Hello!
 
Hi,
 
This is info from a working group of scientists NOT newspapers or
magazines which tend to twist words and facts around.
 
It turns out there is more than one Caulerpa invader!
 
Here is the gist of the Mediterranean Caulerpa workshop March 1998;
 
REPORT OF THE WORKSHOP ON INVASIVE CAULERPA 
SPECIES IN THE MEDITERRANEAN
 
Extracts of the UNEP(OCA)/MED WG. 139/4 report of March 20 th 1998
Heraklion, Crete, Greece, March 18-20th 1998
 
Nota : this document is extracted from the report adopted by the
participants at the Workshop on invasives species of Caulerpa in the
Mediterranean, organized by the Mediterranean Action Plan
at Heraklion (Greece) on March 18-20th. Numbers preceedings paragraphs
correspond to the document distributed, modified and adopted par the
assembly. The final report of this workshop will be soon published by
the PAM secretariat (Athens).
 
Introduction
 
1. The Extraordinary Meeting of the Contracting Parties (Montpellier,
July 1996) approved the organisation of a Workshop on Caulerpa species,
which have been expanding in recent years, to which interested
Mediterranean scientists would be invited to exchange scientific
experience and views on the subject.
 
2. The Secretariat decided to hold a "Workshop on Invasive Caulerpa
Species in the Mediterranean" from 18 -20 March 1998. The Institute of
Marine Biology of Crete agreed to host the Workshop at its premises in
Heraklion, Crete. The MAP Focal Points were invited to circulate an
information note concerning the Workshop to all interested scientists in
their countries and to nominate one scientist to prepare and present a
country report covering the situation in the country with regard to the
spread or eventual presence of Caulerpa species.
 
3. The Workshop was attended by 53 scientists, with Albania, Algeria,
Croatia, Cyprus, Egypt, France, Greece, Israel, Italy, Lebanon, Libyan
Arab Jamahiriya, Malta, Monaco, Morocco, Slovenia, Spain, Syrian Arab
Republic, Tunisia and Turkey nominated representatives. A full list
of the participants appears as Annex 1 to this report.
 
 
 
Conclusions;
 After an extensive discussion, the Workshop agreed on the following
conclusions:
 
     a) There exist more than 70 species of the genus Caulerpa but only
a handful of these are present in the Mediterranean sea.
 
     b) Caulerpa taxifolia is a tropical species and was observed for
the first time in Monaco in 1984. Since then it has expanded covering
large areas of the Western Mediterranean and Adriatic coastal region
(more than 3000 ha at the end of 1996). At the same time another
Caulerpa species, Caulerpa racemosa, is expanding in many parts of the
Mediterranean.
 
     c) Caulerpa taxifolia has been studied extensively in the
Mediterranean and the following can be concluded based on the results
obtained:
 
          (i) Caulerpa taxifolia which colonizes the Mediterranean has
some unusual morphological and physiological characteristics with
respect to known Caulerpa taxifolia inhabiting the tropical seas.
 
          (ii) Caulerpa taxifolia can adapt itself to different light
conditions and is found in dense beds down to 50 m depth.
 
          (iii) The growth curves as a function of water temperature
show an adaptation to a large range of temperatures and a resistance to
cold winter temperatures (3 months survival at 10°C).
 
          (iv) There is no connection between the development of
Caulerpa taxifolia and water quality; it develops equally well in clean
and polluted waters.
 
          (v) Caulerpa taxifolia synthesizes 9 toxic substances,
including caulerpenyne which is predominant. The percentage of toxins by
dry weight in Caulerpa taxifolia is usually higher in the Mediterranean
than in the tropical seas.
 
          (vi) lt has been shown that caulerpenyne in solution degrades
rapidly in daylight conditions, in the presence of oxygen and
chlorophylls or phaeophytins.
 
          (vii) No caulerpenyne has been found to accumulate in sea
urchins which have consumed Caulerpa taxifolia.
 
          (viii) No toxicity risk to humans has been observed.
 
          (ix) Caulerpa taxifolia colonizes all types of sea bottoms,
such as, rock, sand, mud and dead Posidonia meadows.
 
          (x) Caulerpa taxifolia invades indigenous biocenoses modifying
biodiversity and ecodiversity.
 
     In view of the above, the workshop agrees that the most serious
risk from Caulerpa taxifolia is the upsetting of the ecological balance.
 
     d) Caulerpa racemosa has not been studied intensively, like
Caulerpa taxifolia.Nevertheless, the following can be concluded based on
the available literature on Caulerpa racemosa inhabiting the
Mediterranean.
 
          (i) Caulerpa racemosa, which is currently colonizing the
Mediterranean, may present different morphological characteristics from
one region to another and from the specimens described in the same
region at the beginning of the 20th century.
 
          (ii) Caulerpa racemosa colonizes all types of substrate such
as rock, sand, mud and dead Posidonia meadows down to 60m depth and
interferes with marine coastal biocenoses. Also, it develops equally
well in both clean and polluted water.
 
          (iii) The expansion of Caulerpa racemosa, according to
preliminary research, may alter marine habitats.
 
 
Later,
 
Emilio Jorge Power
 
PS If you search for Caulerpa taxifoilia you will get a good number of
sites re; the invader.