Restoration of Seagrasses: With Economic Analysis

Abstract

The technique of restoration of populations of land plants is an old one that is well understood by scientists, agronomists, forestry experts, and the general public. However, only recently has attention been turned to restoring underwater areas with socalled seagrasses. From 1947 onwards, attempts have been made to restore suitable marine areas by using important species; however, only very recently (from August 1973) have large-scale restoration projects been undertaken.The efforts that have been made to replant various seagrass species by different techniques are reviewed, but only two seagrasses, Zostera noltii and Thalassia testudinum, have been restored on a large scale. Both of these can be restored successfully; however, the seeding method of Thalassia appears to be the most practical operation of all, and the most potentially valuable for future research into large-scale restoration, as it allows flexibility of location and of depth of transplantation, and involves the minimum of damage to the donor site. It also ensures the most rapid regrowth, besides being in the long run the most economical method yet devised of restoring a seagrass community. An economic model (see Technical Appendix to this paper) and analysis for restoration costs are given and finally a wide range of uses of restoration of such beds of seagrasses are enumerated.

Large-Scale Zostera marina (eelgrass) Restoration in Chesapeake Bay, Maryland, USA. Part I: A Comparison of Techniques and Associated Costs

“…Our results indicate that large-scale Z. marina restoration using seeds is a practical and cost-effective alternative to more traditional transplant methods (Table 5). Cost analysis of Thalassia testudinum seed restoration performed by Thorhaug and Austin (1976) our project were significantly less, and while the costs per hectare were higher, the seeding densities utilized and total hectares seeded in this project were also significantly greater.…”

“…Our results indicate that large‐scale Z. marina restoration using seeds is a practical and cost‐effective alternative to more traditional transplant methods (Table 5). Cost analysis of Thalassia testudinum seed restoration performed by Thorhaug and Austin (1976) included all wages, per diem, expendable supplies, and equipment associated with seed collection, storage, and dispersal. If adjusted to current price levels, dispersing 43,602 T. testudinum seeds over 1 ha would cost roughly $79,200 or $1.82 per seed at current price levels.…”

An Introduction to a Special Issue on Large-Scale Submerged Aquatic Vegetation Restoration Research in the Chesapeake Bay: 2003-2008

“…As planting represents a large proportion of the costs associated with restoration, developing cost-effective new planting methods would reduce the costs of large-scale restoration (Thorhaug & Austin 1976). In 2003, the U.S. Army Corps of Engineers (USACE) Engineer Research and Development Center (ERDC) and the National Oceanic and Atmospheric Administration (NOAA) Chesapeake Bay Office (NCBO) began to plan and implement their respective research programs to promote the development of innovative tools and techniques for the large-scale restoration of SAV and to improve our understanding of the processes that contribute to seed survival and successful seedling establishment throughout the Chesapeake Bay region.…”

Environmental management of a highly impacted, urbanized tropical estuary: rehabilitation and restoration

“…Only recently have feasible large-scale techniques been devised to restore damaged marine ecosystems (Thorhaug, 1974;Thorhaug & Austin, 1976).However, these techniques are not known to all nations or even to many local and United States government agencies, nor are there adequate laws and enforcement procedures to implement them in many nations and states. Particularly in tropical "developing" nations, valuable nearshore fisheries have previously been badly impacted.…”

“…A summary of restoration methods for the seagrasses {including the dominant seagrass throughout the south Florida Gulf of Mexico and Caribbean region, Thalassla testudinum} can be found in Thorhaug & Austin (1976). In brief, early attempts by plug were unsuccessful due to the absence of apical meristem material throughout the rhizomal structure of Thalassia (Tomlinson, 1974}.…”