The ability to correctly identify specimens to their corresponding species is of the utmost of importance to biodiversity conservation efforts. For traded species, morphological identification in the field can be challenging due to the caught individuals’ physic integrity or even the natural high similarity among closely related species.
During fisheries procedures, the captured individuals’ heads, viscera, and fins are frequently cut off to better preserve the fish; this makes it difficult to identify the captured species because it removes key morphological features for a reliable identification that could even serve to mask the illegal capture of protected species and also avoid surveillance. Furthermore, sharks and rays are usually sold by their popular trade names and not by the scientific names, which complicates the efforts to inhibit the consumption of endangered species. The combination of these procedures makes monitoring of captured species even more difficult and highlights the need for new alternatives.
Sharks belonging to the angel shark group, genus Squatina, are represented by three species in the southwestern Atlantic listed in the IUCN Red List as “Endangered,” and they are also currently protected under Brazilian law, which prohibits their capture and trade. Nevertheless, the angel sharks’ morphological identification is problematic due to the high similarity among the species. This could trigger a problem for the management of these endangered sharks since the correct management of any species is based on the ability to precisely identify them and the ability to quantify its capture. Nowadays, DNA-based tools are been applied coupled with traditional morphological techniques for an Integrative Taxonomic approach, particularly in cases where traditional methods fail.
Our research group has already published studies using genetic markers to evaluate the illegal trade of protected species, such as guitarfishes, in 20121. The study revealed the illegal capture and trade of the guitarfish, Pseudobatos horkelli, from the northern region of Rio de Janeiro to the border with Uruguay in the Rio Grande do Sul; as a result, the protected guitarfish comprised 56% of total sampling in Brazil. To support the use of techniques of DNA-based identification, DNA barcoding gained the scientific community’s attention in 2003 when a research group at the University of Guelph published a paper entitled, “Biological identifications through DNA barcodes2” that proposed a new species identification and discovery system using a short DNA fragment from a standardized genome region which contains enough variability to identify different species.
Following the same problem encountered with the guitarfish, the DNA barcoding methodology was applying in our study, “The fishing and illegal trade of the angel shark: DNA barcoding against misleading identifications,” published in the Fisheries Research Journal in 2018 in order to investigate potential trading of endangered species along the São Paulo coastline in southeast Brazil. The study was made by a collaboration between the Laboratório de Genética Pesqueira e Conservação (GenPesC) from the Universidade Federal de São Paulo (UNIFESP), Baixada Santista Campus and the Laboratório de Biologia e Genética de Peixes (LBGP) from the Universidade Estadual Paulista “Júlio de Mesquita Filho” (UNESP), Botucatu Campus costed by the São Paulo Research Foundation (FAPESP).
This study identified a total of 75 specimens of the Spiny angel shark, Squatina guggenheim, five of the Hidden angel shark, Squatina occulta, as well as an unexpected species, five individuals of the Brazilian guitarfish Pseudobatos horkelii, listed as “Critically Endangered” species. The identification was possible through the DNA sequencing of muscle tissue samples, labeled as “cação-anjo,” a Brazilian common name for these species, from different fisheries’ landing sites. Our results highlighted a weakness in the current evaluation methods for fishing regulation in Brazil and revealed the continuous fishing and commercialization of endangered protected species. Thus, giving clear evidence that the current conservation and monitoring measures are not efficient to prevent or inhibit illicit environment acts in Brazil.
Furthermore, the Brazilian fisheries catch data statistical system fell apart in 2007, and since then there was no standardized method to generate a national fisheries catch-data, the most basic information to build reliable management and conservation plans for sustainable fisheries activity. So, the implementation of DNA-based techniques in order to identify the captured species of fisheries products could improve the sustainable fisheries management and endangered species conservations avoiding their illegal trade, and also supplying authorities with a powerful and reliable tool to improve wildlife trade surveillance and fisheries statistics.
These techniques have a reduction in costs and are now accessible and could be implemented on large-scale, even in developing countries such as Brazil. Our results demonstrate that endangered species are still now illegally captured and traded without an effective response of authorities what raise awareness about environmental laws flexibilization, such as the Ministerial Ordinance nº 445, the Brazilian Red List of Threatened Species. These results should be considered before any environmental law flexibilization. Furthermore, the Government should base its actions on scientific results and not only on lobby interests of the Fishing Sector in order to avoid a reduction in marine wildlife protection and promote sustainable fishing activity.
To sum up, the DNA barcoding methodology is fundamental for conservation efforts and fisheries management. In addition, it has become very effective in the quantification of exploited natural populations, evaluation, and inspection of endangered trade species, as well as the certification of processed products. It’s imperative to emphasize the applicability of science results to provide alternatives to current issues, improve regulations, and monitor for illegal wildlife trade.
These findings are described in the article entitled The fishing and illegal trade of the angelshark: DNA barcoding against misleading identifications, recently published in the journal Fisheries Research. Prof. Dr. Fernando is the head of the laboratory and all the projects are under his supervision. The study was part of the Scientific Initiation project by Ingrid Bunholi.
- Alexandre de‐Franco, B., Fernandes Mendonça, F., Oliveira, C., & Foresti, F. (2012). Illegal trade of the guitarfish Rhinobatos horkelii on the coasts of central and southern Brazil: genetic identification to aid conservation. Aquatic Conservation: Marine and Freshwater Ecosystems, 22(2), 272-276. https://onlinelibrary.wiley.com/action/cookieAbsent
- Hebert, P. D., Cywinska, A., Ball, S. L., & DeWaard, J. R. (2003). Biological identifications through DNA barcodes. Proceedings of the Royal Society of London. Series B: Biological Sciences, 270(1512), 313-321. https://royalsocietypublishing.org/action/cookieAbsent
- Bunholi, I. V., Ferrette, B. L. S., De Biasi, J. B., de Oliveira Magalhães, C., Rotundo, M. M., Oliveira, C., Foresti, F. & Mendonça, F. F. (2018). The fishing and illegal trade of the angelshark: DNA barcoding against misleading identifications. Fisheries Research, 206, 193-197. https://linkinghub.elsevier.com/retrieve/pii/S0165783618301541