TRENTON — Clinging jellyfish have continued to expand their presence along the Jersey Shore with their appearance in the northern Barnegat Bay.

The Department of Environmental Protection warned those who use the area, which is popular for boating, fishing, swimming, crabbing and other recreational activities, to watch for the dime-size creatures that attach themselves to submerged aquatic vegetation and algae in back bays and estuaries.

They are not found on ocean beaches.

The touch of the clinging jellyfish's 60-90 tentacles produces severe pain and other localized symptoms that could require hospitalization.

They first appeared in the Shrewsbury River in 2016 but are native to the Pacific Ocean. The polyp phase of its life cycle persists from season to season in the Monmouth County river. It was also spotted in the Manasquan River in 2016 and this year expanded their presence in the Metedeconk River in Ocean County.

What to do if stung by a clinging jelly fish:

  • Apply white vinegar to the affected area to immobilize any remaining stinging cells.
  • Rinse the area with salt water and remove remaining tentacle materials using gloves or a thick towel.
  • A hot compress or cold pack can then be applied to alleviate pain.
  • If symptoms persist or pain increases, seek prompt medical attention.

Contact reporter Dan Alexander at or via Twitter @DanAlexanderNJ