Reefballs, Giving nature a helping hand

By David Head, Reefball New Zealand

 

Reefs are the rainforests of the sea. Like forests the various types of reefs are extremely important as a habitat for an enormous number of species. Any imbalance created by over-exploitation, pollution or physical damage [ storms, anchors, dredging, trawling etc] has a long term effect on the biodiversity in the area. Divers have seen first hand the damage that mans activities has done to the marine environment, these days surpassing the damage done by a reefs other natural peril, storm damage. It was this storm damage to a coral reef in the Caymen Islands that lead to the “reef ball” story.

 

Todd Barber,CEO and visionary who founded the “reefballs” program, had for many years visited the Caymen Islands in the Carribean every Christmas with his family. Every year he dived on the same coral reef and took photos of the same piece of coral.  He came to realize how slowly coral grows.  But one year, following a major storm he returned to see ‘his’ piece of coral reef had been destroyed by the hurricanes surges.

 

To cut a long story short, Todd and a number of friends spent a number of years developing reefballs; a hollow concrete sphere with specially designed holes that could be floated with an air filled bladder and ‘sunk’ into place, or deployed from a barge, to give a damaged reef a foundation to start the corals recovery.  In just over ten years there are now over 500,000 reefs balls in 3700 projects in 44 countries around the world, and the list grows week by week.

 

 

Why artificial reefs? 

 

The use of artificial reefs is hardly a new one. For decades people have been creating reefs from tyres, sunken ships, old cars, concrete culverts and assorted rubble. These, however, can often do more harm than good - leaching harmful chemicals into the ocean or damaging natural reefs when currents dislodge them and toss them around the sea floor.

 

While many in the underwater fraternity are keen on sunken ships as diving destinations more and more people believe that purpose built artificial reefs are a better option, hence the 3700 reefbal projects worldwide.   There two reasons for this, first the environmental effectiveness of a properly designed artificial reef and secondly the cost.  Just the cost of rendering a ship free of oil and other contaminates [ contaminants ? ] could pay for a far  larger, more environmentally sustainable artificial reef.

 

What are reefballs

ReefBalls have been designed to emulate natural reef formations and, as most of the weight is concentrated in their flat bases, will sit on the sea floor without moving, even in turbulent seas.

  Reef Balls are hollow, dome-shaped structures designed to imitate the natural reef formations. Each Reef Ball has its own unique hole sizing and placement, with the surface textured for enhancing settlement of marine life. The units are made with marine friendly concrete which has been combined with additives to create a super-strong, abrasion-resistant structure with a pH similar to ocean waters. They are engineered for underwater stability and longevity, and cause minimal impact to the surrounding areas.

Once deployed, the Reef Ball will begin to come to life through various natural processes. Almost immediately, fish and other mobile marine creatures will migrate into this new habitat in search of safe havens. Primary growth, consisting of a myriad of marine algae, will flourish within the first few months, nurtured by the inputs and outputs of the more mobile.  In New Zealand holes in the base can provide a home for crayfish and the smooth inside an idea home for paua and other shellfish.

Larger reefballs are increasingly being used to make breakwaters to prevent beach ersosion.

 

Reefballs in New Zealand

 

Three years ago I became aware of reefballs when researching methods of prevent beach erosion. Since then I have obtained three reefballs moulds and have loaned these to help two projects to make artificial reefs, one in the Long Bay Marine Reserve being led by Jonathan Jaffray and one in Opotiki being done by the Whakatohea Training Unit.  The objectives of the Long Bay project are to conduct research on the construction and placement of reefballs into two small reefs.  Then to monitor the colonization rates with the hope that the biota and species diversity will increase with the increase of the available habitat.  The Opotiki project involves many in the community and brings a focus to the long term sustainability of kiamoana and the need to give something back to the sea. It has widespread community support.

There is a developing project in the Golden Bay Separation Point Fisheries Management area. This area was closed to mobile fishing methods such as dredge, trawl and Danish seine in December 1980 to try to protect a small remnant (6 miles x 2 miles) of previously extensive bryozoan coral beds. These coral beds were (are) an important nursery area for a variety of fish species.   A New Zealand Company is interested in using reefballs in conjuction with artificial surfing and erosion control reefs

 

With the positive results from the Long Bay reefs in Auckland, it is hoped that more public interest will result in other projects being developed.

 

  The major hurdles to developing many artificial reef projects are the financing and the resource consent procedures.   It is ironic that the while the Resource Management Act is designed to protect our environment it has nothing in it to help the development of positive additions to the marine environment, such as artificial reefs.   The long term hope is that any development that has a negative impact in the marine environment, for example reclamations, wharfs etc will have to make a positive contribution. What better way than to require developers to fund an artificial reef?  The Long Bay study will therefore give the authorities something positive on which to base approval.

Anyone interested should have a look at the reefballs web site [ www.artificialreefs.org ] and its many associated links.