Fish ageing is a critical component of fisheries biology that provides insights into the life history of fish species, such as growth rates and maturity. Ageing data is essential for input into age-structured stock assessment models which help manage fish populations sustainably. Biologists determine a fish’s age by analyzing annual growth markings on various body parts, which reflect seasonal growth variations.

Fish biologists use several body parts for ageing, with the most common being scales, otoliths (ear bones), opercula (gill plates), spines, and vertebrae. These structures show alternating translucent and opaque bands similar to tree rings, which are counted to estimate age.

Age information is foundational for understanding key aspects of fish life, such as growth speed, lifespan, and maturity. This data allows scientists to develop effective harvest strategies, ensuring that fishing activities do not exceed the rate at which fish populations can replenish. It also provides insights into the demographic structure of fish populations and assists in managing gear types to target specific ages of fish optimally.

The Commission organizes workshops to standardize fish ageing techniques across different states, ensuring consistency and reliability in age data used for assessments. These workshops facilitate the exchange of samples and methodologies among ageing experts from various state agencies. The annual Fish Ageing Quality Assurance/Quality Control Workshop maintains consistent ageing practices for specific species across labs from Maine to Florida.

The Commission has conducted specific ageing workshops for species such as American shad, river herring, American eel, Atlantic croaker, red drum, Atlantic menhaden, Atlantic striped bass, black sea bass, bluefish, tautog, and winter flounder. These workshops review and compare ageing procedures, enhancing the precision and reliability of fish age data across the Atlantic coast.

This structured approach to documenting fish ageing practices highlights the integral role of accurate age data in the sustainable management of fish stocks and the collaborative efforts required to achieve consistency in fish stock assessments.