Dephosphorylation

The Process of Removing Phosphate

This is the third installment of a discussion from the Shrimp List, a mailing list for the shrimp farming industry.  The first installment covered managing pH in biofloc ponds.  The second shifted the discussion to managing phosphates in biofloc ponds.  That discussion continues here:

Adam Body (a.body@bigpond.com): Some weeks ago we had a discussion on the Shrimp List about phosphate management in shrimp ponds.  I have collected some information on the topic and posted it to our website.  It includes some of the things that we are finding out about our ponds and the way the algal bloom reacts when we take out free phosphate.  You can check out that information at http://www.flickingfresh.com/Phos/A new tool for pond managers.html.

I’m very keen to hear from anyone who may have some experience or knowledge about  “alkaline phosphatase” because I think it is playing a role in the pond, but I really don’t know....

A Little Help from Wikipedia: Alkaline phosphatase is a hydrolase enzyme responsible for removing phosphate groups from many types of molecules, including nucleotides, proteins and alkaloids.  The process of removing the phosphate is called dephosphorylation.  As the name suggests, alkaline phosphatases are most effective in an alkaline environment.

Alan (alphafourdoji@live.com): I would also be interested in such a discussion.  I recently patented a process for reducing phosphates in wastewater by culturing a phosphate reducing floc in an aquaculture system.  My research has shown that the phosphate reducing floc can be cultured using standard practices.

One of the references on your webpage suggests a phosphate threshold of 0.03 ppm (mg/liter).  I think that might be a typo.  I have found the threshold to be closer to 3.0 ppm.  I don’t even have a phosphate kit that would measure the small ranges mentioned on your web page.  One of your references says:  “Practice suggests that pond PO₄ levels should be kept around 0.05 - 0.2 ppm until the Secchi transparency reaches about 45 cm.”  My kit only measures phosphate from 0.25 to 10 ppm.

Any comments?

Dallas Weaver (deweaver@mac.com): Interesting that you got a patent on it (number and country?).  For decades, the sewage treatment industry has been using bioflocs to remove excess phosphate under aerobic conditions.  Then, they feed it back up under anaerobic conditions.  It seems that the old concept of  “obviousness to practitioners of the art” is no longer relevant in patent law.

If you want to use phosphate limitation to control algae species or growth rates, you are talking about a lot less than a 3-ppm (parts per million) threshold.  That 3-ppm level will grow enough algae to crash a pond on low DO.  I don’t know the correct level, but I do know it is much less than 3 ppm.

Alan (alphafourdoji@live.com): Interesting.  Since my application and usage are unlit tanks under intensive aeration, the crash did not occur, and I was showing phosphate above 5 ppm without a crash.  The critters just didn’t grow at these high levels, and ammonia appeared to be burned without additional carbs; that is, the ammonia wasn’t available to create proteins because it became nitrogen gas.  Again, I don’t have specific proof, but I saw small bubbles that appeared to be nitrogen on the tank surface.

The United States Patent Office issued the patent, Number 7,736,509.

I have found that phosphate is a necessary component to feeding my shrimp (creating lipids).  I hope that is no big surprise.

Adam Body (a.body@bigpond.com): Alan, I use the Palintest photometer and the low range (LR) set of reagents which are very capable of measuring the low ranges mentioned on our webpage.  So, no, the figure is not a typo.  Only under 0.1 mg/l PO₄ do I see any significant changes, and under 0.05 mg/l PO₄, it can really make a difference to the pond bloom.  I am measuring free PO₄ with the sample filtered through a 1-micron filter, and the numbers all relate to mg PO₄ per liter.  As far as generalities about PO₄, I would be extremely reluctant to transfer these figures to other farms or operations because all farms are different (soil types, feed inputs, water parameters), but I can state that having the ability to selectively take out PO₄ simply and cheaply gives managers a degree of control over their algal blooms that they have not previously had.  How they apply this new management tool is up to them, but a good first step would be to begin monitoring your PO₄ to see if its levels are affecting your algal bloom.

Alan (alphafourdoji@live.com): I control tank blooms by recording the amounts of carbs, nitrates and phosphates in my system.  When one of them gets out of balance, I change the percentage of it in my feed.  My worst mistake was adding too many carbs and getting fungal blooms.  They seemed to affect gill function and cause disease.  By limiting the carbs and without a strong light source, the phosphates seem to have no possibility of creating an undesirable bloom, which might explain why my system does not crash with such high phosphate levels.  It also says something about the differences between indoor tank culture and outdoor pond culture.  I ran out of test reagents last week and just received a new shipment.  I am currently working on dropping my PO₄ level from 5 mg/liter!  The shrimp are OK.

