Since 1985, various long-term monitoring programs have been in place in the Apalachicola Bay area that can be utilized to determine the effects of tropical storms and hurricanes on the natural resources of the area. The size, speed of movement, severity, angle and direction of landfall, as well as storm surge height and the amount and location of precipitation all play a role in determining impacts. Short-term impacts seen in the bay from these tropical events include water quality alterations, such as salinity and turbidity changes, water level changes, and loss of sea turtle nests. Long-term impacts include changes to the structure of the beach, dunes, and bayside areas on a barrier island, loss of or changes in submerged aquatic vegetation distribution, and the physical alteration of oyster reefs as well as oyster populations. In particular, Hurricane Dennis in 2005 caused the complete loss of fresh and brackish submerged aquatic vegetation in the upper areas of the bay. Larger storms in 1995 and 2004, such as Hurricane Opal and Hurricane Ivan, caused relatively little damage to natural resources. Hurricane Elena in 1985 caused massive damage to the local oyster industry, which took several years to recover.