In recent days, experts have discovered the bodies of 120 river dolphins in a tributary of the Amazon River near Manaus. It is believed that the cause of death is likely due to the extreme drought and high temperatures in the area.
According to researchers, the unusually low levels of rivers during a severe drought have caused water temperatures to rise to levels that are too hot for dolphins to tolerate. As a result of the lack of oxygen in the water, numerous fish have perished in recent times on the Amazon rivers.
The pink-hued Amazon river dolphins are a rare type of freshwater creature that can only be found in the rivers of South America. They are among the few remaining species of freshwater dolphins in existence, but their slow reproductive cycles put them at a higher risk of danger.
Amid the stench of decomposing dolphins, biologists and other experts in white personal protective clothing and masks continued on Monday to recover the dead mammals from a lake and conduct autopsies on the carcasses to determine the cause of death.
The researchers are uncertain if the increase in dolphin deaths is due to drought and high temperatures. They are investigating other potential factors, like a bacterial infection that may have caused the deaths of dolphins in a lake formed by the River Tefé before it reaches the Amazon.
Approximately 70 animal carcasses were found on Thursday as the water temperature in Lake Tefé rose to 39 degrees Celsius (102 degrees Fahrenheit), which is over 10 degrees higher than the usual temperature at this time of year.
Experts expressed concern as the water temperature dropped for a brief period, but then increased again on Sunday to 37 C (99 F).
Environmental advocates attribute the atypical circumstances to the effects of climate change, which increases the frequency and intensity of droughts and heat waves. The impact of global warming on the current drought in the Amazon is uncertain, as other factors like El Nino also come into play.
In the past week, Miriam Marmontel, a researcher at the Mamiraua environmental institute, recorded 120 carcasses. The institute’s research is dedicated to the mid-Solimoes river basin.
According to the speaker, approximately 80% of the carcasses found in Lake Tefé are pink dolphins, known as “botos” in Brazil. This may account for 10% of the total estimated population.
The tucuxi, also known as the boto, is listed as a threatened species on the red list of the International Union for Conservation of Nature.
Marmontel expressed concern that a 10% loss rate is significant and could potentially endanger the survival of species in Lake Tefé.
The Chico Mendes Institute for Biodiversity Conservation in Brazil has quickly sent out a team of veterinarians and specialists in aquatic mammals to save any remaining dolphins in the lake. These dolphins cannot be relocated to a colder river until scientists confirm that the deaths are not caused by bacteria. – Reuters