Not just dogfish and catfish, sea horses and sea cows – Domestic marine species on the increase

“Domestication has had a higher success rates in the sea relative to that seen in the long history of land species’ domestication” states Dr Marianne Holmer, one of the MarBEF authors from the Institute of Biology, University of Southern Denmark, in a new research paper released in Science entitled ‘Rapid Domestication on Marine Species’.

This modest success in the domestication of land animal species can be attributed partly to the lower diversity of suitable land species compared to the marine environment and the reduced geographical range of terrestrial domestication.

Taming the wild

The first records of domestication of animals and plants, for human food go back 11,000 years. The taming of wild plants and animals by humans for breeding, food and protection was initially focused on land species. This practice quickly led to a surge in domestication of land species within 9,000 years of its initiation. However, since the industrial revolution the increase in new domestic plant and animal species has been modest with approximately 3% of the species presently cultivated on land haven been domesticated.

Pastures new

There are several reasons for this contrast between the success in the domestication of land and marine animal species. First, land domestication has drawn largely from mammals and birds, with few invertebrates (such as bees and snails) domesticated. In contrast a diverse array of marine taxa – molluscs, crustaceans, vertebrates, echinoderms, jellyfish, worms have been domesticated. Many more wild marine species are used for food (more than 3000 marine species compared to fewer than 200 land species) providing further scope for domestication and explaining the rapid increase in the number of aquatic species becoming domesticated today. In addition domestication of land species has been restricted to a few regions whilst for marine species there is a more global trend.

The rise of aquaculture

According to Prof. Duarte from the Spanish Council for Scientific Research “Aquaculture is now emerging as a revolution in agriculture of global importance to humanity”.

While most land species were domesticated earlier than aquatic species we are now witnessing a contemporary phenomenon, where marine species are rapidly becoming domesticated. Four hundred and thirty, 97% of the aquatic species presently in culture, have been domesticated since the start of the 20th century and in the last decade an estimated 106 species haven been domesticated.

Not without consequences

Aquaculture production has been growing at approximately 7 to 8 % per year compensating for the stagnation of fisheries, and is likely to become the main source of marine food for humans as demands continue to grow. This development in aquaculture is predicted to replace fisheries as animal husbandry replaced hunting on the land. However, aquaculture development also has, as currently practised, negative consequences for the environment and biodiversity, including the deterioration of coastal ecosystems by aquaculture effluents and impacts on wild species used as feed.

“This increase in aquaculture has global consequences, both as a food source and in terms of environmental implications” says Dr Nùria Marbá, from the Spanish Council for Scientific Research. Also “the growth in the domestication of marine biodiversity will thus represent a fundamental change in the way humans relate to the oceans”.

Full refrence:
Duarte, C.M., N. Marbá, and M. Holmer. 2007. Rapid Domestication of Marine Species. Science 316: 382-383.