling and reduced wasted resources. As a result, this improved system enhances oyster growth, requires less labor, produces less waste and environmental pollution, and reduces costs.
The measured benefits of the BFF system, in comparison with the numerous systems currently in use, will be shared with other growers, looking for the best method for raising oysters. We believe the BFF system will be found among the best for commercial oyster production.
The Great Eastern Shellfish Company farm raises up to 250,000 premium quality salt oysters from spat to market size every 1-2 years, on Maryland’s Eastern Shore. The biggest challenge for our farm has been the development of an off-bottom containment system that encourages healthy fast oyster growth, keeps the oysters safe, requires minimal maintenance, is low cost, and allows for easier and faster harvesting.
Our farm started with a small number of “Taylor Floats” which were the state of the art for growing oysters off-bottom. Problems with the Taylor Floats were observed and the floats were modified. Each modification made the growing process easier and more secure. Trial and error led to the use of flat mesh bags tied to rectangular PVC floats (our current containment system). Though this state of the art system does well, it has its problems. The oyster floats we currently use produce excessive fouling, are wasteful, and are cumbersome to harvest. Fouling is labor and time intensive to remove, prohibits oyster growth, and reduces water quality.
1. Fouling on oyster bags: Anything you place in saltwater will foul up. Fouling reduces water flow, slowing oyster growth within the bags. Our current system produces an accumulation of biomass fouling that has to be removed from the bags, to maintain the health of the oysters. Removing this fouling consumes a lot of time. We use a push broom to scrub and brush fouling off the bags, one after the other, until they are done. The maximum fouling occurs in the hot summer months when it the hardest time to be doing this brushing. We also have to shake the bags vigorously to get the oysters de-clumped and force out the accumulated muck. Emptied bags, heavy with fouling, are thrown over the dock, piled up in the shallow water on the other side, carried across the beach, onto the lawn, and over to a dump pile where they dry. To use the floats again, barnacles must be scraped off, the shells collected, and spread into the driveway. This entire process is labor-intensive work that never ceases. As the fouling is released to the water, it falls to the bottom, and is impossible to gather. This reduces water quality by producing an anoxic layer on the bottom, impacting the crabs and fish in the area. My license to operate an oyster farm requires that any fouling dislodged from oyster floats must be collected and disposed of in an approved upland site. With the existing system, this is impossible.
2. Wasted resources: When we harvest oysters from our existing floats, 20 large cable ties are cut to release the bags and disposed of. This creates an unnecessary recurring expense. Also, we must continually walk among the floats in the water and examine for holes that oysters could fall through, stitching them shut immediately. Wave action can flop the bags up and down and cause the edges of the bags to crack. Replacing these damaged bags adds to our operating cost. Cable ties and spent bags are disposed of at the landfill, which is not good practice for the environment.
3. Cumbersome harvesting: Lifting bags of market size oysters at harvest is heavy, dirty work. We needed a way to use our existing floats while producing no fouling or as little as possible, with no reduction in production. We have analyzed or tried every system out there. After having made many improvements to our floats over the years, we now have developed a new float that combines the best features of the best containment systems in use. The new ‘Big Flip Float’ (or BFF) containment system reduces fouling, reduces wasted resources, and allows a mechanized way to harvest safely. As a result, this improved system enhances oyster growth, requires less labor, produces less waste and environmental pollution, and reduces costs.
We compared the performance of the BFFs to our standard floats with respect to the following objectives:
1. Enhance oyster production, by allowing good water flow within the bags. Improving off bottom growing conditions may speed growth. If a higher percentage of oysters achieve market size on time, we can get more to market and have fewer to put back for another growing season.
2. Reduce labor, by reducing or eliminating biomass fouling, and hence the need for constant brushing and scraping of the bags and floats.
