aquaculture

Ichiro Nomura, Assistant Director-General, FAO Fisheries Department, notes in the forward of The State of World Fisheries and Aquaculture 2004 –

Developments during the past two years confirm the trends already observed at the end of the 1990s: capture fisheries production is stagnating, aquaculture output is expanding and there are growing concerns with regard to the livelihoods of fishers and the sustainability of commercial catches and the aquatic ecosystems from which they are extracted. The State of World Fisheries and Aquaculture 2004 reports on several of these issues.

It is not only fishers and fish farmers who have these concerns; they are increasingly shared by civil society at large. Moreover, the importance of international trade in fish and fish products, combined with the trend for major fishing and trading companies to operate on a multinational basis, means that such issues are becoming global in nature – affecting a growing number of countries, be they large fish producers or large consumers of fish. It is heartening to note that governments and other stakeholders have begun to collaborate with their neighbours and partners in trade in an effort to find shared solutions.

Concrete examples of positive outcomes of this “globalization of concerns” are the establishment of new regional fishery management organizations and the strengthening of existing ones. It is probable that ongoing discussions among intergovernmental organizations on topics such as trade in endangered aquatic species, the use of subsidies in the fishing industry, and labour standards in fisheries will also result in agreements of overall benefit to world society.

Given the nature and tone of the international discussion on fishery issues and the developments observed during recent years, I believe that fishers and fish farmers, in collaboration with governments and other stakeholders, will overcome the obstacles they face currently and will succeed in ensuring sustainable fisheries and continued supplies of food fish at least at their present levels.

Science magazine (3 November 2006: Vol. 314. no. 5800, pp. 787 – 790 DOI: 10.1126/science.1132294) reported a less bright future: (from the reprint summary)

A Need for a Sea Change
The significance of the ocean’s declining diversity on humanity has been difficult to assess. In a series of meta-analyses, Worm et al. (p. 787; see the news story by Stokstad [a summary, the balance by subscription]) quantify how the loss of marine diversity on local, regional, and global scales has affected the functioning and stability of marine ecosystems, the flow of ecosystem services, and the rise of associated risks to humanity. Similar relationships occur between biodiversity change and ecosystem services at scales ranging from small squaremeter plots to entire ocean basins; this finding implies that small-scale experiments can be used to predict large-scale ocean change. At current rates of diversity loss, this analysis indicates that there will be no more viable fish or invertebrate species available to fisheries by 2050. However, the results also show that the trends in loss of species are still reversible.

The abstract is available, the article is by subscription. New Scientist magazine carry more freely available coverage of the results of Worm’s (et al) research.

Many fisheries scientists have been sceptical of the idea that damage to a few non-fish species could be a threat to major fish stocks. But this study demonstrates, for the first time, that commercial and ecological health go together in the ocean. “Every species matters.”

In a separate article, New Scientist report that striking the balance between the need to conserve wild stocks and economic imperatives continue to challenge policy makers and the fishing industry; leading to some unhappy compromises.

Charles F. Cotton has published a 2002 MSc thesis entitled Optimizing Growth for Aquaculture of Juvenile Black Sea Bass Centropristis Striata L. : Effects Of Temperature, Salinity, Commercial Diet and Feeding Ration. The abstract notes:

A new market has emerged for live black sea bass, Centropristis striata L., in fish markets of the northeast United States and Canada. Efforts to culture black sea bass have been hampered by the lack of information regarding optimal grow-out conditions. This research was designed to determine optimal commercial diet, feeding ration, temperature, and salinity for growth of hatchery-reared, juvenile black sea bass. Optimal diet was Zeigler Salmon Starter (compared to Nelson and Son’s Silver Cup Salmon Crumbles, Trout Crumbles, and Rangen Trout and Salmon Starter). Optimal daily feeding ration was 5% (compared to 2.5% and 7.5%). Optimal water temperature was 25º C (compared to 15º C, 20º C, and 30º C), and optimal salinity was 20 ppt or 30 ppt (compared to 10 ppt). Additionally, growth rates, feed conversion ratio, and mortality were calculated in each experiment. This information will be a valuable guide for culturing juvenile black sea bass.

