Please use this identifier to cite or link to this item: http://hdl.handle.net/10125/63214

OLA KA WAI, OLA KA LIMU: A MIXED-METHOD APPROACH FOR IDENTIFYING LAND-BASED SOURCES OF NITROGEN POLLUTION & CONSIDERATIONS FOR COMMUNITY MONITORING EFFORTS, A CASE STUDY ON THE NORTH SHORE OF KAUA‘I

File Size Format  
Markel_hawii_0085O_10298.pdf 3.56 MB Adobe PDF View/Open

Item Summary

Title:OLA KA WAI, OLA KA LIMU: A MIXED-METHOD APPROACH FOR IDENTIFYING LAND-BASED SOURCES OF NITROGEN POLLUTION & CONSIDERATIONS FOR COMMUNITY MONITORING EFFORTS, A CASE STUDY ON THE NORTH SHORE OF KAUA‘I
Authors:Markel, Amy
Contributors:Vaughan, Mehana (advisor)
Natural Resources and Environmental Management (department)
Keywords:Natural resource management
Date Issued:2019
Publisher:University of Hawai'i at Manoa
Abstract:This research aims to link land-based sources of nitrogen pollution to changes of limu (macroalgae) in Kaua‘i’s nearshore environments. Limu are primary producers and the basis of nearshore food webs. In addition to their ecological importance, limu are used as medicine and nutrition for local communities, and are found in cultural histories (stories, proverbs, and ceremony). Macroalgae readily uptake nitrogen in the marine environment, and without pressure from herbivore grazing can be strong competitors with corals for space on the reef. Excess nitrogen can change benthic community composition and habitats. Known sources of excess nitrogen include human excrement and supplemental use of nitrogen (e.g. for fertilizers). More specifically, on Kaua‘i there are concerns about outdated waste management systems (On-Site Disposal Systems such as cesspools and septic), as well as fertilizer from agriculture, golf courses, and resort and hotel landscaping entering the nearshore environment. Methods for identifying sources of nutrient can be costly and technical, making it difficult for communities to monitor nutrient inputs and their effects on nearshore ecosystems. To investigate potential changes to limu communities and identify sources of nitrogen pollution, I used a mixed methods approach to address the following research questions: 1. What are potential sources of nitrogen at these sites? 2. What species of macroalgae are currently present and were historically known in the area? 3. Can macroalgae stable nitrogen isotope analysis be used in place of water sampling to measure nitrogen pollution? 4. How might this method be used as a tool for community-based monitoring efforts? I focused on three sites along the northeastern shorelines of Kaua‘i: Anini, Kalihiwai, and Moloa‘a. Known for the diversity and abundance of limu, these sites once supported thriving fishing communities. I investigated potential sources of nitrogen pollution by collecting samples of ocean water, stream water, and macroalgae, then analyzing them for stable nitrogen isotopes. These results were plotted on land use maps of identified on-site waste disposal systems, farms, golf courses, and rubbish dumps. I also assessed if water vs macroalgal stable isotope analysis are comparable methods, and then looked closer at water quality characteristics. I took percent cover estimates of macroalgae species at each sample location to investigate the current algal community. I also developed a species list from herbarium collections. These lists were compared to lists of historically known species for each of the sites based on macroalgal herbarium specimens from Bishop Museum’s online macroalgal database. Finally, the method and logistical considerations were assessed for the following categories: habitat types and species availability, time and effort, finances, technical training and laboratory training, supplies needed, and storage and shipment. These methods can provide communities with a lot of valuable information, and my assessment of methods and logistics can provide information considerations for a method that would best fit different types of communities’ interest and needs and the cost and effort and training required.
Description:M.S. Thesis. Ph.D. Thesis. University of Hawaiʻi at Mānoa 2019
Pages/Duration:105 pages
URI:http://hdl.handle.net/10125/63214
Rights:All UHM dissertations and theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission from the copyright owner.
Appears in Collections: M.S. - Natural Resources and Environmental Managament


Please email libraryada-l@lists.hawaii.edu if you need this content in ADA-compliant format.

Items in ScholarSpace are protected by copyright, with all rights reserved, unless otherwise indicated.