4.3: AQUATIC FOOD PRODUCTION SYSTEMS http://www.mrgscience.com/ess-topic-43-aquatic-food-production- systems.html

Significant Ideas: Aquatic systems provide a source of food production. Unsustainable use of aquatic ecosystems can lead to environmental degradation and collapse of wild fisheries. Aquaculture provides potential for increased food production.

You have 10 seconds to look at the diagram each time… What is the relationship between population and marine fish catch? Why do you think there is a difference between total marine fish catch and that excluding China? How has kg of fish per capita changed? Why? What is aquaculture? Demand for aquatic food resources continues to increase as human population grows and diet changes.

Key definitions

Where does the food web begin? Do a google search for a marine food web Paste into the google doc: https://docs.google.com/a/wis.edu.hk/document/d/1XdwwXXyb7nPHCALP z_CkMq1yJq5kNDOP1lIJ08SHq8U/edit?usp=sharing Make sure your web is different from your classmates’ What are the similarities and differences?

Describe the patterns of productivity of oceans Can you suggest reasons?

Photosynthesis by phytoplankton supports a highly diverse range of food webs. Plankton are the most abundant life forms in the ocean ​The first link in all marine food chains are the phytoplankton, or 'plant' plankton, Plankton use sunlight to make sugars from carbon dioxide and water (photosynthesis). Because they need sunlight, they can only live in the photic zone, the upper most 80m that receives sufficient sunlight for photosynthesis. Through photosynthesis, phytoplankton make food for themselves and give off oxygen. Phytoplankton produce all the food at the bottom of the ocean food chain, so they are called primary producers. Most of the photosynthesis on Earth happens in the oceans and phytoplankton produce a large share of the oxygen in the air we breathe.

Illegal, unreported and unregulated If you were presented with this graph in the exam what questions could you be asked about it?

Aquatic (freshwater and marine) flora and fauna are harvested by humans. Seafood is an important source of protein and fats around the world Aquatic environments also provide fish and invertebrates that are important for economic reasons, for example providing ingredients for medicines and resources for jewellery (e.g. pearls).

Case study: controversial harvesting of a named species

Harvesting some species, such as seals and whales, can be controversial. Commercial whaling was banned in 1986, but a remote Indonesian village is one of the few places still hunting whales using traditional methods. Lamalera, a village of 2,000 people and one of the last communities to hunt sperm whales in the traditional way, with harpoons and ropes.

Lamalerans are allowed to hunt whales as they are considered aboriginal subsistence hunters by the International Whaling Commission. They hunt for their own food stores and for barter with other villages, and sperm whales are not as endangered as other species. But Lamalerans also catch manta rays and other large fish beyond subsistence levels - some of which they sell for cash. The future of the hunt is unclear - many of the most talented lama fas are aging, and overfishing in the area could limit the food supply that brings the whales past Lamalera so regularly.

Points of view – how do they differ? The Indonesian fishermen Greenpeace Your personal view An ambassador International Whaling Commission

Bio rights: The right of endangered species or landscape to remain undisturbed

‘All whale hunting should be banned globally’ Write a response to this statement considering the 4 view points.