Last month, the University of the Philippines-Diliman College of Science (UPD-CS) reported the declining population of dolphins in Tañon Strait, a body of water in the Visayas that is known to harbor a variety of amazing mammals, including rare whales and dolphins.
This was based on the survey the UPD-CS conducted in the strait from July 20 to 23, focusing on dolphin populations within its southern part.
“The initiative revealed deeply concerning trends, such as a decrease in dolphin numbers, a reduction in species diversity and evasive behavior possibly linked to increasing human activity in the area,” the UPD-CS reported.
Fewer, more elusive dolphins
In a news release, Dr. Lemnuel Aragones, head of the UPD-CS Marine Mammal Research and Conservation Laboratory (MMRCL) that conducted the survey, said the number of spinner dolphins recorded by the team was fewer compared to past their years’ undertakings.
Earlier surveys witnessed vibrant gatherings of diverse species of cetaceans—including numerous kinds of dolphins and species of whales, with groups of as many as 100 individuals spotted in a single day.
However, the recent survey was starkly different, showcasing only three species—spinner dolphins, common bottlenose dolphins and dwarf sperm whales.
Only between 80 and 90 individual spinner dolphins were encountered throughout the four-day survey, compared to 100 in just one day.
Aragones added that the team observed the evasive behavior of the dolphins—which is a sign of possible stress or disturbance due to the persistent presence of aggressive dolphin-watching boats.
Overfishing
By the definition of the Fisheries Code and Amended Fisheries Code, Tañon Strait—that separates the islands of Negros and Cebu in the Visayas—is a municipal fishing ground, hence off-limits to commercial fishing.
Municipal fishing grounds are the areas between the shorelines and 15 kilometers (km) toward the sea.
The areas are for the exclusive use of small, mostly subsistence fishermen, who have limited capacity to fish in distant waters.
Protectors of Tañon Strait have complained against overfishing in the area, a very important fishing ground both for Negrenses and Cebuanos.
Oceana Philippines, an international nongovernment organization advocating for sustainable fishing practices to conserve the world’s oceans, said commercial fishing vessels have been frequenting the Tañon Strait in the past.
The group is also pushing for the implementation of the Amended Fisheries Code and the enforcement of monitoring devices in commercial fishing vessels to detect the behaviors of commercial fishers.
Tourism woes
To generate jobs and livelihood opportunities, local governments in Negros and Cebu promote ecotourism in Tañon Strait, including whale and dolphin watching.
Lately, Aragones said his team observed a notable change in the behavior of dolphins, a possible sign of stress or disturbance, probably due to the persistent presence of aggressive dolphin-watching boats.
Aragones and his team, who have been monitoring the region since 1997, observed a significant increase in the number of dolphin-watching boats.
Although he noted that the area now hosts around 60 boats, down from the original 260, he still fears that this may still be too much.
“Too many dolphin-watching boats in the area disrupt the cetaceans’ habits,” he said. Marine mammals like dolphins and whales belong to cetacean family.
Less fish, less dolphin food
Aragones suspected that overutilization of the area’s resources is a contributing factor to the decline in the dolphin population.
“There should also be a comprehensive assessment of fisheries resources in the entire strait as there is clearly less food now for these creatures,” he explained.
To preserve the delicate ecosystem and to safeguard the remarkable marine mammals in Tañon Strait, the scientists have proposed several measures, including a moratorium on adding more boats to the already existing fleet.
They also underscored the need for a comprehensive assessment of fisheries resources, including fishing activities in Tañon Strait, as a decline in food availability may be exacerbating the dolphins’ struggles.
Furthermore, strict monitoring and regulation of illegal unreported and unregulated fishing practices in the area are necessary.
Sustainable tourism practices needed
The marine mammal expert emphasized the importance of educating boat operators on responsible dolphin-watching protocols.
He said a certification process that trains operators to navigate around dolphins without causing stress could play a pivotal role in protecting the charismatic animals.
Research also suggests that previous ecotourism activities negatively impacted dolphin behavior, reinforcing the need for responsible and sustainable tourism practices.
Tañon Strait is not the only area affected by unsustainable tourism practices.
Beach resorts like Boracay, El Nido, Puerto Galera and other popular tourist spots have experienced environmental degradation.
