aquaculture – Shark Research & Conservation Program (SRC)

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An introduction to aquaculture

January 15, 2016/0 Comments/in Conservation, Ocean News /by aanstett

By William Evans, SRC Intern

When most people think about aquaculture, commonly known as fish farming, they automatically assume that it is the culturing of the different types of fish that we commonly see in our local supermarkets like salmon and tilapia. In 2008, only 37% of the total global fish supply was provided by aquaculture and by 2030, aquaculture is projected to supply over 50% of the world’s total fish supply (Kobayashi, 2015). Despite aquaculture’s increasing demand, there are still negative associations that coincide with the industry. Increasing consumer awareness of the product source and safety can negate many of these misconceived notions. There are resources like the Monterey Bay Aquarium Seafood Watch Program that recommends what food is safe to eat in a specific state and the sustainability of that industry.

This table displays data taken in 2008 and the projected data for capture fisheries versus aquaculture in 2030. (Source: Fish to 2030)

Because a majority of our fishing practices are unsustainable because of actions such as longlining and bottom trolling, we are depleting our global fisheries. Aquaculture is gradually being used to fill the void where wild caught fisheries once were. Although a large portion of aquaculture is still used for food production, there are other uses for aquatic farming. Some examples include stock enhancement, research, ornamental fish production for aquarium trade, as well as supporting the production of pharmaceutical, biotechnology, and nutritional products (What is Aquaculture, 2015) . Aquaculture’s effect on biotechnology can help improve the conservation and management of wild stocks by providing useful information about the fish species such as fish health and growth rate (Bartley, 2005). Biotechnology in aquaculture also assists in increasing the nutritional value of fish feeds, increase the growth rates and productivity of cultured species, and help protect environments by increasing the sustainability of aquaculture (Bartley, 2005).

This photo from the World Wildlife Fund shows the amount of salmon that can be cultured in a smaller area. They also state that it only takes between 1.3 to 1.7 pounds of feed to produce one pound of salmon, in comparison to the 10 to 12 pounds of feed to make one pound of beef. (Source: http://www.worldwildlife.org/industries/farmed-salmon)

The feeds used in aquaculture are usually composed of fishmeal and fish oil, which is not a sustainable part of the industry. Currently there are efforts to use vegetable products or terrestrial animals, like chickens, in some aquaculture feeds. The Soy-In-Aquaculture Managed Research Program is researching to determine the chemical amount found in soybean meal that can be then used in feeds for aquaculture. At the Aquaculture Investment Workshop 2015, which was hosted at the University of Miami, the U.S. Soybean Expert Council stated that soy production in the U.S. has increased 1.5 times per year and “US farmers will continue to respond to [the] demand,” says USSEC CEO, Jim Sutter (Nadkarni, 2015). This desire for the use of soy reflects on the need to conserve aquatic ecosystems and increase the sustainability of this industry.

As stated before, aquaculture and marine conservation are combined through stock enhancement strategies and restocking. Stock enhancement is adding individuals to a healthy population and restocking is adding individuals to depleted populations. Usually these strategies consist of releasing farm -raised juveniles into the wild for populations that are overfished or threatened by habitat loss and ocean acidification (Stock Enhacement, 2015). This process is strategic as to what point in the lifecycle the species should be released into the wild, where specifically they should be released and the timing, and the dynamics of the ecosystem. Currently, NOAA is working with partners for stock enhancement for a variety of species such as black abalone, blue crab, oysters, queen conch, spotted seatrout, winter flounder, and many more. By providing support to these species that are at risk due to an array of pressures, aquaculture can help alleviate some of the pressures on the wild stocks.

