This post is one of a series on projects supported by the Anderson Cabot Center’s Marine Conservation Action Fund (MCAF). Through MCAF, the Aquarium supports researchers, conservationists, and grassroots organizations around the world as they work to address the most challenging problems facing the oceans. In today’s post, scientists Hamera Aisha and Gill Braulik, Ph.D., share hopeful findings from their recent study of the endangered Indus River dolphin after a recent expedition in Pakistan.
The Indus dolphin, locally known as the Bhulan (pronounced bhull-an), is an endangered freshwater dolphin found only in the Indus River in Pakistan. These dolphins are very different to their marine cousins, as they are brown and blind and have a very long rostrum, or beak. Their poor vision has evolved as a natural outcome to living in murky water. The Indus dolphin belongs to one of the most ancient families of cetaceans (whales, dolphins, and porpoises) and are not closely related to the well-known marine dolphins. Indus dolphins are endangered because their habitat has been reduced to only one fifth of its historic range. This is because of construction of barrages (gated dams) across the river that divert water for irrigation, which means little is left for the dolphins. Dolphins also become stranded in irrigation canals, particularly during the low-flow season. When the canal gates are closed and water flow stops, without rescue they generally die. An increase in intensification of fishing has also caused a large increase in dolphin deaths from entanglement in fishing gear in the last five years.
Estimating the size of the remaining population of the Indus River dolphin is of great importance to evaluate the effectiveness of conservation and management initiatives. WWF-Pakistan conducts huge survey expeditions every five years to monitor the dolphin population. These surveys are one of the major happenings in Pakistan’s wildlife conservation community due to the scale of the expeditions, the logistical and security challenges, and the high importance of estimating the dolphin numbers. Every survey also brings a great opportunity for training of both the provincial wildlife departments and university students. Early expeditions were pioneered by Dr. Gill Braulik, and now the surveys are led by WWF-Pakistan and Gill provides training in standard survey techniques. The fourth comprehensive Indus dolphin survey supported by the Marine Conservation Action Fund was conducted from March 20, 2017, to April 13, 2017. The expedition covered the three sections of the river with the largest number of dolphins (Chashma to Sukkur barrages) and included a team of 20, traveling in four boats carrying all scientific supplies, food, camping equipment, and drinking water.
Each day during the expedition, we would travel down the river in rowing boats from dawn until dusk. At first, we were able to see dolphins in small groups of two or three individuals, but as we got closer to their core habitat there were larger aggregations of as many as 30 individuals at one time. One of the best things about this survey was the passion of the researchers and the amazing team spirit: although the work was hard and the weather was hot, we are all driven by the passion of conserving dolphins. The team’s excitement whenever members spotted a dolphin was always the same as it was on the very first day, even after weeks of traveling through harsh field conditions in the remote regions in the Indus River. The magical beauty of these majestic creatures and the way they share the Indus River with humans and other biodiversity in peace make them a symbol of love and respect for those that live along the Indus River.
There were countless fascinating encounters with the dolphins during the survey that left us dazzled and speechless. One such unusual incident happened near the end of our survey. We spotted a tiny ripple in the river, but were not sure what it was until we reached it. It turned out to be a dolphin calf perhaps just a few hours old that was learning to surface to breath. It was barely the size of the length of a hand and appeared almost at the same spot over and over again every 30 to 40 seconds. We were thrilled by this sight and wondered at how much effort it must have been putting into this exercise, which seemed so smooth as if someone was lifting it up from the inside of the water. We thought that the mother dolphin should be nearby as well. Then, suddenly, we saw the mother dolphin jump high out of the water from the exact same location as the baby. Perhaps she was in the process of teaching the little one to surface and had been lifting it up from underneath in the water?
Overall, the survey results indicated a marked increase in the population of the Indus dolphin. This amazing news is worth celebrating. Despite the great news of the increase in number of dolphins, we also have a number of unsolved questions as to why the population is going up. These questions will be answered through careful research that will help us understand more about the complex relationship of these majestic dolphins with the mighty Indus River. This will give us another reason to go back to the Indus River, as deep in our hearts we now belong to the Indus River in the same way as the Indus dolphins do!