The Marine Resources Research Institute notes that the first reported spawning of black sea bass occurred in 1884 with fish captured off South Carolina and shortly afterwards, ripe fish captured off Massachusetts were spawned. Since then there has been increasing information developed on the culture of this typical reef dwelling species. It is unclear if the 1884 date is correct. There is no doubt about the value of the species, and the, as yet undeveloped, potential for aquaculture.

Randal L. Walker and Deborah A. Moroney from the Shellfish Aquaculture Laboratory, Marine Extension Service, University of Georgia, USA; have published their findings entitled Growth of juvenile black sea bass, Centropristis striata, fed either a commercial salmon or trout diet. They observe:

An opportunity exists to expand Georgia’s commercial fishery by developing aquaculture techniques for the black sea bass, Centropristis striata. Black sea bass fillets sell for $1.25 to $1.50 per 0.45 kg wholesale. However, live, 0.9 to 1.13 kg fish are sold on the sushi market at a wholesale price of $3.50 to $8.00 per 0.45 kg. Little biological information exists concerning the culture of this potential aquaculture species. Six 600-L tanks on a flow-through system were stocked with 12 juvenile fish each (ranging in total length from 153 to 235 mm). Fish were pot-trapped from an offshore population. Tanks (3 for each diet) were randomly assigned a diet of either a commercial trout or salmon chow. Fish were fed a two percent daily ration (grams dry weight of food to grams wet weight of fish). Rations were adjusted biweekly to account for fish weight increases per treatment. Fish fed the salmon chow were significantly heavier after 10 weeks (P = 0.0209) and after 14 weeks (P = 0.0003) than fish fed the trout chow. Fish fed trout chow increased from 196 grams to 304 grams (55% increase) in 14 weeks, while fish fed the salmon chow increased from 163 grams to 386 grams (137% increase). Based upon fish growth and cost of feed, salmon chow is the preferred diet over trout chow for rearing black sea bass.

Again, from the Shellfish Aquaculture Laboratory, Marine Extension Service, University of Georgia, USA; Richard W. Kupfer, Dorset H. Hurley and Randal L. Walker have published their findings entitled A Comparison of Six Diets on the Growth of Black Sea Bass, Centropristis striata, in an Aquacultural Environment. The abstract notes:

Two studies of juvenile black sea bass, Centropristis striata, were conducted to address questions concerning the biological feasibility of aquaculture of C. striata. Juvenile C. striata and rock sea bass, C. philadelphica, were trapped inshore, while sub-adult C. striata were trapped in nearshore waters of coastal Georgia, south of Savannah. Catch composition of inshore trapping was dominated by Centropristis philadelphica (80%). Few C. striata were caught. A comparative growth study of juvenile C. philadelphica and C. striata fed a 3% daily ration (gram dry weight feed/gram wet weight of fish) was performed over 27 days. Overall juvenile C. striata mean increase in growth was 42% ± 5.3% (SE), with 10% mortality; whereas, C. philadelphica mean growth was 14% ± 4.7%, with 65% mortality.

Sub-adult C. striata (164 g mean weight ± 1.74) were subjected to six ration treatments for 18 weeks. Three replicate 500-L tanks were used per treatment, and each tank was stocked with 15 fish. Ration treatments consisted of a high-protein trout feed, a lower-protein trout feed, and an equal mixture of both delivered daily in rations of 2% and 3% dry weight feed/wet weight fish. All rations were adjusted biweekly based upon mean fish wet weight per treatment. At week 16, ANOVA revealed no significant differences (p=0.4096) in mean fish weight among treatments with a pooled treatment mean fish weight increase of 48%. Based on cost effectiveness, the lower-protein 2% ration was judged the optimum choice among the diets tested. This study reinforces the biological feasibility of rearing trapped C. striata on a commercial diet of 2% dry weight feed/wet weight fish.

