By: Dr. Rafael Riosmena-Rodriguez and Dr. Jorge Manuel López-Calderon
The seagrass beds are highly productive marine ecosystems that provide a huge amount of ecosystem services. Angiosperms are plants that have developed morphological and physiological strategies to survive submerged in the ocean. Despite its importance, to date, remain one of the least charismatic coastal ecosystems and unknown to mankind, and its rate of disappearance of the world’s coastlines is four times greater than that of tropical forests.
In Mexico 9 species inhabit seagrass beds, in which Zostera marina (Zm) is the dominant species in the Pacific and Gulf of California. Information regarding the status of seagrass beds is scarce, are devoid of a framework of environmental protection and few protected areas that have seagrass beds. In this report we assess the conservation status of prairie Zm in Laguna San Ignacio (LSI) to identify critical areas for the conservation of this species. To achieve this were sampled in situ (2008-2010), were used Landsat images (1970-2000) and information from previous research in the areas of study. Thanks to this, we obtained a set of indicators of the conservation status of the marine angiosperm.
We found that, in descending order, currently there 7320 ha in LSI, 218 seeds m-2 for LSI. The low density of seeds found in LSI indicates that it is a perennial population in this wetland but its density is the lowest in the entire known range of species’ distribution. In LSI seagrass coverage has declined 37% in the last 15 years. In LSI overfishing and the use of prohibited fishing gear are one of the main factors that damage to the prairies of Zm. In LSI the critical areas for the conservation of Zm are north and southeast, in North and Estero de Pitaya sections, where there exist greater coverage and higher grassland seed banks.
Regulations are needed to protect seagrass in Mexico in addition to long-term annual monitoring of key sites such as the three wetlands analyzed in this thesis in order to determine the effect of local origin disturbances (change of use of soil) and global (ocean warming) on seagrass beds.