Short-finned pilot whales beached on Redington Beach, Florida
Whale beachings, while heartbreaking, are a phenomenon that spans species, geographies, and defies simple explanations. In Florida, the shores of Redington Beach witnessed a distressing mass stranding of short-finned pilot whales in July 2019. More recently, echoing this somber event, an adult sperm whale beached itself off Venice Beach, Florida, tragically perishing as a result. These incidents prompt a fundamental question: Why Do Whales Beach Themselves? Despite ongoing research, the complete picture of whale strandings remains elusive, yet scientific inquiry sheds light on several potential causes.
Cetacean stranding, commonly known as beaching, describes the perplexing act of whales and dolphins stranding themselves on land. Globally, approximately 2,000 stranding events occur annually, and the majority unfortunately lead to the animal’s death. While concerning, these beachings are not frequent enough to pose a significant threat to whale or dolphin populations as a whole. Individual live animal strandings are often attributed to underlying health issues or injuries. Factors such as severe weather, advanced age, navigational errors, and hunting activities conducted too close to the coastline can also contribute to these incidents.
Certain whale and dolphin species exhibit a higher predisposition to mass strandings. Toothed whales (Odontoceti) are particularly vulnerable. This group encompasses dolphins, porpoises, and all whale species possessing teeth. A key characteristic of toothed whales is their complex social structures and tendency to live in large groups. If one member of such a group becomes ill or distressed, its calls for help can inadvertently lead other members to follow it ashore, resulting in a mass stranding event.
Remarkably, Orcas, also known as killer whales, sometimes intentionally beach themselves as a hunting strategy for shoreline seals. This behavior, primarily observed in Orca pods near Argentina, involves a calculated approach where they wait for opportune waves to assist their return to the ocean after a successful hunt. This learned behavior, believed to be passed down through generations within pods, highlights the intelligence and adaptability of these marine predators. Unintentional beaching is exceedingly rare for Orcas.
In a poignant example from spring 2022, a 47-foot male sperm whale beached itself in the Florida Keys. Subsequent examination by Florida Fish and Wildlife Conservation Commission (FWC) researchers revealed a grim cause: the whale had ingested marine debris. This ingestion obstructed its digestive system, preventing it from consuming its natural diet, leading to a severely weakened and emaciated condition that ultimately resulted in the stranding.
The role of sonar and other loud underwater noises in whale beachings is also a subject of intense scientific scrutiny. Some researchers hypothesize that sonar signals and other forms of man-made underwater noise pollution may significantly contribute to stranding events. Military operations utilize low and mid-frequency active sonar to detect submarines and for various acoustic exercises. While not universally harmful to all marine species, these frequencies can be lethal to some. Exposure to low-frequency sonar can cause hemorrhaging in susceptible animals, while others may beach themselves in a desperate attempt to escape the distressing sound. Mid-frequency sonar poses a particular threat to Cuvier’s beaked whales, potentially inducing decompression sickness. This condition, resulting in tissue damage from gas bubble lesions, may occur because sonar exposure triggers panic, causing whales to surface too rapidly. Alarmingly, mass strandings of beaked whales have been observed to occur almost exclusively in conjunction with sonar testing activities.
If you encounter a marine mammal that appears injured or stranded, it is crucial to refrain from attempting to push it back into the water. Stranded animals are often ill or injured and require the specialized assistance of trained responders. Instead, please immediately contact the FWC Wildlife Alert Hotline at 888-404-3922 or the Southeast Region Stranding Network at 877-WHALE HELP (1-877-942-5343).
For those passionate about the well-being of Florida’s marine mammals, consider supporting conservation efforts through a donation to the Marine Mammal Fund. Contributions directly aid in the protection of these magnificent species and support vital research aimed at deepening our understanding of their lives and behaviors.
