Making the Deep Sea Atlantic Red Crab Fisherya sustainable and profitable industry forVirginiaFinal Project ReportAtlantic Red Crab Company, LLCCasey’s Seafood, Inc.Graham & Rollins, Inc.Virginia Fishery Resource Grant ProgramProject Number FRGP – 2014-22

AbstractIn the summer of 2015 about 303,000 red crabs were off-loaded in the NewportNews small boat harbor. This activity occurred in part because of a Virginia FisheryResource Grant. The wholesale value of the crabs was a little more than 600,000for the crabs unloaded at the dock. Many of those crabs were sold directly into themarket. However, 48,000 of the 303,000 pounds of crab were put into a live holdingfacility, which was built at the dock. The Fishery Resource grant funded some of theequipment that went into that experimental construction. The majority of the fundsfor site work, construction and equipment for the project were provided by industry.The primary purpose of this fishery resource grant project was to develop the onshore live holding system for deep sea Atlantic Red Crab caught in off-shore Virginiawaters. A live holding system makes crabs continuously available so that bothexport and domestic markets can develop. Hopefully a live holding facility willassist a Mid-Atlantic fishery to grow to a catch of a million pounds or more.The capital-intensive on-shore refrigerated recirculating marine water system wasbuilt at Casey’s Seafood, 807 Jefferson Ave., Newport News. By the time system wascompletely operating it could hold water at a temperature less than 40 F and keepthe water clean in which the crabs were held. The system’s capacity was about10,000 pounds of live crabs.The biological filters in the system use natural nitrifying bacteria to reduce andeliminate ammonia in the water, which is produced by the crabs. Ammonia must bereduced or eliminated from the water or the crabs will die. Because the bacteriamust build naturally in the filters it took most of the summer to condition them.They are now fully functioning and able to remove both ammonia and debris fromthe seawater in the holding system. The crab boats supplied the initial seawater inthe system and subsequent exchange water. The boats took the water on-boardwhen far offshore. Before the filters were fully functioning, the crabs in the systemwere kept alive through frequent water exchanges. Because the biological filters arenow fully functioning, exchanges are less critical but must still be done on a periodicbasis to maintain water quality.Bringing the filters on line required close collaboration between industry andacademia. Frequent water quality samples of the recirculating system were doneduring the summer. Tests for total ammonia, nitrite, nitrate and alkalinity weredone in order to ascertain when the filters were coming on line. During this processindustry personnel learned how to operate the filters. Industry employees, withoccasional university consultation, can now keep the filters running.2

Project’s PurposeCreate a sustainable year-round Mid-Atlantic deep-sea red crab industry by building outand improving local red crab infrastructure so industry participants can continuouslysupply domestic and foreign markets with live crab. The primary infrastructure needs arelive holding system, which can maintain high quality crabs for extended periods of time.The market has the potential to expand to over 1 million pounds per year as there isapproximately that much quota available.Project DescriptionA large recirculating marine seawater system, capable of holding in excess of 10,000pounds of live red crab was built in the Newport News commercial small boat harbor atCasey’s Seafood, 807 Jefferson Avenue, Newport News, VA 23607. This system wasintended to provide a continuous supply of live crabs to both domestic and internationalmarkets.Construction of the large holding system in Newport News was almost completewhen this photo was taken in April of 2015.With the exception of the deep-water ocean pressure, the holding system is capable ofmaintaining water parameters similar to the ocean conditions where the crabs are caught.The crabs are caught at depths of 2,000 feet in water that is 40 F. Red Crabs manage thedramatic pressure differential between were they are caught and the ocean surface3