3. Reduce costs and waste by reducing the disposal of cable ties and damaged bags.
4. Improve our water quality, by slowing or ending the release of biomass into the water.
Our new Big Flip Float system uses a commercial size flip float that compares to only one other oyster grower in Maryland. This other grower uses 3000 floats with one big bag suspended within. It puffs up and below the float, allowing fouling to dry, while the oysters remain in the water. They flip the floats, and stay ahead of fouling. But their floats are small compared to the Big Flip Floats. In order to produce a large quantity of oysters they must deploy a large number of floats. Our BFFs are bigger, holding at least 1200 oysters, requiring fewer floats. If we produced one million oysters we would need only 800 BFFs plus 800 more to start the follow up crop. 1600 of our BFFs would occupy far less water than 3000 of the smaller floats.
Pros: This BFF unit can be easily flipped over with a lever device (already in use by other growers). Flipping will bring the wet side up into the air and sun, for fouling control. The oysters always stay in the water, so the wet side can be left up for as long as it takes for the fouling to disintegrate. There will be little if any biomass fouling brushed into the water. Biomass will not be given a chance to accumulate, so that the oysters are always in a clean cage. This may allow for faster growth. The new bags can be open and closed easily and will not use cable ties that are cut and disposed of. The bags are plastic, and should have a long life span.
Cons: In order to do regular flipping, this system requires that the water bottom be walk-able. The BFF must be stored on edge and can’t be stacked, requiring more storage space.
Operating Practice for Previous Flat Bag Float System:
1. Prepare floats: A slotted PVC pipe is slid onto one end of the new oyster bag to close it and stiffen the end of the bag. Two or three small cable ties secure the pipe to the bag. The bags then get loaded with 200 to 250 baby oysters, taken from our upweller when they’ve reached planting size. The open end of the bag gets another slotted pipe slid onto it, and more cable ties seal the bag closed securely. A cleaned PVC float is then carried out of the storage area and transported to the float assembly area, where it is laid upon a float building rack. Five bags loaded with baby oysters are laid on the float. The ends of each bag are secured to the float with a total of 20 large cable ties. The loaded floats are then placed in the water. When all of the new floats are in the water they are ganged up and towed out to deeper water. Each float is secured to a long line, which is stretched between two posts, seventy feet apart.
2. Maintain and monitor floats: We walk among the floats in the water and examine each for holes, and stitch shut immediately (about 15 months from September to November.)
3. Harvest and process for market: 20 large cable ties are cut to release the bags from the floats and discarded. We use a push broom to scrub and brush biomass fouling off the oyster bags, one after the other, until they are done. We also have to shake the bags vigorously to get the oysters de-clumped and force out the accumulated muck. Emptied bags, heavy with fouling are throw over the dock and piled up in the shallow water on the other side. Thrown bags must be picked up and carried across the beach, up onto the lawn, and over to a dump pile where they dry and the flies clean them. To use a stored float again, the barnacles must be scraped off, the shells, collected, and spread into the driveway.
New Big Flip Float operating practice:
1. Prepare floats: The Big Flip Float has two rectangular plastic mesh cages at each end of a 3 foot by 10-foot PVC pipe float. Each of the two cages extends above and below the float by four inches. The unit can carry 1000 to 1500 oysters. We build the mesh cages and secure them to our existing floats, using a pneumatic staple gun and air compressor. The cages are loaded with 1000-1200 baby oysters, taken from the upweller when they’ve reached planting size. Loaded floats are then placed into the water in the Fall. A large float will be quite seaworthy and arrange neatly in rows of five, attached to a long line to hold them in place. Five BFFs are secured to long lines using very short tag lines at the corner elbows of the PVC floats, on one side only. The long lines are tied low on the posts and clipped to the side of the float, not over the top.
2. Maintain and monitor floats: The BFFs are monitored and flipped at regular intervals (every other week), for about 15 months. The BFFs are brushed only as needed, if at all.
3. Harvest and process for market: The weight and size of the Big Flip Float required that we build an angled track and winch system. Instead of manually lifting bag after bag of oysters up out of the water to be dumped out, we only have to reach under the hoisted float and cut 3 small cable ties, letting the oysters fall out of the cage with a little bumping. Cages are dumped, reversed down the ramp, lifted back up, and the other half dumped. The emptied floats must be secured from floating away until we are done with the day’s harvest. Then they are carried to the storage area. Oysters are then washed, sorted, counted and packaged as usual.
