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Finfish spoke with Professor Chris Bridges, one of the researchers responsible for closing the lifecycle of Atlantic and Southern Bluefin Tuna that has received much prominence and excitement in the global aquaculture community over the past year.

Professor Bridges is Group leader : Ecophysiology / Fish physiology at the Institute for Zoophysiology Heinrich Heine University, Düsseldorf Germany.

Chris is a fish physiologist who has been looking at the reproductive biology of bluefin tuna for over 10 years. The basics interests of his research group are to look at the adaptations of specific species to environmental factors. 

The group has developed specific assays for reproductive biomarkers in large pelagic species together with an array of ELISA tests for steroid hormones and specific reproductive markers such as vitellogenin and Zona radiata protein.

They are supported by a well funded biological tool room. The tool room experts have designed and constructed many of the devices used for implanting and managing the brood stock. Their work has also included the use of data loggers in monitoring brood stock behaviour and environmental variables within grow out cages.

Here’s a transcript of our conversation.

Welcome to Finfish Chris.

Andrew:  Chris, what was the key step that unlocked the ability for you to achieve the Tuna spawning breakthrough?

Chris:  I think the design and use of the implant system which was further developed in the REPRODOTT project together with the knowledge we obtained as a group of European scientists on the Biology of the Reproduction of Bluefin Tuna were really the basis of the present success of both the REPRODOTT and ALLOTUNA projects.

This experience and technology was also made available to the Clean Seas operation in Port Lincoln Australia where they were the first to obtain fertilised eggs in a land based facility.

The use of GnRHa hormone implants pioneered by the Yoni Zohar and Dinos Mylonas in other fish species has made a major contribution to the sustainability of a number of aquaculture species. 

This was combined with the development of implant tags by our group which could be used underwater without  the need to handle large pelagic species.

These tags ensured that the implant was placed correctly within the muscle tissue, that it was anchored securely and at the same time gave a visual indication of the depth of implantation and the identification of each fish. Further developments are now going on using Titanium provided by Thyssen-Krupp for the implants.

Andrew:  how long ago did you define the problem and begin a concerted effort that led to the solution?

Chris:    This goes back to the initial work started by the European commission funded project DOTT in 2002 which backed onto a previously purely biological  EU project BFTMED  in which we were involved to look at wild tuna populations.

DOTT was conceived to bring together many European researchers to look at the problems involved in the domestication of Tuna.

Following this project the REPRODOTT study then started in 2002 -2005 which involved a whole consortium of European countries with specialists in all fields of reproduction.

The successful conclusion of REPRODOTT with the production of fertilised bluefin tuna eggs in captivity in Mazarron in Spain in July 2005 after hormonal induction was a major breakthrough. 

These results were greeted enthusiastically by the European Commission and our commercial partners Tuna Graso. So much so, in fact,  that in 2007 in an open call for sustainable aquaculture projects in our next project SELFDOTT was recommended for funding by the referees.

At the same time, parallel to this work, the region of Puglia had decided to support the aquaculture industry with structural funds from the European Union and the project ALLOTUNA was conceived under the coordination of the University of Bari.

The breakthrough results of obtaining over 20 million eggs in the tuna farm of Mare Nostro last week in Calabria was due again to an international consortium of European scientists providing their expertise and know-how.  This concerted effort by European scientists supported by the tuna farming industry in Spain, Malta and Italy together with the European commission has made  this success possible.

Andrew:    what is your vision for how you would like to see the knowledge that you have created used?

Chris:  We see the role of our group in the development of new tools and techniques for use in the fisheries and aquaculture industry. This can be done by combining with the industry (such as Tuna Graso) to solve some of the bottleneck problems within tuna aquaculture.  At the same time however the sustainability of the fishery and/or aquaculture are of paramount importance at an ecologically viable cost.

Andrew: are you continuing your research in related areas?  Where next?

Chris: As I said above, new projects SELFDOTT and ALLOTUNA will continue to the next two to three years. 

We plan to extend our suite of analytical tools for studying the reproductive behaviour of tuna.

We are also combining our skills in terms of muscle biopsy sampling from live fish for genetically  fingerprinting and sex determination of brood stock.

We will also shortly be delivering a sex determination system based on Zona radiata protein antibodies to helping in the work of CSIRO in monitoring the Indonesian southern bluefin tuna landings. 

First you can see we have plenty to keep us busy for the future.

Andrew:     To your mind, what is the largest challenge that stands in the way of achieving sustainable aquaculture production on a global basis?

Chris:     Two major challenges are  already present within the aquaculture sector.  The first is the lack of space within the marine environment, especially the coastal environment for fish farming.  One of the most exciting possibilities is a movement to offshore fish farming perhaps in collaboration with the offshore wind farms such as those being proposed by the Blue-H  group. 

