Procedures for efficiently producing high-quality fecundity data on a small budget

Though fecundity estimation has typically been very time consuming, efficient methods have recently been developed. Building on these developments, we describe procedures for efficiently producing precise, accurate, fecundity estimates for highly fecund Atlantic cod, using a low-cost laboratory setup. Capturing images with a standard flatbed scanner and analyzing them with free image analysis software (total equipment cost ≈ $100) we were able to process individual samples in as little as 5 min. We show a strong relationship between mean oocyte diameter (range 200–900 μm) and oocyte density (r2 = 0.971, n = 50), and thus are able to estimate fecundity using gravimetric and auto-diametric methods. Testing the precision of the auto-diametric method we find estimates produced by both methods to be highly correlated (r2 = 0.961, n = 26). The success of these methods should assure fisheries scientists that fecundity estimation is no longer the daunting task it once was, and catalyze further production of fecundity data.