A unique New Zealand facility produces whitebait species which it sells commercially to fund restoration efforts. Of all the ways to hunt and fish, few are more quintessentially Kiwi than the act of gathering whitebait. In New Zealand, whitebait refers to the larval form of five Galaxiid species. These larval fish are caught as they return upstream from the ocean to continue growing and, eventually, to spawn. From August/September through the end of November, it’s rare to find a stream that flows into the ocean without someone standing watch over their whitebait net. To call it a popular Kiwi hobby is nearly an understatement. Across the country, however, recreational and commercial catches have been in decline. Of the five species one can catch, four are labelled by the New Zealand Department of Conservation as declining or threatened. This is due to a variety of factors including an increase in river and stream pollution from industry and farming, and the introduction of aggressively invasive plant and fish species. The decision of the government to continue to allow whitebait fishing has become a controversial decision across the country, with many calling for restrictions or a total ban of commercial harvesting. Hope for the future There is, however, hope for the whitebait species of New Zealand. Located an hour north of Auckland, in the small town of Warkworth, Manāki Whitebait (a.k.a. New Zealand Premium Whitebait) is New Zealand’s first, and only, whitebait farm. The term Manāki is a Te Reo word that means to support, cherish or take care of others. The name is fitting. Originally built as a restoration hatchery, a small, dedicated team led by Paul Decker, Managing Director of the Mahurangi Technical Institute, began by cultivating all five species of whitebait. The hatchery was constructed and initially funded using private donations. This model, however, is difficult to maintain in the long term. In the words of Decker, “we knew we can’t keep doing this, but we need to keep going.” They needed a new financial model. Commercial productionFortunately they discovered that one of the whitebait species, the Giant Kōkopu, was an ideal candidate for commercial production. The Kōkopus viability stems mainly from its breeding characteristics. Unlike some of the other whitebait species, which spawn only once after two years growth and then die, the Giant Kōkopu is capable of breeding year after year, with their oldest brood being 10 years old - this is nothing for a Giant Kōkopu, which can live for 30 years. The Giant Kōkopu also offers a higher rate of fecundity than other species and responds well to artificial rearing environments, growing from hatch to larval harvest in only 12 weeks. A new model was born: they were going to rear Giant Kōkopu commercially to generate income for their restoration work. This model was one that Kiwi investors could not resist. While all investors involved in the Giant Kōkopu commercial operation are Kiwis, of note is the heavy Māori interest. Whitebait is a culturally and historically important food for the Māori. Local and nearby Māori investment fund managers saw, in this model, the chance to profit while working to bolster wild Whitebait populations. This offers the benefit of allowing the long-standing cultural tradition of Whitebait collection to remain viable for future generations. Clean RAS productionWhile technologically speaking Manāki is not breaking new ground in RAS, the hatchery offers a shining example of conservation-oriented rearing practices. They have been able to achieve commercial production without the use of synthetic inputs, either in the form of treatments or spawning inducers. This is born of the desire to avoid introducing foreign contaminants into local waterways via their restoration releases, and to allow the fish destined for wild re-stocking to remain as hearty and self-sufficient as possible. The hatchery’s ability to avoid these inputs is due to its regimented cleaning routine. “Clean and green is what we say...we do more cleaning than probably most places in the world” says Decker. This commitment to clean production has allowed them to begin the process of organic certification, which Decker believes they will achieve without issue. They’ve also become the suppliers to educational institutions such as the National Aquarium which seek to source their display fish as sustainably as possible. Working business model As a means of generating funds for restoration work, Manākis business model is working. The hatchery is currently doing several releases each year, including one release of 10,000 fish in Tawharanui National Park planned for May of this year. As more releases are conducted, interest from schools and environmental organizations in using their Whitebait in restoration projects is increasing. Decker foresees this trend continuing in the future.The path to this point has not been without its challenges. Since it was the only Whitebait farm in the country, sourcing appropriate feed posed a problem. To rear efficiently, they had to switch from live to pelletized feed. Fortunately, their chief scientist, fish nutritionist Dr. Tagried Kurwie, was able to work with their feed producer to develop a Whitebait specific formulation, allowing them to achieve an FCR of 1.2:1. Culturing live feed for hatchlings, broods and stock earmarked for release still presents a challenge, as techs must learn the ins and outs of multiple culture techniques. Challenges overcome In the early days the team at Manāki was also having trouble with certain environmental cues causing their stock to change to a darker colour. In a discerning marketplace that demands translucent to light coloured