Not far from Tañon Strait, the Cebu whale shark watching in Sorsogon and Oslob have led to disturbances of ecosystems and altered behaviors of the whale sharks.
In Sorsogon, tourists on boats chase whale sharks to get a glimpse of the huge docile creature, and swim close to them for photo opportunities.
In Oslob, Cebu, whale sharks are fed to make them stay in the area, altering their supposedly “wild” behavior of filter-feeding plankton in coastal areas, and later on migrate to other areas as they tend to be more dependent on the food provided by tourist operators in the name of “eco-tourism.”
Protected area
Known as the Tañon Strait Protected Seascape, it is a Protected Area by virtue of Proclamation 1234 of 1998.
The area is about 160 km long. It connects the Visayas Sea in the north to the Bohol Sea in the south. Its width varies from 5 km to 27 km, with the narrowest point in the south.
With an area of more than 5,000 sq km, it is the largest marine protected area in the country and is supposed to be protected by the Department of Environment and Natural Resources (DENR), which implements the Expanded National Protected Areas System (E-Nipas) Act.
Demystifying dolphin population decline
Theresa Mundita S. Lim, executive director of the Asean Centre for Biodiversity (ACB), said there are several reasons that may cause the decline of cetacean populations.
“Pollution is one. Marine debris, such as plastics can be ingested by dolphins, which mistake them for jellyfish and other sea creatures that they feed on,” Lim told the BusinessMirror in an interview via Messenger on August 21.
Lim, a biodiversity expert, said ghost nets can also entangle large marine wildlife like dolphins, and cause them to drown.
Worse, she said oil spills may also suffocate large marine wildlife, driving them away, the same way that noise pollution can also drive them away.
“Noise can disorient them, thus, affecting their normal movement, driving them away, and could even result in strandings,” Lim said.
Meanwhile, she said severely polluted waters due to chemicals, or high levels of bacteria from domestic waste, can cause various diseases.
Lastly, any form of disturbance, such as irresponsible tourism can drive away their populations and they may choose to travel through other routes.
According to Lim, Asean is known to host an assortment of dolphin species. Spinner dolphins, she said, naturally occur in other parts of Southeast Asia.
“They migrate across the waters of Indonesia, Malaysia, and the Philippines, as they are found within the Coral Triangle area,” she said.
Alarming, sad
Reacting to the UPD-CS report, Oceana Philippines Vice President Gloria Estenzo-Ramos said the declining population of dolphins and what is happening now in Tañon Strait is both alarming and sad, but said it is not surprising.
“I am not surprised by this development. There still seems to be no sense of stewardship and genuine sense of responsibility to enforce the Enipas Act, and Fisheries Code, to name a few, and the management plan duly approved by DENR under the sterling leadership of then-BMB [Biodiversity Management Bureau] Director Mundita Lim and DENR 7 Regional Director [Isabelo] Montejo,” Ramos, an environmental lawyer, told the BusinessMirror on August 21.
Stronger law enforcement
Ramos said there’s a need to revive policies and programs that strengthen protection in Tañon Strait.
“We would like to see the Coastal Law Enforcement in Region 7 [CLEAR 7] to be active again. The Tañon Strait Protected Area Management Board met regularly and approved the resolution to require vessel monitoring measures for all commercial fishing vessels transiting in Tañon Strait,” Ramos said.
Ramos’s leadership in Oceana saw the creation of many Bantay Dagat (Sea Patrol) volunteer groups in Negros and Cebu, among its various initiatives to protect this very important body of water.
According to Ramos, Cebu province under then-Gov. Hilario Davide III became the first province to require vessel monitoring.
She added that climate change aggravates the impacts of “human indifference, apathy and greed in illegally, shamelessly and recklessly exploiting our declining marine resources.”
Ramos agreed that plastics and water pollution abound.
She said, “Sadly, the ecological dots are still to be connected, especially by the duty holders, the government, except for a few.”
Ramos pointed out: “The call now is not to wait for duty holders to do the right thing. We have to be that society that we long to be and future generations deserve—less talk, more action—a mantra for all who still cares.”
Overfishing, unsustainable tourism threaten Tañon Strait
Source: News Paper Radio
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