Analysis of benefits of sargassum on Galveston Island and indications for beach management policy

Loading...
Thumbnail Image

Date

2009-05-15

Journal Title

Journal ISSN

Volume Title

Publisher

Abstract

Sargassum fluitans and natans, types of brown algae, wash up on Galveston Island, Texas annually from May to August. Sargassum smells bad, hurts tourism and impairs sea turtle hatchings. Coastal managers are confronted with the difficult choice of cleaning Sargassum off the beach or leaving it alone. The current beach management practice is to rake the algae with tractors and deposit it at the base of the dunes. The environmental impacts of raking and ecological benefits of Sargassum are unknown. The Galveston Island Park Board of Trustees (GIPBT) used to rake all beaches under their management before Hurricane Alicia in 1983. Then, citizens started to complain that raking was causing erosion. Now, there are people who argue for both raking and leaving the beach alone. Environmental policies require complex decisions that take into consideration social, economical, ecological, and cultural values. The GIPBT initiated the Sargassum Policy Committee to gain knowledge of different stakeholder values and scientific research to develop beach management. The first study analyzed elevation changes over a year period on raked and unraked beaches on both the West and East end of Galveston Island. The Analysis ofVariance results indicated that there is not a difference in elevation changes between the raked and unraked beaches over a year.The second study analyzed the effects of Sargassum on the dune plant Panicum amarum. Plants were asexually grown in a greenhouse in sand without (control) and with Sargassum. The effects of small versus large amounts, top versus mixed with sand and washed versus unwashed Sargassum were tested. The results indicated that the addition of Sargassum increased plant growth. The treatments with large amounts of Sargassum and unwashed treatments showed significant growth changes at the 95% confidence level. The last component analyzed the collaborative potential of the Sargassum Policy Committee through observations of meetings and surveys of the members. Daniel and Walker’s Progressive Triangle was used to assess the relationship, procedural and substance dimensions of collaborative learning. Then, suggestions were made for increasing collaboration. The combination of scientific research and stakeholder values has resulted in the creation of sound beach management.

Description

Keywords

coastal erosion, dunes, coastal management, Panicum amarum, raking

Citation