| dc.description.abstract | Aquaculture is a growing business in various parts of the world, Sweden included. As the commercial
use of oysters increases, so does its demand. Farmers will need to produce a high quality product
that is appealing to the customer and cost-effective for the farmer. One major issue for farmers is
biofouling, as unwanted organisms settle and grow on the oysters, reducing their value and quality.
This thesis explored a method for reducing the problems caused by a group of biofouling organisms,
the calcifying tubeworms. The method included using a heated sea water treatment, in which the
oysters were dipped into heated water for a short time period. Included in the experiment was the
Swedish native oyster Ostrea edulis and the invasive species Magallana gigas. Due to its invasive
status, M. gigas is prohibited to culture in Swedish water. The demand from the market has farmers
wanting a legislation change, therefore its inclusion in this thesis was relevant. Using a range of
temperatures based on previous successful studies on blue mussels, tests were conducted to see if
the method could be applied to oysters too and if so, if the two different species had any differences
in tolerance to stress from the heat treatment. Tubeworm mortality was also tested separately. The
results indicate that M. gigas had a higher tolerance towards the stress from heat treatment while
the mortality of O. edulis significantly increased with temperature. Alongside a surprisingly low
threshold for high mortality in tubeworms, a conclusion was made that the method was suggested to
be applicable to Swedish aquaculture, but the method must be optimized further to suit our native
species to yield an effective result with low oyster mortality. | en_US |
