As an angler, I would contest that carp are not the prettiest fish or the most prestigious but they are a heck of a lot of fun to catch. As a young boy, my brother (shown on the left) and I always loved to go to the nearby lakes and ponds and catch whatever we could. We would hear tales about released pet fish that grew to gigantic sizes that ruled the lakes and ponds. We would always go for our friend’s goldfish that they released into the city lake to no avail. Catching fish and understanding their importance grew on my brother and I from a young age and fueled us to catch as many different fish as we could. This thrill for the catch is what fuels conservation efforts and education from the very kids who grew up having this childhood.
Recently in Pymatuning Lake in northeastern Ohio, thousands of carp have washed up on the shore for what looks like no reason. Upon investigation, it was determined that these fish all died because of Koi herpes virus (KHV), a virus that causes mass mortality in carp (Kempter et al., 2012).
As I have become older I have realized how bad it is to release pet fish into the wild. These fish can transmit diseases to the wild populations and can have terrible effects on the local population numbers. Once a pet fish is released it can infect carrier fish in the wild so that even if the pet fish gets eaten or dies, that KHV is still alive in the environment. Common carriers in Pymatuning lake are other species of carp along with northern pike and possibly pet fishes released into the lake. Officials on scene at Pymatuning are saying that the virus has a mortality rate of between 80-90% which is very high for a contagious lake virus (Knoedler, 2017). This is increasingly important because carp make up a good portion of most bodies of water when they are present with percentages ranging up to 96% of all fish biomass in some areas (McColl et al., 2007). The good news in this situation is that the virus is very specific to carp so there is little concern that it will spread to other fish types. It is believed that this year’s cold weather should kill the virus over time (Knoedler, 2017).
Conservation and public education are important for the public in situations just like this which is why when things like this happen experts are very reactionary and will throw a great deal of information into the public light to educate the public as much as possible.
This situation just goes to show that the tales about fish being released into lakes should stay tales and should not become a reality. From this situation, the severity of releasing fish becomes more apparent to those who may lack knowledge of how bad the activity really is. So just keep in mind that next time a pet goldfish is released into a pond or lake it could spell the end for the native species that call the body of water home.
Sources:
Kempter, J., Kielpinski, M., Panicz, R., Sadowski, J., Mysłowski, B., & Bergmann, S. M. (2012). Horizontal transmission of koi herpes virus (KHV) from potential vector species to common carp. Bull Eur Assoc Fish Pathol, 32, 212-219.
Knoedler, M. (2017, September 21). Dead carp test positive for virus in Pymatuning Lake. Retrieved September 25, 2017, from http://www.erienewsnow.com/story/36426536/dead-carp-test-positive-for-virus-in-pymatuning
McColl, K. A., Sunarto, A. G. U. S., Williams, L. M., & Crane, M. S. T. J. (2007). Koi herpes virus: dreaded pathogen or white knight. Aquaculture Health International, 9, 4-6.