Inshore: Atlantic Cod Life History Profile - The Fisherman

Inshore: Atlantic Cod Life History Profile

Atlantic-cod
Atlantic cod can live more than 20 years and grow up to 70 pounds or greater (although the IGFA world record stands at 103 pounds, 10 ounces).

Atlantic cod are members of the Family Gadidae that includes the cod’s close relatives haddock and pollock. Atlantic cod are found throughout the northern Atlantic Ocean from Greenland south to North Carolina on the western side, through Scandinavia and the British Isles on the eastern side.

They are a heavy-bodied fish with a large head, blunt snout and a distinct barbel growing out from the bottom of the chin. Their coloring varies widely, ranging from light yellowish-green to red and olive, usually with darker speckles on the head, fins, tail and body.  The belly is light colored and usually spotless.  Individuals can easily change color. Cod have an obvious white lateral line down each side of the fish, which has a distinct “hump” just before the gill plates. They are most often found between 150 and 300 feet deep, but have been observed as deep as 1,200 feet.

They are known by several common names including cod, codling, market and steakers. Another name that I have argued with my mother-in-law with for years is scrod, or “catch of the day.” Depending upon where you shop, scrod may be cod, but they may also be whatever the “catch of the day” was available at the fish pier and call it scrod. It does make for some interesting conversation at the dinner table.

Identifying Atlantic cod is relatively easy. They do resemble pollock, with several distinctive differences in appearance and habitat. Cod have specks all over their body and can be found in several color phases, while pollock are generally all silver in coloration. Both species share what I refer to as a triple “A” dorsal fin. Just as it implies each fish have three separate “A” shaped dorsal fins on their back and both have a single barbel growing from under their chin.

But here’s what really separates the two species – cod are bottom dwellers and I usually see them hunkering on the bottom of the sea floor, or deck, or inside a shipwreck. Pollock on the other hand are observed in the middle of the water column, never on the sea floor or inside a shipwreck. While this may not be a big deal for anglers, it does tell you where and how to place your bait while pursuing both species. If I see fish directly on the bottom, they are 95 percent of the time cod and in the middle of the water column practically 100 percent pollock, even if I cannot physically see the body markings discussed above.

According to the Massachusetts Division of Marine Fisheries, Atlantic cod spawn in the winter and early spring near the ocean floor and swim offshore to reproduce.  They are capable of reproducing at 2 to 3 years old when they are between 12 and 16 inches long. Smaller females have around 2.5 million eggs, while larger females can produce up to 9 million eggs. Larvae hatch after 10 to 40 days. Atlantic cod can live more than 20 years and grow up to 51 inches and 77 pounds, although much larger ones have been recorded commercially.

Small cod will eat shrimp and other small crustaceans, and adults eat many types of shellfish, as well as herring, mackerel, capelin and young haddock. Pollock and larger cod are some of the species that prey on young cod.  Spiny dogfish, sharks and marine mammals feed on adult cod.

There are two primary stocks of Atlantic cod off our shores, the Gulf of Maine and Georges Bank. According to the 2017 stock assessment, the Gulf of Maine stock is overfished and below the target biomass level. A revised 10-year rebuilding plan was implemented for this stock in 2014. According to the 2017 stock assessment, the Georges Bank stock is overfished and is scheduled to rebuild by 2027. Both stocks are subject to overfishing, but fishing is still allowed at reduced levels.

The typical cod rig consists of a high-low rig baited with fresh or lightly salted clam. Veteran cod fishermen are careful not to over-bait their hooks, which typically range from size 5/0 to 7/0 Octopus style hooks. Regardless of whether you fish mono or braid as your main line, it is strongly recommended that you attach an 8- to 10-foot trace of fluorocarbon leader material at the terminal end. Many cod sharpies also dress their baited hooks with brightly colored plastic skirts. Chartreuse, hot pink and blue speck are among the more popular colors. Others prefer adding a twister tail or jelly worm.

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