without apparent physiological stress. Red crabs have been held in a live holding systemat the Virginia Seafood Agricultural Research and Extension Center for as long one year.A smaller live holding system, which could hold about 500 pounds, was installed atGraham & Rollins, 509 Basset Street, Hampton, Virginia 23669. Its purpose was tosupply crabs to the retail operation and also allow Graham and Rollins to experiment withpicking red crabs if the supply of blue crabs wasn’t sufficient to keep their picking houseoperating at peak efficiency. However, after a summer’s experiment with the system,Johnny Graham, the president of G&R, decided that it wasn’t efficient use of his coldroom and that the bigger holding system could supply whatever needs he had. Heremoved his system.Outfitting the boat that was originally slated to fish for red crabs in the Mid-Atlantic, theBenthic Lady, was not completed. So it was not sent fishing and the research intended tobe done on it was not accomplished. Instead another boat, the Hannah Boden, did mostof the fishing, in the summer of2015, for the red crab. In all about300,000 pounds of red crab wasunloaded at the dock from theHannah Boden and one other boatthis summer. All the boats that fishfor red crab have RefrigeratedSeawater holds.However, the boat had a catchcapacity of 40,000 pounds, whichwas too large for the systems inNewport News. So it operated at lessthan peak efficiency. It broughtcrabs to the dock between May 19and September 9, 2015.A smaller boat, the Sea King, with acapacity of about 15,000 pounds anda handling system that will easeunloading is being retrofitted in aboat yard currently. She will havegreater water-cooling capabilitiesthan the larger boats and will beoutfitted with heat exchangers.The Hannah Boden supplied crabs to theproject in the summer of 2015. She was oneto the two boats that survived the “PerfectStorm.” A bestselling book and moviedetailed that harrowing storm.4

This will allow the boat to maintain higher quality since fouled water in the hold becausecan now be rapidly exhausted while pulling clean ocean water into the hold. The heatUnloading redcrabs from therefrigeratedseawater hold ofthe HannahBodenexchangers will enable transfer of the stored cold energy from the chilled exhaust waterto the warmer incoming ocean water. Then the increased mechanical chiller capacity ofthe boat should be able to finish the job of cooling the water to 40 F. Last summer theHannah Boden sometimes had to idle at the fishing grounds for 18 hours waiting for thechillers to cool the water to the desired temperature. The crew does not start fishing untilthe water in the hold is cooled to 40 . The improved chilling capacity may increase therate of water exchange on the trip back to the dock. This should allow the boat to arrivewith little free ammonia in the hold water. The on-shore filters can rapidly eliminate theammonia that is in the water that is pumped off the boat into the land based holdingsystem. None of the red crab boats have room to carry biological ammonia filters.Specialized Equipment UsedThe large holding system in the small boat harbor uses mechanical devices to chill or heatthe water, filter solids and microscopic proteins, reduce ammonia and kill bacteria in thewater that circulates over the crab. All these water quality control devices are on a “sideloop” that is independent of the system that supplies water to the crabs in the trailer. Themachines in the side loop are:1.Two 5-ton heat pumps/chillers.The pumps were custombuilt by Larry Yee,Queens, New York. Whencrabs are in the trailer thetarget water temperature is40 F. Depending on theambient temperature, thepumps can either heat orcool the water. The pumps5

are somewhat redundant. If one malfunctions the water can still be cooled, preventingcrab loss.2.Two Aquaculture Systems Technologies Propeller-Washed Bead FiltersThe large propeller wash bead filters catchthe “solid” debris that accumulates in thesystem. There is a sight glass in the top ofthese pressurized filters, which go fromwhite to dark when the filters haveaccumulated debris. When the filters getdirty a propeller is turned on to agitate andknock the debris from the floating beads.The accumulated debris settles to thebottom of the filter and is exhausted bygravity flow before the tank is put back online.When the crabs are in the tank, the filters need to be back-washed once a week. Ifpressure gauge reading in the tanks increases it is an indication that the filters arebecoming clogged. In addition to catching solids, these filters also eliminate someammonia as nitrifying bacteria clings to the solid beads.3.One 80 watt UV Sterilizer 45 gpmThe Ultra Violet Sterilizer is afterthe solids filter because it needs clearwater to work. Rays from the ultraviolet tube do a non-selective kill ofthe bacteria in the water that ispushed through the sterilizer. If thewater is cloudy the sterilizer is lesseffective. Most of the beneficialnitrifying bacteria clings to the beadsin the filters and is not pushed intothe sterilizer. The bulb needs to be changed every nine months or so to maintain peakefficiency. The sterilizer is the last component in the side loop to be fully pressurized.6

