I study the environmental effects of oyster, clam and mussel farming. In this photo from April, I’m standing in the Sacca di Goro, a shallow lagoon in Italy, south of Venice. I make the 120-kilometre round trip here from the University of Ferrara every week during sampling months — April to the end of July and November to December — to study the growing oysters.
Oyster farming has a smaller ecological footprint than fish farming does because oysters do not require feeding, which can cause eutrophication — an overgrowth of nutrients that chokes off marine animal life. They also do not require any drugs, disinfectants, pesticides or any form of growth additives.
The oysters in these baskets — called lanterns — are between one and four centimetres in diameter. The oyster farmers in the lagoon then move the molluscs to the open sea, where they grow to roughly 10 centimetres, or commercial size. Fishers sometimes take the lanterns out of the water to mimic tides, which are not prominent in the Mediterranean Sea. Being out of water is like going to the gym for the oyster — it builds muscle meat and texture.
I don’t like to eat oysters. This can be tricky because the fishers usually offer me some. But I’m excited about the potential uses for the discarded valves, or shells. For example, they can be used to build artificial reefs, be ground up to make body scrubs or be applied instead of lime to raise the pH level of agricultural soil.
To calculate the environmental impact of oyster farming, I survey the fishers and map their use of fossil fuels, plastic and other resources that might harm the environment. Then I measure how much carbon the oysters capture as they grow. I focus on the valves, which are made almost entirely of calcium carbonate.
I hope to prove that oyster farming absorbs more carbon than it emits.
Source: Ecology - nature.com
