Invasive jellyfish removed from Kaunakakai Wharf.   

By Melissa Kelsey

Unusual and unwanted creatures made a stinging entrance to Kaunakakai Wharf several weeks ago. There was a population explosion of Mangrove Upside Down Jellyfish, mildly stinging sea invertebrates with tentacles in shades of brown and green. A man and two children were stung several times, according to Lori Buchanan, Field and Outreach Coordinator for the Molokai/Maui Invasive Species Committee (MoMISC).

Last Thursday morning, six workers from Department of Land and Natural Resources (DLNR) and MoMISC eradicated around 200 Mangrove Upside Down Jellyfish from Kaunakakai Wharf. Workers caught the jellyfish with nets, counted them and classified them by size for future reference, according to Cecile Walsh, a DLNR Aquatic Invasive Species Research Associate.

To protect themselves from the stinging cells, the workers wore protective body gear. Warnings were posted at the wharf for swimmers to beware even after the jellyfish were removed, due to the possibility of stinging cells still floating in the water. Throughout the project, the invasive species workers conducted public outreach by showing the jellyfish to children at the wharf and alerting them to the danger.

Scientifically known as Cassiopea sp., the jellyfish are not native to the Hawaiian Islands and were probably stowaways on a sailing vessel, according to Walsh. She said the species is unique because individuals freely expel stinging cells into the water as opposed to stinging only upon contact.

Kaunakakai Wharf is a popular swimming area for Molokai’s residents, and Buchanan said it is used even more frequently during paddling season in the summer months. As a result, DLNR and MoMISC made it top priority to remove the jellyfish from the water.

Walsh said the timing of the jellyfish removal was even more urgent because the jellyfish are an invasive species that reproduce during the summer months. Cassiopea sp. had previously been found on Molokai in 2006 in Puko`o Lagoon and Old Kamalo Wharf, according to a DLNR report describing their removal from a different habitat on the Big Island of Hawaii.

A Second Invader
The jellyfish are not the only invasive species on the target list for removal from Molokai’s waters. An invasive algae commonly known as gorilla ogo is threatening coral reefs on Molokai, according to a DLNR document. Scientifically called Gracilaria salicornia, the algae is spreading on coral reefs and culturally significant fishponds along southern Molokai. At areas such as Kaunakakai Harbor, Keawanui, Ualapue and Kaloko`eli, gorilla ogo could smother coral reef habitats on Molokai if its growth is not stopped, according to the DLNR.

For a project that will continue through April of 2010, DLNR employees are undergoing a formal process to remove the algae and develop a bio-secure processing and recycling system to prevent future growth. Last week, the same team that removed the jellyfish from Kaunakakai Wharf also began the first stage of the algae project by doing survey research at invasion sites, according to Walsh.