What are the two principal types of storm systems that pose a threat to the coastal zone?

Answer tropical and extratropical cyclones;

Water flows along the east coast and across the western tropical pacific towards south america, while they both are directed towards that way,  el niño does not directly affect the southern flow of water along the coast. 

Mexico has a host of environmental problems, including significant chemicalpollution  from factory discharges and waste dumping, but the main threat to itsbiodiversity  probably stems from  deforestation  and other natural habitat losses. forest habitat is lost for a number of reasons