4.Two fluidized bed ammonia filtersThese relatively simple filters do the heavy lifting as far as ammonia removal isconcerned. There is an air manifold in them powered by a blower. Air from the blowerbubbles through the water and keeps the specialized “Kaldnes” beads, commonly calledKMT, in the filters fluidized. KMT, invented in Norwegian universities in the 1980s,have multifaceted surfaces in each bead, which the ammonia (nitrifying) eliminatingbacteria can cling to. There are interiorpassages through the bead is that protect thenitrifying bacteria so it can follow a natural life cycle from generation to death and thenregeneration. The dead and spent bacteria are constantly replaced with younger heavierfeeding bacteria. As the beads tumble in the bubbling water they self clean. Surface arealargely determines ammonia removal capacity. The quantities of nitrifying bacteria on thebeads move up and down in response to the amount of ammonia in the system.5.One Regenerative BlowerA Sweetwaterregenerativeblower forces airthrough thefluidized bedfilters with arotating impeller.This type ofblower is muchmore efficient thana compressor insituations werelow air pressure can do the job. The impeller doesn’t touch anything as it spins so theseblowers last a long time and require relatively little maintenance.7

6.One RK2 25PEm 25-40 gpm protein skimmer with venturi pumpIn addition to the solid waste and ammonia in thesystem there are organic substances in the waterfrom crab metabolic by-products, algae, etc. Thesedissolved materials create water turbidity lesseningthe UV’s effectiveness and cause other problems.Venturis in the protein skimmer or foamfractionator inject fine air bubbles into a watercolumn. When that happens the aforementionedmicroscopic pollutants attach to the bubbles andmake foam. This foam can then be skimmed orremoved from the water column keeping the waterclearer and cleaner. In the RK2, in the picture tothe right, air is injected into the water column inthe gray canister. Organic substances in the waterattach to the bubbles and foam. The foam is thenfloated off through the clear Lucite canister at thetop of the skimmer. Most of the water is returnedto the reservoir.You can sometimes see nature’s own foamfractionator at work in the ocean surf. The foamcoming off the ocean is created in the same way it is in the protein skimmer.7.Side loop pump for the water cleansing systemWater is supplied to the cleaningand sanitizing system by a small 2inch pump. It is the same type ofpump that is used in many homeswimming pools. Once the watermoves through that side loop systemit is recirculated into the trailersystem.8

8. Crab TotesThe crab’s claws are banded when they are caught and held in arefrigerated seawater hold. When unloaded and placed in the liveholding system trailer, the crabs are packed in stacking fish totes.The totes are constructed so they nest one way and stack, withoutnesting, when turned 180 on each other. About 40 pounds of crabgo into each tote. The totes are stacked four high and under acascading water stream coming from a manifold attached to theceiling of the trailer. A fifth but empty tote is placed on top of the“four stack” to protect the crabs in the top tote from the pressurizedwater cascading in the totes. Each of the totes has a series of holesdrilled in the bottom of the tote. The holes allow water to drain tothe tote below. However, the rate of water coming from the supplymanifold is greater than the drain rate of the totes. Because of thisdifferential each tote eventually fills with water, immersing thecrabs completely. Water then spills over theside totes while also continuing to drainthrough the tote bottoms. The trailer is slightlysloped so water coming from totes goes to adrain to the reservoir below the trailer. Thatreturned water is then cleaned and sanitized inthe “side loop” system (described in 1 through6 above) and then recirculates back throughthe trailer.A two-way valve at the front of the trailer canbe adjusted to control the amount of watersent to the manifold (the gray pipe in thepicture) that supplies the water to the crabtotes. The white stopcocks are opened asstacks of crab filled totes are moved belowthem. Only the stopcocks are opened that havetotes beneath them. If there aren’t many crabsin the trailer, the valve in the front of thetrailer is kept mostly open so that the supplypump does not have to pump againstOnly the bottom four totescontain crab. The top tote isto catch water coming fromthe pipe above and let itdrain down through thelower totes.backpressure. Backpressure causes extra wearon pumps and increases electricity bills.9Drain holes inthe bottom ofthe tote

9.4” trailer supply pumpIt takes a large pump topull chilled and cleanedwater from the reservoirand push it up to themanifold in the trailerabove. The pump motor isfive horsepower.10.One 39x8X3 foot fiberglass water reservoirThe approximately 7,000 gallon capacity reservoir tank is fully insulated and holdstemperature well. It is not filled to capacity when operating.This picture shows how the chillers, filters, UV and skimmer, which are discussedabove, are hooked together.10

