hawaii wetland joint venture - Pacific Coast Joint Venture

they used to breed in lowland areas but don’t now due to predators and humans. She
would expect that they would use Honu’apo with protections from predators and humans.
• NRCS: Greg Koob shared that the NRCS has released a new landowner brochure on nene:
“Nene & Hawaiian Farmers.” The brochure advertises financial and technical assistance
provided by the NRCS to landowners experiencing nene crop loss. This assistance is
available through the EQIP & WHIP programs to landowners on the Big Island and Kauai.
To view the brochure go to: ftp://ftpfc.sc.egov.usda.gov/HI/pub/technical/biology/nene_brochure.pdf
or
http://www.pia.nrcs.usda.gov/technical/biology.html. Additional information can be
obtained at any local NRCS field office.
5. Mangrove Removal at Wai ‘Opae & Alula Bay by Ann Kobsa, Malama O
Puna
Ann provided an overview of the restoration of coral pool and reef ecosystem invaded by alien
red mangrove (Rhizophora mangle) that was conducted at WaiʻOpae during 2009. Here in
Hawaii the non-native mangroves grow to higher densities and shed more biomass than in their
native range, thus negatively impacting fish and reef ecosystems as well as the native land
vegetation. At the start of the project red mangrove was overtaking the rare native coastal
forest and coastal plants at Wai ‘Opae. The area had about 20 acres of mangroves covering an
extensive network of tidal pools and ranging from dense mangrove swamp with trees up to 80
ft tall, to mangrove thicket from 3 to 20 ft. tall, to sparse mangrove keiki colonizing bare
pahoehoe. However after injection of the mangroves with Habitat (imazapyr) and with
assistance from volunteers to pull out young keiki the situation began to reverse. Soon
extensive die off of the mangroves occurred. In the interior of Wai ‘Opae dead mangroves
were replaced by a natural growth of interspersed milo trees and new milo seedlings. In
addition, replanting of hala, milo and naupaka were conducted and already the native coastal
vegetation is beginning to rebound and reclaim its previous home.
Wai ‘Opae is the largest of the hand full of sites invaded by red mangroves on Hawaii Island.
The other smaller sites, mostly on the Hilo side of the island, have since been treated. Thus
very little invasive red mangrove is left before full removal of this species occurs on Hawaii
island. The next project site will be the small one acre at Alula Bay, on the west side, where a
thick grove of mangrove is taking over the rare anchialine ponds and digging into an ancient
heiau structure. Here Malama O Puna and the Big Island Invasive Species Council will be
completing a manual removal of the mangrove and the underlying pickleweed that thickly
blankets and chokes out native aquatic plants. Monitoring will be conducted, both pre and post
removal to determine the effects to the aquatic environment. Also, comparisons will be made
between use of the injection method at Wai ‘Opae and the manual approach at Alula Bay.
Following this presentation Ann lead a Wetland Site Visit to Alula Bay to further discuss the
issues and actions planned. Many thanks to Ann for traveling around the island to present this
information!
Hawaii Wetland Joint Venture Meeting 4/21/11 4