EurOCEAN 2000 - Vlaams Instituut voor de Zee

specimen of bottlenose dolphin captured in the Black Sea. The prototype designed during those
tests was subsequently used to the open sea trials (S. Vito Lo Capo, Sicily, Italy, Fig.1). That
study outlined that psychological repelling signals lose their effectiveness with time, probably
as a consequence of habituation to the emitted signals. That project also included a census of
dolphin by-catches which occurred during small fishery operations in Sicily. Data were
acquired through fishermen log-books and interviews.
In order to design a new acoustic prototype, according to our previous results, a new research
project was submitted to the frame of Technology Stimulation Measures for SMEs of the
Marine Science and Technology (MAST) programme, thanks to the financial aid of an
Exploratory Award (contract n. MAS3-CT97-0133). The project, entitled "Electroacoustic
prototype for controlling the behaviour of Marine Mammals (EMMA, contract n. MAS3-
CT98-0184), was approved and then started in August 1999.
The scientific and technical objectives of EMMA concern the implementation of an acoustic
device for controlling the behaviour of dolphins, in their natural environment to prevent the
interactions with the coastal small fisheries. The new prototype will be based on physiological
and not psychological dolphins response. Since the project started recently, in this paper we
present the consortium, the project plan and the activities to date.
EMMA is structured in ten tasks and six sub-tasks (Fig. 2). Its framework follows these steps:
1. creation of bibliographic database;
2. theoretical studies of dolphin Sonar;
3. identification of the most important organs of dolphin Sonar;
4. creation of morphometric database (original morphological data of Odontocetes auditory
system);
5. mathematical evaluation of the Natural Frequencies of Resonance (NFR) of main
components of the Sonar;
6. tank experiments to measure the actual natural oscillations of the different components of
dolphin Sonar;
7. definition of acoustic deterrent signals through a mathematical model and the results of
tank experiments; in this task the effects of dolphins habituation to the repulsive signals
will be considered;
8. design and realisation of the new prototype to be tested during the subsequent steps;
9. floating cage experiments to evaluate the efficiency of the selected signals;
10. possible re-designing of emitted signals structure;
11. assessment of the efficiency of selected signals in open sea experiments;
12. design and realisation of a set of prototypes and their testing during real fishing actions in
a wide sea area close to S. Vito Lo Capo (Fig.1).
At the present we gathered over 400 papers on dolphin sonar, cetacean acoustic capabilities,
auditory system, dolphin-fishery interaction. We also completed the study of the functioning of
dolphin's hearing and sound transmitting system. The melon, the air sac system (tubular,
vestibular and premaxillary sacs), the lower jaw and the timpano-periotic bulla were selected as
main organs for evaluating the NFR. The collection of biological samples from stranded
dolphins is in progress.
After the first EMMA plenary meeting, held in Trapani (22-23 February 2000), we began to
design the Emma project Web Site. The user-friendly structure foresees public pages, and
others only for the project partners. In order to monitor the ongoing of EMMA and to get the
feedback from all partners involved, the achievement of each task and further steps of the
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