Colombia: Scientists explore remote seamounts to protect hammerhead sharks

In 1995, when Colombia protected the island of Malpelo by setting up the Malpelo Fauna and Flora Sanctuary, the area had a recorded 43 species of crustaceans, six species of starfish, and 70 species of fish. These figures, the only ones available, were from 1972, when the Smithsonian Tropical Research Institute led its first expedition to the island.

Over time, scientists carried out more expeditions, and the number of recorded species grew. By 2016, the National Natural Parks System of Colombia had cataloged 1,500 animal species in the area. Nine of them “are not found in any other part of the world … and about 40 species are threatened or vulnerable,” according to a parks system press release.

Yet a large part of the life cycle and the ecology of some of these species remained unknown, especially for migratory species like the scalloped hammerhead shark (Sphyrna lewini), which visits the island frequently. For example, no one knew the routes by which the sharks in this population move through the sea, how deep they swim, where else they congregate, the locations of all their breeding areas, or their relationships with other populations of scalloped hammerheads. Today, after more than 20 years of work, researchers from the Malpelo and Other Marine Ecosystems Foundation, a Colombian NGO, have found answers to some of these questions.

United within a strategic ecosystem

Malpelo Island is Colombia’s westernmost point, located about 500 kilometers (310 miles) off the Pacific port city of Buenaventura. Getting there takes a 36-hour boat ride, and those who make the journey need authorization from the National Natural Parks System of Colombia before they can admire the island’s impressive marine biodiversity and study its secrets by diving. However, many people also enter the area illegally to hunt for the most abundant species of shark around the island: the scalloped hammerhead, a species considered critically endangered on the IUCN Red List.

When the foundation was created in 1999, one of its first tasks was to monitor and prevent illegal fishing — the main threat to this ecosystem — as well as bycatch and overfishing, which occur outside the protected area. This work continues today with support from philanthropists and government entities. However, it wasn’t until 2004, when the island’s importance at a regional level as a linkage between coastal and oceanic ecosystems became clear, that scientific expeditions and monitoring began with force.

Part of this work began alongside scientists from neighboring countries that make up the Eastern Tropical Pacific Marine Corridor (known by its Spanish acronym, CMAR): Ecuador, Costa Rica, Colombia and Panama. The team — led by foundation director Sandra Bessudo, James Ketchum of the Mexican non-profit Pelagios Kakunjá, and Peter Kimley, at the time a professor at the University of California — decided to conduct all of their expeditions using the same technology so they could compare and share the information. They chose to use satellite telemetry and acoustic telemetry to track the sharks’ movements. With this technology, they began monitoring and sharing data about the sharks that entered and exited the waters of the Galápagos Islands (Ecuador), Cocos Island (Costa Rica), Coiba Island (Panama) and Malpelo Island (Colombia).

“It was very important to know the movement of these sharks, especially understanding which places are their feeding areas, their breeding areas, and where they travel through, with the goal of protecting them, because they do not only live in one country; they are highly migratory,” said Bessudo, the scientist who signed the documents to promote the declaration of Malpelo as a protected area during the administrations of former Colombian presidents César Gaviria and Ernesto Samper. “It is important to have regional information so that all these countries can protect these species.”

Felipe Ladino Archila, an ecologist with the Malpelo Foundation, is tasked with tagging the scalloped hammerhead sharks. Ladino said satellite telemetry consists of implanting a GPS device into a shark’s dorsal fin. This work must be done without diving equipment and using only one’s lung capacity, to avoid frightening the shark. Once attached to the animal, the device sends information to the Argos satellite system about the date, the shark’s location, its temperature, and its depth in the water. A Malpelo Foundation team then processes this information.

Acoustic telemetry, which also functions using a device attached to the shark, can provide similar information about the shark’s journey, but over a longer period of time. These devices can last up to 10 years, sending information from wherever the shark has visited, as long as there are receivers in the area. Unlike satellite telemetry, sound receivers that have been installed around the islands and along the Colombian Pacific coast receive the information. “With this method, we’ve shown the connectivity of sharks that have been tagged at other sites and that have arrived in our area years later. We detected a scalloped hammerhead shark [that had been] tagged in Malpelo that was at Cocos Island, [and] in the Galápagos, but also traveling toward the mainland,” Bessudo said.

From these initial alliances between researchers from the region, the MigraMar network was created. Today, it comprises 22 scientists and more than 30 partner institutions, including the Malpelo Foundation. The team has managed to identify some of the scalloped hammerhead sharks’ breeding areas and monitor their journeys as they venture toward the oceanic islands of the eastern tropical Pacific. The network has also shown the importance of creating protected corridors, routes that are free of fishing, so the sharks that leave the Galápagos Islands, for example, can reach Malpelo Island without being caught by fishers.

