Küstenbiologie - Coastal Biology

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Shipworm Baltic Teredo-Lab

Teredo-Lab

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Test panels in the Baltic Sea

Commonly pine wood panels of ca. 20 x 30 x 2 cm are used for exposure experiments.

After 4 weeks of exposure they are taken to the lab for analysis. The fresh entry holes of teredo larvae are counted under a microscope. Afterwards the keeping of panels in an aquarium is quite easy, you don´t even have to feed the animals (see "biology"). After 6 - 8 months you can expect to see fresh larvae.

 

Breeding Teredo

So why would I want to breed the underwater monster?

In controlled experiments in the laboratory I hope to test different wood species and impregnations in a short time. In natural populations the time and number of teredo larvae fall is not predictable. Test panels have to stay in the field for several years to get a reliable result for teredo. However, even then it is hard to compare the results to earlier periods with differing conditions (larvae density, climate, currents, salinity etc.).

Unfortunately the aquaculture of bivalves is not easy. The larvae are small (0,7 mm) and sensitive. Teredo larvae are hard to distinguish from other bivalves, so you cannot just fish them out of the sea, but you must make the adults breed in the aquarium.

This is called a d-veliger, from the shape of the shell. Above you see the ciliate "velum", the organ of (modest) locomotion. Transport is mainly passive, carried by the currents. The larvae need a few weeks in clean sea water, with a regular diet of microscopic algae. So before teredo you need to culture Isochrysis galbana.

 

In a "plancton reactor" the algae are cultured, with a constant, but not too intense, stream of air bubbles to keep the cells in suspension.

You could also use synthetic algae mixes, which are used for feeding invertebrates in coral aquaria. This would simplify matters, experiments to that effect are carried out in the coastal biology laboratory.

When the process is established, we will be able to to test wooden parts of any form or size against the destructive effect of shipworm infestation. We can manipulate the condition to fit a planned place of operation (salinity of the Baltic, temperature of the Caribbean, etc.). Even an extraordinary mass invasion could be simulated for addition security.

Simultaneously, a monitoring of exudates with chemical or ecotoxicity tests might be relevant and can be implemented rather easily.

Last Updated on Friday, 21 January 2011 22:13