Further, from the Shellfish Aquaculture Laboratory, Marine Extension Service, University of Georgia, USA; Alan Power, Tiffany Lee, Todd Recicar, Mary Sweeney-Reeves, and Randal L. Walker have published their findings entitled The Growth and survival of juvenile black sea bass, Centropristis striata, on an artificial (Salmon chow) versus a natural (grass shrimp) diet. The abstract notes:

This study examined growth and survival rates of juvenile black sea bass Centropristis striata (Linnaeus, 1758), that were fed two distinct dietary treatments, – one, a commercially available salmon chow and the other a diet consisting of natural live grass shrimp (Palaemonetes pugio, Holthuis, 1949). The diets were fed at a 2.5% ration (grams dry weight of food/ grams wet weight of fish). Fish were reared in replicated (N=3 per dietary treatment) 65-liter flow-through tanks for six weeks between May 7 and June 25, 2001. The fish provided with live shrimp had a mean survival of 69 ± 5.9% and increased in size from an initial mean wet weight of 20.7 grams to 30.4 grams – a growth rate of 0.194 grams per day. A higher mean survival of 80 ± 6.7% and a slightly lower growth rate of 0.184 grams per day (mean wet weight increase from 20.4 grams to 29.6 grams) were recorded for fish fed the salmon pellet diet. However, there were no statistically significant differences detected in either growth (p=0.7849) or percent survival (p=0.4999) between dietary treatments. Based on these results, we recommend using the commercially available salmon chow because of its convenience and supplementing it occasionally with grass shrimp to provide essential amino acids common in natural diets.

According to the Marine Resources Research Institute (South Carolina Department of Natural Resources), the red drum (Sciaenops ocellatus) is a long lived marine finfish (> 50 years of age) which has an estuarine dependant early life history (ages 0-4). Throughout the southeast USA, this species (known locally as spottail bass) is one of the top three fish preferred by saltwater anglers.

Lawrence W. McEachron, C.E. McCarty, and Robert R. Vega have reported on the Successful Enhancement of the Texas Red Drum (Sciaenops ocellatus) Population. From the abstract:

Red drum (Sciaenops ocellatus) is an estuarine-dependent sciaenid that inhabits estuaries, bays, and coastal regions from New York to Mexico. In Texas, the red drum population began a dramatic decline in the 1970s, prompting the Texas Parks and Wildlife Department (TPWD) to set up a three-pronged recovery plan. Management approaches were: 1) Initiate an independent monitoring program to assess relative abundance; 2) Implement restrictive regulations to reduce fishing pressure, including license restrictions, size, bag, and possession limits, a commercial quota, restrictions on netting, and a ban on commercial sale of red drum; and 3) Develop and start a marine enhancement program based on the release of hatchery-reared fingerlings and assessment of subsequent survival.

Recently, the red drum population in Texas coastal water rebounded because of several factors that had a positive effect on the recovery. TPWDs long-term management plan utilizing hatcheries and stocking to supplement natural spawning played a role in reversing the decline of the red drum population. The strategy used by the TPWD can serve as a blueprint for other marine enhancement programs.

The FAO have reported on Aquaculture Development of Red Drum (Sciaenops Ocellatus) in Martinique and the French West Indies. Note – the report is contained with other aquaculture reports on the page. From the summary:

The aquaculture of red drum (Sciaenops ocellatus) has been the subject of research and development work in Martinique since 1985. It was during the initial eight-year period that research findings showed the suitability of the species for domestication and mariculture.

However, whilst biological and technical knowledge is a compulsory prerequisite, it is not the only requirement for development. Operations throughout the production chain need to be synchronised, right through to product selling and company profitability. This explains the lengthy development process.

Since 2000, research reorganisation at IFREMER, the separation of larval rearing from growing-out, and the political and financial support of Martinique Region, have given a fresh impetus to our work, and development is now really taking off.

However, Martinique should not be the only island to benefit from this example; other Caribbean countries must also be given the opportunity to put the small-scale aquaculture model into practice.

There are about 100 abalone species in the world. The FAO have prepared a training course on the artificial breeding of the Ezzo Abalone (Haliotis discus hannai).

