Aquaculture: The Future of Farming the Water, Fish for Brains, Oldest Fig Wasp and more

Download this episode.

Aquaculture - The Future of Farming the Water

The feed barge and trout cages at Aqua-Cage Fisheries on Georgian Bay, courtesy Steve Naylor

Aquaculture is the world's fastest growing food production system, and now rivals wild capture fisheries as a source of the world's seafood. In many ways, you might see this as the logical progression of our shift from hunting and gathering food to domesticating it and growing it ourselves. We first did it on land with agriculture, and now we're doing it in the water. Despite our perception here in Canada, aquaculture is not just salmon, by any means. A huge proportion of the world's aquaculture is seaweed and shellfish. When it comes to fish, most are freshwater species, like carp, which are farmed using traditional methods in Asia that are thousands of years old. Aquaculture has enormous potential to provide even more food to the world's growing population. But it suffers from many of the pitfalls we faced with agriculture, especially when pursued as a large scale, capital-intensive, industrial system. The biggest concerns are environmental, as aquaculture can have impact on wild species and habitat. Fish-farming, in particular, shares many of the problems that land-based high-density animal farms have. Disease and parasites can be a significant problem, as they can spread in high-density fish farms, and there are worries that they might then create problems for wild fish. High-density fish farms also produce high-density fish waste. There are also conflicts over use, as the best sites for fish-farms can be near recreational areas, and fish farming can be perceived as the intrusion of a new industrial activity on natural ocean ecosystems. Researchers are looking for solutions to the technical problems associated with aquaculture, but society is ultimately going to have to decide just whether we're wise enough to domesticate the waters, the way we've domesticated the land.

Appearing in this program are:

• Mr. Gord Cole, owner and operator of Aqua-Cage Fisheries, a rainbow-trout farm operation on the Wasauksing First Nation near Parry Sound, Ontario.
• Dr. George Leonard, Aquaculture Program Manager for Ocean Conservancy, a US-based environmental group.
• Dr. Thierry Chopin, professor of Marine Biology and aquaculture researcher at the University of New Brunswick, St. John.
• Dr. Laura Halfyard, aquaculture researcher and Professor at the Marine Institute of Memorial Univerisity of Newfoundland.

Listen to this segment:

Related Links
Dr. George Leonard
Dr. Thierry Chopin's Lab
Dr. Laura Halfyard
UN FAO (Food and Agriculture Organization) Aquaculture Department
Department of Fisheries & Oceans Canada, Aquaculture site
Ocean Conservancy Aquaculture page
World Wildlife Fund Aquaculture Program

Fish for Brains

Archaeologist Dr. David R. Braun at the fossil site in northern Kenya

Apes and humans are similar in many ways, in terms of biology and behaviour. But one of the key differences is the size of our brains. Although humans have bigger brains, it has been the subject of great debate as to why and how that came to be. But a new discovery by Dr. David Braun, an Archaeologist from the University of Cape Town, has shed new light on this discussion. Beneath a layer of volcanic ash on the shore of Lake Turkana in Northern Kenya, he excavated hundreds of bones, and several thousand stone tools, dating back 1.95 million years. The site included many catfish bones and at least 15 other fish, as well as turtle and crocodile, which show signs of having been cut with the stone tools. It provides the earliest definitive evidence of early humans butchering and eating aquatic animals. By expanding their diet to fish and seafood, early humans were adding the fatty acids essential for brain growth.

Listen to this segment:

Related Links

Paper in PNAS
News release from George Washington University
News release from Johns Hopkins University
Dr. Braun's web page 

Oldest Fig Wasp

34-million-year-old fig wasp fossil. The arrow indicates the pocket where the pollen is stored. Courtesy Natural History Museum.

A fossil found on the Isle of Wight in England more than 100 years ago, and first identified as an ant, has now been correctly identified as a 34-million-year-old fig wasp. It is the oldest known fig wasp fossil. The wasp is almost identical to the modern species, which proves that this tiny but specialized insect has remained virtually unchanged for that many years. Dr. Stephen Compton, a Senior Lecturer from the Faculty of Biological Sciences at the University of Leeds, made the identification. He said the key was the pollen pocket on the underside of the wasp; it still contained pollen from a fig tree, albeit fossilized. The age of this fossil points to the fact that the complex relationship that exists today, between the fig wasp and its host trees, developed more than 34 million years ago, and has remained unchanged since then.

Listen to this segment:


Related Links
Paper in Royal Society Biology Letters
News release from the University of Leeds
News release from the British Natural History Museum
Dr. Compton's web page

Theme music bed copyright Raphaël Gluckstein.
Creative Commons License by-nc-nd-2.0