In fact, according to Bessudo, the MigraMar network influenced the creation of a MigraVía or “swimway,” a kind of protected corridor, between Malpelo Island and Coiba Island. This migration corridor has been protected since 2017, when the Colombian government expanded the Malpelo protected area toward the border with Panama, and Panama did the same with the Coiba protected area. Scientific data from MigraMar also supported the creation of a MigraVía between Ecuador and Costa Rica.

“The information that we’ve collected has been used to drive the creation of new areas like Bicentenario in Costa Rica, Hermandad and Cabuyal in Ecuador, and Malpelo and Yuruparí in Colombia,” said Erick Ross Salazar, MigraMar’s director. “The efforts of this network of scientists have also supported the expansion of protected areas like Cocos Island in Costa Rica, the Cordillera de Coiba in Panama, [and the] Revillagigedo [Islands] in Mexico.”

In Colombia, according to Ladino, the Malpelo Foundation has tagged more than 300 sharks using acoustic and satellite telemetry. “Of those, we have some sharks that continue to generate information after 10 years of being tagged. Of the scalloped hammerhead sharks that we tagged in 2018, we found that two ended up in the ports of Panama because they were captured in the Pearl Archipelago,” Ladino told Mongabay Latam.

In the midst of this monitoring work, the Malpelo Foundation has also been responsible for counting the scalloped hammerhead sharks during underwater visual censuses to try to determine how much their populations have decreased over time. These censuses are conducted twice a year: once during the cold season, when there are more sharks, and again during the warm season, when there are fewer.

With that information, in 2021, the researchers concluded that the scalloped hammerhead shark population decreased by up to 73.3% between April 2009 and August 2019. “Basically, they’ve decreased due to overfishing and illegal fishing to collect their fins, which are later exported to Asia. Before, we had images with more than 2,000 sharks, and now, we do not find groups of more than 300 animals,” Bessudo said.

From Malpelo to the Gulf of Tribugá

In addition to monitoring the scalloped hammerhead sharks’ journeys through the ocean and determining their population, in 2015, the Malpelo Foundation set out to find the answer to a question vital to their conservation: Where are their breeding areas? The researchers began a genetic study and determined that the young sharks along Colombia’s Pacific coast were related to the adult sharks around Malpelo Island.

Later, in 2018, they tagged five pregnant female sharks to determine where they gave birth and to understand their level of exposure to illegal fishing. They discovered that the females traveled from Malpelo toward the northern Colombian Pacific coast, in the Gulf of Tribugá, to give birth.

With this information, the researchers periodically monitored the female sharks. Once these sharks approached the coast, they estimated the places with the highest probability of being breeding areas based on interviews with local residents, fishing records, and the presence of mangroves in the areas.

“After several years of work, we found that [in the Gulf of Tribugá] there is a breeding area where there are many newborn scalloped hammerhead sharks. This shows us that, from an oceanic island more than 700 kilometers [about 435 miles] away, females are arriving to have their young. And it is right there where the Tribugá Port Project was being considered, which would have been terrible for the conservation of that species,” Ladino said.

This discovery led to the researchers working hand in hand with fishing communities in the Gulf of Tribugá. According to Ladino, they are working to reduce incidental catch because the coastal communities in Chocó department, where Tribugá is located, have many artisanal fishers. “And although they do not target the sharks, sometimes [the sharks] do fall into their fishing gear, and because of this they have been very attentive to joining this process of conserving scalloped hammerhead sharks,” Ladino said.

With the help of the fishing communities, the researchers have also followed newborn sharks in breeding areas to tag them with acoustic transmitters. The information they have collected so far indicates that the sharks stay in the area for five to six months and later move toward open water — possibly toward the seamounts. It’s believed that they then use the seamounts as a launchpad to travel to Malpelo Island, Cocos Island and the Galápagos Islands.

“Today, fishers have more awareness of the need to have healthy ecosystems, and that is what we have been working on with them. When we have projects that are funded, we have had the possibility of having payments for environmental services for the fishers who support us with their information,” Bessudo said.

Discovering the importance of seamounts

Since its creation, the Malpelo Foundation has conducted more than 40 scientific expeditions. In addition to revealing new information about sharks and other resident and migratory species from Malpelo Island, all of these expeditions have been the foundation for declaring the area a UNESCO World Heritage Site in 2006 and for expanding the Malpelo protected area from 9,500 square kilometers (about 3,700 square miles) to 27,000 km2 (about 10,400 mi2) in 2017. Because of this expansion, the seamounts were protected; these ecosystems are rarely studied, not only in Colombia but throughout the world.

