Individual study: Salinity tolerance of Great Lakes invaders
Ellis S. & McIsaac H.J. (2009) Salinity tolerance of Great Lakes invaders. Freshwater Biology, 54, 77-89
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Ponto-Caspian gammarids: Change salinity of the water
A replicated, controlled laboratory experiment in 2009, on specimens taken from a river in Canada (Ellis & McIsaac 2009) found that invasive freshwater shrimp Echinogammarus ischnus, were killed when salt was added to water. Within five hours, 66% of shrimp died from exposure to saline water (30% salinity). It did not make a difference if the water salinity was increased gradually or immediately. Only 33% of shrimp treated survived for up to two days and 0% beyond two days. Ten shrimp were placed in each of 12 glass jars. The water in four of the jars had 30% salinity from the beginning (using unfiltered river water). The salinity in another four jars was 4% at the start of the experiment and increased every hour to 8, 14, 24 and 30%. Four jars were controls (freshwater only). Every hour for five hours, and after 24 and 48 hours, dead animals were removed and live animals counted.
Ponto-Caspian gobies: Changing salinity
A replicated, controlled laboratory study from 2006 to 2007 at the Great Lakes Institute for Environmental Research in Canada (Ellis & McIsaac 2009) found that round gobies Neogobius melanostomus cannot survive for more than two days in water with 30% salinity. All fish survived five hours in water of 30% salinity. It did not make a difference if the water became salty gradually or immediately. Up to about a fifth of the fish were still alive after 24 hours. However, after 48 hours, all fish were dead. Gobies were taken from a river in Canada. Ten gobies were put in each of 12 aquaria containing 16 litres of filtered river water. The water in four of the aquaria had 30% salinity from the beginning. The salinity in another four aquaria was 4% at the start of the experiment and increased every hour to 8, 14, 24 and 30%. Every hour for five hours, and after 24 and 48 hours, dead gobies were removed and counted.