Whale Shark Sightings Summary

Annual Maps | Annual Survey Reports

The Gulf Coast Research Laboratory actively maintains an online database of whale shark sightings in the northern Gulf of Mexico. The database includes more than 370 whale shark sightings from 2002 through 2010. Recreational fishers, charter fishing operators, offshore petroleum workers, and divers provided their information through personal interview or through the Online Whale Shark Sighting Survey. Whale sharks were often observed in aggregations as large as 200 animals. Such large aggregations are relatively rare worldwide.

Whale shark sightings occurred in waters with depths from 20 to 1000 meters. Approximately 85% of sightings have occurred from June through October as shown in Figure 1 for 2002 - 2007. Most sightings take place southwest of the Mississippi River Delta during summer and northeast of the Delta during fall. The estimated size of the whale sharks sighted has ranged from 3.7 to 10.7 meters total length. Based on the estimated size at maturity for whale sharks (~9.5 meters), the majority of the sharks sighted in the northern Gulf of Mexico were immature. See Figure 2. Gender is not typically recorded.

Percent occurrence by month of whale sharks observed in the northern Gulf of Mexico
Figure 1. Percent occurrence by month of whale sharks observed
in the northern Gulf of Mexico from July 2002 through November 2007.
Numbers above histograms indicate number of individuals observed.
Numbers in parentheses indicate the number of sightings.

Distribution among size classes of whale sharks observed in the northern Gulf of Mexico
Figure 2. Distribution among size classes of whale sharks observed
in the northern Gulf of Mexico from July 2002 through November 2007.
Numbers above histograms indicate number of individuals observed.

Annual Sighting Maps

The maps plot the locations of whale shark sightings during the Click a thumbnail map for a larger view.

Please contact Jennifer McKinney for more information.

Annual Sighting Survey Reports

These one-page reports summarize sightings and provide information on monthly shark sightings, shark size distributions, top sighting reporters, and more. Follow the links to view the annual report.

2009

2008