Reef watcher

Issue 2, number 3, December 1998

Its Spring!

Calling all Reef Watchers......

We need your help! Its time to submit more surveys for Reef Watch. The return of surveys have been slow over the winter months so its time for each of you to get back in the water and help monitor our marine environment. We would love for each of you to complete at least one survey in the next month. The more surveys that are completed the more successful Reef Watch will become to reaching our goals.

A big thank you goes out to all those members that did manage to brave the cold weather and return numerous surveys during the colder months.

Species under the spotlight

This is the beginning of a new column,. We have decided to put a species under the spotlight in each newsletter to get you better acquainted with our marine life. If you want to know more about a particular species we will Endeavour to cover it in the next Reef Watcher issues.

The Sea Urchin

Phylum: Echinodermata

About 800 known species exist, with around forty nine species found in Southern Australia.

Australia has an increasing number of marine species being introduced into our waterways via ballast water which are causing many environmental and economic problems. At present there are at least 15 known varieties of fish, crustaceans, molluscs. seaweed and toxic algae have already been introduced. Many of these species are beginning or are at present causing serious environmental problems or threatening economically important industries.

What is Ballast Water?

Ballast water is seawater taken onto ships in overseas ports in order to ensure vessel stability for ships with little or no cargo. The ballast water is held in specially designed ballast tanks and cargo holds until it is discharged in Australian ports. The water contains organisms and sediments which are generally foreign to Australian waters. Everything from fish to crustaceans to bacteria have been found within the ballast water. If the environmental conditions are favourable for the organism, it is able to grow, breed and spread.

Each year in Australian ports about 121 million tonnes of water is discharged from overseas ships.

Impacts of Exotic Species

The impact of introduced or exotic species into Australian waters can be potentially devastating for our natural environment. The introduction of introduced organisms can affect local marine life ion many ways, including competition with native species for habitat space or food, preying on them or generally changing the habitat. Exotic species can also affect commercial fisheries through the introduction of diseases and parasites, especially in those areas used for aquaculture. Many of the ports in Asian countries where ballast water is taken on are heavily polluted and are known to harbour aquaculture diseases which are not currently found in Australia

What are some of the exotic species?

Japanese kelp (Undaria pinnatifida) - believed to be introduced in the 1980's in Tasmania. This kelp grows rapidly and densely, forming canopies which can out compete native seaweeds for habitat space. Commercially viable species such as the abalone which feed on the native kelps maybe be affected in the long term if the native kelp declines. This species has now been found in Port Phillip Bay, Victoria.

Northern Pacific Sea Star - first discovered in Hobart in 1986, originating from Japanese ballast water. It has spread rapidly through the south eastern waters of Tasmania. They are able to breed quickly in favourable conditions and compete with native species for habitat. They also feed on scallops and mussels which may cause problems for the local shellfish industry as population numbers increase.

European fan worm - originating in Northern European waters it has been found in four of Australia's port. In an earlier addition of Reef Watcher we mentioned the discovery of the Sabella worm at Port Noarlunga Jetty by Reef Watcher Mary Anne Stacey. As reported the species although neither predatory or toxic they can displace native species such as scallops and mussels. They are also very hard to eradicate.

Toxic Dinoflagellates- Dinoflagellates are a group of microscopic algae which are unicellular and move around using a flagella (a whip-like organ used for locomotion). can produce a toxin which can cause dangerous paralytic shellfish poisoning in humans if the ingest the fish or shellfish that have consumed the algae. One species has caused the temporary closure of 15 shellfish farms in Tasmania.

Alexandrium minutum. is a toxic dinoflagellate. Alexandrium minutum is present in the Port River where it usually blooms in the summer/spring each year causing the closure of the river from fishing. Alexandrium minutum. and other dinoflagellates species can multiply rapidly and when conditions are favourable such as high nutrient levels, stable water and high water temperatures they can cause a explosive growth in population and aggregate to create what are generally called red tides or algal blooms.. Most red tides are harmless but some tides can produce toxins which can kill fish and even cause oxygen depletion resulting in the death of fish. There are also potentially fatal secondary effects if any human or vertebrate predator such as fish eat the contaminated animal. At present there is a ban from taking shellfish from the Port River. It is likely to remain this way until Fisheries experts determine that there is no longer a risk to public health.

What's being done about it?

In 1990 the Australian Quarantine and Inspection Service (AQIS) introduced voluntary guidelines fro ships entering Australian Ports from international waters. They were adopted by the Marine Environmental Pollution Committee of the Maritime Organisation in 1991.

These guidelines include:
*when ballast water is taken on board a certificate must me obtained from the relevant authority indicating that water and bottom sediment in that area is free from toxic organisms

Eliminating organisms in the water during the voyage to Australia
try to ensure that when ballast is taken that it is free of sediment
try to avoid taking ballast from shallow waters where sediment uptake is more likely
avoid ballasting when toxic dinoflagellate blooms are occurring
treating water as it is discharged in Australian ports
The ballast water may also be sterilised at sea either chemically or physical sterilisation. This involves using things like chlorine, hydrogen peroxide or UV light. Heat is far more environmental friendly compared to the use of chemicals however it is not very economical or efficient as large amounts of fuel are required to heat the tanks.

As you can see most of the guidelines are fairly generalised. Further guidelines need to be established to ensure the reduction of deballasting in our waterways. The introduction of exotic species to Australian waters can have dire effects for our native species There are also the associated affects caused through a decline in our native species such as the reduction in those species which are economically viable to Australia. The management of ballast water is a complex issue however their is a direct need for legalised guidelines for ships de ballasting in Australian waters. The means to reduce the risk of introduced species have not yet been met. Further research and the development of new techniques for deballasting water in our ocean need are required.

