Digital library

This volume addresses the potential for combining large-scale marine aquaculture of macroalgae, molluscs, crustaceans, and finfish, with offshore structures, primarily those associated with energy production, such as wind turbines and oil-drilling platforms. The volume offers a comprehensive overview and includes chapters on policy, science, engineering, and economic aspects to make this concept a reality. The compilation of chapters authored by internationally recognized researchers across the globe addresses the theoretical and practical aspects of multi-use, and presents case studies of research, development, and demonstration-scale installations in the US and EU.

4.1 Historical Perspective

Aquaculture has a tradition of about 4 000 years. It began in China, possibly due to the desires of an emperor to have a constant supply of fish. It is speculated that the techniques for keeping fish in ponds originated in China with fishermen who kept their surplus catch alive temporarily in baskets submerged in rivers or small bodies of water created by damming one side of a river bed. Another possibility is that aquaculture developed from ancient practices for trapping fish, with the operations steadily improving from trapping-holding to trapping-holding-growing, and finally into complete husbandry practices (Ling, 1977).

Table 5. Possible environmental Impacts of aquaculture

Source: Modified from Pullin, 1989

Chinese who emigrated to other Southeast Asian countries probably carried the knowledge with them and inspired the local people to take up fish farming. Brackishwater aquaculture is thought to have originated in Indonesia with the culture of milkfish and grey mullet (Ling, 1977) and must have spread to neighbouring countries like the Philippines which has been practising it for about 300 to 400 years (Baluyut, 1989).

The husbandry of fish is therefore not a new phenomenon. Ancient practices based on the modifications of natural bodies of water or wetlands to entrap young fish in enclosures until harvest, have just evolved into more systematic and scientific methods and techniques.

Other regions of the world have shorter traditions of aquaculture. In North America, it is about a century old; in Africa, aquaculture production consists almost exclusively of tilapia culture in freshwater ponds and dates back to the 1940s (UNDP/NORAD/FAO, 1987). Aquaculture development has been very recent and is just gaining momentum in Australia, New Zealand, and the Pacific Island countries (Rabanal, 1988b).

In the past two decades, there has been much debate amongst industry, the state development agencies and the research institutions about the potential of the Irish seaweed sector. Seaweed gathering and processing is a traditional activity in Ireland bringing economic activity and employment to coastal communities. Ireland’s seaweed and biotechnology sector is currently worth €18 million per annum and employs 185 full time equivalent people (Morrissey et al., 2011). The potential to increase employment, exports and wealth from seaweed in Ireland was looked at by the National Seaweed Forum which was established in 1999 to join industry with research bodies, state agencies and departments to make recommendations for the future development of the industry. 

One such recommendation was the development of seaweed cultivation. With this in mind, groups such as Bord Iascaigh Mhara (BIM), Taighde Mara Teo (TMT), National University Ireland Galway (NUIG) and Queen’s University Belfast (QUB) initiated seaweed cultivation trials. These early trials had varied success and allowed for experimentation and year-on-year technique improvement. Farming seaweed as opposed to simply gathering seaweed requires a thorough knowledge of seaweeds and perfect manipulation of the seaweed life cycle. Mastering this has concerned Irish seaweed researchers and industry practitioners alike over the last decade. 

The Seaweed Hatchery project has focused on developing new techniques, and improving existing knowledge of seaweed cultivation. This manual is one such output of the project. The manual is offered to the industry as a guide to the hatchery techniques required to develop new aquaculture opportunities for Laminaria digitata. 

As with all BIM ‘Aquaculture Explained’ manuals, it is based on the research and experiences of the group and includes both hatchery and sea trial cultivation results obtained over several years and sites. An attempt has been made to provide an easy to use document filled with practical advice for those interested in growing kelp.

With continued human pressure on marine fisheries and ocean re- sources, aquaculture has become one of the most promising avenues for increasing marine fish production in the future. This review presents recent trends and future prospects for the aquaculture industry, with particular attention paid to ocean farming and carnivorous finfish species. The benefits of farming carnivorous fish have been challenged; extensive research on salmon has shown that farming such fish can have negative ecological, social, and health impacts on areas and parties vastly separated in space. Similar research is only beginning for the new carnivorous species farmed or ranched in marine environments, such as cod, halibut, and bluefin tuna. These fish have large market potential and are likely to play a defining role in the future direction of the aquaculture industry. We review the available literature on aquaculture development of carnivorous finfish species and assess its potential to relieve human pressure on marine fisheries, many of which have experienced sharp declines.