From the introduction:

Abalones have been long considered as a valuable fishery product. From as far back as 1880 until 1952, studies were mainly focussed on its habitat, taxonomy, spawning season, breeding, feeding habits, and growth. Throughout this period studies were also concentrated on artificial propagation and rearing methods suitable for selected areas, as well as on transplanting and releasing adult abalones to potential on-growing sites.

In the 1960′s, on the basis of successful seed rearing experiments, studies were conducted with the view to produce seeds on an industrial scale. These studies, eventually succeeded in the establishment of a seed production system.

Maritime countries have given priority to aquaculture development with the objective of preserving and increasing their natural resources. It is in line with this aim that the Democratic People’s Republic of Korea (DPRKorea) has embarked on an intensified development of numerous aquatic resources. The suggested method of abalone culture is to release hatchery-bred juveniles into natural waters and allow them to grow mainly on natural feed organisms. This method fully considers the fact that it takes 3 to 4 years for abalones to attain the desired marketable size. However, due to the increasing demand of the high valued gastropod, a number of land-based intensive farming techniques have been developed.

The Korean-US Aquaculture note that Halotic discus hannai is one of the most common species cultured in Korea. The species, sized 120~180mm in shell length, spawn in June to July. It is this foot which is the edible part of the animal and is considered a great delicacy by a number of Asian cultures. High prices are paid for abalone meat, which constitutes between 28 to 46% of the abalone’s live weight (depending on season and location).

Good current information about the marketing of aquacultural products is not always that easy to find on the net, particularly if you are seeking information about alternative species. One such article is available – sadly not updated since 1995. George Luker, Conrad Kleinholz, Andrea Robbs, and Nikita Walker report on Marketing Alternative Aquaculture Species. They focus on channel catfish (although other species are mentioned) in the Oklahoma region.

The Delaware Aquaculture Resource Center Home Page offer a report by LaDon Swann and Jean Rosscup Reipe from Purdue University entitled Making Wise Choices When Direct Marketing Your Aquaculture Products – again, this information appears to be from around 1995. Current market realities should be factored into any planning based on these reports.

Auburn University offers David J Cline’s Marketing Options for Small Aquaculture Producers – a document from around 2000. This document contains useful information for small-scale producers wishing to understand a more commercial approach to the marketing of fish. There document contains information relevant to the marketing of all aquacultural species, not only fish.

West Virginia University Extension Service offer a 2001 document which focuses more on the marketing and less on a specific fish species. Written by Leo Ray, Common Sense Marketing, like the title above, discusses the need to produce high quality products, aimed at lucrative niche markets. Ray observes the scale of aquaculture can be deceptive:

Most aquaculture is small business. There are exceptions – the catfish industry is definitely not a small industry. It is however, primarily composed of small businesses. Small business can be anything from a few thousand dollars in sales, to several million in sales. It really should not be classified by size and dollars of sales, but by structure. And most aquaculture is established around the family farm, with mom and pop running it.

We think of the catfish industry as a large, mature industry, however, approximately 40% of all catfish raised is sold in one state, the state of Texas. Think of the size the catfish industry will be when it supplies catfish to all the states like it does Texas. And that will happen someday.

Fundamental to discovering the niche, and essential to marketing is research. A White Paper on Marketing Research Needs for the North Central Region (Michigan) has been prepared by H. Christopher Peterson and Karl Fronc in 2005 for the North Central Regional Aquaculture Center. They observe:

The need to place special emphasis on marketing research derives from the strategic challenges that the aquaculture industry faces. Like producers in many commodity industries, aquaculture producers are faced with dramatic increases in global supply (most especially in China), mature demand in the developed world, and falling prices overall. Industry profitability has suffered as a result.

Rather than commodity based production, niche or otherwise, Peterson and Fronc note added value as being a key point of distinction and identify areas of future research:

The four areas of research do point to the critical four issues that research should address: what consumers want, what supply chain structure is needed to deliver what they want, what business strategies are responsive to what they want, and how can producers be positioned to actually implement the strategies that make sense.