aquaculture

R. J. Slack-Smith has written and the FAO published a manual entitled Fishing with Traps and Pots. It describes the basic elements of fishing with traps and pots for small-scale fishermen. It presents the various types of traps and pots and their construcion and gives guidance on how to choose the appropriate gear, how to rig it, how to use it to improve the catch, how to select places to fish, soaking time and finally care of the catch. The document is also available (as a .pdf) for download.

From Chapter 1:

Fishing is one of the oldest ways by which people have fed themselves and their families. Except for gathering shellfish by hand and spearing fish, primitive trapping is probably the oldest form of fishing.

In early times, flowing water caused by tidal movement and changes in river and lake levels were probably used to trap fish behind rudimentary barriers, often made from sticks and stones. It is likely that early humans found that fish catches could be improved by driving fish into these barriers. They would have found that catches from these barriers decreased over time, as fish became accustomed to them, and would have had to move the traps to fresh areas where more fish could be caught. It would have been hard work to construct new traps, either by moving stones from the old trap or finding new ones. Primitive fishers probably tried making barriers from lighter, more readily available material such as tree branches, brush and vines. This led to the fishers inventing lighter, movable traps made from brush and nets made from vines which they could carry with them when they moved to new areas. They may even have tried bigger, more complicated corral-type fish traps in lakes, rivers and coastal waters.

Marine Aquaculture: Opportunities for Growth (1992) is available, online as a free book (.pdfs), and also can be bought as a hard copy. The big advantage of the .pdf document, apart from the agreeable price, is the ability to search on any word, across the document.

The authors, the Committee on Assessment of Technology and Opportunities for Marine Aquaculture in the United States, and the Marine Board, Commission on Engineering and Technical Systems, National Research Council appear to have completed a comprehensive job – the Table of Contents:

Front Matter i-xii
Executive Summary 1-8
Introduction 9-19
Status of Aquaculture 20-63
Policy Issues 64-91
Environmental Issues 92-115
Engineering and Research 116-157
Information Exchange, Technology Transfer, and Education 158-168
Conclusions and Recommendations 169-177
Bibliography 178-205
Appendix A: Review of World Aquaculture 206-231
Appendix B: Freshwater Aquaculture in the United States 232-240
Appendix C: Federal Marine Aquaculture Policy 241-152
Appendix D: Sociocultural Aspects of Domestic Marine Aquaculture 253-268
Appendix E: Committee Biographies 269-273
Appendix F: Participants in Special Sessions 274-276
Index 277-290

The Catalog of Fishes is searchable, for free, online; courtesy of the California Academy of Sciences. It is also available as three, hardbound books.

The catalog covers more than 53,000 species and subspecies, over 10,000 genera and subgenera, and includes in excess of 16,000 bibliographic references. Entries for species, for example, consist of species/subspecies name, genus, author, date, publication, pages, figures, type locality, location of type specimen(s), current status (with references), family/subfamily, and important publication, taxonomic, or nomenclatural notes. Nearly all original descriptions have been examined, and much effort has gone into determining the location of type specimens.

The Genera are updated from Eschmeyer’s 1990 Genera of Recent Fishes. Both genera and species are listed in a classification using recent taxonomic schemes. Also included are a lengthy list of museum acronyms, an interpretation of the International Code of Zoological Nomenclature, and Opinions of the International Commission involving fishes.

The Catalog of Fishes consists of three hardbound volumes of 900-1000 pages each, along with a CD-ROM (not sold seperately). This work is an essential reference for taxonomists, scientific historians, and for any specialist dealing with fishes.

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.

Raising fish in rice paddies brings to farmers in Asia an important source of protein, as well as extra income. Rice–Fish Culture in China is an important addition to the English language literature in this area. Along with biological and ecological aspects of rice–fish culture, this free online book (edited by Kenneth T. MacKay) addresses its economic and social dimensions.

From the preface and introduction:

A National Rice–Fish Farming Systems Symposium was held in China at the Freshwater Fisheries Research Centre of the Chinese Academy of Fisheries Sciences in Wuxi, Jiangsu Province, 4–8 October 1988. China has had a long history of rice–fish farming. As rural areas have been industrialized in recent years, rice–fish farming has gained attention because it is an organic method that combines rice and fish production while maximizing labour and ricefield resources.

Rice has always been the number one grain crop in China in terms of both area and yield. During the 1950s, the tradition of rice–fish farming developed substantially but the benefits were not significant. Fish harvests were poor because the method was based only on traditional experiences and technical difficulties were encountered. However, rice–fish farming developed rapidly and by 1988, 800 000 ha were being harvested with a average yield of 133 kg/ha. In some areas, yields exceeded 3750 kg/ha and many farmers harvested 15 000 kg of rice and 1500 kg of fish per hectare. The incomes of these farmers increased considerably. The techniques of rice–fish farming improved markedly as additional skill and experience were acquired.

Research was focused on the common needs of fish and rice for water, light, and nutrition under local conditions. Many new techniques were developed to suit various locations: ridge and ditch systems; semidry land; ditch manure pits; ditches with floating water; and rice–duckweed–fish systems.

Rice–fish farming is no longer limited to the household economy and to production for personal or family consumption. It is now part of farmland improvement, soil improvement, and environmental protection. Rice–fish farming has increased the productivity of ricefields and is fast becoming an important part of the commodity economy. It has also played a significant role in reforming the structure of rural industries.