Whitebait, this was troubling. However, the team was able to determine what was causing this transition, and they have been able to sort out these issues. Another great challenge has been keeping the saltwater system full. Being located about 5 km from the nearest saltwater, Manāki must regularly truck in salt water to keep the RAS system topped up. One release-stock specific challenge has been developing a procedure for “wildizing” the fish meant for release. In the weeks leading up to their release, none of the staff can let themselves be seen over the tank. This is so that in the wild these fish will not associate humans with feeding and will thus be as skittish and survival-oriented as their wild born counterparts. Like any well-built operation, Manāki was determined to overcome these challenges because, at the end of the day, staff knew they had something special to offer the discerning public. In the words of Paul Decker, “everyone says it’s the best product they’ve ever tasted.” This is, in part, because they’re able to purge the fish before harvest. Purging the ‘bait Purged Whitebait offers a cleaner, purer taste without any of the unpleasant grittiness one can find in wild Whitebait. They’re also able to kill their harvest instantly and maintain the cold chain to market. The lack of stress response and short turn-around time between harvest and sale means the fish end up being the best looking on the market. “You can see the freshness in them…they’re glistening,” says Decker. “They’re the sturgeon of the Pacific.” Having proven to the investors that this can work, Decker and his team are looking toward a bright future. They are currently assessing sites for a new, modern facility. This is an important next step because within the next couple of years they hope to be producing 50-100 tons per year. Barriers to export They are also working to remove barriers to increase exports. Currently, their product will occasionally be stopped during export because Whitebait is flagged as an endangered species. The team at Manāki is focused on ensuring these holdups are avoided. They’re also hoping to increase international recognition of the delicious, high quality nature of their New Zealand Whitebait. In many other national markets, Whitebait is used a generic term for low quality white fish. Naming the company’s Whitebait Manāki is, in part, to help differentiate it, an approach comparable to that of the Malepeque Oyster growers. With the lessons of the past in their back pocket and the vision of a new facility in their eyes, Decker and the team at Manāki Whitebait will continue to change the Whitebait market for the better.

Soy peptides (SP) can be used to enhance the immune response and survival of juvenile Japanese flounder (Paralichthys olivaceus) under heat stress, according to a recent study. SP, a soy protein enzymatic hydrolysate, contains bioactive substances that could be utilized as an immune-stimulating feed ingredient. “Feed companies would greatly benefit from the study, as SP may now be a new ingredient source. Fish farmers may also exploit the potential of SP for increasing the defined function of cultured fish, especially in the context of climate change,” one of the authors, Janice Ragaza, told Hatchery International. Ragaza is an associate professor at the Department of Biology, Ateneo de Manila University in the Philippines. At the time of the study, she was still doing her doctorate studies on Fisheries Science at the Laboratory of Animal Aquatic Nutrition, Faculty of Fisheries, Kagoshima University in Japan. In the study, diet inclusions with zero, two, five and 10% SP were fed to juvenile flounder. “If the objective is for maximum growth, then the inclusion levels should be greater than 10% SP. If the objective is for thermotolerance, 10% SP is the optimum,” she said. After a feeding trials, the experimental groups were subjected to heat stress to measure survival rate and heat shock protein 70s (HSP70s) in gill, liver and skin. A significant reduction in HSP70s was observed among all groups during recovery period. “HSP70s usually show up when the organism experiences heat stress. The reduction in number over time means that the organism is reaching its equilibrium (i.e. normal, pre-stress) condition,” she said. She compared HSP70s to cooling fans inside laptops. “Like cooling fans, HSP70s bring the fish under heat stress, e.g. increase in water temperature, to stable conditions. With more HSP70s in the tissues, the fish is therefore more stable amid the stress exposure.”                                                                                         

At Northern Divine Aquafarms, we first used RAS to grow salmon smolts in1998. This was before the term “RAS” was coined and we just called it “recirc”. We soon realized that this technology allowed us to produce smolts six months earlier and three times as big when compared to our flow-through system. I remember thinking “why would you grow fish in anything else?” Lots of people had the same idea which led some to start growing fish right through to harvest in RAS. Early days, early challenges It was 17 years ago that we started to harvest our first RAS-grown sturgeon for meat. Today, the sturgeon, caviar and coho salmon grown at Northern Divine have the cleanest taste possible at harvest; however, that is not how it started 17 years ago. Farmers growing fish such as catfish in ponds have been battling this problem for years, though many others who grow fish in net pens or flow-through systems have, for the most part, not historically encountered this challenge. When RAS came along there were initially no problems with off-flavour since most of the production was for