Warmer weather triggers annual migration up Delaware River for striped bass
By Joe Zedalis/Times of Trenton Staff
on April 06, 2014 at 6:30 AM, updated April 06, 2014 at 6:36 AM
The recent spell of warmer weather has put the dismal and dreary winter further behind and will trigger the annual striped bass spawning run up the Delaware River.
The bass — stimulated by plumes of freshwater runoff from winter snows in New Jersey, Pennsylvania and upstate New York — have moved from offshore Virginia into Delaware Bay and some into the river itself.
Water temperatures were about 45 degrees in the river off Trenton on Friday, according to the U.S. Geologic Survey’s website. Experts said the warmer weather, followed by warmer river water, will rouse the stripers and send them bustling northward, where females will lay eggs and males will fertilize the next generation of bass.
“As soon as the water hits 50-52 degrees, it pushes them up the river,” said Karl Hoepler of Bensalem, Pa.-based Delawareriverbass.com. Bass like to feed off herring and shad, and, Hoepler said, “There are some shad being caught off Yardley (Pa.), and I expect a good, solid run.”
And when the fish begin their run, Hoepler, who has fished bass in the Delaware River for 25 years and been a fishing guide for seven, said the waters off Trenton and Florence are some of the best places to land the coveted gamefish.
“One of the best places to catch medium-sized bass is right in the shadow of the capital,” Hoepler said. “The best area for big fish is the flats off Florence.”
In New Jersey, the closed season for striped bass is from April 1 to May 31 in the Delaware River and its tributaries — from the Route 1 Bridge in Trenton downstream to and including the Salem River and its tributaries, according to the New Jersey Department of Environmental Protection’s Division of Fish and Wildlife. Any striped bass caught during a closed season must be released immediately. The possession or killing of a striped bass during a closed season is a violation of the law and could result in prosecution.
In Pennsylvania, however, recreational freshwater anglers can harvest a daily limit of two striped bass measuring 20 to 26 inches between April 1 and May 31, from the Calhoun Street Bridge downstream to the Pennsylvania state line, according to the Pennsylvania Fish and Boat Commission.
The Pennsylvania law differs because a 2009 state of Delaware study determined a harvestable number of male striped bass — fish in that 20- to 26-inch range — are in the river during April and May. Female stripers — especially those that will be spawning — are significantly longer, with those 36 inches and longer exclusively female fish. Hoepler said fish as big as 55-60 pounds could be caught in the river this spring.
Anglers fishing the Delaware River from the New Jersey shoreline, or returning to New Jersey by boat and/or car in April and May must abide by New Jersey’s Delaware River striped bass regulations.
Hoepler said he expects the bass population to move upriver with little interruption.
“Personally, I don’t see a staggered run,” Hoepler said. “Normally the big females go up river and the males follow. But this year, I think it’s going to be steady with a lot of fish.
Other than the flats on the Susquehanna (River), the best place for spring stripers is the Delaware River.
“The stocks are getting heavier. There are days where we’ve hooked 25 fish and had another 15 bites. I am very optimistic. If the water doesn’t warm too quickly, we could be catching bass into the first week of June.”
On Wednesday, Hoepler said reports indicating bass, most of the them below legal limits, were hitting bloodworms in the area of the Ben Franklin Bridge despite high and muddy water conditions in the river.
Russ Allen, supervising biologist for the N.J. Division of Fish and Wildlife, said the fish would spawn when water temperatures reach about 60 degrees. Allen said the biggest spawning area for the bass is the area between the Delaware Memorial Bridge and Philadelphia bridges, but some continue upriver as far as upstate New York. The Delaware River is one of three known spawning grounds for stripers along the Eastern seaboard. Stripers also spawn in the Hudson River, and the largest spawning grounds for stripers is the Chesapeake Bay.
Allen said the bass would follow the shad and herring upriver. The stripers also will eat mossbunker, which were also starting to show up in Delaware Bay.
“We’ve had great reports on the herring and shad numbers from commercial fishermen off Virginia,” Allen said.
“We all feel, if things go smoothly, it could be a good year. The shad class is a big fishery above Trenton and this is one of the best classes we’ve had in a while. We had a moratorium on herring and there was no harvest allowed at all, so we are hoping to jump-start that population.”
The striped bass also are making a comeback since the drought of 2012 led to lowest birth total in years. He said the classes of 2009 and 2011 “were great.”
“In the last six or seven years, we have had only one bad year,” Allen noted.
Allen said male bass begin spawning at 3 or 4 years of age. Females begin producing eggs when they reach the ages of 6 to 8.
“We’re looking at those males from 2009 and 2011 to start contributing now and the females in the near future, to keep the entire river sustainable for the near future,” Allen said. “Once the water temperatures get into the 40s, they start to get active.”
Allen and Hoepler agreed the snowy winter will aid the striper run.
“There will be a lot of runoff and that’s a good thing,” Allen said. “It might mean the run starts a little later than normal but it all depends on the temperature. A mild, moist spring with gradual warming will be a good thing.”
“Personally, I feel like it’s the first winter in about eight years that has been really cold,” Hoepler said. “The lakes in northern Pennsylvania and New York are still frozen. As the snow melts, the reservoirs will fill up and have to be dumped, and that means more cold water in the river. In some years, there has been little or no water in early May above Trenton.”
The river right now is swollen and very dirty from mud and debris washed into it by recent rain, he said.
“That freshwater scent is rolling down the river,” Hoepler said. “I think they’re ready to move.”
Current water temperatures and river height data for the Delaware at the Calhoun Street Bridge can be found here.