دانلود رایگان کتاب پرورش صدف که جزو غذاهای دریایی میباشد بزبان انگلیسی watch – Sea Food Report – Farmed Oysters
Oysters are filter-feeding bivalves that inhabit most oceans in the world except near polar extremes. Aquaculture production of oysters accounts for 95% of total global production (capture and aquaculture). Although oysters are cultured in 46 countries, the main areas of aquaculture production are China, Korea, Japan, the United States, and France. Oyster seed can be reared in hatcheries or collected from the wild, depending on technical sophistication, practicality, and tradition.
Grow-out of oysters is accomplished in natural, inter-tidal orsub-tidal waters. Grow-out techniques involve suspension of oysters in the water column, via rafts, floats racks or trestles, or bottom culture, in which oysters are grown directly on the seabed. Because oysters are filter
feeders, oyster aquaculture facilities generally improve coastal water conditions by converting nutrients and organic matter to biomass. Moreover, the water requirement for oyster hatcheries is low, thus only a small amount of effluent is discharged. Farming of oysters is not entirely
benign, however, as oysters can be introduced inadvertently to non-native areas, where they can impact native oyster populations. Aquaculture has played a rolein some introductions of nonnative oysters and subsequent disease transfers, but there are also ongoing attempts to restore coastal areas with non-native oysters (and stimulate aquaculture production of those species in these areas), and this is also cause for concern. Additionally, there are growing concerns regarding impacts of genetically altered oysters being raised in the wild …..