smolts which no one was eating. As farmers realized the benefits of growing fish in RAS, they started to experiment with growing several species to market size. Unfortunately, in many instances, the market knew there was a problem before the farmer. One of our first harvests of sturgeon for meat went to a banquet at an aquaculture conference 15 years ago. Various types of seafood were served at different stations throughout the venue. The first sturgeon that came out was delicious; this was the first time that many people had ever tried sturgeon. An hour or so later, they refreshed the platter with meat from the next fish they cut. And oh oh. This one had a slight muddy off-flavour. I didn’t know why it tasted that way, but we quickly realized that we needed to find a fix. Nature of the problem? A muddy off-flavour in fish is bad for business, and fish coming out of many RAS have off-flavour. The amount of off-flavour will vary with the system, water quality parameters, species and size of fish, and even individual variations. Wild fish from certain lakes and rivers also have this off-flavour. Consumers don’t want to eat fish with that flavour and they won’t likely buy it a second time. An even bigger problem is that they may stop buying that genre of fish altogether. What is the cause? Compounds causing off-flavour in the water also get into the fish. The main compounds are the naturally produced organic chemicals geosmin and 2-methylisoborneol (MIB). These compounds are produced by certain bacteria (cyanobacteria and actinomycete). If you want to read all of the gory details, check out the excellent summary by Davidson et al in Aquaculture Engineering 61 (2014) 27-34 or other published papers from the Freshwater Institute. By design, recirculating aquaculture systems grow plenty of bacteria. The systems need nitrifying bacteria; thus, biofilters are designed to optimize surface area and living conditions for bacteria. The bacteria which produce geosmin and MIB also live there and the off-flavour causing compounds enter the fish via the gills and then accumulate in the fat. The fattier the fish, the worse it will be. The more geosmin and MIB in your system, the worse it will be.Solving the problem There is only one solution and it is very simple - depurate, purge. (But let’s not call it that anymore for the sake of our customers). Let’s call it “conditioning” or “finishing” which sounds a little more delicious and safe. Whatever you call it, it requires taking your fish out of the RAS and putting them either on flow-through water or onto another water source that does not contain off-flavour compounds. Many methods don’t work. We can’t just kill all the bacteria in a RAS because, as we discussed, we actually need some of those bacteria. There has been research on ozonating the culture water which has not been successful. Nam-Koong et al Aquacultural Engineering 70 (2016) 73–80 demonstrated that treating the water with ultrasound will remove off-flavour compounds from RAS, but the energy required would not be economical. For now, farmers have to transfer the fish into a “finishing” system. But for how long? That depends on many factors including the level of geosmin and MIB in the culture water, the species, size, and lipid content of the fish, the water temperature, etc. You can read reports that suggest anything from less than one day up to three weeks of conditioning. To finish caviar takes longer . . . way longer. When I attend trade shows where caviar companies have their booths I go from one booth to the next sampling their caviar. “How does it taste?” they ask. “Like mud,” . . . I think. The next booth, “like dirt”. The next booth, “like earth”. Wow. How can you grow a fish for so long and then harvest it with an off-flavour? Basically, producers have to condition their fish until they can’t taste off-flavours anymore and that will be different at every farm, varying with every variable. And there will also be variability from fish to fish, so don’t limit taste tests to just one fish. Terry Brooks, of Golden Eagle Aquaculture in British Columbia, Canada has the process down to a science. He conditions the fish in two stages where he first reduces the levels of geosmin and MIB in the RAS for a period of time, and then moves them to a new flow-through tank for a very short period of time. By tasting his RAS-grown coho salmon, you could never tell if they were from the wild, from a saltwater net pen, or from his RAS farm in Canada. “If people get a hint of off-flavour, you’re done,” he says. So, why is there still a problem? Some farmers still send off-flavoured fish to market. …Please stop. It’s bad for business. For all of us. But why does this still happen? There are a number of reasons: some newcomers to the industry have not read the literature; sometimes it takes longer to get rid of off-flavours than the literature indicates; or some farmers have just received bad advice. How do you know that off-flavour is gone? There is one way and it is very easy: taste it. Taste a few fish. Taste them often. Get good at identifying even the tiniest hint of off-flavour. And then sometimes you have to make the difficult choice to delay harvest. I know that sucks, but ignoring it is probably the main reason that off-flavoured fish still ends up in the market. Delaying means delayed cash flow, change of processing schedule, maybe sending the harvesters or processors home, and telling your customer that they are not getting any fish that day. If you send the fish anyway, before they have clean flavour, then you are killing your business, and harming the rest of the RAS farmers. Justin Henry is the former general manager of Northern Divine Aquafarms, a sturgeon and salmon RAS in British Columbia, Canada. He now heads up Henry Aquaculture Consult Inc, an international advisory and consulting service for the aquaculture industry.   He can be reached at: This e-mail address is being protected from spambots. You need JavaScript enabled to view it

