When salmon is farmed in large-scale monocultures, the fish tend to become susceptible to disease and parasites. Researchers working for the organization Nofima have now found a way of combating the parasite salmon lice in fish farms without using any dangerous toxins. Wrasse loves to eat lice, so the researchers simply added wrasse to the salmon populations and the result was astonishing.

During the trials, the most efficient lice eater turned out to be the Ballan wrasse (Labrus bergylta). In addition to being highly efficient, it also gathered lice at lower temperatures than the other Wrasse species that took part in the experiment.

When Ballan wrasse was used, roughly 2-5% wrasse was needed for salmon living in sea cages. This means that a population of 100 000 salmon will need somewhere between 2 000 and 5 000 wrasse to stay deloused. A new larger project will now be prepared to make sure there is an adequate supply of the lice eaters in Norway. The project will go on for three years and has received funding from The Fishery and Aquaculture Industry Research Fund (FHF).

The effort which is now commencing is unique in both a Norwegian and global context. Norway is the only salmon-producing country that is using wrasse on a large scale to combat salmon lice,” says Arne Karlsen, managing director of FHF.

Removing large amounts of Ballan wrasse from the wild to keep in salmon farms could cause serious damage to the wild populations and the goal of the Norwegian project is therefore to cover at least 25% of the demand with farmed wrasse by 2013.

In addition to Nofima and FHF, the project will also involve SINTEF Fisheries and Aquaculture, the Institute of Marine Research and the Norwegian University of Science and Technology.

Several Norwegian projects are already taking a closer look at the Ballan wrasse, including a research venture concerning Ballan wrasse farming that started last year with funding totaling NOK 12 million from the Research Council of Norway, FHF and industry partners.

” It is estimated that the total Norwegian effort on Ballan wrasse farming is in the vicinity of NOK 100 million,” says Kjell Maroni, research and development director at FHF

The researchers will now have to find out how to carry out large-scale wrasse farming without being plagued by the same problems with disease and parasites as the salmon farms.



Fish with Ich Credit: Dehai Xu, Ph.D

According to new research presented by Dehai Xu, Ph.D. at the 240th National Meeting of the American Chemical Society (ACS)*, a vaccine against the feared ich disease might be available in the foreseeable future.

Ich is a disease dreaded by hobby aquarists and professional fish farmers alike. It is caused by the ciliated protozoan Ichthyophthirius multifiliis (hence the name ich) and can easily kill of all the fish in an aquarium or fish pond. Fortunately, it seems to be unable to infect humans. Among aquarists, it is chiefly known as White Spot Disease since the parasites cause small white nodules to form on the skin and in the gills of infested fish.

Today, ich outbreaks in large commercial fish farms are often treated by adding hundreds of gallons of a formaldehyde solution to the water. This is far from an ideal solution, since formaldehyde can be toxic to both humans and fish. It is classified as a known human carcinogen by the WHO International Agency for Research on Cancer (IARC) and is associated with both nasal sinus cancer and nasopharyngeal cancer. And as anyone who has ever combated ich in an aquarium knows, ich treatment is something you have to do over and over again since the parasite is usually only sensitive to treatment during one of its multiple life stages. This means repeatedly adding large quantities of formaldehyde solution to the pond. Even when formaldehyde ich treatment is successful, it provides no long-lasting effects since the fish develops no immunity. If new outbreaks occur, a new treatment cycle has to be carried out.

It is therefore no surprise that the series of vaccine tests carried out by Dr. Xu and his colleagues Dr. Phillip Klesius and Dr. Craig Shoemaker, who are with the U. S. Department of Agriculture’s Agricultural Research Service (ARS) in Alabama, have sparked vibrant interest within the aquatic world. For anyone from commercial fish farmers to public aquaria and hobby fish keepers, an ich vaccine would be a dream come true.

“Outbreaks of the parasitic disease caused by Ichthyophthirius (Ich) can result in losses of 50-100 percent of fish,” Dr Xu explained while presenting the team’s findings at the ACS meeting. “The disease is very common, and almost every home fish hobbyist has encountered it. Once the parasite infects fish, and starts growing in the skin, fins, and gills, there is no really effective treatment. Ich causes losses estimated at $50 million annually. It would be much better to prevent the disease. To vaccinate against Ich, you would need much less medication, and it would not pose an apparent threat to the environment. And you would need just one treatment to make the fish immune for life.”

