Center for the Inland Bays’ fish tally brings in key data and community involvement

By Lynn R. Parks  |  Photograph by Peggy Hepburn
From the May 2014 issue

waterways1Ron Kernehan had written about the fish that live in coastal Sussex’s estuaries. In fact, he and J.C.S. Wang collaborated on the 410-page “Fishes of the Delaware Estuaries,” published in 1979 by E.A. Communications.
But he’d never seen many of them.

“Now, I get to feel them. Touch them. Get up close and personal,” says Kernehan, who lives on Lewes Beach. “It’s very exciting.”

A retired financial adviser who has a bachelor’s degree in fish biology from Cornell University and a master’s in fisheries science from the University of Massachusetts, Kernehan is heading up an ongoing survey of the fish populations of Delaware’s inland bays, being conducted by the Center for the Inland Bays. Twice a month, from April through October, he and more than 100 volunteers venture out to 17 sites in the Indian River Bay Estuary (which includes Rehoboth Bay) and Little Assawoman Bay Estuary. At each location, they stretch out a 30-foot seine and, with one end on the shore and the other extended into the water, they drag the net, perpendicular to the shore, for 100 feet.

The volunteers then count and identify the specimens captured; each haul can contain 2,000 to 3,000 fish, Kernehan says.

In addition, the first 25 of each species are measured. That’s where that “up close and personal” part comes into play.

All of the fish — except those that are difficult to identify, which are carried off to a lab for further analysis — are then put back in the water, perhaps to be hauled in another day.

This is the first comprehensive, long-running survey of the bays’ inshore fish populations. The University of Delaware has been checking fisheries in the deeper parts of the bays (more than 10 feet deep) since the mid-1980s. “But that’s a completely different fish community than close to the shore,” Kernehan says. “We have no historical data about those [inshore] populations.”

And information about fish is important because they are “an environmental indicator of the health of an area,” Kernehan explains. The healthier an estuary, the more fish there are and the greater the diversity of the population.

This is the fourth year for the survey. While the citizen scientists haven’t collected enough data to establish growth or decline trends, they have enough information to say that the bays are home to many creatures.

“There are a lot of fish out there,” says Kernehan.

“The estuaries support a great diversity of fisheries,” agrees Roy Miller, retired state fisheries administrator and one of the volunteer team leaders. “We all know that the inland bays are far from pristine. They suffer from a variety of insults, primary among them an excess nutrient load. They are struggling. But they are far from dead.”

In 2011, more than 56,000 fish were counted in the survey, from 47 different species. That count included more than 22,000 Atlantic silversides, or shiners, small fish that are a major food source for striped bass, bluefish and Atlantic mackerel.

The next year, more than 46,000 fish were counted, from 43 species. That included 17,000 mummichog, or minnows (diminutive killifish used as bait), and 5,000 blue crabs. “Counting crabs means a lot of dodging of claws,” Kernehan says. “I can say that, definitely, blood has been shed in this effort.”

Data have not yet been compiled from 2013. But that will long be remembered as the year Kernehan’s team pulled in a bluntnose ray whose tail barbs, one 7 inches long and the other 4 inches, had to be cut out of the net. “I’d never handled a stingray before,” Kernehan admits. “But as luck would have it, I’d just watched the TV show ‘River Monsters’ and they’d picked up a ray.” Following the show’s example, after the barbs were freed from the net he immobilized the tail by grasping it in his gloved hand, picked the ray up by its two breathing holes and placed it back in the water.

Editor’s note: This story is the second in a season-long series focusing on ecological features of coastal Delaware’s inland bays. Rehoboth Bay, Indian River Bay and Assawoman Bay are “impaired waters,” according to a 1996 designation by the federal government. As such, the state is required by law to clean them up.

That cleanup is ongoing. While a 2011 assessment by the Center for the Inland Bays says that “water quality in the inland bays remains fair to poor,” the assessment also sees reason for hope: “Some environmental indicators suggest that accomplishments made under the 1995 Inland Bays Comprehensive Conservation and Management Plan are bearing fruit and may be moving the bays back in a healthy direction.”

Each story in our series will take a look at a specific issue facing the bays’ watershed — or perhaps a resident of the watershed, be it a bird, mammal, fish or plant — and ask: Is that issue an indicator of ecological trouble, or does it show environmental progress? How is that living thing essential to, or affected by, the bays’ health? And how do our efforts regarding all of these things help restore the bays to the healthy ecosystems they once were?

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