The Philippines’ perennial shortage of milkfish fry may find its resolution in the National Broodstock Development Program (NBDP), an initiative of the Department of Agriculture – Bureau of Fisheries and Aquatic Resources through the National Fisheries Research and Development Institute (NFRDI).“A broodstock development program is considered one of the limiting factors faced by many industry stakeholders. This may be addressed with the help of the government by establishing a broodstock development facility which will cater to the needs of interested stakeholders for their broodstock requirements by operating a breeding and hatchery facility,” Francisco Santos, OIC-Chief at the Aquaculture R&D Division of the NFRDI, told Hatchery International.“With the increased number of hatcheries operating in the locality, producing and obtaining juveniles for aquaculture use is seen to have greater feasibility and economic viability,” Santos said.NBDP, which has been approved but not yet signed, covers the stock inventory of existing breeders, hatchery facilities and manpower, selection and upgrading of broodstock, development of breeders, screening and identification of program recipients, upgrading of knowledge and skills through training and technical staff.“While milkfish is important, its production has been hindered by various problems. Among the most critical of these is the limited supply of fry,” he said.Based on 2015 figures, the milkfish requirements of the Philippines was estimated at 2.5 billion fry. Private and government hatcheries supplied only one billion. The rest were either imported, mostly from Indonesia, or were wild fry.

California salmon hatchery managers likely gave a well deserved sigh of relief when record winter rains of 2016/17 ended a five year drought and restored flows to the state’s salmon producing rivers. But the legacy of those drought years continues to haunt them, as poor adult returns this fall have reduced the egg production goals at Coleman hatchery, the states largest producer of Chinook fry, by half, according to Sacramento area media. Coleman aims for 12 million smolts to release each spring into Battle creek, a tributary of the Sacramento river. This year, it will be around six million. Poor adult returns to their natal stream, prevented staff from collecting and fertilizing enough eggs. However, there were plenty of Chinook around the California Central valley last fall, enough to provide a commercial and sports fishery, and other hatcheries met and exceeded their goals, but the Coleman fish just didn’t come straight home. Managers say that giving smolts a ride down river in the spring, in response to past drought conditions, is to blame. Hatchery staff were able to collect sufficient eggs and sperm to produce fry on target during the drought years. But spring river conditions in 2014 and 2015 were described as “abysmal”. Warm water temperatures and low river levels could harm the freshly released smolts and increase the likely hood of predation, so in those years they were pumped into tanker trucks and driven the 280 miles down stream to acclimatization pens at the mouth of the Sacramento river. This means that they missed the normal “river imprinting” process and that has disoriented the fish that attempted to find their way home this fall. Historical returns to the Coleman are around 143,000 adult fish. Last fall saw merely 3,000. That was only enough to collect and fertilize about four million eggs. But staff were able to round up some of the missing brethren. Wire tags indicated that many of the strays ended up at Nimbus hatchery on the America River, another branch of the Sacramento, and they gave up another two million eggs for Coleman production. In an effort to avoid mixing genetic strains, US Fish and Wildlife Service officials declined to bring in fish from other watersheds to increase Coleman numbers.

The Wilsgård Offshore Tank Fleet (OTF) is a barge-based smolt production concept under development by Norway’s Wilsgård Fiskeoppdrett AS for use in Norwegian fjords. A key part of the design is a recirculating aquaculture system (RAS) explains managing director Fredd Wilsgård. “The OTF is 100% closed and has no emissions. That means that we clean all the water that comes in and we clean all the water that goes out.” By cleaning the water that comes into the OTF, no unwanted organisms (bacteria, sea lice, etc) enter the production system. Also, the production water is cleaned and sterilised before it leaves the system. And it’s 100% secure against escapes. One of the goals of the OTF is site area optimization. Since the OTF cleans water coming in and going out of the system, it will neither be affected by nor affect the environment. As Wilsgård points out, “this means that you can establish larger OTFs, more OTFs and that they can be located in the same fjord. If you look at traditional area use at a site, 200 × 600 metres, you can place six OTFs in such an area and deliver large smolt at up to 70 traditional concessions.” The OTF is designed to take on fry at 30–40 grams and rear them to 500 grams before the fish are transferred to traditional fjord-based cages for a period of about 12 months. Since the OTF takes fry into production, the area required on land is also significantly reduced. The company has applied for eleven development licenses, with a total maximum allowed biomass of 8580 tonnes for the OTF.