Occurrence and Growth Rates of Young-of-Year Northern Kingfish, Menticirrhus saxatilis, on Ocean and Estuarine Beaches inSouthern New Jersey

Abstract

Young-of-year (YOY) northern kingfish, Menticirrhus saxatilis (family: Sciaenidae), were sampled and tagged on ocean and estuarine beaches in southern New Jersey to determine patterns of habitat use, movements, and growth rates for this infrequently studied life-history stage. Beach seines were used to sample YOY biweekly during May–October 1999 at eight ocean, one inlet, and two estuarine beach sites, which resulted in capture of 2172 individuals. Recently settled YOY were first collected at lengths of 7–12 mm standard length (SL) on 7 July in the Great Bay estuary, at 18–32 mm SL on 21 July near the inlet and at 10–34 mm SL on 22–23 July at six of the ocean sites on Long Beach Island. Small fish (< 30 mm SL) continued to be collected in all areas through early September suggesting protracted spawning. Overall, catch per unit effort was greatest at the inlet site during August. A portion of the fish was tagged with internal sequential coded wire microtags on nine dates at one location in the estuary (n = 260 fish, 32–162 mm SL) and less regularly at three sites (n = 519 fish, 34–194 mm SL) on ocean beaches. None of the fish tagged on ocean beaches were recaptured, however, 14% of the fish tagged in the estuary were recaptured from 3–22 days after tagging. Recaptured fish grew quickly (0.7–2.8 mm/day, average 1.8 mm/day) and these growth rates corresponded well with growth rates calculated from regressions of the increase in maximum length over time using length frequency data. The fast growth rates accounted for the fact that by late September or October, when most fish had left the study sites, the largest remaining fish had reached 200–225 mm SL. The abundance and rapid growth rates of young-of-year northern kingfish on ocean and estuarine beaches suggest that both types of habitats can be important for this species.