A study published in the Regional Studies in Marine Science journal indicates that the future of the elasmobranchs species in this region of the country depends largely on the fact that the authorities continue preventing the target capture of these cartilaginous fish, as is done today. Giving some opportunity to the extraction of these important marine animals, could put their sustainability at risk.
Colombia’s National Authority of Aquaculture and Fisheries (AUNAP) (Autoridad Nacional de Acuicultura y Pesca) through Resolution 1743 of 2017, drastically prohibits target fishing of sharks and rays, as well as shark finning (practice consisting of cutting off a live shark's fins and throwing the animal back into the sea). According with this regulation, the capture of these fish is only allowed if they fall into fishing gears incidentally (accidentally) and up to a maximum of 35 percent of the total resources caught during the fishing operation. The exception is in the Archipelago of San Andrés, Providencia and Santa Catalina, where these incidental captures (by-catches) cannot exceed 5 percent of the total capture.
This legislation seeks to avoid the intentional or target extraction of these elasmobranchs, as they are also known, to maintain their populations and reduce their vulnerability. This regulation takes into consideration that sharks are important species in marine ecosystems and many of them help to regulate the populations of other species in the ocean.
It is a legally justified policy for their protection and now academically supported by a group of researchers based on a study recently published in the Regional Studies in Marine Science journal. The research indicates that any type of industrial fishing directed to their capture in the insular territory of the Caribbean, which includes the Seaflower Biosphere Reserve – one of the largest marine conservation areas in the world –, could impact them and reduce their populations until they could become endangered.
Sharks have been in the oceans for approximately 400 million years and have resisted climatic changes and environmental impacts throughout the planet’s history. But due to human action, they currently have the highest percentage of threatened marine species in the Red List of the International Union for Conservation of Nature (IUCN), as explained in the website of Oceana, international organization dedicated exclusively to the protection of the world’s oceans.
“Many shark species do not withstand high fishing pressures, among other reasons, because they have a late maturity (many years after their birth), have few offspring, and reproduce once every one, two or even three years”, explains Paola Mejía, marine leader of WCS Colombia and co-author of the study ‘Effect of a precautionary management measure on the vulnerability and ecological risk of elasmobranchs captured as target fisheries’, led by the Squalus Foundation and with the participation of researchers from the Regional Corporation for the Sustainable Development of the Archipelago of San Andrés, Providencia and Santa Catalina (Corporación Regional para el Desarrollo Sostenible del Archipiélago de San Andrés, Providencia y Santa Catalina) (Coralina), the Secretariat of Agriculture and Fisheries of the Archipelago Governorate (Secretaría de Agricultura y Pesca de la Gobernación del Archipiélago), the Ministry of Environment and Sustainable Development (Ministerio de Ambiente y Desarrollo Sostenible), the Ministry of Foreign Affairs (Cancillería) and Conservation International (CI).1.
The whale shark is saved
The research analyzed the vulnerability and the ecological risk of 13 shark species and two ray species, comparing two periods: one with target fishing – concentrated especially between years 2000 and 2009 – and the second in which that capture had already been prohibited. It analyzed two aspects: biological productivity that deals, among other things, with reproductive cycles and the susceptibility of these marine animals to fishing pressures.
Regarding productivity, the biennial or triennial reproduction (once every two or every three years respectively) of most sharks of this insular zone was confirmed. Also, they require a long time to reach sexual maturity. They are viviparous, that is, the offspring develop within the mother’s body and are born well developed, miniature adults. This implies that their populations will always need a long time to replace the individuals caught in fishing activities, as their potential for recovery is low.
Regarding susceptibility, of the 15 species analyzed, only one remained unaffected by fishing pressures: the whale shark. But other nine species, among which is the Caribbean reef shark (Carcharhinus perezii), are more easily captured and impacted.
Other sharks susceptible to fishing activity are the bull shark (Carcharhinus leucas), the silky shark (Carcharhinus falciformis), the lemon shark (Negaprion brevirostris), the mako (Isurus oxyrinchus), the great hammerhead shark (Sphyrna mokarran), the tiger shark (Galeocerdo cuvier), the blacktip shark (Carcharhinus limbatus) and the scalloped hammerhead shark (Sphyrna lewini).
Some species that did not show a high vulnerability, but could not withstand extraction processes indefinitely, are the Caribbean sharpnose shark (Rhizoprionodon porosus), the smooth dogfish (Mustelus canis), the nurse shark (Ginglymostoma cirratum) and the rays spotted eagle (Aetobatus narinari) and southern stingray (Hypanus americanus).
Two decades ago, shark fishing in this insular department was intense and catches of up to 120 tons per year were recorded; this, in a region where the consumption of their meat is not a priority. Fortunately, attending the request of the communities, the Council of State, through a verdict of popular action (sentence 0088 of September 2012) ordered the main authorities of the Department to implement protective measures to stop this practice that violates the collective rights to have a healthy environment and achieve an ecological balance that guarantees the conservation of the species.
To date, this order has been complied, but there is no certainty that, in such a large marine area, there is no illegal fishing. Therefore, another of the conclusions of the research, explains Paola Mejía, is that decision makers should maintain the prohibition of directed fishing, in consensus with local fishermen, and that surveillance and control of vessels that do not respect the legislation should be strengthened. Simultaneously, the research recommends the design of projects or ventures, for example, related to recreational diving and ecotourism, to give the locals alternative sources of income and to highlight and raise awareness of the importance of the protection of these species.
1.The authors of the study were Paola A. Mejía-Falla, of WCS Colombia; Andrés Felipe Navia, of the Squalus Foundation; Erick Castro, of the Regional Corporation for the Sustainable Development of the Archipelago of San Andrés, Providencia and Santa Catalina (Coralina); Carlos Ballesteros, of the Ministry of Foreign Affairs of Colombia; Heins Bent Hooker, of the Direction of Marine, Coastal and Aquatic Resource Matters (DAMCRA) of the Ministry of Environment and Sustainable Development; Juan Pablo Caldas of Conservation International Colombia (CI) and Anthony Rojas, of the Secretariat of Agriculture and Fisheries of the Governorate of the Archipelago of San Andrés, Providencia and Santa Catalina.