MARINE ENHANCEMENT PROJECT

Project Title:	Marine Enhancement Project			Project Code:	N/A
Funding Source:	Peel Development Commission (RDS Funding), Peel Regional Fish Stocking Association and the then Water and Rivers Commission (now Department of Water)
Start:	April 2003	End:	June 2003	Project Officer:	David J Lennon & Associates

Background

The Peel-Harvey Catchment Council (PHCC) sort to investigate opportunities to enhance the fish habitat in the regions waterways, particularly in the man-made canal estates in the Peel region. To this end, the PHCC commissioned this feasibility study to provide recommendations and appropriate technical material to consider the placement of artificial habitat into nominated areas of the regions man-made waterways.

Funding for the feasibility study was provided by the Peel Development Commission, through the Regional Development Scheme, the Water and Rivers Commission and the Peel Region Fish Stocking and Management Association.

Study Approach

This study was conducted during the period from April to June 2003, and included the following: review of existing literature; two meetings with stakeholders supplemented by one-on-one meetings with developers and other relevant individuals; and above and below water inspection of potential sites.

In order to help prioritise where efforts and resources should initially be directed, each site was judged and ranked on 11 attributes. Enhancement strategies were then developed for sites ranked in the top three. These were:

Mandurah Ocean Marina and Hall Park Public Swim area.
Port Bouvard - Northport, and Port Mandurah - Mariners Cove.
Port Mandurah - Leeward.

Enhancement of the Peel Waterways

The initiative to investigate how the potential enhancement of the Peel Region's man-made waterways should be considered as a 'pilot 'program. It is an ongoing process of deploying modules and observing results.

An enhancement program such as this is not just about enhancing the physical attributes of waterways, but also about enhancing our understanding of the local system and how it is affected by our built environment. It is this improved understanding that can then be used to 'enhance' future decisions on the direction of the program, management of the Peel's waterways, as well as further coastal development and research. Environmental management plans are only as good as the information they are based upon and this program over its lifetime can contribute valuable data as well as foster greater interest and support from the community for the sustainable use of the region.

At this stage of the program, there is no objective to target the enhancement of specific species. However as experience is gained, it may then be appropriate to explore specific enhancement activities that target certain species, as well as how natural areas may be enhanced/restored or protected from wave erosion.

Methods of Enhancement

Three primary means of enhancing the constructed waterways are provided.

Structural Design Changes
Perhaps the foremost inadequacy in canal design from a biological perspective is our tendency for engineering, economic or aesthetic purposes, to construct straight lines. There are few straight lines in nature, yet our built environment has an abundance of straight lines as well as smooth faces. This limits the biological 'attractiveness' of the structure and could be likened to creating a level uniform meadow with only one type of grass.
This can be improved in a number of ways. If the structure (eg. canal wall) is yet to be built, then the construction of an irregular block face below the waterline can add diversity and ledges that will assist colonisation by encrusting organisms. This has the added advantage of helping to dissipate wave energy (ie. boat wash). Addition of modules such as Reef Balls to the base of the wall can further enhance its biological attractiveness.

An option for walls or breakwaters already constructed is the addition of rock spurs. Rocks or Reef Balls are placed in a pile just out from the toe of the rock wall; no rocks actually form a connection to the wall. This creates a node that fish can swim around and inbetween and increases the width and length of the walls 'useable' area. This option is recommended for Mariners Cove, Leeward, and Eastport.

Incorporation of intertidal habitat is another way developments can improve their biological productivity. Examples already exist at Mariners Cove, Leeward and Eastport. There exists the potential to introduce seagrass into some canal areas, for example Northport. This can be a community project and is highly recommended.
Enhancement using Reef Balls
Reef Balls are a US invention that has now become the world's leading artificial reef module, with over 500,000 deployed worldwide in 3,500+ projects. They are considered the best choice of module for the programs by the PHCC due to their stability, natural appearance, hollow void spaces, and effectiveness. Reef Balls can add valuable contrasting substrate to areas underneath jetties, along walls and within rock wall spurs.
It is recommended that four different sizes of Reef Balls be used, and initial numbers of modules for each site varies from approximately 40 to 180. Reef Balls are made using a patented mould system and it is recommended that 11 moulds be purchased, however this can be varied to suit the final program schedule and funding.

It is recommended that a non-profit organisation be established to construct and deploy the modules, and module construction could involve volunteers including school groups.
Enhancement using Non-Reef Ball Concrete Modules
There is the option of making custom modules out of concrete using balloons, buckets, sand, and other materials and some imagination. This could be something school groups could get involved in and they could then monitor their creations. This encourages students to think about what different animals require in the way of habitat, and could generate useful designs for elsewhere.

PHCC Marine Enhancement Project 2003 »

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