Phosphate levels change from day to day.  Check them on a clear day, then on a cloudy day.

Adam, I am almost certain that your ponds could biologically  “sink phosphate laden wastewater” by the biological processes outlined in my patent.  If you can manage a pond at those precisions, I could probably throw a very high phosphate laden wastewater in your ponds, and it would sump out most of the phosphate before your test kit could measure a change.

Robinson Bazurto (buhocol@hotmail.com): Using an algal turf scrubber, you are able to remove huge amounts of TP (total phosphorus) and TN (total nitrogen) and reduce TSS (total dissolved solids).  In addition, an algal turf scrubber increases DO levels, requires less labor and provides algae, which can be used as a feed.

Adam Body (a.body@bigpond.com): Alan, thanks for the comments.  As you indicated, there is a very big difference between tanks and large outdoor ponds.  This probably accounts for our different experiences.

Alan (alphafourdoji@live.com): Adam, thank you, too.  I am keeping one outdoor tank, and as if on cue, it experienced a bloom, which stressed the shrimp.  I think I dodged a bullet because I wasn’t hitting them with too much phosphate.

Eric De Muylder (eric.de.muylder@skynet.be): I am surprised that nobody talks about avoiding high phosphates in the water in the first place.  That should to be the focus.  One of the reasons for high phosphate levels in shrimp pond water is the utilization of low available phosphate sources like monocalcium phosphate and dicalcium phosphate in shrimp feeds.  It has been proven over and over that they are not available to the shrimp, but most South American and Asian shrimp feed manufacturers are using them.  Removing them from shrimp feed, which would not affect shrimp growth, should be the first step in reducing phosphates in pond water (and effluents!).  The next step should be adding digestible sources of phosphates to shrimp feeds.  The problem here is that some of those sources are highly water soluble and leach out of the feed pellet before the shrimp consume them.

David Griffith (drwgriffith@gmail.com): Eric—of course, of course—that’s the first thing we looked at and indeed are still discussing it with our feed supplier.  We don’t use monocalcium phosphate or dicalcium phosphate in our shrimp feeds.

What has been an important issue however is our elevated FCRs (feed conversion ratios) caused by low survivals, so indirectly the feed, whatever its source of PO₄, is the major cause of the problem.  With better survival rates and consequent improvements in FCRs, the problem will be reduced, no doubt, but not resolved.

Source: The Shrimp List (a mailing list for shrimp farmers).  Subject: Phosphate Management.  August 13–25, 2010.

Country Reports

Australia

National Algae Collection

The Australian National Algae Culture Collection (ANACC), housed in world-class microalgae culture facilities by the Australian Quarantine and Inspection Service, contains more than 300 algal species and many strains within those species.  It specializes in environmentally and economically significant marine microalgae isolated from tropical and Antarctic waters.

CSIRO Microalgae Supply Service, a business adjunct to ANACC, supplies the world with high quality microalgae starter cultures for research and business applications.

All cultures are grown under controlled environment conditions and selected strains are axenic (bacteria-free).  Other services available under collaborative or special arrangements from CSIRO Microalgae Supply Service include: strain deposition, identification and isolation; pigment analysis; and training in culturing techniques.

The most common strains used in aquaculture include northern hemisphere strains such as Chaetoceros muelleri (CS-176), Isochrysis sp T.ISO (CS-177), Chaetoceros calcitrans (CS-178), Nannochlorospis oculata (CS-179) and Tetraselmis suecica (CS-187).

Over the last decade, following requests from the domestic aquaculture industry for endemic strains more suitable to local conditions, CSIRO research has focused on the isolation and characterization of Australian strains.  The most common Australian strains requested for hatchery supply include Skeletonema pseudocostatum (CS-252), Nitzschia closterium (CS-5), Navicula jeffreyae (CS-46) and Nannochloropsis oceanica (CS-246).

Aquafeed.com, a free online newsletter about aquaculture feeds, has published a great list of the world’s algal collections.

Information: John Cooksey, World Aquaculture Conference Management, P.O. Box 2302, Valley Center, California 92082, USA (phone 1-760-751-5005, fax 1-760-751-5003, email worldaqua@aol.com).