Many universities and research and development companies also focus on other topics aside from food production. For example, at the University of Miami, although some research and development is focused on biotechnology and increasing the yield of certain species, there are other studies concerned with bioenergetics, nutrition, developing proper protocols for shipping of various species, and many more. In October, Professor Bruce Barber received an $83,000 from the Aquaculture Resource Council to fund his research in the state of Florida to advance aquaculture for shellfish, tilapia, shrimp, and even alligator (Cotton, 2015). Because he believes that the Sunray Venus clam could potentially be the “next big aquaculture crop” for the state of Florida, he is focusing most of his research around this unexploited food source (Cotton 2015). Research like Barber’s can potentially change the market as to what consumers actually eat and can help protect the wild clam stocks in this region. Most of the public does not know that aquaculture can be used for restocking, stock enhancement, and even to do further research on wild aquatic species. Educating the public about topics that illustrate an intersection between aquaculture and marine conservation can change some of the negative associations with aquaculture. Consumer awareness and education through outreach and informal education about topics like aquaculture can change the mindset of the public to being more conscious of the benefits of such a controversial field.

Sunray Venus Clams: The Sunray Venus clam, the focus of Barber’s research, is potentially Florida’s upcoming, large aquaculture crop (http://cutthroatclams.com/hello-world/)

Sources:

Cottton, Emma. “Professor Bruce Barber receives grant for aquaculture research.” The Current. 26 October 2015. Web. < http://theonlinecurrent.com/professor-bruce-barber-receives-grant-for-aquaculture-research/>

Fisheries and Aquaculture topics. Biotechnology. Topics Fact Sheets. Text by Devin Bartley and Rohana Subasinghe. In: FAO Fisheries and Aquaculture Department [online]. Rome. Updated 27 May 2005.

Kobayashi, Mimako, et al. “Fish to 2030: The Role and Opportunity for Aquaculture.” Aquaculture Economics & Management (2015): 282-300. Print.

Nadkarni, Avani. “Aquaculture Investment Workshop 2015 blog: Recap on all the news here.” Intrafish. 05 April 2015. Web. 15 Nov 2015. <http://www.intrafish.com/free_news/article1411080.ece>

“Aquaculture for Stock Enhancement.” Aquaculture. National Oceanic and Atmospheric Association, n.d. Web. 12 Nov 2015. < http://www.nmfs.noaa.gov/aquaculture/science/11_stock_enhancement.html>.

“What is Aquaculture.” National Oceanic and Atmospheric Association, n.d. Web. 12 Nov 2015.< http://www.nmfs.noaa.gov/aquaculture/what_is_aquaculture.html>.

Global population growth, wild fish stocks, and the future of aquaculture

October 28, 2014/2 Comments/in Conservation, Ocean News /by aanstett

By: Hannah Calich, RJD Graduate Student

For many years we lived in a world where the state of our fish stocks was not a primary concern. However, our population has become so large, and our technology so advanced, that we are utilizing resources at a rate that was once inconceivable. We have significantly impacted many of the world’s fish stocks and it is no longer biologically or economically feasible to continue harvesting them at this rate. Thus, we must develop ways to relieve pressure on wild fish stocks while continuing to provide the world with the fish protein it requires. Given the projected human population, and the current status of wild fish stocks, it will be up to the aquaculture industry to help the ocean meet the world’s demand for fish protein.

The global human population has been projected to reach over 9 billion people by 2050, and over 10 billion people by 2100 (Figure 1; UN, 2012). While the rate of population growth has been slowing, and may eventually reach a plateau, feeding a population of 9 to 10 billion people represents a significant challenge.

Projected world population based on a medium population growth variant (data from UN, 2012)

Along with the world’s population, meat consumption has been steadily rising. In the 1950s the world’s population was consuming 44 million tonnes annually; by 2009 that figure had increased to 272 million tonnes. When the increase in human population is taken into consideration those figures suggest that the annual per capita meat consumption rate has more than doubled, to almost 90 pounds per person (Brown, 2011).

While on average the world’s meat consumption has been rising, there are regional trends in who can afford to eat meat. As Brown (2011) said, “wherever incomes rise, so does meat consumption” (pg. 173). As a result of incomplete or insufficient diets, currently 800 million people suffer from chronic malnourishment worldwide (FAO, 2014).

