Author: fisher.645

Kevin Fisher

Sea Lamprey in the Great Lakes

 

Retrieved from: https://upload.wikimedia.org/wikipedia/commons/6/6f/Diversas_lampreas.1_-_Aquarium_Finisterrae.JPG on 11/02/2017

Sea Lamprey (Petromyzon marinus) (depicted above) is an invasive, eel like, jawless fish that looks like something straight out of a horror film. It was first reported to have invaded from Lake Ontario to Lake Erie in 1921, believed to have been facilitated through the opening of the Welland Canal. Sea Lamprey were initially not a problem, but with the enactment of policies to prevent pollution, salmonid stocking programs and stream restoration they began to proliferate and soon spread to the other Great Lakes (Sullivan et al., 2003). Sea lamprey have a very unique life history (shown below), spending the majority of their life in a larval stage, called an ammocoetes, in which they are sedentary filter feeders living in stream beds. Once they have reached a certain point, they emerge from stream beds and transition to a parasitic phase in lakes. One adult parasitic Sea Lamprey can apparently kill up to 40 pounds of fish in its life time (Morrison, 2017). The parasitic life stage of Sea Lamprey is especially devastating to Lake Trout (bite mark pictured below), whose population declined rapidly with increased abundance of Sea Lamprey in Lake Erie. This led the Great Lakes Fisheries Commission to establish an integrated Sea Lamprey management plan in 1986 (Sullivan et al., 2003). Control measures taken rapidly saw declines in the populations of Sea lamprey through the use of pesticides, barriers to reproduction, trapping, and even the release of sterile males (Klassen et al., 2004). With the initial success of the program people believed that the program may be able to successfully eradicate Sea Lamprey from the Great Lakes (Sullivan et al., 2003). While the program has been extremely successful, decreasing the amount of fish killed from 100 million pounds to 10 million pounds per year in the Great Lakes (Morrison, 2017). The complete eradication seems unlikely. A recent report from the Great Lakes Fisheries Commission also conveyed a startling discovery, Sea Lamprey populations have been increasing for the past few years in Lake Erie and Superior (Morrison, 2017). While the current levels are still near historic lows, the recent trend of increasing populations has fisheries managers worried (Morrison, 2017). No one really knows why there has been an increase in these populations, but two hypotheses have been given that may explain why this trend has occurred. The first, is that the restoration of stream habitats have allowed the Sea lamprey to establish into new tributaries that they were historically not present. The second, is that the mild winters that have been experienced throughout the Great Lakes region in the last two years have led to more favorable conditions during spawning (Morrison, 2017). While the integrated Sea Lamprey management plan has been a great success in curbing the spread of this species, there are still unknown factors which require continued vigilance to keep this invasive threat under control.

Retrieved from: https://greatlakesinform.org/sites/default/files/sealamprey_lifecycle_seagrant%20UMN_with%20credit.jpg on 11/2/2017

 

Klassen, W., Adams, J.V., Twohey, M.B., 2004. Modeling the suppression of sea lamprey populations by the release of sterile males or sterile females. Journal of Great Lakes Research 30, 463–473.

Morrison, A. A., Oct. 24 2017. Sea Lamprey on rise in Lakes Erie and Superior. Great Lakes Today. Retrieved from: http://news.wbfo.org/post/sea-lamprey-rise-lakes-erie-and-michigan on 11 November 2017.

Sullivan, W.P., Christie, G.C., Cornelius, F.C., Fodale, M.F., Johnson, D.A., Koonce, J.F., Larson, G.L., McDonald, R.B., Mullett, K.M., Murray, C.K., 2003. The sea lamprey in Lake Erie: a case history. Journal of Great Lakes Research 29, 615–636.

 

The Asian Carp Threat in Ohio

            Asian carp are a group of invasive species, which have spread in the US through both accidental and purposeful release. There are three species of Asian carps currently present in Ohio’s lakes and rivers: Bighead Carp, Silver Carp, and Grass Carp. Bighead and Silver carp where accidentally released from aquaculture facilities in Arkansas during the 1970s (Freeze and Henderson, 1982) and have spread throughout the Mississippi River Basin, including the Ohio River. Grass Carp on the other hand were stocked to ponds and lakes to control aquatic vegetation growth.

Grass Carp have been previously found in Lake Michigan, Erie, and Ontario. In Ohio, currently only sterilized Grass Carp may be stocked but the process that is utilized is not always 100% effective. New surveys conducted this year by the Ohio Department of Natural Resource have found that Grass Carp are successfully spawning in the Sandusky River, near Lake Erie (Seewer, 2017).  This is some of the first evidence that this species can naturally reproduce in the Great Lakes. The expansion of Grass Carp populations has been a concern of fisheries managers throughout the past few decades, because they can consume large quantities of aquatic vegetation. A decline of aquatic vegetation around shorelines and in wetlands surrounding Lake Erie may reduce habitat, impacting native fish species that utilize these areas for food or to spawn. While this species is a pressing worry to Lake Erie and increased efforts for control are currently being developed (Seewer, 2017), the estimated impacts of Bighead and Silver carp are far more concerning (Zhang et al., 2016).

Bighead and Silver carp are both filter feeders, primarily consuming zooplankton (Burke et al., 1986). They are primarily located in and around the Ohio River, but there have been reports that these species have been found in small numbers within Lake Erie. The main concern associated with these species is their ability to grow to large sizes (18-23 kg) in a relatively short amount of time (4-5 years) (Henderson, 1978).  Zooplankton are especially important for juvenile fish as well as fish that are important prey species for commercial and sport fish. A model of potential impacts by Zhang et al. (2016) found that these species may be able to alter current food webs, which could affect a 7-billion-dollar annual sport fishery in the Great Lakes (Southwick Associates, 2007).

There are still many unknowns associated with Asian carp’s potential for proliferation within Lake Erie, but significant efforts are underway to develop plans for controlling the spread of these species.  More information regarding current regional and national management and control of Asian carp can be found at http://asiancarp.us/documents/2017ActionPlan.pdf  and http://asiancarp.us/documents/Carps_Management_Plan.pdf.

 

Burke, J.S., Bayne, D.R., and Rea, H. (1986). Impact of silver and bighead carps on plankton communities of channel catfish ponds. Aquaculture 55, 59–68.

Freeze, M., and Henderson, S. (1982). Distribution and Status of the Bighead Carp and Silver Carp in Arkansas. North Am. J. Fish. Manag. 2, 197–200.

Henderson, S. (1978). An evaluation of the filter feeding fishes, silver and bighead carp, for water quality improvement. In Smitherman R.O., W.L. Shelton, and J.H. Grover, (Eds.). Culture of exotic fishes symposium proceedings. Fish Culture Section, American Fisheries Society, Auburn, Alabama, 121–136.

Seewer, J. (Sept. 24, 2017). Invasive grass carp pose risk to Lake Erie. The Columbus Dispatch, B5.

Southwick Associates. (2007). Sportfishing in America: an economic engine and conservation powerhouse. American Sportfishing Association, Multistate Conservation Grant Program. 

Zhang, H., Rutherford, E.S., Mason, D.M., Breck, J.T., Wittmann, M.E., Cooke, R.M., Lodge, D.M., Rothlisberger, J.D., Zhu, X., and Johnson, T.B. (2016). Forecasting the Impacts of Silver and Bighead Carp on the Lake Erie Food Web. Trans. Am. Fish. Soc. 145, 136–162.