Seamounts are considered marine biodiversity hotspots, especially for pelagic fish species, which live in the midwater zone or close to the surface. It’s also believed that they help with nutrient transport and circulation, which are favorable for species productivity, biomass and diversity. Therefore, because they’re key feeding and resting areas for highly migratory pelagic fish species, these sites have been considered natural biological corridors.

However, “there is still very little information about the role that [seamounts] play in the conservation of species at risk of extinction, like sharks,” several researchers wrote in a 2020 article titled “Association of sharks with Las Gemelas Seamount and first evidence of connectivity with Cocos Island, Pacific of Costa Rica.”

Because of the lack of available information about these seamounts, the Malpelo Foundation has been conducting expeditions since 2019 to find out more about the species that live there and their relationships with the seamounts. Salazar of MigraMar told Mongabay Latam that in April 2022, a group of scientists from MigraMar, including Ladino, traveled to Coiba Island in Panama, which hosts a recently expanded protected area, to generate a baseline estimate of the marine resources in the area.

“We were 200 meters [about 660 feet] deep, exploring the underwater Navegador seamount. With the methodology we use, baited cameras, we were able to find a school of 70 scalloped hammerhead sharks traveling through the ocean. In Colombia, we have to work to conserve this seamount, because the data tell us that it is a unique and vital ecosystem for the connectivity of scalloped hammerhead sharks,” Ladino said.

Seamounts are a clear example of the importance of coordination between countries for the protection of these underwater biological corridors. Ladino said the Navegador seamount is located inside Colombia’s Yuruparí National Integrated Management District, which borders the Coiba Island protected area and where regulated fishing is permitted. However, because of the large number of sharks that congregate there, there may be a great deal of incidental catch. “Panama already gave all their effort; in their part of the seamount, you cannot fish, and one would hope that the same thing will happen in Colombia. Otherwise, we are sending a message that in one country you can fish and in another you cannot, and this would affect the process of conservation,” Ladino said.

The scientists have no doubts about the need to conduct more marine expeditions in the Colombian Pacific. However, carrying out these expeditions presents an enormous challenge. In addition to needing support from donors, since the expeditions are costly, researchers also need specialized equipment to descend to 300 m (about 990 ft) deep and record the species they find there with cameras. “It is difficult to study seamounts because there are no islands; you are in the open water. You also need specialized equipment, like a manned submarine with a 360-degree window, or cameras with bait,” Ladino said.

With the information that the Malpelo Foundation collects about the seamounts, its technicians hope — in the framework of the Colombian government’s goal of expanding its marine protected areas to cover 30% of its waters by the end of 2022 — that the Malpelo Fauna and Flora Sanctuary and the Yuruparí National Integrated Management District will also be expanded, as former Colombian president Iván Duque announced in 2021 at the United Nations Climate Change Conference (COP26) in Glasgow, Scotland. Bessudo and Ladino said they believe this is the only way to ensure the sharks have more safe corridors for their journeys through the ocean.

That’s a task that should be possible to undertake, because they’ve set a precedent showing that work between nongovernmental organizations, communities and public institutions is possible, according to Julia Miranda, the former director of the National Natural Parks System of Colombia who worked closely with the Malpelo Foundation on the most recent expansion of Malpelo. “Led by Sandra Bessudo, the foundation has received not only international support and cooperation for strengthening the Malpelo Fauna and Flora Sanctuary, but also support from public institutions for the expansion of the protected area,” Miranda said.

 
Banner image: Scalloped hammerhead sharks in the Malpelo Fauna and Flora Sanctuary. Image by Sandra Bessudo for the Malpelo and Other Marine Ecosystems Foundation.

This story was reported by Mongabay’s Latam team and first published here on our Latam site on June 8, 2022.

 
Editor’s note: After the original publication of this story in Spanish on Mongabay’s Latam site, Colombia announced the expansion of the Malpelo Fauna and Flora Sanctuary to more than 47,000 km2 (18,150 mi2) and of the Yuruparí National Integrated Management District to 120,000 km2 (46,300 mi2), according to the NGO Mission Blue. With this expansion, plus the creation of two additional areas conferring marine protection, Colombia achieved its goal to protect 30% of its marine territory. According to the Marine Protection Atlas, 3.8% of the country’s waters are fully or highly protected from fishing.

Article published by Rebecca Kessler

Conservation, Critically Endangered Species, Ecosystems, Endangered Species, Environment, Marine Animals, Marine Biodiversity, Marine Conservation, Marine Ecosystems, Marine Protected Areas, Oceans, Protected Areas, Sharks

Colombia, Latin America, South America

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