1 The Mg and Mn are the common elements that concentrate in
the top and bottom branches of the three coral species. Mg
concentration in G. ventalina is not due to its growth rate. The
Mn concentrations in the three corals is a common result that
may be caused by high Mn content in sea water due to high
precipitation rates along the coast incorporated to the skeletons
during their past growth.
2 The Sr/Ca ratio in the corals suggests secondary calcite cements
and calcitization, and high concentration of Sr in Acropora palmata
and Acropora cervicornis. However, little differences in the
growth rate in Acropora palmata are probably associated with
the rate of calcitization, little changes in Sr concentration and
the negligible influence of temperature and water depth in its
growth.
3 Concentrations of trace elements like Cr, Co, Ni and V in the
corals are influenced by natural concentration of these components
in the sea-water.
4 High Zr concentration in the three corals from Puerto Morelos
may be due physicechemical reactions during low pH values in
the sea-water and/or Zr adsorption by organic matter and
macroplankton.
5 Depletion of terrigenous input seawards into the reef system is
supported by a low significant correlation between Zr and the Y/
Ho ratio value.
6 The enrichment of heavy rare earth elements in relation to light
rare earth elements reveals abundant inorganic ions CO3
2 and
OH with high pH (8.2) in modern sea water and particulate
organic carbon. The Eu positive anomaly and the Nd/Yb ratio
values for the three corals suggest development of the species in
modern shallow marine waters. The (Pr/Pr*
) vs. (Ce/Ce*
) binary
diagram showed a negative Ce anomalies with the exception of
the top and second top branches of G. ventalina suggesting the
presence of well-oxygenated shallow waters and high nutrient
content. Gorgonia ventalina shows a higher La positive anomaly
for the bottom branch compared to the other species is related
to the changes in the pH conditions of sea water.