One of the dead finless porpoises at the Kuwait beach.
What caused death of 4 beached porpoises? Human fault or accident?

Four finless porpoises (Neophocaena phocaenoides) were found dead on Kuwait beaches in the last three days. Local authorities, scientists and NGOs rushed to the sites and are trying to understand what caused the death of these animals. One of them presented with a deep laceration, leading to the hypothesis that it was hit by a boat, but the other animals didn’t present any visible cause of death. One of the animals measured 1,10m in length, confirming it as a juvenile.
Porpoises are a very distinctive group of cetaceans, somewhat dolphin-like, small and beakless, closely related to dolphins. Some anatomical and structural characteristics, such as their peg-like teeth as opposed to the conical of the dolphins separate porpoises in a different family, the Phocoenidae.

Porpoises are continental shelf animals and favour temperate seas in both hemispheres of the planet. They are generally hard to see from the surface of the sea and rarely perform acrobatics like the dolphins. They generally swim in twos or threes, avoid boats and humans and are shy animals.
The finless porpoise in particular is found in warm, Indo-Pacific waters and can be found not far from shore in the Arabian Gulf area and all along the beaches of Pakistan, India, Bangladesh, Indonesia, Vietnam, Thailand, Malaysia... Maximum lengths are reached by males and can go up to 2 meters. The usual length of an adult animal, male or female, ranges between 1.5 m and 1.7m. This porpoise’s main characteristics are the lack of any dorsal fin (hence the name “finless”), the lack of a beak and the rounded forehead, which rises steeply from the animal’s snout, often forming a bulbous “melon” above the upper lip.


What could the beached animals have died of?
The scientists are still trying to deliberate what caused the death of these animals in Kuwait. Accidental entanglement in fishing nets is the main worldwide threat to porpoises today, and accidents involving hits from jet skis or recreational craft are often happening as well. Natural causes, such as navigation errors, infection, or rough weather cannot be excluded, as big marine mammals have beached throughout human history.
There is, however, another possible cause of stranding, mainly involving mass strandings of whales and dolphins in several countries worldwide, but impossible to affect porpoises as well, as all aforementioned animals are Cetaceans and function in similar ways: The SONAR.


There is evidence that active sonar lead to beaching. On some occasions whales have stranded shortly after military sonar was active in the area, suggesting a link. Theories describing how sonar may cause cetacean deaths have also been advanced after necropsies found internal injuries in stranded whales. In contrast, whales stranded due to seemingly natural causes are usually healthy prior to beaching. The large and rapid pressure changes made by loud sonar can cause haemorraging. Evidence emerged after 17 whales beached in the Bahamas in March 2000 following a United States Navy sonar exercise. The Navy accepted blame, agreeing that the dead whales experienced acoustically-induced haemorrhages around the ears. The resulting disorientation probably led to the stranding.

Another means by which sonar could be hurting cetaceans is a form of decompression sickness.
Cetaceans may also interpret the unfamiliar sound of SONAR as a predator and change its behavior in a dangerous way, panicking and trying to escape in any way, often resulting on a beach. Multiple incidents of strandings in many corners of the earth, mainly of whales and dolphins and much more rarely of porpoises, have proven that sonar may have a “beaching effect” on these animals.
Let us hope that these porpoise deaths in Kuwait were due to natural causes or an isolated incident and the country will not experience any more in the near future.


By: Nancy Papathanasopoulou - Kuwait Turtle Conservation Project

Read By: 5634
Comments: 0
Rated:

Comments
You must login to add comments ...
About Us   |   RSS   |   Contact Us   |   Feedback   |   Advertise With Us