With the SARE grant we conducted a field trial of the new BFF system, in comparison with our current flat bag float system. Results were measured in a test area (with big flip floats) and a control area (with flat floats), over the course of one growing season, from September to March of the following year.
After loading and launching the first few BFFs, it soon became obvious that the original cage design had two flaws. One, the doors did not hold shut tight enough and a lot of baby oysters fell through during heavy wave action. To stop the loss, 6’ cable ties were used to secure the doors.
The plastic stiffener pipes fastened to the bottom of the cages and covered with mesh to keep baby oysters from getting stuck underneath, worked fine and no bay oysters got stuck under the pipes. However, the stiffener pipes were also supposed to act as ‘speed bumps’ to retard wave induced migration of oysters. The oysters all piled up at the ‘down-stream’ ends of all the floats. This created a new problem. As the oysters grew in size and weight, the concentration of weight placed a great strain on the cable ties/mesh intersection points. As a result, the affected cages broke loose at the heavy end, further straining the remaining cable ties to either snap or tear through the mesh, allowing the entire cage to fall off the float. This only happened to three or four floats however, and the rest of the BFFs came through the winter storms intact.
To improve the design and stop any losses due to the design of these first few floats, all construction ended a new variation was developed. New cages had non-opening ends that had every side of the end panels folded around the corner and stapled into the mesh of the cage. This strengthened the cage.
The stiffening pipes with mesh covers made an easy place to attach a mesh curtain to each of the two pipes on the top and bottom of the cage and the side edges of the curtains were stapled to the sides of the cage. This ‘curtain’ further stiffened the cage and ended any wave-induced migration.
With the design problems solved, a door system was designed using metal crab pot wire covered with plastic mesh to make doors. Each cage was subdivided into three compartments so for each compartment a hole was cut and the doors fastened on with 6” cable tie ‘hinges’. These doors made it easy to load and unload.
As the oyster sales of existing crops in standard floats progressed through the winter, the too small ‘put backs’ were loaded into the technically corrected BFFs and at the end of the season there were 100 BFFs in the water housing oysters.
After the severe winter storms, virtually all of the improved BFFs suffered no additional damage or problems.
It is interesting to note that with all BFFs made with no more to be made, it was painful to think about continuing to use the old system of flat bags strapped onto a float and having the best system and the worst system working together. So, with 2000 existing flat bags that we had in storage, we figured out a way to cut up two bags and turn them into a box cage. We made four boxes and secured them to a float, learning that we can make a BFF out of the old flat bags. After the SARE project, we will be able to convert all of our remaining standard flat floats into Big Flip Floats.
MATERIALS NEEDED TO BUILD a BFF:
A roll of plastic mesh having mesh openings the size suitable to contain the size oysters you wish to contain. We used 3/8″ square mesh.
One inch pvc pipe
A bag of 6″ cable ties
A bag of 24 ” cable ties as used in air conditioning systems
A pneumatic staple gun or hand staple tool (but your hand will give out before you get one cage built and a bag of loose staples
A box of staples for the staple gun ( staples as used to make crab pots)
An air compressor and air lines.
A bottle of pneumatic tool oil
A utility knife and or heavy duty scissors
A measuring tape.
Some kind of work table.
A roll of 1″ square vinyl coated crab pot wire
A saw to cut the pvc pipe to the lengths you need
INSTRUCTIONS TO BUILD A BFF:
(photos attached below show process)
1. Obtain a roll of plastic mesh having the mesh opening size you desire to contain the size oyster you wish to contain. We used 3/8″ mesh as it was small enough to contain spats and yet big enough to contain market size oysters too. So, load it once and flip to keep it clean until the oysters within are big enough for market.
2. Decide on the width of the containment cage. It depends on the size of the float you will use. Our floats were already at hand as we were using them to convert into BFFs. The width from inside to inside of the float was 32 inches and that is the width of the containment cages we built.