In their efforts to develop a vaccine, Xu and his colleagues have focused on the use of so-called trophonts.

The ich protozoa goes though three life stages:

• The ich trophozoite feeds inside the nodule (”the white spot”) on the skin or gill of the fish.

• The ich trophozoite falls off and becomes an ich tomont, i.e. it enters an encapsulated dividing stage. During this stage, the tomont is attached to plants, gravel or other objects in the environment.

• The ich parasite will then start dividing itself, producing trophonts. The trophonts will move around freely in the water, looking for fish to infect.

Trophonts burrow into the skin and fills of a fish and start to feed, thus completing the cycle. When Xu, Klesius and Shoemaker began their research project very little was known about how fish develop protective immunity to trophonts, so the researchers basically had to start from scratch.

Eventually, they were able to show that vaccination with live ich theronts and trophonts killed with high-frequency sound waves stimulated production of protective antibodies in channel catfish (Ictalurus punctatus)

“This study demonstrated that vaccines against Ich induced protective immunity and could provide a unique solution to prevent this parasitic disease through vaccination,” Xu said. “An Ich vaccine would have great impact by preventing the disease, minimizing loss of valuable fish and increasing profitability of aquaculture.”

Injecting fish in a laboratory setting is one thing, administering a vaccine to thousands or even millions of fish in a huge commercial farm is another, so the next goal will be to find a way of carrying out large-scale vaccinations. It might for instance be possible to produce a large quantity of Ich antigen and then creating a vaccine that can be administered as food or in a “bath”.

For aquarists however, injecting each fish with the vaccine might actually be a feasible solution, provided of course that an injectable vaccine would be produced for the aquarium market.

* http://portal.acs.org

President Obama himself has been quoted as saying that the BP oil spill is the “ worst environmental disaster America has ever faced,” and well, so has just about anyone else asked what they thought about it. All sorts of different environmental groups are sounding the klaxons and screaming “catastrophe along the Gulf coast”, while the major news agencies such as; CBS, Fox, and MSNBC are all slathering “Disaster in the Gulf” into their main stories and reports.

Even Tony Hayward, the official fall guy for BP, after some early happy talk, has admitted that the spill was an “environmental catastrophe”. Rush Limbaugh, a rather obnoxious anti-environmentalist, has been on of the few which has argued that the spill, which he calls “the leak” – is not the disaster that everyone is making it out to be. He scoffs the apocalyptic claims of the vast majority of the various green groups.

It appears that Mr. Limbaugh has indeed got a point. The Deepwater Horizon explosion was a horrible thing to happen, especially for the 11 rig workers who died out there, and it certainly isn’t “a leak”; it is the largest spill that the US has witnessed to date.

It is also dealing some heavy blows to the economy and also the psychological well being of the coastal communities that depend on drilling, tourism and of course fishing. While it is impossible to know exactly how much damage has really been done as the event only took place some 3 months ago, it doesn’t seem to be doing any serious environmental damage.

“The impacts have been much, much less than everyone feared,” explains Jacqueline Michel, a geochemist who also is a federal contractor who is involved in coordinating the assessments of the shoreline in Louisiana.

It is true that the oil spill has killed birds, but so far, it is less than 1% of the number which were killed in the Exxon Valdez oil spill out in Alaska 21 years ago.

Of course, we have heard all those horror stories about those poor oiled dolphins, however, it is interesting to note that the wildlife response teams have only collected three visibly oiled bodies of mammals. When the spill first occurred, there was a harsh restriction put on fishing and shrimping. After a few tests on the shrimp and fish in the area, it was discovered they were clean, and the restriction lifted.

Yes, Lousiana, it has been warned could experience a speeding up in the deterioration of their marshes, which is happening anyway…

So as you can see, the spill has been touted as being the worst ever.. But is it just being hyped up for public entertainment? I mean would as many papers be sold if it weren’t the biggest disaster in the Gulf Coast? So who benefits from all he doom and gloom? Or is this an effort to try and calm people and divert attention away from what IS a big disaster? We don’t really know at this point.. We may never really know.. But stay tuned, and hopefully someone will sort out this mess.

Tiger Prawn

The boys in white lab coats over at CSIRO and in the prawn industry have managed to breed and improve upon Black Tiger Prawn, and they are producing bumper crops in aquaculture farms and have been winning awards.

These prawns are so good in fact, that they have even won FIVE gold medals at the Sydney Royal Easter Show for the past two years running, including “Champion of Show” which happens to be the most decorated award possible.