The second challenge of an ecologically viable aquaculture revolves around the use of pelleted artificial feeds and this is  indeed part of the remit of the SELFDOTT and ALLOTUNA projects.

Andrew:      Thank you for sharing your insights with us Chris.  The Finfish community wishes you well with your research endeavours and we look forward to staying in touch with you and your work.

There is mounting evidence that the soaring demand for fish (based on its widely promoted health giving nutritional qualities) will be subject to significant competition.

Growth in the aquaculture industry has been buoyant due the challenges faced by wild capture fisheries. This however does not mean that the backers of aquaculture companies will have a free ride to future prosperity or the license to print money - any time soon.

We have canvassed the subject of Omega-3 long chain fatty acids on this site through several posts.

The health-giving properties of fish oils have not gone unnoticed. The fact that there has been a sustained growth in demand for fish has been recognised by food producers from other sectors.

Due to several factors, massive budgets are being directed at the ability to produce Omega-3 long chain fatty acids from non-fish sources:

This level of activity is interesting in the world of aquaculture for two reasons:

• Firstly, the widely appreciated health giving properties of consuming oily fish is a major driver of the increasing demand for fish in human nutrition.
• Secondly, the major cost component in the aquaculture value chain is feed. The critical components of aquaculture feed include protein and suitable oils. Traditionally this has been sourced from fishmeal, but this is now unsustainable.

Patenting in the field of aquaculture has increased markedly over the last few years with at least a trebling of the number of patents registered between the early 1990s and the mid naughties.

We searched using the key words ‘aquaculture’ and ‘fish farm’ to identify relevant documents from a number of data sets including US, Japan, Germany, EU and the World Intelllectual Property Organisation (WIPO) and INPADOC. The search produced just over three and a half thousand patent documents out of a total data set of over 50 million.

This bar chart shows the scale of the uplift in patenting activity we have witnessed within this data set.

We will analyse aquaculture patenting activity in greater depth in a series of forthcoming posts, so if this is of interest please stay tuned.

If you would like to be advised of new posts to this site, please take advantage of the ability to register for email updates in the sidebar.

The data generated here is supplied by Thomson Scientific using their patent data analytics suite. In this instance the Delphion product was used to generate the data.

I conducted a search to identify the organisations most active in seeking patent protection for aquaculture innovations.

My preliminary search used the key words ‘aquaculture’ and ‘fish farm’ to identify relevant documents from a number of data sets including US, Japan, Germany, EU and the World Intelllectual Property Organisation (WIPO) and INPADOC.

The search produced just over three and a half thousand patent documents out of a total data set of over 50 million.

The organisations with the most active patent portfolios are as follows:

NUTRECO AQUACULTURE RESEARCH    77
NORWEGIAN INSTITUTE OF FISHERIES AND AQUACULTURE    30
UNIVERSITY OF MARYLAND BIOTECHNOLOGY INSTITUTE     24
MARTEK BIOSCIENCES CORPORATION     19
SEABAIT LIMITED     17
WYETH     16
NORSK HYDRO    14
OMEGATECH    14
VELCRO INDUSTRIES    14
AQUACULTURE CRC    13
HENKEL KOMMANDITGESELLSCHAFT AUF AKTIEN     13
ASCOM NEXION    12
FISHFARM TECH    12
DSM IP ASSETS    11
MARICAL    11
OMS INVESTMENTS    11
BOARD OF REGENTS, THE UNIVERSITY OF TEXAS SYSTEM     10

The patent count that I have produced here is raw data on the number of patents across a number of jurisdictions.  As such it represents a measure of the investment that organisations are dedicating to intellectual property protection rather than a count of the number of individual inventions.

The data generated here is supplied by Thomson Scientific using their patent data analytics suite. In this instance the Delphion product was used to generate the data.

A recent posting by Michelle on this website referred to a paper (sustainability-of-fishmeal-and-oil) that provided information on the sustainability of fish meal and fish oil in aquaculture diets.

A recent article in a recent reLAKSation newsletter contributes to this debate. Some of the relevant, interesting parts of the article are paraphrased below (the full article can be seen on the Callander McDowell website here and by following the prompts to reLAKSation No. 350).

Various environmental groups are targeting aquaculture for its use of fish meal and, in their view, the consequential depletion of wild fish stocks. Detractors of aquaculture persist with arguments many of which have no basis in either fact or logic; it’s frequently a case of “I’ve made up my mind so don’t confuse me with the facts”.

In fact, the use of fish meal in manufactured aquaculture diets simply represents a different and, importantly, a more efficient presentation of the natural food of fish. The logic behind the increasing pressure on feed manufacturers to substitute the fishmeal content of aquaculture feeds (or a large part of it) with vegetable proteins has some merit, but only within reasonable limits.

