It began harmlessly enough in early June when a New Jersey fisherman brought a dime-sized jellyfish from Barnegat Bay to a nearby aquarium. The aquarium, in turn, contacted biology professor and director of Montclair State University's Marine Biology and Coastal Sciences program Paul Bologna.
A leading jellyfish authority, Bologna took the jellyfish back to campus, where biology professor Jack Gaynor's DNA analysis confirmed suspicions that it was Gonionemus vertens, or clinging jellyfish. This was the first time the tiny – but toxic – jellyfish had been sighted in New Jersey waters.
"The clinging jellyfish gets its name by clinging to eelgrass and other aquatic vegetation in back bays and estuaries," says Bologna. "I've been working in eelgrass beds in New Jersey for over a decade and have never seen them until now." The hard-to-detect jellies cling to eelgrass by day and swim and hunt at night.
Since the first sighting, citizen scientists have contacted Bologna and his team, with the result that they have collected more than 70 specimens from the Shrewsbury River and other locations. The invaders are already threatening to put a damper on summer fun: a former lifeguard was hospitalized for several days after being stung while swimming at night in the Shrewsbury River.
NJ DEP Authorizes Study with Montclair State University
The New Jersey Department of Environmental Protection (DEP) has authorized and funded a 30-day study, beginning June 23, 2016, in partnership with Montclair State to determine the distribution and prevalence of the invading jellyfish. Spearheaded by Bologna and Gaynor, University researchers will sample area waters to collect jellyfish and conduct genetic analyses of specimens.
As a Carnegie Classification Research Doctoral University, Montclair State is prepared for just such research initiatives. "Issues of long-term importance to the state have always been a focus for us and we're always primed for the unexpected," says College of Science and Mathematics Dean Robert Prezant. "The immediate response by Bologna and Gaynor to the relatively sudden appearance of the clinging jellyfish in our coastal waters is an exemplar."
From the South China Sea to the Shrewsbury River
Gaynor and his lab moved quickly to analyze the DNA of those first specimens. "Their DNA is 99 percent identical to a species found in the South China Sea," says Gaynor. "The interesting question is how they got here."
The clinging jellyfish is native to the Pacific Ocean, where two distinct forms are found. Jellyfish from the Pacific Northwest have a painful, but not particularly toxic sting. Those indigenous to the Pacific Coast of Russia, Japan and China pack a powerful, dangerous sting.
The more benign species was sighted near Woods Hole, Massachusetts, as early as 1894. After an eelgrass die-off in the 1930s, the species disappeared. When the jellyfish resurfaced in Woods Hole in the 1990s, they were the more toxic variety.
It is unclear exactly how they got from Asia to America. "All oceans are connected – like one big test tube," notes Gaynor. "It's possible that large ships from Asia dumped ballast water containing clinging jelly larvae when they reached the East Coast. But we don't know that for certain."
Hoping to broaden understanding of how these jellyfish have invaded local waters, Montclair State researchers are sharing their findings with researchers in Woods Hole and China.
Making a Habitat at Montclair State University
The team at Montclair State has set up a clinging jellyfish habitat in their lab. "We've installed a large tank with both males and females that will breed, and produce polyps," explains Gaynor. "This is a self-propagating colony that we could keep going for years."
Ready access to a fresh supply of the jellyfish is critical to fully understanding their life cycle. According to Bologna, research could show that it poses a threat for just a few months a year. "Given that this species has not been recorded in New Jersey, we need to understand its distribution and life history to establish a baseline and support the development of public education and management strategies."
Controlling the Jellyfish Population
"Currently there are no proven methods for removing or eliminating jellies in areas where they're established," cautions Gaynor. While the adult jellyfish, or medusa, are a problem because of their venomous sting, it is resilient polyps, which attach to hard surfaces like bulkheads to reproduce, that present a more lasting challenge. "It's a vicious cycle – so you don't really have a jellyfish problem, you have a polyp problem."
Polyp removal is the best way to combat a jellyfish invasion. While polyps can be removed from bulkheads by scrubbing, it is virtually impossible to remove them all. Environmental Management doctoral student Dena Restaino is studying sea slugs, or nudibranchs, which are natural predators of some jellyfish polyps. "I've been using molecular methods to identify predators of sea nettle polyps in Barnegat Bay to determine their potential for natural jellyfish population control."
Until the population is controlled, the DEP and University researchers urge people to use common sense and avoid vegetation and night swimming in waters where jellies have been found. If stung, they recommend applying white vinegar and hot compresses to the affected area – and seeking prompt medical attention should pain persist or increase.
Decoding Jellyfish DNA
Jellyfish possess a toxic arsenal to defend themselves and capture their prey. In the case of the clinging jellyfish, the damage they can inflict on the human nervous system is vastly disproportionate to their size. Gaynor's team focuses on isolating individual genes, taken from the organism's tentacles that are encoded with toxic proteins. "Down the line, it is possible these proteins would have applications for drug development," he says.
Montclair State Molecular Biology major Kenny Pavan has worked with Gaynor on bioinformatics, such as de novo assembly and gene annotation of functional genes, facilitating the sequencing and comparison of jellyfish genes performed by graduate students Anup Khanal and Zachery Cropley.
Khanal, who has been cloning the hemolytic lectin gene – a gene found in sea nettles that produces a protein that damages and kills cells – will be looking for this gene in clinging jellyfish. "I believe in-depth study of their venom could lead to pharmaceutical advances."
Cropley, who expects to receive an MS in Molecular Biology from Montclair State in August, hopes to compare the sequence of the clinging jelly's hyaluronidase venom gene with that of the sea nettle. Yet for Cropley, the discovery of the clinging jellyfish poses a greater mystery. "The most important discovery we can make is how they came to this ecosystem in the first place."
For Environmental Management PhD student Christie Barry, who has been helping to collect and process the clinging jellyfish, Montclair State offers a unique opportunity to be part of cutting-edge research. "It's really important to understand the impact these jellyfish are having on the ecosystems where they've been found," she says. "If you have large populations of different jellyfish within a system, there's bound to be a significant impact on other organisms and the system as a whole."
Montclair State's jellyfish scientists are in the news. Here are links to some of the coverage:
WNYC: Tiny Creature, Mighty Sting by Alec Hamilton
WHYY: Radio Times with Marty Moss-Coane
The New York Times: An Unwelcome Tourist Arrives in New Jersey: Clinging Jellyfish by Tatiana Schlossberg
NorthJersey.com: N.J. Scientists Track Invasive Jellyfish by James O'Neill