ResultsThe system received its first crabs from the Hannah Boden on May 18, 2015. Betweenthen and September 9, 2015 a total of 13 trips were made with a total weight of 302,884pounds packed. Of that total 47,815 went into the holding system. The dates and totalpounds packed and pounds into the holding system for each trip are reported in TableOne. Subtract the live system quantity from the totallandings for each trip to determine the quantities soldTable One.across the dock on the day the boat landed. TheNewport News 2015 Redquantities in the live system were then sold in subsequentCrab Landings in LBS.days before the boat landed again with more crabs. Thisallows for a more continuous availability of the red crabsto the market.Wholesale prices vary depending on quality, quantitypurchased, sort, whether delivered or picked up, etc.Accounting for those variables, industry participantsestimated wholesale value of red crabs packed inNewport News during the summer of 2015 at a littlemore than 600,000.Red crabs packed in Newport News this past summerwere sold in both domestic and foreign markets. Most ofthe domestic sales were along the East Coast fromVirginia to Florida. Virginia markets did not develop tothe extent expected because it turned out to be the bestblue crab seasons in some time. Blue crabs were lessexpensive than they had been in previous seasons.Newport News live crabs were successfully shipped toChina this summer by a wholesaler purchasing the crabsat the dock.Since the filters are now actively and quickly reducing ammonia, it is hoped even betterred crab markets can develop. It took more than three months for the nitrifying(ammonia eliminating) bacteria to build in the tanks. When crabs are constantly beingadded to the system and removed it can’t be accurately determined how well theammonia filters are working. That is because the quantity of ammonia the crabs areputting into the system is unknown.However it is clear that initially the filters were not eliminating much ammonia.Attempts to condition the ammonia filters, prior to installation, were not successful. Itrequired time for them to condition naturally.At first the crabs in the holding system were kept alive mostly by water exchanges fromthe landing boat. Each time the boat landed, the reservoir in the holding system waspumped down and new, higher quality chilled ocean water from the hold of the boat was11

pumped into the system. Crustaceans can handle higher ammonia levels than fish.However initially ammonia levels in the holding system were not well controlled. OnJune 22, 2015 the Total Ammonia Nitrogen (TAN) was measured at an unacceptable 41parts per million. (TAN is made up of NH3 and NH4. It is the NH3 that kills marinelife.) This high TAN level necessitated shipping some of the crabs to New Bedford forprocessing before they died. Subsequently less crabs were put in the holding system andgradually the ammonia filters began functioning. On the last big load into system crabslived in the system without water exchange for three weeks until they were all sold.Ammonia levels were reduced but not low as desirable. The filters have continued tostrengthen since that time. (See appendix for a report of all the water quality tests taken.)Then pumps had to be disconnected from the reservoir because of the threat of saltwaterflooding from the strong offshore winds produced by Hurricane Joaquin. The stormsystem put five inches of water over the office floor where the holding system is located.The pumps would have been submerged in saltwater had they not been disconnected.The disconnected slightly hurt the filters because no water was being pumped throughthem. However, air continued to be bubbled through the two fluidized bed filters as theregenerative blower did not have to be disconnected. The filters built strength rapidlyafter the pumps were reconnected. With no crabs in the system, chemical ammonia hadto be added to the system to feed the nitrifying bacteria that took so long to build. Sodiumbicarbonate also needed to be adjusted to between 140 and 180 parts per million in orderto keep the filters healthy. Greg Casey was trained in how to do this.With no crabs in the system, TAN was boosted artificially to 10 ppm three times. Thefilters reduced the TAN level to almost zero in two days. It may even be sooner than thatbecause water tests have been spaced out for at least two days. In this relativelycontrolled environment, the filters eliminate ammonia. The real test will be when a fullload of crabs is placed in the trailer.ConclusionsDeep-sea red crabs can be successfully kept alive in an on-shore holding facility once thefilters are successfully conditioned and maintained. The on-shore facility appears to befully functional. That should make crab continuously available to markets, once the SeaKing gets out of the boat yard and starts to supply the facility with crab. Water quality inthe holding facility is high which should allow the holding of very high quality crab.Dependable availability should allow both domestic and international live markets toexpand and the red crab industry to become more firmly established in Virginia.AcknowledgmentsThe collaborating companies wish to recognize and thank the valuable expert assistanceprovided by scientists at the Virginia Institute of Marine Science and staff at the VirginiaTech Area Seafood Research Center in Hampton. Virginia. In particular we wish to thankDr. Dan Kaufmann for his assistance in preparing this final report.12