3. We wanted 4″ of the cage to be under water below the float and 4″ to be above the float and 4″ to be inside the float pipes. So our cage height is 12″
4. Fold the mesh at 12, 32, 12, 32, and 3″ for and over lapped seam. First cut off 91″ of mesh, and then do the folds.
5. Put in 4 stiffener plastic 1″ PVC pipes. Put two on the 32 ” side at the 2nd and 3rd quarters to divide the 32″ section into 3 equal sections. Use 6″ cable ties to secure the pipes to the mesh, use 4 cable ties evenly spaced along the pipe. Repeat this in the other 32 ” section.
6. Next, cut mesh pieces to make strips 32″ long and about 4″ or 5 ” wide. Fold the strips in half at the long 32 ” center line. You will need four of these, one for each of the
7. Staple the folded strip over top of each pipe and place the staples about 2″ apart. The purpose of the mesh cover is to keep baby oysters from getting stuck under the pipe.
7a. Cut out two mesh rectangles 32″ long and about 9″ wide (this depends on the distance from the pipe cover on top and the one on the bottom. staple these to the mesh of the pipe covers .
8. Fold the “box” up and bring the 3″ section over the outside of the 12″ side and staple , one line of staples at the corner and another at the edge of the strip and for
better strength, put another row down the center.
9. Staple through the side of the cage to join the ends of the v of mesh over the pipes to the cage side. Do this to each of the 8 pipe ends. This is important as it will stiffen the cage remarkably. Also staple the edges of the “curtains” to the side of the cage (2 curtains , 4 ends).
10.Cut pieces of mesh to make end pieces. This piece should be the width and length of the cage box open end. In our case, including a 2″ flap on each of the four sides means the piece would be 2o” x 36″ You need two ends so cut 2 pieces.
11. Fold over 2 ” along both of the long sides. Fold 2″ over along each of the two short sides. You have to cut along each end of the long side fold 2″ at each end (4cuts).
This will allow the end of the folded up short side to be flapped over the long side. Staple the folds over flaps and you now have the box end covers.
12. Place an end cover over and end and staple it on, a row of staples along the corners and a row along the edge of the mesh.
13. To get the oysters out you need doors, to keep them in securely and out easily. We made up vinyl coated 1″ square steel crab pot wire mesh. Then for each door we
cut 4″ x 12 ” pieces of plastic mesh to staple onto the inside of the doors. You need 3 doors per BFF cage.
14. Put the completed cage on a work bench and carefully cut 3 openings out of the long side of the cage , at the top of the cage , centered in each of the 3 section of the
cage. Cut 1 ” strips, fold in half the long way and cut to the height and the length of the door opening, Staple them on, This stiffens the edges of the door opening.
15. Use 6″ cable ties to fasten the long edge of a door to the bottom edge of the door opening. Put 1 cable tie at each end of the door and 3 in the middle section evenly
spaced. attach all three doors to the cage openings. The door is not secured where the door meets the top of the cage. That is the side that opens.
GREAT, You now have a BFF cage. Make a second one and attach them to each end of a float. Use 24″ cable ties, one at each end through the double thick mesh and two more next to each of the two curtains. Do likewise on the other side and secure the cage to the float, 4″ up and 4″ below the float. Put on the second cage and the BFF is ready to launch and don’t forget to tie on a rope to secure the float to whatever you are going to secure it to. Make sure you lock the doors with little cable ties so the oysters don’t fall out when you flip the float.
We expected we might see enhanced oyster growth by allowing good water flow within the BFF bags. If a higher percentage of oysters achieve market size on time, we can get more to market and have fewer to put back for another growing season.
At first, there did not appear to be differences in growth between the two systems. However, when comparing two samples of oysters taken from each type of float that had each been launched during the previous Spring, we made a surprising observation. The oysters from the old style float had appeared to have a lot more ‘frill’ or new growth along the edge of the shell. The new BFF oysters exhibited no frill. Our first impression was that this meant they were not growing as quickly. However this was not the case. Oysters from the two samples were measured in length and thickness (from the top shell to the bottom shell). We found that though the BFF oysters were slightly shorter in length, they were also consistently ‘fatter’ in thickness.
