southern pike, grass pike, jack, jack fish, eastern pickerel, gunny

This species feeds primarily on smaller fish until it grows large enough to ambush larger prey from cover. Aggressive in their feeding habits, chain pickerel have been reported to eat a wide variety of bait, and are a popular sport fish that is an energetic fighter when hooked (Scott and Crossman 1973).

Summary of species impacts derived from literature review. Click on an icon to find out more...

Environmental	Socioeconomic

A comparison of Canadian lakes with and without Esox niger found that lakes with Esox niger had significantly lower fish diversity and richness and that fish size distribution was truncated (small-bodied fishes were absent) (Mitchell et al 2010). It has been suggested that predation by or competition with Chain pickerel could impact threatened or endangered species of Canada (DFO 2006, 2011). Numerous parasites have been identified in Esox niger, but the extent to which Great Lakes fish are infected and potential transmission to native species remains unknown.

Chain pickerel is capable of hybridizing and forming viable offspring with related species, including the Redfin pickerel (Esox americanus) and Northern pike (Esox lucius), both present in the Great Lakes Basin (Herke et al. 1990, Scott and Crossman 1973). The consequences of this are unknown.

There is little or no evidence to support that Esox niger has significant socio-economic impacts in the Great Lakes.

Speculation exists that the predation by chain pickerel could have a negative impact on some sport fishes, particularly native trout and other stocked salmonids (Brokaw 2008).

There is little or no evidence to support that Esox niger has significant beneficial effects in the Great Lakes.

Chain pickerel is a popular sport fish in some parts of the Northeast (especially in the winter). In the Great Lakes and Canada, it is of minor importance to recreational fishing overall, although it is often kept if caught. The meat, which is white, flaky, and mild, is considered to be good eating, but contains many small bones. It is not of commercial importance (Scott and Crossman 1973).

Note: Check federal, state/provincial, and local regulations for the most up-to-date information.

Control
Biological
There are no known biological control methods for this species.

Physical
The Maine Department of Inland Fisheries and Wildlife cites removal of fishing bag limits for Chain Pickerel as a management measure in certain lakes, noting that the rationale is biologically sound but negligibly effective because few anglers take advantage of the law and capture more than 10 pickerel per day. (Brokaw 2008 ).

Chemical
Of the four chemical piscicides registered for use in the United States, antimycin A  and rotenone are considered “general” piscicides, but no studies have been found of their effects on Esox niger (GLMRIS 2012).

Increasing CO2 concentrations, either by bubbling pressurized gas directly into water or by the addition of sodium bicarbonate (NaHCO3) has been used to sedate fishes with minimal residual toxicity, and is a potential method of harvesting fish for removal, though maintaining adequate CO2 concentrations may be difficult in large/natural water bodies (Clearwater et al. 2008). CO2 is approved only for use as an anesthetic for cold, cool, and warm water fishes the US, not for use as euthanasia, and exposure to NaHCO3 concentration of 142-642 mg/L for 5 min. is sufficient to anaesthetize most fish (Clearwater et al. 2008).

It should be noted that chemical treatment will often lead to non-target kills, and so all options for management of a species should be adequately studied before a decision is made to use piscicides or other chemicals. Potential effects on non-target plants and organisms, including macroinvertebrates and other fish, should always be deliberately evaluated and analyzed. The effects of combinations of management chemicals and other toxicants, whether intentional or unintentional, should be understood prior to chemical treatment. Boogaard et al. (2003) found that the lampricides 3-trifluoromethyl-4-nitrophenol (TFM) and 2’,5-dichloro-4’-nitrosalicylanilide (niclosamide) demonstrate additive toxicity when combined. In another study on cumulative toxicity, combinations of niclosamide and TFM with contaminants common in the Great Lakes (pesticides, heavy metals, industrial organics, phosphorus, and sediments) were found to be mostly additive in toxicity to rainbow trout, and one combination of TFM, Delnav, and malathion was synergistic, with toxicity magnified 7.9 times (Marking and Bills 1985). This highlights the need for managers to conduct on-site toxicity testing and to give serious consideration to determining the total toxic burden to which organisms may be exposed when using chemical treatments (Marking and Bills 1985). Other non-selective alterations of water quality, such as reducing dissolved oxygen levels or altering pH, could also have a deleterious impact on native fish, invertebrates, and other fauna or flora, and their potential harmful effects should therefore be evaluated thoroughly.

Note: Check state/provincial and local regulations for the most up-to-date information regarding permits for control methods. Follow all label instructions.