The launching of craft from formal/constructed access points is likely to have minimal impact on marine features except where it involves trampling and scouring of the feature. Although an existing slipway may have a continuing impact on a feature, site designation suggests that the site can support the facility with its current level and type of use and maintenance. However, if the usage levels of the site increase greater impacts may occur, such increase therefore require close monitoring.

The launching of craft from non-constructed access points may result in compaction and erosion of features both on land and in the intertidal area.

Anchor drag from swinging moorings may disturb sediment and benthic communities.

Where craft maintenance takes place on water or on mud/sand flats at low tide sediment and benthic communities may by exposed to contamination from anti-foulant products.

Existing marina berthing has no impact on marine features, although new infrastructure development and maintenance activities do have an impact, particularly where it involves land claim and significant dredging (see chapter 5).

Sailing craft will often use the auxiliary engine for lengthy voyages and when the wind is either too light or in an unfavourable direction where tacking against the wind is necessary. When manoeuvring at slow speed it is likely that the craft will be in shallower waters where emissions especially from 2 stroke engines will have the potential to cause greater impacts.

When in sail the main and foresail can often emit a loud crackling noise. This together with visual intrusion may cause nearby shorebirds to be disturbed.

Antifouling paint may be a significant localised source of heavy metal in the marine sediment, but its effects have not been quantified, particularly in the context of other sources of heavy metals such as industry, commercial shipping and agriculture.

Impacts from antifouling paints may be observable where present in high concentrations, particularly in low flushing estuaries and inlets and bays. Such concentrations are most likely to result from maintenance activities in marinas and boatyards or owner-maintenance activities on mud banks and sand flats.

Sewage discharge from craft can have localised impact on marine features, particularly in low flushing estuaries and inlets and bays where it may contribute to reduced oxygen availability. However, its impact in fast flushing areas is negligible.

Although most litter in the marine environment is from sources other than water-based recreation, irresponsible behaviour from some boat users may contribute to the problem.

Disturbance to wildlife caused by sailing craft will vary depending upon the type of activity, the time it takes place and the vulnerability of the wildlife.

Disturbance is observable at feeding, mating and roosting times but is extremely difficult to quantify and should be examined on a case by case basis.

Nationally, sailing has a more significant impact upon wildlife than other forms of water based recreation because it is more widespread than other water-based recreational activities and tends to take place throughout the year, sometimes coinciding with vulnerable periods for wildlife.

Localised impacts may be caused by anchor drag and boat grounding.

Turbidity caused by boat movement is not applicable to sailing craft.

Blank Square - not applicable

m - minimal

w - observable, likely to be location specific

w * - observable at certain times, minimal at other times

l - appreciable

• physical impact on feature

• anchor drag and maintenance activities carried out at low tide

• this refers specifically to the impact of maintenance activities, such as hull scraping on mud banks at low tide

• generally used only for low speed maneuvering

• only used on larger craft

• toilets only fitted on larger craft

• presence of craft in proximity to wildlife

• impacts of anchor drag on benthic/bottom dwelling communities

• depth of reef will determine access by craft

• ingestion of heavy metals

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