Average Size, Big Flip Floats: 2.4” +/- 0.06” (length); 0.8” +/- 0.05” (thickness)
Average Size, Flat Bag Floats: 2.5” +/- 0.07” (length); 0.6” +/- 0.03” (thickness)
One theory is that by having more room in the BFF to move and tumble around, the frill gets knocked off the edge of the oyster. However, with more room to ‘tumble’ in the BFF cages, more energy seems to be going into growth in thickness rather than length. Statistically, the two samples were equivalent in length while the BFF oysters were slightly thicker. The BFFs did indeed show slightly enhanced growth over the oysters grown in the old flat bag system.
By reducing or eliminating biomass fouling, and hence the need for constant brushing and scraping of the bags and floats, we expected that the new BFF system would reduce labor.
20 Old Flat Bag Floats (from March 2010 – April 2011): Total annual time spent working on floats including launch and processing was 27.5 hours.
• Scraping Barnacles off Floats (pre-launch): 3 Hours or 9 min/float
• Processing and Launching Floats: 6 Hours or 18 min/float
• Maintenance and Repair: 5.5 Hours or 16.5 min/float
• Brushing and Cleaning: 2.75 Hours or 8.25 min/float
• Processing for Sales: 8 Hours or 24 min/float
With ~1200 oysters per float, annual labor for the old flat bag system comes to 107 Hours per 100,000 oysters.
35 BFFs (from March 2010 – April 2011): Total annual time spent working on floats including launch and processing was 24.35 Hours.
• Scraping and Cleaning Floats (pre-launch): N/A
• Processing and Launching Floats: 5.8 hours total, or 10 min/float
• Maintenance and Repair: About 10 hours total or 17.1 min/float (Damage only incurred as a result of the way the cages were tied to the floats. When this problem was resolved, virtually all repair needs ended.)
• Brushing and Cleaning: 1 hour total or about 1.7 min/float
• Processing for Sales: 7.6 hours total, or 13 min/float
With ~1200 oysters per float, annual labor for the BFF system comes to 58 hours per 100,000 oysters.
During load operations, significant time savings were gained by using BFFs. So far, the BFFs also require less maintenance. Because the long lines that hold the BFFs in a row of five are attached to the long side of the float, they stay neatly in straight rows. In contrast, the standard floats often sway out of line causing float lines to get caught under the float and sometimes shear off the attached bags.
Brushing fouling off bags on standard floats remains difficult and time consuming. Flipping a BFF over is quite easy and takes only about 6 seconds if using the BFF “flipping wand”. Flipping a BFF requires 6 seconds and an additional 4 seconds to back flip a little to level out the oysters. Ten seconds to flip a BFF is remarkable when compared to brushing and scraping the old floats which takes about two to three minutes to completely clean the bags on a standard float. Ten seconds versus two minutes is a remarkable labor saving advantage achieved as predicted!
At $20/hour annual labor costs for the flat bag floats versus the BFFs would be $2,140 per 100,000 oysters versus $1,160 per 100,000 oysters.
The BFF was expected to reduce costs and waste by reducing the disposal of cable ties and damaged bags.
Cost to build a new BFF is $50, or $4,167 per 100,000 oysters. Cost to build a new flat bag float is $35, or $2,917 per 100,000 oysters. This is a one time startup cost however. Given labor savings shown above, assuming $20/hour, the increased cost for the new BFFs would pay for themselves in 1.25 years.
To open the BFF doors, we needed to cut twelve 6” cable ties. To open six bags from a standard float required the cutting of 20 large cable ties and also cutting 12 small cable ties. Throwing away 12 small cable ties versus 32 cable ties produces less material waste to put into a landfill. At 1-2 cents each, throwing away 12 small cable ties costs $0.25. At 11 cents each, cutting and throwing away twenty large cable ties costs $2.11.