Fish are an important source of protein, nutrients and energy, particularly in poorer nations where essential nutrients are often scarce (FAO, 2014). For example, 150 g of fish protein can provide 50-60% of an adult’s daily protein requirement (FAO, 2014). In addition to being nutritious, fish are often an affordable source of protein. As such, nearly 17% of the global population’s protein intake comes from fish, though again the trends are regional and that number is closer to 50% for some developing countries in Africa and Asia (FAO, 2014). Following the trend of the world’s meat consumption, per capita fish consumption as also increased, from 10 kg in the 1960s to over 19 kg in 2012 (FAO, 2014). Per capita fish consumption has increased in both developing regions (5.2 kg in 1962 to 17.8 kg in 2010) and low-income food-deficit areas (4.9 kg to 10.9 kg) (FAO, 2014). While developed nations still consume more fish, the gap is narrowing.

The surge in fish consumption has left the marine capture industry struggling to meet the world’s demand for fish protein. Global marine capture fisheries have been consistently harvesting between 80 and 90 million tonnes per year since the mid-1980s (Figure 2; FAO, 2014; Pauly & Froese, 2012). However, this stability is not due to stable fish populations. Instead, the stability is due to pushing the boundaries of the ocean’s fish stocks. Specifically, the marine capture industry has been targeting less desirable species, fishing further offshore, and harvesting smaller fish than ever before.

Aquaculture and capture fisheries production in millions of tonnes from 1950-2012 (Source: FAO, 2014)

This high demand for fish protein has put a significant strain on wild fish populations. Currently, approximately 30% of wild stocks are considered overfished, 60% are fished at (or close to) their maximum sustainable limit, and only 10% are being fished under their limit (FAO, 2014). Overfishing not only negatively impacts the ecosystem, but also reduces fish production and has negative social and economic consequences. For example, in areas of poor governance fishers that are unable to legally catch their quotas occasionally turn to illegal, unregulated or unreported fishing techniques to earn a living. These practices can be wasteful, dangerous and negatively impact communities and the environment (FAO, 2014). Simply put, the world’s oceans cannot continue to support the planet’s increasing demand for fish.

Aquaculture has the potential to be the solution to the world’s fish shortage. Global aquaculture production is one of the fastest growing food-producing sectors. In 2012 aquaculture provided almost 50% of all fish for human consumption and has been predicted to provide 62% by 2030 (Figure 2; FAO, 2014). Not only are we raising more fish, but we are also eating more of the fish we raise. The amount of fisheries production used by humans for food has increased from about 70% in the 1980s to move than 85% (136 million tonnes) in 2012 (FAO, 2014). In fact, in 2012 aquaculture production was higher than beef production (66 million tonnes compared to 63 million tonnes) (Larsen & Roney, 2013). This increase in productivity is largely due to an increase in small-scale fish farms (FAO, 2014).

In addition to helping feed the world, aquaculture can play a critical role in the economy. Together, the fisheries and aquaculture industries help support the livelihoods of 10-12% of the world’s population (FAO, 2014). Additionally, fish is one the most commonly traded commodities worldwide and was worth almost 130 billion dollars in 2012; a value that has been predicted to increase into the future. The fish trade is particularly important in developing nations where in some cases the trade is worth over half of the total value of traded commodities. Aquaculture also benefits to the economy because of how efficiently herbivorous fish convert feed into live weight. For comparison, the grain to live weight ratio of cattle is approximately 7:1, it is 4:1 for pork, 2:1 for chicken and less than 2:1 for herbivorous fish such as tilapia or catfish (Brown, 2006). Since herbivorous fish have such a low ratio, focusing on them will allow us to harvest more protein while using less grain.

Aquaculture, in addition to directly providing food, can also serve as a way to support and replenish natural fish stocks. For example, in 2011 the Mississippi Department of Natural Resources raised and released 7,500 cobia in the northern Gulf of Mexico. The project’s aim was to help replenish stocks and to examine the feasibility of releasing fish that were raised in aquaculture facilities into the wild as part of a stock enhancement program (Mississippi Department of Natural Resources, 2011).