AppendixRecord of water quality tests taken during the summer of 2015Water /26/2015 BoatAM5/26/2015 TankAM5/26/2015 l day weekend26.250.1684.4320NAwater dark almost 30.1174.33005/29/1514.250.1093.63406/2/2015 Fore1.880.0262.21306/2/2015 Aft5.350.0592.41606/2/2015 720084.130.034.91807.89.40.076252007.4boat came in with foamCrabs added6/9/2015 Fore6/9/2015 Aft6/9/2015 Live7.9crabs addedcrabs ned torrentially64 oz of nitrifying bacteria addedreservoir loaded with foamfoam coming out of the reservoirUrick did 6/15/15 sampleBucket test for alkalinity 6/16Student did H20 test 6/16Skimmer not skimming A.M. 6/166/18/15450.0425.93608.21Urick did testskimmer working, water andfoam with black organics6/19/1537.50.0452.83608.2less foam water appeared bettersalinity 27.56/22/156/22/1540.75before dilution urick did testadded water with sump onincoming tide after dilution urickdid test2813

6/23/1532.5Urick did6/24/15 Fore9.56/24/15 Aft8.6Urick did all 3tests 6/2420tank salinity 28.3; boat waterpumped on shore but no crab insystem when sample drawnwhite foamOn 523.750.0462.22207/1/15 Fore7.307/1/2015 ty 31.1salinity 29. More boat wateradded after 2,000 lbs of crabwere put in the system. Foam ontank. Foam still white but blackorganics on top of foam. UrickRain the previous night.SquadritoRain over the weekend.SquadritoFair amount of foam in tank.Black organics in it. Student didtest8.425.67.3832.17.531.7Squadrito-Urick (salinity/pH)Squadrito-Urick nitrate phsalinity2008.129.2Some Boatwater already in tankwhen sample drawn @ 8:15 a.mSquadrito-1992 lbs into Trailertotal 250015.371608.1528.9foam below bottom of deck;white but with black flecks; Urick7/6/15 sk'mmr18.632208.327.6little foam on the tank; 1,000 lbcrab in tank, Squadrito7/7/15 sk'mmr21.887/8/2015 sk'mmr14.137.929.6sample taken at 8:10 a.m. afterboat pump7/8/2015 Fore7.387.529.6Boat samples early a.m.7/8/2015 Aft8.637.4Water still being pumped fromboat8.029.5Squadrito, little foam in the tank.Water clarity good 1100 lbs intrailer29.2Squadrito, No foam, Waterclarity good 200 lbs in tank7/1/15 shoreskimmer16.507/2/15 607/20/15 shore tankb4 any boat water20.25Urick6Urick7/20/15 fore tank7/20/15 sk'mmrafter boat water7/21/15 sk'mmrUrick, a little foam in tank,nocrabs in trailer14.5157.61430Urick, but crab not yet added30Urick, little foam, 1700 lbs intrailer, no water exchangesubsequent to sk'mmr tanmeasurement 7/20 crabs added7/20

