Good question with heaps of ramifications Alex!

In identifying impacts on macroinvertebrates.... our watershed research program has identified a range of deleterious impacts that grows and grows... like Topsy! We engaged overseas experts in macroinvertebrate research to assist us with objective assessments ~ we carried out systematic sampling of our streams and rivers..between 1999-2003

What we found has not been published... there are too many loose ends and the visiting macroinvertebrate scientist from Canada failed to deliver his sampling statistics and final report...  However, you may find the following helpful..

Ecotoxic impacts ~ among the most serious include de-fouling paints and  agrichemicals applied in the watershed (pesticides, herbicides, insecticides etc) Dr Ron Griffith from Guelph Uni Canada may be able to help with this aspect)

Engine impacts ~ outboard motors discharge very high percentages of the fuel expended directly into the waterway ~ often as high as 50% according to Marine authorities in Australia ..  you may wish to follow this line with Marine researchers..

Physical impacts ~ works and measures by river engineers are listed among the three most serious impacts on macroinvertebrates as a result of severe physical disturbances occasioned by these works and measures.... ecological repair processes may take between 15-30 years to completely heal the habitat damage

Livestock impacts ~ grazing livestock can completely change the macro-invertebrate community by changing the sediment, nutrient and stability status of their habitats...

Willow removal programs ~ these nescient programs have impacts similar to all the above combined... for published research on this topic, refer Dr Michael Wilson Murray Darling Authority Canberra Australia...

Change of Flow/temp impacts ~ irrigation abstractions and diversions change the flow regimes so much they alter the energy balance of in-stream ecosystems with consequences for habitats and their communities... eg reduced flows often mean warmer flowing waters and algae blooms

and there are more ... good luck !!

Other impacts include erosion and disturbance of shoreline habitats from boat wakes. In small freshwater lakes with a lot of boat traffic boat wakes can have a big impact on shoreline habitats. Also, boat traffic can disturb wildlife, the noise and wake can disturb nesting birds and foraging animals.

A big problem with boating traffic is the introduction of aquatic invasive species from watershed to watershed. Careless boaters can move non-native species from one water body to another through bilge water or through plants and other organisms clinging to the boat trailer or prop. Another source of introductions is the careless emptying of bait buckets which releases new potentially invasive species.

There is a fair amount of literature on these topics from research conducted in the Great Lakes and nearby watersheds.

Boats are vectors for the introduction and distribution of non-native species. The classic example is zebra mussels in the mid-west United States, where mussels that attached to boat hulls and equipment were transported overland between the Great Lakes and in-land lakes. Boat traffic between water-bodies is a focus of prevention of invasive species spread, and put-ins have been described as focal points for invasive species introduction within "gravity" models.

Alex, boat traffic has the indirect effects on the MZB, and almost impossible to prove significantly that water traffics caused changes in the MZB assambledges. Benthos is very resistant to interference from any physical/technological activities. Non of benthic species vanished from the water traffic, until it becomes a source of strong toxic water pollution, that is a direct reason for vanishing a species!

Good luck!

Hi All,

Thank you for taking the time to respond. Some very good points raised which can potentially aid my research.

Thanks again! 

Hi Alex, 

  Not to toot my own horn, but check out my publication here on researchgate, where i try to link boat impacts to community composition of dragonflies. But more importantly, take a look at all the references in the paper, im confident many of them will be super helpful to you.

~aaron

I have read that wake wash from boats disrupts dragonfly emergence.  It makes sense, but I have not looked for the literature on the topic.

Morning Alex,

Indeed it would appear that boats are vectors in freshwater ecosystems in Britain and elsewhere.  As indicated earlier the hulls of craft have been responsible for transmissions of byssate bivalves such as the Dreissena spp.. The Pollox et al., enclosed.  Furthermore, there are a wide range of different boat designs that have different levels of dispersal capability depending on how they range.  There are some yachts that even carry ballast water and there is the possibility that these may disperse invertebrate stages.  The spread of Dreissena to Spain from the Canal du Midi I am convinced was within bow-thrusters as this is a site that large numbers of invertebrates can be spread.  This suggestion, although  based on evidence, was not  considered likely.  Even flatworms can be spread on boat hulls.  In addition I have found Corbicula and Dreissena on retrieved anchors on boat decks.

Hope this helps

Dan

 Hi all,

Thank you for the informative responses! The advice and help given is greatly appreciated.