While aquaculture has shown great promise, like any industry it has it’s flaws. Two of the primary environmental concerns with aquaculture are preventing ecosystem degradation, and raising carnivorous fish without harming prey populations. Ecosystem degradation comes in many forms but can include: habitat destruction, disease, pollution, and changes to a species’ population genetics. Raising carnivorous fish, such as salmon or tuna, is controversial because while they are economically important species, their growth depends on the availability of large quantities of small prey fish, such as pilchards. Harvesting large quantities of wild prey fish for fish meal can seriously impact the prey’s natural populations (Brown, 2006). To continue to grow sustainably the aquaculture industry needs to reduce its environmental impact as well as become less dependent on wild fish for feed, and increase the diversity of culture species.

While there are important sustainability concerns surrounding the aquaculture industry, the industry is progressing and adapting at a very fast rate and fortunately, these concerns are becoming less relevant. Since the world’s population is only predicted to increase, finding a way to meet the world’s demand for fish without relying on wild stocks is essential. So long as the aquaculture industry continues to develop in a way that is environmentally sustainable, aquaculture will have an important role to play in providing healthy fish protein and jobs for the world’s economy.

References:

Brown, L. R. (2006). Plan B 2.0: Rescuing a Planet Under Stress and a Civilization in Trouble. Washington, DC: Earth Policy Institute. Retrieved September 4, 2014 from http://www.earth-policy.org/books/pb2

Brown, L. R. (2011). World on The Edge. Washington, DC: Earth Policy Institute. Retrieved September 4, 2014 from http://www.earth-policy.org/images/uploads/

book_files/wotebook.pdf

FAO. (2014). The State of World Fisheries and Aquaculture 2014. Retrieved September 4, 2014 from http://www.fao.org/3/a-i3720e.pdf

Larsen, J., & Roney, M. (2013). Farmed Fish Production Overtakes Beef. Retrieved September 4, 2014 from http://www.earth-policy.org/plan_b_updates/2013/ update114

Pauly, D., & Froese, R. (2012). Comments on FAO’s State of Fisheries and Aquaculture, or ‘SOFIA 2010’. Marine Policy, 36(3), 746-752.

Mississippi Department of Marine Resources. (2011). Cobia Released on Popular Mississippi Offshore Artificial Reef. Retrieved September 4, 2014 from http://www.dmr.state.ms.us/index.php/news-a-events/recent-news/272-11-131-lst

UN. (2012). World Population Prospects: The 2012 Revision. Retrieved September 4, 2014 from http://esa.un.org/unpd/wpp/unpp/panel_population.htm

Global Fishmeal and Fish-oil Supply

October 21, 2013/2 Comments/in Conservation, Ocean News /by aanstett

by Beau Marsh, RJD Intern

Fishmeal and fish-oil are global commodities produced for both animal and human consumption. These products are manufactured from whole fish catches, as well as the by-products of fish processed for human consumption. Fishmeal and fish-oil are utilized for livestock and aquaculture feeds, and fish-oil is being increasingly sought after by people for the omega-3 fatty acid content. In the review paper by Shepherd & Jackson (2013), information from the United Nations Food and Agriculture Organization (FAO) and the International Fishmeal and Fish-oil Organization (IFFO) is used to analyze the trends of fishmeal and fish-oil use. The data also suggests the role fishmeal and fish-oil will play in the future of animal and human consumption. In the past 50 years, fishmeal and fish-oil consumption has seen considerable change.

World fishmeal ( ) and fish-oil ( ) production for 1964–2011 ( , El Ni˜no years)(source: Shepherd & Jackson 2013).

Global production increased from the 1960’s until it peaked in 1995. Since 1995, there is a clear pattern of decreasing annual production.

Fishmeal and fish-oil predominantly come from forage fishes (i.e. whole fishes), while an additional portion come from the processed by-products of fishes caught for human consumption.

Fishmeal and fish-oil industry supply-chain (source: Shepherd & Jackson 2013).

Fishmeal offers a nearly optimal diet for animal feeds. Its benefits were initially recognized for agricultural purposes. In 1960, agriculture constituted 98% of fishmeal consumption, splitting it between pig and poultry feeds. Aquaculture has grown to the dominant use of fishmeal and fish-oil. Presently, aquaculture has expanded to the point where it consumes over 73% of global fishmeal production.

