Explanation of Indicator
Every year many marine mammals, predominantly dolphins, whales and manatees, are found stranded on Florida coasts. Strandings include dead animals or live animals that are generally taken to a marine zoological park for rehabilitation. The reasons marine
mammals beach themselves are unknown. However, it is suspected that increasing amounts of toxins in the ocean may be related to this behavior. If this link is accurate, then this indicator not only shows the numbers of mammals washing ashore, but it is
also a direct indicator of the ocean’s health. The Southeastern United States Marine Mammal Stranding Network tracks marine mammal strandings from Texas to North Carolina, Puerto Rico, and the U.S. Virgin Islands. The main database is housed in the Smi
thsonian Institute in Washington, D.C. Manatee strandings are not included in this indicator.
Data Characteristics
SOURCE
Information on marine mammal strandings is available through Dr. Dan Odell, coordinator of the Southeastern U.S. Marine Mammal Stranding Network, which maintains the Marine Mammal Stranding database. Dr. Odell can be contacted at Sea World of Florida, 70
07 Sea World Drive, Orlando, Florida 32821-8097, or at (407) 363-2662.
ACQUISITION
Stranding reports and tabulations are available through electronic data transfer or in hard copy. There are no costs associated with the acquisition of these data.
COLLECTION
The information is continually updated and tabulated quarterly. The southeastern region encompasses the coastal zones mentioned above, but this indicator only considers the Florida coast.
Data Limitations
Often, marine mammal strandings on Florida’s coast go undetected because of the remoteness of the site or because of the incomplete coverage of the state’s volunteer network. Some of the increases observed since the early days of the Network may be due t
o increased awareness of and participation in the program, and not due to increased strandings statewide. While these limitations exist, these data are the best information available on marine mammal strandings on the Florida coast. The data have become
more accurate and will continue to improve as the Network expands.
Data Analysis
The 17-year period of record shows a generally upward trend in the number of documented marine mammal strandings. From 1978 to 1982, strandings increased by 79 percent. A declining trend took place from 1982 to 1984, with a 35 percent reduction recorded
during that period. However, from 1984 to 1988 a sharp increase in the number of strandings was observed. The 178 strandings recorded in 1989 reflected a 38% decrease from the 1988 figure, and since 1991 the numbers have been around 300 per year. The
causes of marine mammal strandings and the fluctuations in the number of strandings from year to year are not known.