Seagrass-Watch Magazine Issue 47 - March 2013 | Page 11

volunteers, thus the costs are subjected to contractor fees inflated by profit margins and mobilisation and de-mobilisation expenses. Where vessel injuries are actively regulated by local, state or federal governments, prescriptive management and litigation fees for damage assessment and restoration must also be considered as part of the cost. Recent cost estimates for seagrass restoration at scales comparable to vessel injuries range from USD570,000 to USD972,000 per hectare, far surpassing the cost of land-based restoration(29). Given the uncertainty and high cost of restoration it appears scientifically and economically feasible to recommend that managers give priority to protecting seagrass habitat from vessel damage rather than to focus primarily on repair and restoration. Seagrasses can be protected by adequately marking channels and the location of meadows with buoys and signage for a fraction of the cost of restoration(28,29). However, restricting power vessels from seagrass flats requires a sustained investment in maintenance and enforcement which must be supported by dedicated government policies, public awareness, prescriptive regulations and reasonable budgets(3, 4). A recent cost-benefit analysis suggests that the additional cost of enforcing “no power vessel” zones was worth the benefit of added seagrass protection(4). Mandated boater education and licensing programs that require operators to learn how to “read the water” and navigate to avoid injuring seagrass meadows or how to properly remove a vessel from a grounding site can provide the foundation of an effective seagrass protection and conservation program. To date, there are no comprehensive assessments of the outcomes of the many different local, state and federal programs aimed at limiting vessel damage. Where assessments of individual programs have been evaluated the results are inconclusive, because many of the programs have lacked the capability to sustain the infrastructure, enforcement and financial resources needed to have meaningful long-term effects. With respect to vessel impacts, seagrass conservationists have several feasible options to work with, but a long way to go before we can say we have adequately addressed the problem. This article contains supporting information online at www.seagrasswatch.org/magazine.html or contact [email protected] Moorings Aerial photograph of a vessel mooring field over seagrass meadows in Marblehead Harbour, MA, USA. Small white features in the harbour are moored vessels. CC MARCH 2013 11