Rutgers University Marine Field Station Holds Open House

By PAT JOHNSON | Sep 18, 2019
Photo by: Pat Johnson Rutgers University Field Station held its annual Open House. Hundreds of curious folks walked the quarter-mile wooden bridge to visit the former Coast Guard station off Great Bay Boulevard in Little Egg Harbor.

Little Egg Harbor — Rutgers University Field Station held its annual Open House on Saturday, Sept. 14, and hundreds of curious folks from local towns and even other states walked the quarter-mile wooden bridge over the salt marsh to see what is happening in the former Coast Guard station off Great Bay Boulevard in Little Egg Harbor.

What they would learn is the field station is an engine of marine science. Rutgers Marine and Coastal Sciences plays a part in research projects that have a bearing on our state’s future: offshore wind energy, global warming and climate change, fisheries management and even hurricane forecasts.

Ken Able may have retired after 30 years as director of the station, but he was again on hand Saturday as he always has been to give a talk to the visitors. This year the focus was on the “Underwater Natural History of the Mullica Valley,” soon to be a book by Able.

Able has contributed greatly to the knowledge of how juvenile fish use the slow-moving creeks in the marshland as their nursery. Each week volunteers and students take samples of the creatures and fish moving under the waters of Big Sheepshead Creek on the highest tide. Then back in the laboratory, they count and sort them. The station has accrued 49,000 samples over 30 years and has the largest continuous data set of what inhabits Great Bay, part of the Mullica River watershed.

The scientists at the station also developed acoustic tags that are placed on selected species of fish: stripers, bluefish, hickory shad, winter flounder and horseshoe crabs. Within the watershed are receiving stations that listen for the pings of the tagged fish. In this way, charts of where and when fish are moving within the watershed have been completed. “Flounder prefer deep water, and you can see it shows them right off the station,” said Able. “But that doesn’t mean you will catch them; they have to be hungry.

“Fish travel using tidal currents. When they go upstream, their stomachs are empty; when they come downstream, their stomachs are full.”

Sea level rise is happening on the Jersey Shore, Able said. Tide data from a tide gauge in Atlantic City goes back to 1912 and shows a rise of 1½ feet over the century. Globally the rise is only half a foot. The reason for the difference is that the Jersey Shore has been subsiding, or sinking, since the last ice age.

Able also pointed to “ghost forests” of Atlantic white cedar to show the effect of sea level rise. Using carbon dating on tree stumps along what used to be fresh water swamps, scientists have learned some of the stumps date back to the fifth and 14th centuries, depending on where they are found. The trees died because salt water is creeping up the land and replacing fresh water. Atlantic white cedar grows only in fresh water.

Warmer winters due to global warming are also bringing more southern species of fish into the area, such as cow-nosed rays and Atlantic croakers. Even some birds are widening their range: brown pelicans and cormorants weren’t here 30 years ago and are now more common.

Bald eagles are making their nests here at the shore, and Able said researchers have been peering into those nests to see what they are eating. A photo of a collection of tiny skulls shows muskrats have a new predator, but bones of a catfish puzzled Able. “Catfish only come to the surface at night, and eagles only fly in the daytime, so we have to figure that one out.”

Someone in the audience asked if mosquito ditches were adding to the destruction of the salt marsh, but Able said he didn’t think so, as they have been around a lot longer than we realized. “Back in the 1700s they were used as fences (boundary lines) for salt-hay farms. If you dug a ditch 8 feet wide and 3 feet deep, then you could claim the land.”

Researchers also collect seal poop to find out what seals are eating; there is a large haul-out of harbor seals on a beach near the station.

Lastly, river herring are returning in great numbers to the Batsto River to spawn. However, they don’t appear to be using the fish ladder to access Batsto Lake as was hoped. The water from the Pine Barrens is tea-colored because of the tannins in the oak leaves that make up the detritus; that is one of the reasons the Mullica River is not returning striped bass fry (babies) to the watershed. Striped bass may be spawning in the river, but the tannic acid is not allowing eggs to develop.

Of Hurricanes and
Horseshoe Crabs

In another part of the station, Joseph Brodie, director of Atmospheric Research for the Department of Marine and Coastal Sciences at Rutgers, explained that the Underwater Remotely Operated Vehicles developed by Rutgers were being utilized to help detect tropical storm and hurricane paths in the Caribbean. For Dorian, seven UROVs were deployed to send back data on water temperature.

