Upstream solution is key to saving reef

Study: Cooperation with landowners needed to stem sediment runoff

A recent University of Hawaii study finds that cooperation among landowners and prioritizing repair of eroding agriculture roads, such as the one pictured, is the most cost-effective solution to reducing sediment runoff to West Maui reefs.
* Photo courtesy University of Hawaii

A recent University of Hawaii study finds that cooperation among landowners and prioritizing repair of eroding agriculture roads, such as the one pictured, is the most cost-effective solution to reducing sediment runoff to West Maui reefs. * Photo courtesy University of Hawaii

Cooperation among West Maui landowners is key to reducing sediment runoff to reefs, whose coral coverage is down significantly in the region’s northern waters, according to a recent University of Hawaii study.

The study, “Upstream Solutions to Coral Reef Conservation: The Payoffs of Smart and Cooperative Decision Making,” addresses the increased runoff of sediment and other land-based pollutants affecting the production of goods and services critical to many coastal residents. UH assistant professor and ecological economist Kirsten Oleson published the paper in the Journal of Environmental Management with the help of graduate students Kim Falinski and Joey Lecky.

“Managers are always striving to make the most of their limited budgets,” Oleson said in a news release. “We used simple methods to identify cost-effective solutions to address erosion from unpaved agricultural roads — a problem common to many areas in Hawaii and elsewhere.”

The research team compared the costs and benefits of alternative actions that could be taken to repair agricultural roads and to reduce sediment runoff across the West Maui landscape, the news release said. Seven management scenarios were considered, defined by whether decisions were made cooperatively or independently among landowners and by the approach to road repair — to minimize costs, sediment or both.

“Often, when faced with selecting what conservation actions to take, land managers will prioritize based on total area or least cost,” Oleson said. “What we show is that this type of decision making comes at a cost. A much better option is to choose based on cost-effectiveness — how much bang you get for your buck. It also pays off to make choices across the broader landscape, not just your own backyard.”

Researchers discovered that targeting specific runoff “hot spots” is more cost-effective than targeting all road segments within a given land parcel, the news release said. Additionally, the best environmental gains for the lowest costs are achieved when landowners cooperate and target cost-effective road repairs, although collective action can be counter-productive when not coupled with cost-effectiveness.

This new analysis could persuade West Maui landowners to work together and prioritize which road segments need repairs to help the overall health of the area’s reefs. Financing the repairs and work, though, is an entirely different story.

“Of course everybody wants to keep the soil where it is and keep coastal areas healthy, so there’s a benefit in partnering in projects,” West Maui Watershed Coordinator Tova Callender said Tuesday. “But there’s fear over liability . . . and the financial cost of doing improvements.”

West Maui’s reefs and watersheds have been recognized by multiple state and federal programs as needing special protection, according to the news release. Coral coverage in the region’s northern reefs has declined from 30 percent to 10 percent between 2000 and 2015 — likely due to sediment runoff from rainfall.

Land-based pollutants have degraded Hawaii’s reefs for decades. When coral are covered in sediment, it reduces their ability to photosynthesize and grow and allows for algae to take over, according to the news release.

Callender also pointed to the 2014 coral bleaching event that devastated the Valley Isle’s reefs and killed much of their old coral. She said events, such as this, prove why landowners must work together to build resilience into runoff systems.

“The clock is ticking on the health of the reefs,” she said.

Maui County’s landscape has changed over the years, with many landowners moving out of agriculture and into development. Major West Maui landowners are the state, Maui Land & Pineapple Co., General Finance Group and Kaanapali Land Management Corp.

Callender said landowners do not have the same resources and capacity to partner with groups over watershed issues like they did 20 years ago. She said years ago when macro algae began washing up on shore and on pool decks, landowners formed an initiative and used their own equipment and resources to fix the issue.

“Landowners are still wanting to do right by the land, but if you don’t have the equipment or manpower anymore at their beck and call, it becomes a little more challenging,” she said.

Rather than simply asking landowners for money and “putting a burden on them in perpetuity,” Callender has sought to find ways to add value to their land. She said it is easier for landowners to match government funds, provide access to their lands and give labor where they can.

“A lot of landowners are in transition. They’re land rich, not cash rich,” she said.

Callender has had “good cooperation with landowners” in addressing runoff issues and believes it will get better with more funding opportunities. Maui Land & Pineapple Co. has been “very supportive” with research, she said.

The West Maui Ridge to Reef Initiative, a consortium of agencies and organizations addressing adverse impacts to coral reefs, has focused much of its efforts toward mitigating runoff in the Wahikuli and Honokowai watersheds. Callender, who supports the initiative, said groups have raised about $1.2 million in federal funding since 2012.

The funding has helped launch pilot programs that have improved old agriculture roads and led to the planting of vetiver, a highly-effective sediment control grass, to lock sediment higher up in the West Maui Mountains, Callender said. She hopes to expand vetiver plantings throughout the watersheds, adding that the Coral Reef Alliance is in the process of securing a large grant for the work.

“It’s good start,” she said of the money raised so far. “It’s given us an opportunity to start a lot of pilot projects, but the scale is the problem. In-stream sediment sources require a different scale to fix and all of this is a start that just scratches the surface of what’s needed.”

* Chris Sugidono can be reached at csugidono@mauinews.com.

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