Pennsylvania Fish & Boat Commission Biologist Report. Delaware Estuary. Delaware and Philadelphia Counties Striped Bass Survey

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1 Delaware Estuary Delaware and Philadelphia Counties 2012 Striped Bass Survey The Pennsylvania Fish and Boat Commission (PFBC) assessed the striped bass spawning stock in the Delaware Estuary between May 4 and 21, The survey was conducted at 21 index sites ranging from the mouth of Rancocas Creek, NJ (river mile 109) downriver to the mouth of Raccoon Creek, NJ (river mile 80). Each index site was sampled twice using an electrofishing boat. A record high total of 726 striped bass were captured in Males accounted for 70% of the total catch and ranged from 5 to 40 inches long, while females accounted for 5% of the total catch and ranged from 19 to 45 inches long. Sex could not be determined for the remaining 25% of fish captured, which ranged from 4 to 26 inches long, primarily because they were sexually immature. Area 6 Fisheries Biologist Greg Murphy with a 44 inch female striped bass captured in the Delaware Estuary near Little Tinicum Island, Delaware County.

2 Catch rates in this 2012 survey were very high compared to their corresponding longterm averages computed from 1996 to 2011, particularly for total catch (all sizes of striped bass combined) and for striped bass 12 inches. In 2012, average catch rates were as follows: 38.9 fish/hr for total catch; 21.7 fish/hr for striped bass 12 inches; and 3.2 fish/hr for striped bass 28 inches (see Figure 1). The 2012 catch rates for total catch and for striped bass 12 inches were the highest catch rates observed since beginning the fully standardized sampling program in 1996, although sampling also occurred in 1994 and 1995 to first establish sampling sites and techniques. The catch rate of slot size striped bass (20 to 26 inches), applicable to angling in April and May in Pennsylvania, was 6.1 fish/hr in 2012, which was comparable to the rate observed in 2011 (4.3 fish/hr). Average Catch Rate (fish/hr) Long-term ( ) Total Catch 12 Inches 28 Inches Striped Bass Figure 1. Average catch rates of striped bass captured in the Delaware Estuary between May 4 and 21, 2012 compared to their corresponding long-term averages (1996 to 2011). The record high number of striped bass captured in 2012 may have been influenced, in part, by increased salinity levels in the lower spawning grounds of the Delaware Estuary.

3 Although salinity thresholds for striped bass spawning tend to vary among systems, they typically spawn where salinities are less than 5 ppt. Highly successful spawning has been observed in the Chesapeake and Delaware Canal at salinities of 0.70 to 1.50 ppt. The lack of precipitation in the winter and early spring of 2012 allowed the salt line to advance upstream further than usual during the spring spawning period (April and May). Consequently, this may have concentrated spawning striped bass further upstream than usual and increased catch rates in Pennsylvania. Other fish species more commonly associated with brackish water or saltwater were also observed further upstream and in greater numbers than usual for May, including Atlantic menhaden, locally known as bunker, and Atlantic needlefish (Figure 2). Figure 2. Atlantic needlefish captured in the Delaware Estuary in A total of 371 striped bass sixteen inches long and longer were tagged with a pink colored U.S. Fish and Wildlife Service reward tag in 2012 (see photo). The information gathered from tags depends upon reports from anglers. Tag reports allow biologists to monitor movements, determine where fish are harvested, estimate annual fishing

4 mortality, and document angler release rates. Note the three inch pink spaghetti-like tag near the tip of the left pectoral fin. Please report reward tags to the U.S. Fish and Wildlife Service by calling Between 1995 and 2011, the PFBC tagged a total of 3,574 striped bass in the Delaware Estuary. As of December 31, 2011, 18% of the 3,574 tagged fish were reported as caught. Recreational anglers accounted for 89% of the tagged fish caught, while commercial fishermen accounted for 8%. Though, reporting rates vary between these groups. Three percent of the tagged fish caught were credited to other collectors, such as scientific researchers. Striped bass tagged by the PFBC in the Delaware Estuary have been caught by anglers fishing waters ranging from North Carolina to Massachusetts. Since 1995, approximately 76% of the tagged striped bass have been caught in New Jersey (44%), Maryland (16%), and Delaware (16%), while the remaining 24% have been caught in Pennsylvania (7%), Massachusetts (5%), New York (4%), Virginia (3%), Rhode Island

5 (3%), North Carolina (1%), and Connecticut (<1%). See Figure 2. Fifty percent of the tagged fish caught have been released; 48% have been harvested; and 2% have been found dead, dying, or have been used for scientific research. Recreational and commercial fishermen have harvested 48% and 78% of their striped bass catches, respectively. The ratio of female to male striped bass in the harvest was 1.5 to 1, indicating substantially more harvest pressure on the female segment of the population. 50% 44% 1995 to 2011 N = 653 Percent of Tag Returns 40% 30% 20% 10% 0% 16% 16% 7% 5% 3% 4% 3% 1% 1% 0% NC VA MD DE PA NJ NY CT RI MA UN State of Recapture Figure 2. Percent of tag returns by state of recapture for striped bass tagged by the PFBC in the Delaware Estuary between 1995 and Unknown recapture location = UN. Some anglers reported excellent catches of striped bass from the Pennsylvania portion of the Delaware Estuary in As an example of an exceptionally good day, at the peak of the spawning period in May, the average catch rate per angler within one group of five anglers was reported to be 5 fish/hr. On that day most fish caught ranged in size from 20 to 29 inches, with one fish as large as 43 inches. The group caught 154 striped

6 bass in total. Fishing should continue to be very good to excellent during April and May in the future based on the high number of small, young fish observed in Typical baits include blood worms, clams, eels, and legally caught fish, such as white perch. Lures may also be productive. Fishing regulations in the Delaware River and Estuary vary by state, location (tidal vs. non-tidal), and month. If you plan to fish for striped bass in the Delaware River and Estuary, it is recommended that you review the Pennsylvania Summary of Fishing Regulations and Laws for the Delaware River and Estuary. Be advised that New Jersey regulations apply if you cross the PA/NJ boundary line, which is in the Estuary/River. In addition to a valid Pennsylvania fishing license, anglers targeting striped bass in the Delaware River and Estuary below Trenton Falls are required to register through the PFBC s free on-line system, the Pennsylvania Saltwater Angler Registry (PA-SARP). Likewise, if fishing across the state line in New Jersey, Pennsylvania anglers must also register in the free New Jersey Saltwater Recreational Registry Program. Anglers that wish to consume striped bass are advised to consult the fish consumption advisory information provided in the rear of the Pennsylvania summary book. The current one meal per month advisory was derived from samples of slot size fish (20 to 26 inches) and fish over 28 inches collected from the Delaware Estuary in The advisory will be updated in the near future, meaning revised or staying the same, based on samples of slot size fish and fish over 28 inches collected from the Delaware Estuary in 2010 and Greg Murphy Area 6 Fisheries Biologist