2.6 MARTNAS AND RECREA TTONAL ROATTNG 



Introduction 



Water quality impacts of marina-related activities include marina construction, 

 maintenance dredging to maintain necessary water depth, day-to-day marina operation, and 

 boat use. Mooring fields, which are also included in this brief discussion of marina-related 

 non-point source problems, cause water quality degradation associated with boat use. A 

 review of the literature concerning environmental impacts and marinas and boats prepared 

 by Chmura and Ross (1978) oudines key issues. Quantitative scientific measurements of 

 the severity of impact, however, have been fairly limited, and have primarily dealt witii 

 effects of specific contaminants such as anti-fouling agents. 



The degree to which marina construction activities degrade water quality and alter 

 estuarine habitat depends upon the location and capacity of the facility, shore protection 

 measures installed, amount and location of dredging, building materials used, on-shore site 

 character, and other factors. Alteration of estuarine salt marsh and in-shore habitat, 

 disturbance of unstable shoreline features, and use of anti-fouling treatments on pilings are 

 major concerns. 



Maintenance dredging causes increased turbidity, resuspension of organic materials and 

 any associated contaminants, and disturbance or removal of benthic bottom communities. 

 "Agitation dredging," or the disturbance of in-place sediments by propellors or hulls may 

 also cause similar impacts in severe cases. Disposal of dredge spoil, particularly if the 

 material is contaminated with organic matter, hydrocarbons and heavy metals is a major 

 issue 



Boat maintenance activities associated with marina operations contribute a range of non- 

 point inputs. Scraping, painting, washing, and dockside refueling introduce 

 hydrocarbons, detergents, and heavy metals (copper, mercury, cadmium, and lead) 

 associated witii anti-fouling agents. Stormwater runoff from paved marina site surfaces 

 may contain boat scrapings, spilled paint and oil, sediment, pesticides, nutrients, and 

 detnis and litter associated with work and storage areas. 



With regard to boat operation, hydrocarbons derived from boat motor exhaust increase 

 contaminant concentrations in the water column and may form a visible sheen on the water 

 surface. Certain constituents evenmally reach the underlying sediment Similarly, anti- 

 fouling paint residuals can cause increased concentrations of heavy metals and other 

 contaminants in the water column, bottom sediments, and tissues of aquatic biota. 

 Theoretical calculations completed during the preparation of the Areawide Water Quality 

 Management Plan (based on flushing rates and boat densities) indicated that Warwick 

 Cove, Apponaug, and Bullocks Cove could be most vuhierable to increased heavy metals 

 concentration. 



Because raw sewage discharge from boats contributes to bacterial contamination of 

 shellfish, which may be consumed raw, shellfish beds in marina areas are categorically 

 closed to the taking of shellfish. Sewage discharge also contributes loadings of organic 

 constituents and nutrients to receiving waters. Problems associated with sewage discharge 

 are complex and are not limited to concerns regarding open water discharge. Where wastes 

 are transferred from boats at pump-out facilities, they must go to municipal sewage 

 treatment plants. Not only is plant capacity a major concern in itself for many coastal 



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