Blueback herring Alosa aestivalis are anadromous, iteroparous, winter spawners in the St. Johns River, Florida, but published data about this population are limited. We collected adults by electrofishing in the upper St. Johns River during the 2002-2005 spawning runs to examine the abundance, distribution, size, sex ratio, reproductive biology, and feeding habits of the population. When possible, data from the present study were compared with those for blueback herring collected with seine nets in the lower St. Johns River during the 1972 and 1973 spawning runs. Blueback herring began upstream migration by January and stayed in the river until at least April. The average fish size was significantly smaller in 2002-2005 than in 1972 1973, but sex ratios were not different from 1:1 in 5 of the 6 years studied. The more recent collections suggest that blueback herring females released multiple batches of eggs during one spawning season (spawning a batch every 3-4 d on average) and that spawning occurred as far upstream as river kilometer 400. Males and females fed actively during the entire spawning run. Overall, the stock is persistent, but its status is unknown and the smaller individual sizes evident today suggest that this population is experiencing higher mortality now than a few decades ago.

This paper reviews the history of fishing, regulations, and stock assessments for Florida's anadromous shad species-American shad Alosa sapidissima and hickory shad A. mediocris-and assesses their Status in Florida's St. Johns River based oil a creel survey and ail electrofishing survey. Historically, these anadromous shads constituted an important fishery in Florida. Landings were first reported in the 1860s, and scientific assessments occurred in the 1950s, 1960s, and early 1970s. Netting restrictions effectively ended the commercial fishery in the 1990s. We used recreational catch rates as a proxy for stock size and found it to be low but stable during 1993-2005. The mean length of American shad was significantly less during 2002-2005 than it was historically (1958), and the recent proportions of female American and hickory shad were significantly lower than the historical proportions,. These data were interpreted as demonstrating a negative, but perhaps only an historical, effect of fishing. The rebuilding of Florida's anadromous shad stocks via fishing regulations was not evident; this may require more time, or perhaps factors other than fishing are interfering with the rebuilding process.