Cost for cable tie waste for BFFs is about $21 per 100,000 oysters per year, and $176 per 100,000 oysters per year in the flat bag system.
By slowing or ending the release of biomass into the water, we expected that water quality might also be improved.
When a BFF is flipped over, and the side that was in the water becomes the top, it is brown and fouled with marine growth, although not as much as is present on the old style flat float. This is because regular flipping prevents massive fouling. After flipping, the fouled side is in the air and drying. After about 2 weeks in the air and sun and rain fall, the mesh turns green again (as it was new). The BFFs do as predicted and self clean very well. No biomass fouling is discarded into the water.
The seaworthiness of the BFFs is better than the standard floats. In fact because of this observation we put BFFs inside deeper water farther out and they ride the waves well. The standard floats under the same rough conditions end up with torn bags or bags torn loose.
For the most part, the BFFs have less storm damage and general wear and tear than do the bags strapped onto floats. When bags fall off from flat-bag floats, they fall to the bottom and are hard to find, while the BFF cages that fall off can be easily found.
While the BFF system reduces fouling by self-cleaning, we also observed that the BFF system allows the oysters to stay remarkably clean as well. Compared to the oysters grown in the old style floats, the BFF grown oysters were very easy to clean for market preparations.
As the long line is directly clipped to the BFFS on their sides, the rows of BFFs stay neatly lined up and look neat and proper. The old flat floats are clipped to the long line at each end of the float with a 2-3 foot line, making them loose and slopping looking by comparison. As a result, the farm looks neater and more organized.
The BFF cages do not flop up and down with wave action, but ride the waves much better and therefore we are able to put them out farther in the deeper water. We could not utilize the deeper water with the old flat floats because they did not fare well in the rougher waters. This means that with the BFFs, we can use all of the water that we lease and can put out more floats and increase our capacity for production.
- Steps to Build a BFF Cage: 1
- Steps to Build a BFF Cage: 2
- Steps to Build a BFF Cage: 4
- Steps to Build a BFF Cage: 6
- Old Oyster Bags Converted to Become a BFF
- ‘Old Float’ Grown Oysters
- The Bottom Rarely Gets Brushed
- Flipping Wand
- BFF Unloader
- Discarded Cable Ties
- Oysters Growing in a BFF
- Steps to Build a BFF Cage: 5
- BFFs Ready to Add Oysters and Launch
- Brushing Fouled Bags
- Bottoms Up to Self Clean
- Discarded Oyster Bags
- Steps to Build a BFF Cage: 3
- Steps to Build a BFF Cage: 7
- Flipping a BFF
- ‘BFF’ Grown Oysters
- BFFs Out Working
May-August, 2010: One hundred BFFs were constructed. Thirty five BFFs were loaded with baby oysters ¾” to 1” in size from our up-weller. Twenty flat-bag ‘control’ floats were loaded and launched. This was done to compare growth progress in both types of floats.
As market sized oysters have been processed and sold from existing crops in standard bags, the oysters that were not big enough yet were loaded into BFFs and put back out to continue growing. We found the BFFs much easier to load and deploy than the bags to be strapped onto floats.
Also, the BFF unloading rack was been constructed and erected in the water.
May 2010 – April 2011: Control floats and new BFF floats were monitored and maintained (cleaning, brushing, flipping, and repairing). For performance comparison, we logged the time to prepare and load floats, time spent cleaning and repairing and handling bags and floats, time to harvest and process oysters for market, and costs for implementing each system.
October, 2010: We brought a BFF to the Harbor Day event in Ocean City, MD. A BFF demonstration video was shown, comparing it to brushing a standard float.
January, 2011: We appeared in the East Coast Commercial Fishermen’s & Aquaculture Trade Exposition (https://marylandwatermen.com/Trade_Expo.html), showing a sample BFF, the demonstration video, and flyers describing the benefits of the system. It attracted moderate attention from watermen and folks who were interested in pursuing aquaculture for oysters.
