This may help (and save some writing by Mike).
Below are some comments written by Mike from another site concerning this spring's SMB spawn on the Skuke / Delaware and Susky Rivers:
High mid to late spring flows usually result in limited SMB reproductive success. It has not been a good SMB YOY year in the Schuylkill, Delaware, or lower Susquehanna, although in an unusual occurrence, contributions from tributaries, where the flows apparently had less of an impact, have boosted the river YOY indices at some specific locations. Examples: Delaware River at Point Pleasant (Tohickon Ck confluence), Susquehanna River at Pequea (Pequea Ck confluence). There is no doubt that tributaries contribute to river populations, but the unusual condition this year is that the contributions are so obvious based on the abundance or sizes of the fish in and near the tribs. The timing of the high flows in the tribs must have been out of phase with those in the rivers just enough to allow for good reproduction and/or the successful part of the spawning period in the tribs was delayed in comparison to the rivers. This clearly was true in the Pequea Ck case as the fingerlings were much smaller than those produced in the Susquehanna R as seen at the time of the YOY surveys in both.
More details on the Skuke surveys:
The smallmouth bass YOY (young-of-year) index per 50 meter site was 1.8 fingerlings per 50 meters and was below the Schuylkill River 3.8 fingerling average. Largemouth bass fingerlings were present in many of the sites as well, but in low numbers. The low numbers of LMB are typical. The sampling site at Valley Forge continues to be the worst site for SMB fingerlings and it is centrally located in the reach of river that has shown a substantial decline in adult bass abundance due to habitat degradation. Bridgeport, on the other hand, continues to be fairly good. In all, ten shoreline sampling stations comprised of six 50 meter sampling sites each were electrofished from Port Clinton downstream to Bridgeport. Sites are variously described as Port Clinton, Berne, Cross Keys, River Rd, Fritz Island, Union Twsp Park, Towpath Park, Spring City, Valley Forge, and Bridgeport.
A silver lining for SMB anglers:
When YOY numbers decline for a number of years the decline in reproduction over time eventually affects the abundance of bass. The reduced numbers of bass, if reduced enough, survive better and grow much faster. This has been documented by research on SMB's in the Susquehanna done by the PFBC. SMB's are now growing at a rate that has accelerated by one year, meaning that if they formerly hit 15 inches in 4-5 years, they are now hitting it in 3-4 years.