Source: Shepherd & Jackson 2013.

In regards to fish-oil, its main purpose was for both margarines and shortenings or for various industrial uses. After fish farming began in the 1980’s, it has expanded to where aquaculture now consumes over 80% of global fish-oil production. In addition, fish-oils high in omega-3 fatty acids, notably eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are increasing in demand for human consumption.

Source: Shepherd & Jackson 2013.

With the growth of these emerging markets, there is a greater demand on the fishmeal and fish-oil industry. Due to recent, more stringent fisheries regulation, there is a reduced source of whole fishes available. Therefore, greater amounts of fish by-products are being incorporated into the final products, and marine ingredients in fishmeal compounds are becoming more expensive. A cost effective response has been to substitute in vegetable components and land-animal by-products as a cheaper source of proteins and lipids. This is not an ideal solution because of potential human health concerns such as transmissible spongiform encephalopathies (TSE). It also causes a diminishing effect on the fatty acid make-up of the fish.

Multiple approaches are being taken to solve the fact that the need for fishmeal and fish-oil continues to grow, but their production remains static or decreases. Possible future solutions may be genetically modified plants or transgenic farmed fish, both of which would render high levels of omega-3 fatty acids. However, genetic modification inevitably receives consumer criticism, so these techniques are unlikely in the near future. Another solution already underway is the use of other sources such as krill species and algal biomasses for the valuable oils. This should hopefully reduce some pressure on the omega-3 oil resources; however, the incorporation of vegetable oils continues to increase.

A separate issue affecting fishmeal and fish-oil resources is the lack of regulation and responsible management in Asian fisheries. These fisheries are among the world’s largest aquaculture producers, but decades of overexploitation have hurt production. Additionally, the regional practice of feeding with trash fish exacerbates the problem. Low-level trash fish causes the depletion of fisheries and diseases to spread throughout the fishes. These instances of poor management have triggered multinational agencies to work with local governments in order to implement healthier practices.

Every year fewer marine ingredients are available because of increased fisheries regulation and the increasing demand from aquaculture and human consumption markets. While it is fortunate to see responsible management implemented over fisheries, emergent challenges arise. These challenges have sparked innovation which has developed alternatives (some more controversial than others) to the forage fish supply. Substituting marine ingredients has proven to be efficient in aquaculture, but what are the implications for the end consumer? While the fish species may show successful growth, there are reduced levels of omega-3 fatty acids in the fishes. These oils can also be extracted from algae or krill, but it is less efficient. Fishmeal and fish-oils are valuable resources that require responsible and efficient management which without could mean compromising the health of human consumers and aquacultures.

REFERENCE

Shepherd, C. J. and Jackson, A. J. (2013), Global fishmeal and fish-oil supply: inputs, outputs and markets^a. Journal of Fish Biology, 83: 1046–1066. doi: 10.1111/jfb.12224

Sea Ranching: More Economically Feasible then Other Harvesting Techniques?

August 26, 2013/1 Comment/in Conservation, Ocean News /by aanstett

By Samantha Feingold,
Marine conservation student

Atlantic Cod fish (Gadus Morhua). A common commercial species. This study investigated the economic feasibility of various harvesting practices. (NOAA, 2010)

In Need of Protein!

Fifty or sixty years ago, fishermen’s catches were much more diverse and productive. Routinely fishermen returned to their slips to show off several tuna and grouper, sizing longer then the workers were tall. Looking back at old photographs of a daily catch, one would think the fish were prehistoric or from a science fiction movie. It was fabled that colonists of New England appeared to walk over water via the backs of codfish or lobsters. Today, catches have significantly downsized; the fish are much smaller and the catches are less diverse. As a result, fishermen are being forced out of the industry or otherwise seeing a smaller profit. Meyers and Worm (2003), prominent marine biologists, have reported that 90% of large predatory marine fish in several areas have been depleted–and most fishermen would agree. Meanwhile, human population continues to rise. Today global population is 6.9 billion. If the growth rate stays constant, it is projected that by 2050 global population will reach 9.3 billion people (the difference being the current population of China and India combined; UN 2011). In 2009, fish consumption was 12.4 percent of total animal protein globally (24% in low income food deficit countries; FAO 2012). As human population rises and fisheries continue to decline, a global crisis for fish protein is escalating. The advancement of fishing technology, poor fisheries management, and growing population, are combining to create a global demand for aquaculture.

