AquaBiota now offers monitoring of crayfish and large freshwater clams using eDNA. A few liters of water from a lake is enough to detect the presence of the critically endangered noble crayfish or the introduced signal crayfish. Being a vector of the crayfish plague the signal crayfish constitutes a serious threat to the native noble crayfish. Human introductions from one lake to another are the main source of spread of signal crayfish and the crayfish plague. The eDNA method does not require equipment such as traps and boats. Since crayfish plague spores can be spread on such equipment our method minimizes the risk of spreading the disease when monitoring several lakes in one monitoring campaign. In one single day between 5 and 10 lakes can be surveyed making the method highly effective compared to traditional crayfish monitoring. In the near future we will be able to detect eDNA from the fungus causing the plague. This means that collected water samples can be used, in a later stage, for analysis of the crayfish plague fungus.
Using the same or other water samples we can also analyze which species of large freshwater clams are present in the lakes. In Sweden there are 4 species on the red list, the freshwater pearl mussel and the thick-shelled river mussel are endangered and the painter’s mussel and the depressed river mussel are near threatened. The non-native species zebra mussel is also possible to detect. We are also able to detect a large number of fish species such as salmon, trout, perch and asp.
Signal crayfish, cought in Lake Vättern. Photo: Alfred Sandström, SLU Aqua