Source: World Aquaculture Society.  The CD/Abstracts of Australian Aquaculture 2010.  The CSIRO Microalgae Supply Service: Supplying Quality Microalgae from the Australian National Algae Culture Collection.  Cathy Johnston (cathy.johnston@csiro.au, Manager, CSIRO Microalgae Supply Service, Australian National Algae Culture Collection, CSIRO Marine and Atmospheric Research, G.P.O. Box 1538, Hobart, Tasmania, Australia 7001), Ian Jameson, Lesley Clementson and Susan I. Blackburn.  Hobart, Australia, May 2010.

China

Job—Sea Cucumber Technician

The Lim Shrimp Organization (consultants for shrimp farming projects) is looking for a qualified sea cucumber technician for a hatchery and sea ranching project in the Pacific Islands.  Applicants must have at least three years of experience with the maturation and growout of sea cucumbers.

Information: Djames Lim (CEO), Lim Shrimp Organization, 1 Maritime Square, Unit 09-06, Harbour Front, Singapore (phone 65-90622467, email djameslim@limshrimp.com).

Source: Email to Shrimp News International from Djames Lim.  Subject: Technician Wanted - Tropical Sea Cucumber.  August 21, 2010.

Indonesia

Government Must Revitalize Its Fishery Program Soon

On August 23, 2010, Riza Damani, Secretary General of the People’s Coalition for Fishery Justice, said,  “The government must revitalize [its fishery] program soon.”  He said in Lampung Province there were at least 25,000 hectares of shrimp ponds that should be revitalized because their production is very low.

Riza Damani also asked the government to take stern actions against companies that take over traditional ponds and then make management changes that violate environment regulations.

Diseases are spreading from Lampung Province in Sumatra to East Java and South Sulawesi.

The Ministry of Maritime and Fisheries hopes to complete a special shrimp and fish disease research center in Central Java by the end of 2010.

Source: Seafood.com (an online, subscription-based, fisheries news service).  Editor and Publisher, John Sackton (phone 1-781-861-1441, email jsackton@seafood.com).  Indonesian Government Urged to Upgrade 25,000 Hectares of Shrimp Ponds to Boost Production.  August 24, 2010.

Indonesia

Shortage of Product, Processors in Trouble, Want to Import Shrimp

Some Indonesian shrimp processors may go out of business because of the shortage of product.

Made L. Nurdjana, Director General of Aquaculture of the Ministry of Marine Affairs and Fisheries, said shrimp production in 2010 will only reach 350,000 metric tons, a drop of 50,000 tons from an earlier forecast.

One of the reasons for the drop in production is that Central Proteinaprima (CP Prima), a major farmer/processor, faces financial problems and has not recovered yet.

Mohamad Najiki, president of Kelola Mina Laut, a seafood processor, said he intends to request that the government allow shrimp imports because supplies from farms cannot be guaranteed!

Source: Seafood.com (an online, subscription-based, fisheries news service).  Editor and Publisher, John Sackton (phone 1-781-861-1441, email jsackton@seafood.com).  Some Indonesian Shrimp Processors Facing Business Failure Due to Cutback in Shrimp Supply.  August 16, 2010.

Mexico

Nayarit—Government in the Process of Registering Shrimp Farms

During a recent meeting in the state of Nayarit about the registration of unregistered shrimp farms, Abelino Ortiz Márquez, the local Deputy of Fisheries, said there were 169 shrimp farms in Nayarit, 99 of them already registered.  Soon, 42 additional farms will be registered, 36 in Valle de la Urraca and 6 in the area of Tecuala, Periódico.  You can view some of these farms in Google Earth (a free download from Google).  Search for  “Valle de la Urraca, Mexico”.  Zero in on: 22°33'45” N; 105°38'26” W.

Delegates at the meeting noted that Nayarit’s production of farmed shrimp was greater than the production of wild shrimp from the local estuaries.

Source: FIS United States.  Government Begins Adjusting Shrimp Farms.  Analia Murias (editorial@fis.com).  August 12, 2010.

Myanmar

Shrimp Farming Declining

Shrimp exporters are increasingly relying on the uncertain wild catch because the once-booming shrimp farming industry is in decline.  Buffeted by sanctions, the lingering after effects of Cyclone Nargis and the global recession, shrimp farms have been going downhill since 2004, after several years of good business.

