Species
Atlantic Tomcod
Microgadus tomcodAlso known as Frostfish, Winter Cod, Tomcod
Atlantic tomcod are small coastal codfish that thrive in chilly estuaries and brackish bays, often migrating into freshwater shallows during the depths of midwinter to spawn under ice. Hudson River populations famously evolved rapid genetic resistance to lethal levels of toxic polychlorinated biphenyls through a specific mutation in their aryl hydrocarbon receptors. As vital forage fish, they anchor nearshore food webs by funneling energy from bottom-dwelling invertebrates to larger marine predators.
MarineEstuarineCold-Water
—observations
—countries
—peak records
Least ConcernConservation statusIUCN Red List categoriesLCNTVUENCREWEXLeast ConcernRed List categories, explained →
Diet & preyAmphipods, Mysid Shrimp, Polychaete Worms
Predators
- Striped Bass
- Bluefish
- Harbor Seal
ThreatsIndustrial chemical contamination, estuarine warming, dredging, and shoreline development
HabitatsShallow coastal waters, estuaries, salt marshes, and tidal river mouths
Life span3–4 years
Classification
- OrderGadiformes
- FamilyGadidae
- GenusMicrogadus
- SpeciesMicrogadus tomcod
Range data is not available yet.
Interaction riskLow
- Low
- Moderate
- High
- Very high
- Why interaction risk is low
- Safe to observe at a normal distance.
Responsible observation
- Timing: Look for spawning aggregations in tidal rivers and estuaries between December and February.
- Identification: Note the chin barbel and three separate dorsal fins that distinguish them from juvenile cod.
Predator D Ross Robertson / Public domain · cc0
Image unavailableClose Relative 
Same Family NOAA / Public Domain (NOAA) · Public Domain (NOAA)
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