By Syed Muhammad Abubakar
GWADAR: It was back in 2008 when a study conducted by Pakistan’s National Institute of Oceanography (NIO) titled “The Impact of Sea Level Rise on Pakistan’s Coastal Zones – In a Climate Change Scenario” presented alarming statistics on sea level rise in Pakistan. The study showed that the Mean Sea Level (MSL) is slowly but gradually rising at a rate of about 1.1 mm/year. The authors of this study warned that a sea level rise of about 2 meters is expected to submerge an area of approximately 7,500 sq. km. in the Indus delta.
Sea level rise can be more disastrous, if it’s accompanied by amplified recurring storms which can result into devastating floods. Sea level rise can also lead to stronger wave action, higher tidal amplitude and greater possibility of storm surges that can affect the wildlife inhibiting these coastal areas. The NIO study further confirmed that these extreme weather events have been witnessed in many parts of Balochistan, where the low-lying areas are highly vulnerable to even minimal changes in sea level rise.
Jiwani, a coastal town in Gwadar, has a healthy population of mangroves and it also offers potential habitat for wildlife, including the endangered olive ridley and green turtles.
Marine turtles are in the long list of those species whose survival is at the stake due to anthropogenic climate change and studies have confirmed that climate change may lead marine turtles to extinction. It is affecting their nesting sites in the Caribbean Islands and with a minimal 0.5m sea level rise, one-third of the beach area of Caribbean states could be lost, resulting into unprecedented loss for the populations of various species of marine turtles and their nesting sites.
The IPCC AR5 Report clearly highlights that ocean thermal expansion and glacier melting have been the significant contributors to sea level rise, as it is very likely that the global mean sea level rise was 1.7 mm/year between 1901 and 2010, whereas between 1993 and 2010, the rate was 3.2 mm/year.
Marine turtles have been deeply studied in Pakistan. It was possibly Murray in 1884 to be the first to report on marine turtles in Pakistan by informing that the marine turtle species of olive ridley turtle and green turtle are found in Sindh. Whereas Shockley in 1949 reported green turtle from Jiwani, Balochistan, where he highlighted major feeding and nesting sites of the species. Due to their healthy population, the locals used to call a part of the Jiwani Peninsula as ‘turtle cliff’, presently Daran.
Increased temperatures altering turtle sex
Marine turtles being cold blooded species are affected by temperature shifts on the nesting beach, as the temperature of the sand helps to determine the sex of turtles. Generally, the eggs laid in the depth of the sand, which is the cooler part, hatch to become males, whereas the eggs in the upper part, which is the warmer area of the nest, hatch to become females. Scientists predict that there will be more female than male hatchlings, which can disturb the genetic diversity of sea turtles. Warmer oceans can even affect the availability of food for these ancient species.
Daran beach in Jiwani is one of the virgin beaches of Pakistan that are yet to be explored by the people of this initiative. Jiwani is an important habitat for marine turtles, as confirmed in a research.
The nesting of green turtles, one of the species of marine turtles, on Daran beach starts in August and continues till March, with peak between August and November. The author of this research Moazzam Khan, who works as a technical advisor on marine fisheries at World Wide Fund for Nature-Pakistan (WWF-Pakistan) in a conversation with Data Stories informed that ‘Climate change impacts on Daran beach are not very visible at this stage’. He continued that, “In future with unprecedented sea level rise, it can possibly impact the marine turtles and their nesting sites as well.”
Tariq Zehri, Director General, Balochistan Environment Protection Agency (BEPA) talking to Data Stories said: “Daran beach faces the problem of coastal erosion due to sea level rise which actually began three to four decades back when the sea started to encroach upon some areas and retreated in some. Especially at Daran the sea has intruded inland due to which the sandy beaches are threatened, which means that there will be lesser space for marine turtles to lay eggs.” He further said especially the green turtles which were already listed as endangered in the IUCN Red List of Threatened Species would get further threatened.
Tariq further informed that the provincial government of Balochistan was currently working on a proposal in collaboration with WWF-Pakistan for submission to Green Climate Fund (GCF), which also focuses on dealing with coastal erosion alongwith empowering coastal livelihoods.
The Makran coast anomaly
Dr. Ghulam Rasool, the director general of Pakistan Meteorological Department (PMD) had a different opinion to share. He explained that the impact of sea level rise on Makran coast would not be substantial, as increasing temperatures of the sea will blow stronger winds in the Arabian Sea that would push sea water from western (Makran) coast towards eastern (Sindh) coast.
“However global warming will make the coasts of Jiwani and Gwadar vulnerable to tropical cyclones and storm surges, which will increase coastal erosion, thus endangering the habitat of marine turtles,” Dr. Ghulam Rasool cautioned.
How temperature rise is producing more female turtles?
Over the course of investigation it was learnt that the ideal temperature for Temperature-Dependent Sex Determination (TSD) is 29°C, as both males and females are produced in equal proportions. Above 29°C mainly females are produced, whereas below 29°C more males are born. Through the lens of climate change, it means that more sea turtles will be females in future. In the short run, over the next two to three decades, it is not going to be a problem and may even benefit the turtle populations, as with more females produced, there will be more females laying eggs, thus leading to population expansion of marine turtles. However, in the long-run, in the next century or afterwards, the situation may get out of hand, as there will be lesser males left to mate with a humongous population of females, therefore marine turtles might face extinction in future.
Furthermore, as sea turtle eggs hatch in a relatively narrow thermal range, which revolves around 29°C temperature, therefore if incubation temperatures are too low, the embryo does not develop and if the temperatures are too high, then even the development of embryo fails.
Significant researches aren’t available in Pakistan which fully confirm that marine turtles are vulnerable to climate change and the research community of Pakistan must investigate it thoroughly. Not to forget that Pakistan is ranked on seventh position in the list of top ten countries most vulnerable to climate change, even though its emissions are less than one percent in the global carbon trajectory.
However in order to cater its development requirements and dealing with the looming energy crisis, the country is setting up coal-fired power plants across the country, including a 300 MW coal power plant in Gwadar district. The national emissions will increase to fourfold due to this, which will further increase Pakistan’s vulnerability to climate change and eventually endanger the survival of Daran beach and marine turtles that call Daran its home.
Main image: Canva
Syed Muhammad Abubakar is an international award-winning environmental writer with an interest in climate change, deforestation, food security and sustainable development. He tweets @SyedMAbubakar and can be reached via email@example.com