7/24/1516.757/28/15 skimmr10.757/31/15 skimmr25.758/11/15 skimr19.258/12/15 skimr15.759/9/15 fore tank8.759/9/15 aft tank14.38TAN9/11/157.80.2090.3489.41803029Urick, slightly more foam withblack flecks, 1900 lbs of crabadded to tank (7/27) with 400still in there from last week.Crabs added 7/2728Urick, about 1500 lbs in tank.Water clarity excellent, tan upmore than during similar periodlast week. Possibly cuz of weakcrabs8278.127Squadrito, very little foam in thetank, water clarity good, 150 lbscrab left in trailer & all of thatwill go out today. Next crabs notuntil next Wed. Aug 12Urick, no crabs in system for 4days. 6.5 drop in TAN first solidindication filters are kicking in.NO2 4 times higher thanprevious best (confidence intests)30Urick, boat water exchange,1300lbs of crabs into trailer, boatcaught 20,000-all shipped exceptfor those in trailer27Urick, 1500 lbs in trailer on 9/19.900 still there on 9/26. Dataindicates filters are cycling12.258/26/15 skimmr9/9/15 skimmr7.7178/7/15 skimmrDate7.8Urick, thin layer of foam someblack flecks in it, 900 lbs in trailer1500 yesterday7.7Squadrito. This TAN was turnedaround quick enough that redcrab participants used it to makereal time shipping .8PPTSalt28.7CommentsSqadrito. Reading after exchangefrom the boat but no crabs inthe trailer. Shore tank waterbetter than aft tank, but not asgood as fore tank. Indicatesshould not do further exchangefrom aft. Boat landed withapproximate 30,00. About 5,200in shore trailer system butprobably some of those will betaken out.Urick. Boat in on 9/9. As many as5700 lbs of crab were put in thetrailer while boat unloaded andby the end of the day 4800 in thetrailer. On 9/10 another 1000were sold so this reading wastaken with about 3800 lbs intrailer

.0260.2510/8/15 skimm10/9/15 tank10/9/157.6Squadrito. 800 lbs soldyesterday, leaving about 1200 inthe trailer. Out of those 800,about 25 lbs were found dead orabout 3%. If that ratio applies tothe remaining crabs in thetrailer, there are about 40 lbs ofdead crabs in the 1200.Tomorrow this group of crabswill have been in the trailer for 3weeks.No crabs in tank. Jim removedboth the main 4"pump andsideloop 2" pump last Thursdaybecause of coming high lunartides. Reconnected the 2" pup onMonday. Will probably have totake it down again becauseJoaquin. Lowest TAN readingsince May 180.86Joaquin and strong offshorewinds led to 12 consecutive hightides. Both pumps had to bedisconnected. Casey's had 6"water in the office. Two inchpump reconnect on 10/61.18Tank water at 42F & skimmerwater at 61. Always had somedifferential but not that big.Need to scope out. Also will startfeeding the tank ammoniumchloride to keep the nitrifyingbacteria alive.1.26Just a little ammonium chlorideadded to tank-about 12 gramsAdded two small scoop ofammonia10/10/1510/12/150 10/12/1510/13/15Measure with stripsAdded two small scoops ofammonia3 .5-- 1Strip measurement rick. The 3800 lbs remained inthe trailer 6 days. This morning(9/16) another 1,020 sold. Deathloss 144 (12% of those pulled).After morning sales about 2600in the tank. 3 or 4 inches of foamon the tank.Spectophometer MeasurementSpect measurement. 860 gramsof ammonium cloride added totankStrip measurement a.m.Strip measurement after 250grams of ammonium chlorideadded316

23-Oct7.7410/26/158.9SpecAnother 250 gramsammonium cloride & plenty timeto mix. Spec measurementsubsequently.Spec added 5 lbs sodium bicarbsubsequently 20spec a.m. reading added fivepounds of sodium bicarbsubsequent to 50 reading10/27/157.95010/27/157.8120spec p.m. reading10/29/156.55110spec; a.m. reading added 2.5bicarb after reading10/30/155.4 100spec outof rangespec a.m reading added another2.5 lbs of bicarb after readingspec added another 2.5 lbsbicarb12010/31/15120speca.m reading added 500grams ammonia in p.m.4.85180spec; added 5 lbs bicarb @ 6a,sample taken @11a11/5/150.21150a.m. sample 1/13/150.1914082Greg added 8 lbs bicarb, 1.5 lbammonia after sample taken11/16/150.1118012Greg adds 2 lbs ammonia and 1lbs of bicarb in 5.5 155.517I added bicarb and ammonia at10 a.m. Sample taken at 1.sample 8:30 a. Greg added 5 lbsbicarb and 1 lb ammonia at 2:30p. yesterday Guesstimateyesterday p.m150 Alkalinity and5 tansample taken at 2:30

5. One Regenerative Blower A Sweetwater regenerative blower forces air through the fluidized bed filters with a rotating impeller. This type of blower is much more efficient than a compressor in situations were low air pressure can do the job. The impeller doesn't touch anything as it spins so these