The use of fishmeal in fish feeds has dramatically increased in recent years; however, around one-third of world fishmeal production is used outside aquaculture in terrestrial animal feed destined for pigs and poultry.

So, to put this into context, environmental groups are urging the replacement of fishmeal with vegetable protein, while terrestrial animals that naturally eat vegetable protein, are fed with marine protein from fishmeal. Hmmm. Some dodgy logic there.

Surely, the first step to reduce the fishing pressure on fish destined for fishmeal production should be that fishmeal should be removed from land animal feeds and fed to farmed fish, which, by the way, utilise the protein far more efficiently. The issue of substituting some of the fishmeal in aquaculture diets can then be properly considered.

Perversely, rather than reducing the terrestrial demand for fishmeal, it seems that (in the EC) there is actually pressure to increase it. The reLAKSation newsletter reports that “a team of veterinary experts from the European Commission have approved a project reintroducing fishmeal in the feed of young ruminant animals such as calves and lambs”.

One reason for doing this is that meat, milk and eggs from farm animals fed fishmeal are beneficial for human health. The obvious question is why they wouldn’t promote the increased consumption of oil rich farmed fish instead? 

I´m looking for information related with alternatives to convert aquaculture waste into a valuable by product. Specifically I´m talking about faecal matter from salmon farms that could be taken out before it gets to the bottom of the sea.

 I´d really appreciate if anyone can help me.

An international campaign aimed at forbidding the use of antibiotics in aquaculture was launched on 5 June in Chile. The project also demands that all sanitary standards regarding antibiotics for Chilean salmon consumers be brought in line with standards such as the United States’ FDA rules or those of the European Union.

Chile proposes a sole State agency, which would regulate and monitor the use of antibiotics both in human use and animal health. Another of the issues demanded is free access to historic information on the volumes and types of antibiotics currently imported and used by the salmon industry.

For years, environmental organisations have requested information from Chilean health organisations such as the National Fisheries Service, Sernapesca, but have never received an answer.

This campaign is aimed at controlling the use of antibiotics within the the bacterial resistance study launched by the United Nations’ World Health Organization.

What are appropriate principles for antibiotic use in aquaculture?

If we are going to be able to achieve the marked growth required to meet demand for fish what role must antibiotics play?

How can we effectively balance the valid concerns about over use and the needs for health management in large and dense captive fish populations?

The organic movement as represented by the Organic Trade Association have some strong views on these matters. The Organic view of the world can be reviewed here.

An interesting article on the trend from antibiotics to probiotics to prebiotics in humans could point the way towards sustainable practice in aquaculture. Please consider the article here.

What is the current state of the art for aquaculture? Are our aquaculture food, food supplements and drug companies experiencing any demand from producers for probiotics or prebiotics?

Sea lice pose a huge health threat to both wild and farmed fish. Researchers have investigated the efficacy of a treatment for sea lice in wild sea trout.

Sea lice are important exoparasites of fish, both in the wild and in aquaculture.

These tiny crustaceans can lower the fitness of the fish and indirectly cause fatalities due to open lesions that prevent the fish from maintaining its osmotic, or salt/water balance. If infection rates are severe, the parasites can feed on the fish at higher than the growth rate. It follows then that developing stock are more prone to this distressing phenomenon due to their small size.

To investigate means of tackling this disease, wild sea trout were tagged with Passive Integrated Transponder tags (PIT tags). Fish are therefore identifiable and traceable using a tag scanner on recapture of the fish.

There were two groups, one treated with a prophylactic substance designed to control the parasite and the others untreated. The experiment took place in the north-west of Scotland.

It was discovered that the treatment had a significant effect on the condition factor of treated fish. Indices of condition indicated that the fish that received the prophylactic suffered less growth constraints whilst in open sea.

Possible subsequent effects on growth and survival to sexual maturity could have significant implications on stock conservation due to the direct relationship between fecundity and size in the female.

Control of this parasite is important, not only for farmed stocks, but also for wild stocks as farming situations are thought to act as sources of infection for this pest. Further research could well bring about more effective controls and superior management of our natural and farmed fish stocks.

More on this approach to sea lice control is available via this link.

During consultations related to the European Aquaculture Technology Platform (EATP) Mr Frank van Ooijen of Nutreco Holding NV drew together the major challenges facing aquaculture in the optimisation of feed for fish farming. The challenges he highlighted were:

• ensure access to raw materials in a dynamic world
• source fish meal and oil from sustainable sources
• look for independent certification
• further improve feed conversion ratios
• step up the substitution of fish meal and oil
• ensure health and safety: limit undesirable substances
• increase knowledge of fish nutritional requirements
• increase knowledge of the link between fish nutrition and fish health

The slides used by Mr van Ooijen to support his presentation may be viewed here.