April 2011: Thirteen (13) control floats were harvested and processed.
Education & Outreach Activities and Participation Summary
Other producers using floats like our existing system are locked into hand brushing or power washing fouling from their containment bags. Other growers could save a lot of time and money by using the float modification we propose. During this field trial, we documented and observed pros and cons of the new system. If other growers want to adopt the new Big Flip Float system, it would be our pleasure to share lessons learned, so that their learning curve is not as arduous as ours has been. Knowledge gained about the use of a commercial size flip float, from the notes and data acquired through this field trial, will be disseminated to other commercial growers.
If the new system works for us, it will likely work for others and be counted among the best oyster growing systems currently is use. We hope that the results of our field trial will help other commercial growers in their search for a good system.
1. A video illustrating the benefits of the BFF’s was posted on You Tube (http://www.youtube.com/watch?v=rn_fHc1w0Hs&feature=related) , and is available to state agencies or aquaculture research centers, for posting on their websites.
2. In October, 2010, at Harbor day in West Ocean city, we had an old flat bag float in the water with oysters in it, as well as a BFF with no oysters in it, set up on display. We had brochures about BFFs and a video on a TV set showing us on the farm flipping the BFFs. People were there to see all the commercial fishing boats and plenty of folks including the watermen stopped by to see my display and discuss what they were and what aquaculture was about. We were there for a full day and had at least 100 inquiries.
3. Then, in January of 2011, we had a BFF, brochures and the video of us flipping BFFs on the farm, at the East Coast Commercial Fishermen’s & Aquaculture Trade Exposition. We had the BFF displayed on its edge in a location where everyone in attendance had to pass by. People stopped to look, touch, and photograph and ask questions. Quite a few people wanted to know if we sold BFFs. Hundreds of visits over the 3-day event showed not only the BFF, but helped show that innovations in aquaculture are on-going, and that the BFF concept was (for commercial aquaculture) one of the two top new methods for upper water column use oyster farming on a commercial scale. At the Expo, a reporter from AmericanFarm.com, spoke with us and we were featured in an article on aquaculture, “Shellfish Farmers Aim to Restore Industry” (http://www.americanfarm.com/publications/the-delmarva-farmer/archives/474-shellfish-farmers-aim-to-restore-industry, July 22, 2011).
The proposed Big Flip Float system enhances oyster aquaculture sustainability by:
– improving productivity, reducing costs, and increasing net farm income
The elimination of fouling will reduce labor costs and hence improve the productivity of a small farm with limited human resources. The reduction of fouling will also result in cleaner cages with improved water flow, which may lead to improved oyster growth.
– improving water quality and protecting natural resources
The reduction of fouling reduces the release of biomass into the water, improving the local water quality of the existing ecosystem, especially with respect to turbidity, which inhibit the growth of sea grass. Sea grass is a vital habitat for local shrimp, crab, and fish populations.
Lessons learned with respect to the BFF design were to use two smaller cages side by side instead of one big cage. Any cages like this must also have “curtains” inside to separate the large area into smaller areas to prevent wave induced migration of 600 oysters at one end of the cage. This creates high stress points and does not give optimal growing conditions. Cable tie straps must be inserted through the cage mesh at the ends of the cage where the mesh is double thick as well as next to the internal curtains.
To empty the BFFs must have a system to easily push the BFF up out of the water, tip it on edge to open the doors, and dump the oysters to go on to be cleaned, sorted and packaged. Our BFF un-loader is built and proven effective.
Overall, the BFFs have proven to be a labor saving blessing to the farm. With a prototype made and deployed, the idea is working out fine. Soon we will have all existing flat bag floats converted into BFFs.
We will continue to show the BFFs at trade shows around the area and always mention the essential part played by SARE for which we are forever thankful.
Some of the first BFF cages built had deficiencies, and as more were made the design improved. Lessons learned have gone into the current BFF design so that we can now convert the whole farm into an efficient oyster growing machine that saves labor and materials. The whole project has been a win, win blessing.