Brodie said Rutgers has signed a Memorandum of Understanding with Ørsted, the Danish company developing an offshore wind farm 15 miles off Atlantic City on the Continental Shelf. Ørsted plans to build between 85 and 100 turbines to supply half a million homes with electricity. Rutgers is doing collaborative research services for the company. “We want to make sure they have the right data to make the right decisions,” said Brodie.

Since 2011, Rutgers has been sending wind data to the New Jersey Bureau of Public Utilities from its weather station on Great Bay Boulevard, and also a buoy off New York Harbor.

“There is a tremendous wind resource off the shore that can supply a lot more energy than any turbines built on land. Also, in New Jersey, where would you find that land? Couple that with the high demand for electricity in the Middle Atlantic states and the shallow continental shelf off New Jersey, and we’re in a great position.”

Another resource of the Atlantic shore but of a wildly different kind is the fierce-looking but harmless horseshoe crab. Norm Wainwright of Charles River Biomedical facility in South Carolina was in the station to explain how his company makes an important product for the medical industry from horseshoe crabs’ blue blood. Limulus amebocyte lysate has been found to be particularly sterile and is used in testing the purity of antibiotics, vaccines and other medical drugs. The crabs’ blood is blue because it is based on copper rather than iron.

Horseshoe crabs are caught off South Carolina and cleaned; then a quarter of their blood is drained from them in the lab. The crabs are then returned to the water within 24 hours, and their survival rate is greater than 95 percent, according to the Charles River brochure. Wainwright also had tiny baby horseshoe crabs swimming about in a dish of salt water. These were grown in the lab from eggs. “We plan on releasing a million crabs a year that we’ve grown in the lab to sustain the population,” he said.

Across the room was Thomas Grothues, biologist and research associate professor, who has been exploring the response of fish and other marine life to the closure of the Oyster Creek nuclear power plant in Lacey Township. For 50 years before its closure in the fall of 2018, the nuclear plant used water from Barnegat Bay to cool its reactors. Billions of gallons of water were sucked into the plant daily from lagoons leading from Oyster Creek, and with it came untold numbers of plankton, including fish, clam and oyster larvae that were put through the reactor and “fried,” said Grothues. But some larger species preferred the warmer waters discharged into the lagoons. “Striped bass may have stayed in the area feeding longer than usual.”

The three-year research project on how the temperature in the areas near the plant has changed sea life has been inconclusive, he admitted.

“Changes in the growth assemblages of fish may take longer,” he said. The impact of Superstorm Sandy in 2012 also throws off any baseline for scientific studies.

When the reactor was operational, the water leaving the plant was 10 degrees hotter than the water in the bay, but it would stay on the top layer of water. Grothues said since the Atlantic Ocean between Cape Cod and Cape Hatteras in North Carolina has the highest temperature swing in the world (6 degrees) within a single tide due to cold-water upwellings on the one hand and the warm Gulf Stream on the other, most fish in our part of the ocean are acclimated to swings in temperature. “They are already adapted,” he said.

Already the average temperature in the Mullica River has risen 3 degrees because our winters have not been as cold as they used to be. “We are seeing new fish, tropical fish surviving through the winter, mostly gobies and butterfly fish. You know there are 192 species of fish in Barnegat Bay, but we are used to seeing only a fraction of these, the ones we like to catch.”

Research on how stormwater and upriver activity may affect the pristine Mullica River watershed is being conducted through the use of nutrient sampling buoys.

The data-collecting buoys are deployed once a month in six areas of the watershed to collect water samples, said field researcher Gregg Sakowiez. These are analyzed for nutrients such as nitrates and chlorophyll that determine the health of the waters. The buoys also record water temperature, salinity dissolved oxygen, pH levels, turbidity and weather.

Although the science activities in the Rutgers University Marine Field Station were fascinating, as always it was the touch tanks and sampling tanks of fish and sea creatures in the wet lab that got the most attention. Lab researcher Roland Hagan said he had the boat and trawler out all week to gather the wide variety of critters: two types of blowfish, eel, kingfish, flounder, starfish, seahorses, pipefish, conch, crabs and more.

Outside on the deck of the station, volunteers were helping kids make shark wind tunnels and butterfly crafts, and Linda Gaffner, a graduate of the Rutgers Environmental Stewards Program, developed a game (with Judy Burr) to make sea level rise more personal and understandable. Throw the dice and answer questions about shoreline protection and things we can do to mitigate another disaster. On a beautiful September day, with the wind off the sea, even the possibility of another Superstorm Sandy seemed remote and in capable hands.

patjohnson@thesandpaper.net

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