Hawai'i is among the ecoregions with high levels of marine invasive species, according to a Nature Conservancy study published this week in the journal Frontiers in Ecology and the Environment.

The report said 84 percent of the world's coasts, including those in Hawai'i, are being affected by marine species foreign to those areas.

It named Hawai'i as a region with high invasion levels, with 73 invasive marine species, 42 percent of which are considered harmful and are disrupting other species or wider ecosystems.

The study only includes species for which scientific data is available on their ecological impact, and local scientists believe Hawai'i may have many more marine invasive species, The Nature Conservancy's Hawai'i field office said.

"Many in Hawai'i have seen what alien algae have done to some of our reefs," said Celia Smith, a professor and seaweed specialist in the University of Hawai'i's botany department. "We need all the tools that can be provided for wise management of our coasts."

Technologies such as an underwater vacuum called the Super Sucker can help remove invasive algae, which smother reefs. Hawai'i lawmakers are considering bills to fund full-time operation of the Super Sucker in Kane'ohe Bay for a year.

Invasive species tend to crowd out native plants and animals and alter natural environmental processes. They can also harm fisheries and cause disease.

Key pathways for the spread of invasive species in Hawai'i are shipping and aquaculture, the study said.

"Everyone in the world depends on healthy oceans and coasts for survival," said Stephanie Meeks, acting president and CEO of The Nature Conservancy. "Invasive species are severely impacting native plants and animals and are causing significant economic damage at the same time."