Aquaculture: A Diverse Industry

The urgency of aquaculture innovation is relatively recent, but the industry is beginning to see a boom, especially in South America and Asia. Aquaculture is the umbrella term for fish farming and is most commonly visualized as growing fish in ponds, tanks and offshore cages. It is often understood as producing fish from eggs, growing them to marketable size, and breeding them to produce viable eggs, which is called full-cycle aquaculture. Within full-cycle aquaculture, the spectrum of diversity of systems is wide, yet there is a great need for advancement. But other than full-cycle aquaculture, newer, less recognized forms of aquaculture exist: for example, sea ranching.

The Study

In a recent study by Halldórsson, et al. (2012) the authors investigate a type of aquaculture termed ranching, whereby fish are attracted in their natural environment to a certain location repeatedly and then ranchers harvest them as a group once they have reached a marketable size. This does not involve caging the fish. This practice is also commonly referred to as herding or aggregating fish. Most ranching practices utilize feed to attract the fish, although there are recent studies trialing the use of acoustics as the attractant. This type of ranching differs from the practice of on-growing, whereby fishes are captured as juveniles, then fattened up in offshore cages before finally harvesting them for market. Halldórsson et al. suggest that sea ranching can be more economically feasible than full-cycle aquaculture, traditional fishing and on-growing. I will consider this thesis.

Methods

Halldórsson, et al. compared production of coastal cod (Gadus morhua) in Iceland. The study examines which practice would be most profitable for an existing fishing company with a 200 ton cod quota, fishing permit and 30 ton boat: continue to fish, ranch, on-grow, or develop a full-cycle aquaculture system. For each of the practices the authors studied various inputs and outputs to estimate the overall net profit and thus economic feasibility of the practice within a fifteen year operating period. To investigate the profitability of ranching, Halldórsson and his team analyzed the work of a particular ranching business that trained the fish to eat at feeding bags that were anchored to the ocean floor. The fish were harvested using a large net that collected them at their feeding stations and then unloaded onto a boat. For fishing, full-cycle aquaculture and on-growing, the authors used data from past studies, supplemented by knowledge from other scientists, aquauculturists and fishermen.

Results

The results showed that ranching was the most profitable, followed by fishing, and then on-growing. Full-cycle cod farming proved not to be profitable and was predicted to remain unprofitable due to high feed costs, the low market price of cod, as well as a relatively high feed conversion ratio (i.e., the ratio of mass of feed to mass of fish produced).

In addition to economical benefits, the authors argue that ranching is advantageous because it does not reduce conventional fishing practices, and will produce a greater yield for human consumption. The authors further argue that ranching reduces the negative impact on the fisheries by minimizing the catch of undersized fish and bycatch (the accidental catch) because of their acquisition strategy. The fish are trained to aggregate at the feeding stations, which makes targeting them easy and avoids the use of harmful fishing techniques.

Analysis of Study

The results of the study are not surprising. Ranching requires fewer inputs than any of the other practices which make it more economical within the analyzed time period. Because the fish roam their natural environment the feed costs are much less then on-growing and full-cycle fish farming. The study estimates that half the feed for ranching and on-growing is wild fish that the cod prey on outside the feeding stations. Feed is often the most costly budget item for aquaculture farms. Therefore, halving the feed reduces the company’s overall expenses significantly.

Cod fishing was concluded to be the second most profitable practice. This might be true if we disregard that cod populations are in decline. Although cod populations in Iceland are healthier than they are in the Western Atlantic, the fishery is most likely not sustainable. Árnason et al. (2009) predict that the Icelandic cod fishery will collapse like the Eastern Cod fishery due to persistent fishing pressure energized by growing demand. As cod continues to be overfished, the cod fishery will become less and less feasible. The Halldórsson, et al. paper does briefly acknowledge this. Its purpose is not to encourage fishing, but instead scale the economic feasibility of the various practices relative to traditional cod fishing; fishing being the baseline to which the other practices are compared. Its analysis does not however, calculate the economic or practical probabilities of the declining cod fishery.