U Hla Maung Shwe, chairman of the Myanmar Shrimp Entrepreneurs Association, said,  “Starting from 1998, shrimp farms boomed until 2003.  But now shrimp exporters rely on the wild catch.  At its peak, from 1999 to 2003, Myanmar was the fourth largest exporter to the USA market after Vietnam, Thailand and the Philippines.  At that time, 95 percent of our farmed shrimp went for export.  Now, only 20 percent is exported, and what’s left is consumed locally....  The USA market accounts for 50 percent of global shrimp consumption.  We lost that big market in 2003 because of sanctions.”  Myanmar still exports to China and the European Union.

In the farmed shrimp trade, Myanmar faces competition from Thailand and Bangladesh, both of which have a tax advantage over Myanmar.   “The EU imposes 13.7 percent tax on Myanmar and Thailand, but Bangladesh is untaxed.  The Thai government refunds 7 percent to its exporters if they export to the EU.  By contrast, Myanmar exporters pay 13.7 percent to the EU and another 10 percent to the Myanmar government,” said U Hla Maung Shwe.

U Tun Aye, managing director of the Shwe Yamone fish processing company, said,  “My factory rarely gets shrimp from farms.  We have to use wild catch, and it amounts to about 60 percent of our exports “.  Shwe Yamone is one of eight fish processing factories in Myanmar that meets EU standards.

Source: The Myanmar Times.  Shrimp Industry Battles Through External Challenges.  Than Htike Oo.  August 23-29, 2010.

Norway

New Law Encourages Lobster Ranching

A new law in Norway grants property rights to sea-ranched lobsters.

Information: http://www.norwegian-lobster-farm.com.

Source: AES News (the online, PDF, newsletter of the Aquaculture Engineering Society).  Editor, Steven Summerfelt, Ph.D. (s.summerfelt@freshwaterinstitute.org).  A Land-based Recirculating Aquaculture System for Production of Market Size European Lobster in Norway.  Asbjørn Drengstig (M.Sc. Managing Director Norwegian Lobster Farm Group, Ltd., P.O. Box 391, 4067 Stavanger, Norway, email ad@norwegian-lobster-farm.com) and Asbjørn Bergheim (Ph.D., Senior Researcher, IRIS 4085, Stavanger, Norway, email asbjorn.bergheim@iris.no).  Volume-13, Issue-2, Page-2, Summer 2010.

Thailand

CP Foods Makes Big Investment

Adirek Sripratak, president of Charoen Pokphand Foods, Plc. (CPF), said,  “We are committed to investing $187.8 million a year over the next five years to expand production of animal feed and livestock at home and overseas.  Over 60 percent of that amount will go overseas, largely to expand existing operations in Russia, India, Turkey, the Philippines, Malaysia and some African countries.”

In the past year, CPF’s shrimp business has profited from a worldwide fall in shrimp production due to irregular weather conditions and the BP oil spill in the Gulf of Mexico.

Source: FIS United States.  CPF Invests USD 939 Mln to Boost Foreign Revenue.  Natalia Real (editorial@fis.com).  August 18, 2010.

United Kingdom

Big Orange Lobster, A Wild American

American lobster in front of a smaller European lobster

What’s unusual about this orange lobster?  It’s alive!  Lobsters are usually a brownish-green color when living and turn orange when cooked.  This rare reddish-orange-colored specimen was found in the UK.  It’s a non-native, a North American lobster (Homarus americanus) named  “Gumbo”.  American lobsters are larger and more aggressive than European lobsters (H. gammarus), and they are frequently caught off the UK coast.

Gumbo has found a new home at the Birmingham National Sea Life Centre.

Paul Clark, a crustacean researcher at UK’s Natural History Museum, said,  “Recent captures of American lobsters by fishermen on the Sussex coast are a serious concern because H. americanus can carry diseases that are harmful to the European lobster, H. gammarus.”

Miranda Lowe looks after the Natural History Museum’s crustacean collection, which includes around 44,000 samples and species collected during the Discovery scientific expeditions of 1925-1951.  From crabs, krill and shrimp, to 27,000 jars of plankton samples, these important collections may contain species that that are now extinct in the world’s oceans.

Source: Natural History Museum (United Kingdom).  Unusual Orange Lobster Saved from the Pot.  August 6, 2010.

United States

Louisiana—Oily Shrimp

On August 12, 2010, Louisiana’s first shrimping season since the BP oil disaster got underway—but few boats took to the water and the ones that did found oil, a major shrimp wholesaler said.   “We got four boats that went out—out of 1,400—and I’m hearing they’re finding oil, “ said Dean Blanchard, the largest shrimp wholesaler in the United States.   “They drag, they find oil, they throw the stuff back in, and they’re looking for cleaner waters,” he said.

