Hazardous Marine Life

Hazardous Marine Life

Stingrays

Stingrays are shy, peaceful fish. They do not represent a threat to divers unless startled, stepped on or deliberately corralled and threatened. Most injuries occur in shallow waters when divers or swimmers are walking in areas where stingrays reside.


Biology and Identification

Rays are closely related to sharks: class Chondrichthyes — chondr- meaning cartilaginous and -ichthyes meaning fish. It's important to note that not all rays have stingers. Stingrays are a specific group of rays classified in the suborder Myliobatoidei, which consists of eight families: deep-water stingrays, sixgill stingrays, stingarees, round rays, butterfly rays, river stingrays, eagle rays and whiptail stingrays.

The approximate stingray wingspan varies across species from 1 foot to more than 6 feet (2 meters). Some freshwater species can weigh up to 1,300 pounds (600 kilograms).

Distribution

There are species of stingrays in nearly all oceans. Some families consist of only freshwater species, which are typically found in tropical, subtropical and temperate river environments.

Mechanism of Injury

Stingrays are not aggressive by any means, and injuries are rarely fatal. The stingray's defense mechanism consists of a serrated barb at the end of its tail with venom glands located at the base of the barb. The venom is a variable mixture of substances, none of which are specific to the animal; therefore, the creation of antivenom is not possible. Stingrays will strike when threatened or stepped on. The barb can easily tear wetsuits and penetrate skin and may cause deep, painful lacerations.

Epidemiology

It is estimated that stingrays are responsible for approximately 1,500 accidents each year in the United States. Prevalence in other countries might be higher, particularly injuries associated with freshwater species, but epidemiological data is either elusive or inexistent.

Signs and Symptoms

Stingrays can inflict mild to severe puncture wounds or lacerations. The initial symptom is pain, which can be significant and intensify over several hours. Both puncture wounds and lacerations can damage major blood vessels, causing severe, potentially life-threatening bleeding. The barb usually breaks off and may require professional surgical care.




It is common for stingray wounds to become infected despite proper care. Notable possible infections include cellulitis, myositis, fasciitis and tetanus.

Prevention

  • Avoid stepping in murky or low-visibility shallow waters where stingrays naturally inhabit.

  • Stingrays often burrow in the sand, making them difficult to see even in tropical waters.

  • If you are shore diving and suspect there may be stingrays, carefully shuffle your feet while entering or exiting the water. This technique is known as the "stingray shuffle." Stingrays are very sensitive animals, and the vibrations caused by this shuffling may scare them away.

First Aid

  1. Clean the wound thoroughly.

  2. Control bleeding if necessary.

  3. Do not delay professional medical evaluation. The risk for tetanus and other serious infections must be professionally minimized.