On-growing was proven to be unprofitable, which is emphasized by the closure of several on-growing businesses in Iceland. The study neglects to address a negative factor of on-growing which is harvesting the fish when they are likely sexual immature preventing the fish from reproducing. This practice can be argued is worse than traditional fishing because it prevents the success of the future generations.

It should be mentioned that ranching and on-growing are just different ways of harvesting from the open ocean. One important advantage of these two practices over fishing is they return a greater yield because feeding them consistent, nutritious food before harvesting them increases their biomass. Ranching and on-growing does not decrease the pressure on wild cod populations in any known manner.

In the study, full-cycle cod farming saw no profit in the fifteen year timeframe. The concept of full-cycle aquaculture is to efficiently create an environment that mimics the species’ natural environment in order to grow healthy fish, which is a very costly task. In order to earn a profit, it must be large scale, have very significant initial funding and be prepared to operate for years before making a profit. Full-cycle farms are a bigger investment that a 30-ton boat, quota and fishing permit. The practice is currently still developing and evolving, with various inefficiencies to resolve.

The study makes the logical conclusion that full-cycle fish aquaculture is less economically feasible then the other practices. This should not be understood as saying that full-cycle aquaculture will never be profitable given sufficient capital and time. The study was intended to show fishermen who are trying to evaluate their alternatives, which of the different practices is most practical.
Positive Future for Ranching?

Although at first glance the paper might seem skewed (or uneducated regarding full-cycle aquaculture), its purpose as a tool for current cod fishermen is useful. Sea ranching is an interesting concept. It could be a beneficial investment for a fisherman who is looking to get out of conventional fishing. There are issues that must be investigated further, however, including the fidelity of the fish. What if the fish migrate? The study stated that if the ranchers do not harvest 75% of the conditioned cod or more, the economical feasibility would not be viable. Also, what prevents other fish from being attracted to the feed bags? In that case, the ranchers are not only feeding undesired fish costly feed, but they will catch them (an important conservation concern). Lastly, there is a lack of permitting available for these ranchers. Local or commercial fishermen could easily take advantage of the aggregated fish in the area unless they are protected somehow. These are speed bumps that probably could be resolved. Ranching could be beneficial if healthy fish populations are targeted. Ranching, as the authors defined it, may be an effective approach to lessen the negative impact that overfishing has on fishermen and the fishing industry. It is not a large step away from traditional fishing practices, but could have a positive impact on the cod fishing industry (fishermen, processors, buyers and sellers, etc). This is not the solution to declining cod fisheries, but a compelling concept that could be utilized in the meantime.

REFERENCES

Halldórsson, JE., Björnsson B, Gunnlaugsson SB (2012) Feasibility of ranching coastal cod (Gadus morhua) compared with on-growing, full-cycle farming and fishing. Mar Policy 36: 11-17. doi:10.1016/j.marpol.2011.03.001

Arnason, Einar. Intense habitat-specific fisheries-induced selection at the molecular Pan I locus predicts imminent collapse of a major cod fishery PLoS ONE. 4: 1-14 DOI: 10.1371/journal.pone.0005529. http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0005529 (accessed 26 Oct 2012).

Food and Agriculture Organization (FAO) (2012) http://www.fao.org/docrep/016/i2727e/i2727e.pdf (accessed 1 October 2012)

Myers, RA, Worm B (2003) Rapid worldwide depletion of predatory fish communities. Nature 423: 280-283 http://billhutten.s3.amazonaws.com/fw/docs/261.pdf (accessed 1 October 2012)

United Nations (UN). World Population Prospects: the 2010 Revision: Highlights and Advanced Tables (2011) In: United Nations Department of Social and Economic Affairs/Population Division. United Nations, New York City, p 1-142 http://esa.un.org/unpd/wpp/Documentation/pdf/WPP2010_Highlights.pdf (accessed 1 Oct 2012)