The boys in white over at CSIRO’s Food Futures Flagship have tweaked the Black Tiger Prawn DNA, to make sure that the breeding program they have running captures the elite of the group and boost performance of their stocks every breeding season.

For the past several years, about fifty percent of all the prawns sold in Australia were imported from other countries such as Vietnam and China, so developing a local prawn which breeds in captivity is an extraordinary gain for both the local prawn industry and hungry consumers wanting to buy local seafood.

Dr. Nigel Preston, leader of the CSIRO Food Futures Flagship, had this to say about this exquisite prawn. “The new prawn’s yield has exceeded all our expectations. The average industry productivity for farmed prawns is only five tones per hectare, so this year’s average yield of 17.5 tones per hectare is a major leap forward, these huge yields can be replicated year after year which means consistent supply of a reliable and high quality product – all vital factors for the long-term growth and prosperity of the Australian prawn farming industry.”

Aquaculture has yielded approximately 17.5 tones per hectare, more than double the average production in the industry, all thanks to Dr. Preston’s super prawn. Several of the ponds produced 20 tones per hectare, and one even produced a record breaking yield of 24.2 tones per hectare.

Theorists say that if the rest of the Australian Black Tiger Prawn industry followed suit, and adopted this new DNA tweaking technology, Australia’s production could more than double, adding a $120 million boost to the annual value of the industry by the year 2020.

Mr. Nick Moore, general manager of Gold Coast Marine Aquaculture, had this to say about this revolutionary new prawn, and about Dr. Preston’s work.. “Thanks to outstanding work by the staff here, aided by close collaboration with our partners at CSIRO, we have just finished a prawn breeding season that can only be described as staggering, not only have we achieved national and international yield records with no reduction in quality or taste, these prawns are grown in a specially designed, environmentally sustainable production system. This production system and the new breeds have produced a perfect prawn with beautifully textured meat, rich color, robust size and a great taste. The awards (Sydney Royal Easter Show) are professionally judged on many criteria including size, color, taste and texture, so the results speak for themselves.”

With predictable output, and supped up prawn.. Australia is set to make its mark on the prawn industry.

The low temperatures that’s been holding the state of Florida in a firm grip this winter is causing troubles for tropical fish raised in outdoor ponds. Aquarium fish farmers report losing up to 50% of popular tropical species to the cold, and a severe guppy shortage has already emerged – boosted by the fact that Americans are more inclined to purchase guppies and other aquarium inhabitants during the winter season.

Roughly half of the tropical fish sold in the United States is raised in Florida, a state heavily dependant on its warm climate. The fist fish farmers showed up here as early as the 1930s when it was still possible to purchase cheap land around Miami, but nowadays a majority of the fish Florida farms is found in the lake-rich part of Florida located between Tampa and Orlando. Up until a few years ago, the number one cargo shipment out of Tampa International Airport was tropical fish.

Fish native to tropical parts of the world normally find it difficult to stay alive if the water temperature drops below 60 degrees F (15 degrees C) and even temperatures around 70 degrees F (20 degrees C) may have a detrimental effect on their immune system. It is therefore easy to imagine what happens if the air temperature suddenly drops below the freezing point – as it has done in Florida this winter.

And even in situations where the cold isn’t severe enough to instantly kill the fish it can send them into a sedentary state where they fail to hide from predators like hungry birds, especially if living in unplanted ponds offering few places to hide. Many fish eating birds have been forced to see their normal hunting grounds being sealed off by ice and fish farms struggling to keep the water temperature up constitute a highly appealing alternative when the hunger sets in.

In desperate attempts to save their fish from freezing to death or being eaten by predators, Florida farmers have been covering their ponds with plastic sheets and pumped in warm water. When the cold turned out to be more than just a short dip, those who could scrambled to get as many fish as possible indoors. Many farmers have been forced to prioritize older fish close to the size needed for shipping, leaving younger fry behind to die.

Farmers that have lost more than 50 percent of their fish are entitled to financial relief from the Department of Agriculture if they file a crop insurance claim.

Telling a wild salmon from a farmed one can be tricky, especially if you don’t want to kill or injure the fish in question. To solve this problem, Dr Elizabeth Adey of the Scottish Association for Marine Science (SAMS) have developed a way of using fish scale analysis to determine the origin of a salmon.

