Navy works with local partners to eradicate invasive species

13 October 2023

From Danny Hayes, Navy Region Hawaii Public Affairs

Divers are going into the water; some are Navy divers, some are Army divers and others are contractors, all sharing the same goal of protecting the marine ecosystem in and around Pearl Harbor. The Navy is actively working to stop the spread of several aquatic invasive species (AIS) that were first observed near Bishop Point and brought to the Navy’s attention during the pandemic.

Natural resource managers and conservation specialists began posting orange signs this summer advising the public that fishing is no longer permitted at several piers and accessible waterways located around the southwestern side of the base due to these AIS. The restrictions are impacting some of the activities that base residents and visitors to the joint base participate in. Residents and base personnel are asking why fishing isn’t allowed from these locations.

In April and May, genetic sequencing was used to identify two octocoral species in the area: Unomia stolonifera and Capnella spicata. Both of these soft corals are not native to Hawaii waters but are considered by subject matter experts to be popular among aquarium enthusiasts. They are not legal to own in home aquariums in Hawaii, however.

Navy environmental scientists were not familiar with the pulsating soft coral that was located around the pier initially, so they had to seek outside expertise to learn more.

Christy Martin, of the Coordinating Group on Alien Pest Species (CGAPS) spoke about the collaboration.

“When civilian colleagues at [Joint Base Pearl Harbor-Hickam] reached out for help to identify ways to control this octocoral, we quickly realized that no single agency had all of the knowledge and experience necessary for controlling or eradicating it to prevent its spread to reefs around the state.”

Christina Coppenrath, a marine resources management specialist with Naval Facilities Engineering Systems Command Hawaii, said there is an important reason those orange advisory signs were placed around those locations.

“The reason recreation has been restricted in affected areas is that these octocorals can spread very quickly when fragmented,” she explained. “In this case, if a small piece of an octocoral’s colony is broken off, it can then drift elsewhere, settle, grow, and reproduce. Activities such as fishing or paddling can end up causing fragmentation and therefore lead to additional spread.”

The Navy is part of a collaborative working group called Hawaii Invasive Octocorals Working Group (HIOWG.) This team of subject matter experts has the immediate goals of providing proper AIS identification and developing the most effective removal and response plan.

The working group participants include: the U.S. Navy, CGAPS; Hawaii Department of Land and Natural Resources -Division of Aquatic Resources; United States Fish and Wildlife Service - Pacific Islands Fish and Wildlife Office, National Oceanic and Atmospheric Administration, National Marine Fisheries Service - Pacific Islands Regional Office; National Marine Fisheries Service - Pacific Islands Fisheries Science Center; US Geological Survey - National Wildlife Health Center; University of Hawaii - Hawaii Institute of Marine Biology (HIMB); Bishop Museum; and Williams College. It is an extensive list of member agencies and expertise addressing a common problem.

“For example, the Navy is leading the survey, removal, and eradication efforts in JBPHH waters,” Coppenrath said. “CGAPS helped develop the working group and facilitates regular meetings. Bishop Museum maintains public species records and specimen examples in their collections. Genetic analyses were performed at HIMB, with assistance in sample transfer and preparation from DLNR-DAR and Bishop Museum. DLNR-DAR and USFWS have surveyed waters outside of JBPHH. Working group subject matter experts from all of the above agencies and organizations have contributed specific knowledge and expertise in marine invasive species eradiation which has directly led to the development of the Navy’s planned removal methods.”

Kapilina Housing residents in Ewa were recently notified about an octocoral removal project the Navy will be conducting this month to remove the invasive soft coral from the area’s marina.

“Preliminary removal efforts are tentatively planned to begin at the end of October or early November,” said Coppenrath. “It is understood that recreation in these areas is valued by many service members, base personnel, families, etc. The intention is not to restrict recreation forever, but it is necessary until the octocorals can be eradicated. Eradication is a very big goal and one of the things that the fishers and Kapilina Beach Homes residents can do to help is adhering to these new restrictions.”

Martin also acknowledged the temporary impact to recreational activities for the local community near Iroquois Point in Ewa.

“We recognize that we are asking a lot of Kapilina residents and marina users. I know this is a big imposition and also that we have been so focused on doing the surveys and trying to plan the eradication work that we have not shared more about the invasive octocoral situation with residents,” she said. “This octocoral is spreading. It can break off pieces and attach to anything to re-grow. We see it on piers, near boats. We found it growing on and drifting around on someone's lost sock.”

Conservationists are hoping education on how harmful releasing non-native species into the delicate environment here in Hawaii can help prevent damage.

Navy Region Hawaii Conservation Manager Nicole Olmsted explained more about the impacts of introducing foreign aquatic species through suspected illegally aquarium dumping can do.

“One very serious threat to the health and resilience of Hawaii’s ecosystems is invasive species. Invasive species are non-native species that are introduced—often via human activity-- and thrive in areas out of their home range, outcompeting native species and harming overall biodiversity.”

What concerns members of the HIOWG and Navy conservation specialists is that these newly discovered AIS are threatening the overall health of the native coral in Hawaii waters.

“Not all introduced species become invasive, but when they do, they tend to become the dominant species which can lead to ecological, economical, and agricultural destruction,” said Olmsted. “Common examples of terrestrial invasive species include the coconut rhinoceros beetle, little fire ant, and devil weed. The marine environment is also experiencing threats from introduced species. As reef-building corals become more stressed from ocean temperature rise, they become more vulnerable and less able to compete with non-native introduced species such as fast growing, predator-free octocorals. The Navy is a proud steward of the environment and entrusted to implement a program for the conservation of natural resources both on land and at-sea.”

Unomia stolonifera is a rapidly growing octocoral and that makes eradicating it somewhat time sensitive.

“We have a very narrow window of opportunity to try to eradicate it, and we need everyone's help and understanding in order to succeed,” said Martin. “It is really difficult to eradicate an invasive species and it may be a few years before we could declare victory, but it won't be possible without everyone's understanding and help.”

Hawaii’s Department of Land and Natural Resources has more information on how to protect the environment and native ecosystems here. If you would like to learn more about reporting aquatic invasive species go to: https://dlnr.hawaii.gov/ais/report-an-aquatic-invasive-species/.