Dragon Search goes national

Dragon Search is a community-based project which aims to engage the community in the collection of weedy and leafy seadragon sightings. The project aims to increase our understanding of these species and thereby improve their direct and indirect management. It is also hoped that the project will increase the community's awareness and appreciation of marine species and habitats and to motivate them to consider reducing their own impacts on the marine environment.

Initiated in South Australia by the Marine Life Society SA, Marine and Coastal Community Network (SA) and Threatened Species Network (SA) with Coastcare funding, the program has now achieved a true national status. There are Dragon Search projects running in all 5 states where seadragons occur. Coordinators from each state met recently in Adelaide at the first National Dragon Search Coordinators Conference.

The conference provided an opportunity for Coordinators to devise a nationally consistent strategy. The national memorandum of understanding drafted at the conference will facilitate such a strategy. One visible result of the meeting will be a new information brochure and survey sheet that is consistent with a national database. A new Dragon Search logo has also been adopted and along with the Dragon Search name will now be registered. A national Dragon Search website will be up and running in the near future and should greatly assist in promoting the Dragon Search Project.

When you are out diving or enjoying the beach this summer remember to keep an eye out for seadragons. If you would like a survey form to report a sighting or would like further information on the Dragon Search project please contact Jeremy Gramp or Vicki-Jo Russell on (08) 8223 5155 or Tony Flaherty (MCCN) on (08) 8302 6568.

Dates to remember!

Reef Watch Dives

All are welcome to attend the end of month dives. These dives are held at different locations each month. It not only allows us to get some surveys completed but to meet some new people. Its really just another excuse for a dive!

Next Months Dive: November 28th Hallett Cove Reef meet 10am

Please call the Conservation Council if you wish to attend this dive or future dives.

Reef Watch October Dive Aldinga

Thanks to all those who came to the October dive at Aldinga. We managed to obtain two boats for the day, a big thank you to Brian and Steve and the Flinders University Dive Club for donating their boats. The morning turned out to be a little windier than we had hoped for so it was decided not to launch the boats. After much deliberation we decided that it would be a far better dive just around the corner at Snapper Point. Our local expert warned us that it was a small walk out to the water from the coastline. However when we saw the distance that we needed to walk we quickly changed our minds (It was suggested (many times) that we should go to the Bushing Fest instead, which would have been a far better option than walking the distance out to the water). However persistence payed off and we decided to head off to dive at the Star of Greece, an old wreck. The water looked absolutely beautiful, near perfect conditions for diving (apart from the small obtrusive waves breaking close to shore and the rocks which we seemed to find us wherever we walked). Five of us decided to dive, whilst two snorkelled. We finally made it into the water and it was well worth the wait. The site displayed varying species of algae, fish and invertebrates. After all our efforts we didn't manage to find the wreck but a good day was had by all, especially finishing off with a BBQ at Midge's sister holiday units (a big thank you for the use of the BBQ area) but alas, there wasn't quite enough time to make it to the Bushing Fest.

Hope to see more of you at the next dive!

The next dive is on November 28. Please call the Conservation Council if you want to attend. The more the merrier. You don't need a dive buddy to participate.

Database

Information that we collect goes into the database. The database is well underlay. The results you obtain from the fish survey will soon beable to be directly entered into the database. The fish database can be viewed from our internet site. Our web address is: [email protected]

Surveys

A big thank you goes out to those you continued returning surveys over the chilly winter months. But its now summer and so its very important that you get back in the water and start returning some more surveys. This will increase the abilities to recognise change to individual sites, especially over time. Hope to see lots of surveys coming in soon.

Dive Buddy list

Reef Watch would like to create a list of people who would like to dive regularly but are not able to because they don't have a dive buddy. If you are interested, please call the Conservation Council of SA and let us know your name, suburb, availability and if you've done the Reef Watch training so that a list can be developed.

The Reef Top - Down

Mary-Anne Stacey

Coralline Algae die back

As you drive over Whitton Bluff on an ebbing tide you could be fooled by the cool pale waters surrounding the reef. Has someone transported us to a tropical coral atoll with palm trees. Pinna Coladas and hot and cold running???? Words escape me in this era of political correctness. What is happening to Port Noarlunga Reef, what is all the whiteness of dying algae. Why is the water so cloudy???

The coralline algae that has resided on the top of the reef is having an exaggerated seasonal die back.

Here is the theory so far.. incidentally it is an opinion only which is open to conjecture, correction, debate and environmental banter.

Last year the dredging caused much death on the reef of the filter feeders. Their death allowed opportunistic and successful species to take up residence in the greater available space. Coralline algae is highly successful. Species of Red algae, some 200 are known to exist. Not all of them have been identified. Since looking more closely I identified two distinct types of coralline algae (also known as red calcareous algae).

Due to this I feel a greater amount of coralline algae covered the reef. Blissfully summer has arrived, with longer sun hours. Recently we have has tides that expose the reef for long periods of time during the daylight hours. This seasonal change has caused the shallower coralline algae to die back. If you dive below the surface on the outside of the reef you will find healthy happy red/pink specimens. Most of the time coralline algae appears dirty mushroom pink, eaten off and battered algae to the surface snorkeller.

As the season progresses watch for the arrival and new growth of other algae's on top of the reef.

Baby Mussels

The clarity of the water - not pretty is it?? We have several factors operating here. The breakdown of coraline algae, the ever present and increased levels of silt is held in fine suspension and takes longer to settle out.

The big news is the mussels are spawning, fine white filaments are being extruded from the top of the shell. Their gametes (eggs) floating in the pea soup that makes up plankton. Watch out for the first signs of the baby mussels settling onto the reef over the next 2 months. When mother nature triggers the right set of environmental conditions we will then know the gestation period of a Black sea horse mussel!

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