Fish scales grow like tree rings and preserves a chemical record of the water in which the fish lived as each new section of the scale was formed. The new method, which was developed in collaboration with the National Oceanography Centre in Southampton, checks the amount of manganese present in the fish scale. During her work, Dr Adey discovered that the scales of farmed salmon have a very high manganese content compared to the levels found in scales coming from their wild counterparts.

“This is probably caused by manganese supplements in fish food, and also because conditions underneath the fish cages promote recycling of manganese in the water column,” Dr Adey explains. Using the new method, Dr Adey and her team was able to distinguish between farmed and wild salmon with 98% accuracy.”Because of its non-destructive nature, this technique could be used to assess the proportion of farmescape salmon present in any river, and therefore identify where additional conservation and wildlife protection measures are needed,” says Dr Trueman, a geochemist with the University of Southampton’s School of Ocean and Earth Science, based at that National Oceanography Centre. “Salmon farming is a big, intensive business. In 2006, around 130,000 tonnes of salmon were farmed in Scotland for the table. Wild populations of Atlantic salmon are in serious decline across their whole range and the total wild population returning to Scottish rivers in the same year is estimated at less than 5000 tonnes. Wild fish are rare and expensiveso there is a strong incentive for fraudulent labeling. Farmed fish also escape into rivers, harming the wild population. Unfortunately, it can be difficult to distinguish between farmed and wild fish.“

In the future, the new technique may also be able to point out which individual fish farms that need to implement more efficient methods for keeping their salmons in. In some Norwegian rivers, more than 50 percent of the salmon are now escapees. Escaped fish can carry disease to wild populations, and there is also a risk of genetic pollution since farmed fish haven’t gone through the same natural selection process as wild fish.

Mars Fishcare, owner of Rena, Aquarian and API, is pulling out of aquarium production and sales due to increased competition in the aquarium market.

“Mars Fishcare Europe is taking steps to refocus its European business in aquarium equipment and water treatment, and to strengthen its position in the European fish food market, ” the company says in a statement. “In recent years, the sharp rise in competition in the tank market has made it difficult for Mars Fishcare to optimise its resources in this area.”

Mars Fishcare has pledged to provide after sales service for all Rena Aqualife aquariums already sold in Europe and to honour the five year guarantee that comes with all recent Rena Aqualife models. Up until now, Rena has been an important player in the European aquarium market, especially in the UK, with its Aqualife range of modern high-quality aquariums intended for customers interested not only in functionality but also in sleek eye-pleasing design.

Starting September 2008 Switzerland legislation is going to be enforcing some new guidelines to for fish owners.  Aquariums will no longer be allowed to be transparent on all sides, and any fish over 20cm will have to be housed in a tank/pond that meets the size restrictions that will be put into place. The new legislation also speaks of the importance of proper maintenance, and water quality, temperature, oxygen levels and salinity should be correct for the individual species being cared for.

Social Fish, to include goldfish, will no longer be able to be kept in a solitary habitat, but will require at least one friend. Forget about freezing your fishy friend or flushing it down the loo. From now on fish keepers will be required to stun the fish before killing it, using a non-prescription narcotic available to the general public.

To read this article in its entirety and see how the new legislation will effect anglers throughout Switzerland visit: http://www.practicalfishkeeping.co.uk/pfk/pages/item.php?news=1671

The Black Sea Bass is a popular fish among sport fishers and sushi lovers alike, but during recent decades the landings have decrease along the United States Atlantic coast. This has caused the National Oceanic and Atmospheric Administration (NOAA), a governmental agency responsible for supervising National Marine Sanctuaries, to launch two separate culture trials focused on Black Sea Bass farming in aquacultures. So far, the results have been promising, according to an article published by Physorg.com.

Fishery biologists at the NOAA National Marine Fisheries Service lab in Milford, Connecticut, have been able to show that Black Sea Bass can be spawned in captivity and grown from larvae to adults in a so called recirculation aquaculture system (RAS). The Black Sea Bass is a hermaphrodite. It starts out as a female and will then turn into a male when it is roughly 2-5 years old.

The geographical range of the Black Sea Bass stretches from Cape Cod to Florida where it inhabits shallow environments along the shore during the summer season. It seems to prefer rocky bottoms and is often found near reefs and man-made structures such as piers and wrecks. Each fall, the adult fish head offshore and stay in deep waters until spring.

If you want to find out more about the Black Sea Bass and how it can be grown in aquacultures, read the full article at Physorg.com.

http://www.physorg.com/news124377274.html