Blanchard said he had heard reports that only around 50 boats out of Louisiana’s fleet of around 5,000 had taken to sea for the start of the four-month shrimping season, but it was impossible to confirm that number.

Source: FIS United States.  Oily, Slow Start to Louisiana Shrimping Season.  Editorial@fis.com.  August 17, 2010.

United States

Louisiana—Video, Comic Steven Colbert on Oily Shrimp

For a five-minute video of comic Stephen Colbert satirizing the shrimp that are being harvested from the Gulf of Mexico, click on the link in the Source below.

Source: AmericanBlog.  BP’s Oily Aftermath, Colbert Style.  August 21, 2010.

United States

Maine—Seafood Source Reports on USA Shrimp Imports

After dropping for ten of the last eleven months, USA shrimp imports increased in June 2010, to just over 100 million pounds, up about 6 million pounds from June 2009, according to figures released by the National Marine Fisheries Service on August 11, 2010.  Through the first half of 2010, however, shrimp imports were still down 2.9 percent, to just over 500 million pounds, from the same six-month period in 2009, when they totaled 1.21 billion pounds for the full year.

Imports from Indonesia, last year’s No. 2 shrimp supplier, were down 32.9 percent in May 2010, but, in June 2010, they were down only 5.1 percent, to 11.9 million pounds.  Through the first half of 2010, however, they were still down 26.7 percent, to 64.9 million pounds.  Indonesian farmers continue to battle the infectious myonecrosis virus, which, according to one industry veteran, has affected more than half of the country’s shrimp farms.

Imports from Thailand, the No. 1 shrimp supplier to the USA in 2009, totaled 34.5 million pounds in June 2010, up 2.5 percent from June 2009.  Through the first half of 2010, they were up 11.2 percent, to 176.6 million pounds.

Imports from Ecuador and China were also up more than 7 percent through the first six months of 2010, totaling 78.8 million pounds and 40.9 million pounds, respectively.

They were followed by Vietnam at 30.6 million pounds (down 1.7 percent), Mexico at 23.2 million pounds (down 14.9 percent), India at 15.9 million pounds (down 15.2 percent) and Malaysia at 20 million pounds (up 22.9 percent).

Shrimp imports for July 2010 are scheduled to be published by NMFS on September 9, 2010.

Source: SeafoodSource.com.  Editor, Steven Hedlund (shedlune@divcom.com).  Turnaround for U.S. Shrimp Imports.  August 11, 2010.

United States

South Carolina—Denny’s

On August 20, 2010, Denny’s (1,500 restaurants in the USA) added five new items to its value menu—including a Fried Shrimp Platter that will contain ten deep-fried shrimp, French fries, coleslaw, cocktail sauce, dinner bread and a choice of a soft drink or coffee for $8.00.

Source: SeafoodSource.com.  Editor, Steven Hedlund (shedlune@divcom.com).  Denny’s Adds Shrimp to Value Menu.  August 20, 2010.

United States

Washington State—Costco, Thailand and WWF’s Shrimp Dialogue

Following a letter of concern from some of its shareholders, Costco, one of the largest wholesale food distributors in the nation, has formally begun a  “sea change” in its seafood procurement policies.  In the letter, the shareholders urged the company to adopt a more comprehensive and robust sustainable seafood policy.  To make their case, they cited statistics from the UN’s Food and Agriculture Organization (FAO), a 2006 Science Magazine report on over-fishing—and the possibility that  “shareholder value” could drop because of inappropriate environmental policies!

Additionally, Costco will partner with the World Wildlife Fund to monitor Thailand’s compliance with the Shrimp Aquaculture Dialogue.

Source: PlanetSave.com.  COSTO Adopts Sustainable Seafood Policy.  August 14, 2010.

Vietnam

23 Companies Caught Using Agar to Increase Shrimp Weight

The National Agro-Forestry-Fishery Quality Assurance Department has suspended two businesses from operation for six months for injecting shrimp with agar, making them heavier.  This was the second time the businesses have been found guilty of injecting shrimp to increase weights.  Another 21 shrimp businesses in the southern provinces of Soc Trang, Bac Lieu and Ca Mau were also found to have used agar for the first time.

Source: Viet Nam News.  Operations Stop at Two Shrimp Processors.  August 12, 2010.