Mi experiencia en el curso de formación de pez sierra, Tumbes, Perú

Claudio Manrique

Traducido por Clara Vasquez & Ruth Leeney  

Durante la realización del curso de investigación y conservación de tiburones y rayas tuve la oportunidad de conocer –entre otros ponentes- a Ruth Leeney, especialista en el estudio del Pristis pristis o pez sierra, representante de Protect Africa’s Sawfishes (Proteja los Peces Sierra de África).

Primera vez que escuchaba sobre dicho pez, en realidad no lo había visto antes ni en fotos ni en dibujos. Tampoco en tiendas de artesanías donde suelen vender huesos de peces con picos alargados. Tampoco lo había visto como adorno en hoteles ni restaurantes.

'Rostra' (sierra) de pez sierra en el Museo de Historia Natural de Lima

De hecho -durante el transcurso de la primera semana del curso- surgió la incógnita de que podría haber algún ejemplar en algún restaurante de mi pueblo, Máncora. Llamé al dueño del restaurante El Espada donde cabía la posibilidad de encontrar algún ejemplar sea por el mismo nombre del restaurante o por referencia de algún conocedor de la zona pero tampoco nos dio razón sobre el pez sierra.

Sin embargo en las entrevistas de campo con los pescadores de la región Tumbes logramos recopilar testimonios de avistamientos de dicha especie, muy esporádicos a lo largo de las últimas cinco décadas y los más recientes durante el presente año y el año pasado en la misma época de verano austral lo cual motivo la investigación de la especie en la zona.

He aprendido a diferenciar al pez sierra del tiburón. He aprendido que existen cinco pez sierra. También he aprendido a trabajar en el campo de la investigación y búsqueda de información que ayuden a conocer más sobre el comportamiento del pez sierra mirando y siguiendo las indicaciones de Ruth y demás participantes del curso.

Un comportamiento del pez sierra que llamó mi atención fue su travesía por los estuarios posiblemente para su reproducción. A partir de ahí surgieron entretenidas conversaciones sobre la Amazonía. Ello me lleva a reflexionar que mientras más conocemos sobre una especie más conocemos del entorno donde vivimos y a la vez aprendemos a colaborar en su investigación y conservación.

Estoy muy agradecido de haber participado durante las dos semanas en las que se llevó a cabo el curso de paso aprovecho para agradecer a Planeta Océano por la beca otorgada, gracias! Por último animar a los principiantes a participar de iniciativas de conservación. En mi caso como habitante de la zona estaré atento a lo que suceda durante el fenómeno El niño que actualmente estamos experimentando.

 

Claudio (far left) and other course participants take a well-earned break after interviews with fishermen at Zorritos port.

My experience at the Sawfish training course, Tumbes, Peru

Claudio Manrique

Translated by Clara Vasquez & Ruth Leeney 

During the training course on the Research and Conservation of Sharks and Rays, I had the opportunity to meet, among other speakers, Ruth Leeney, a specialist in the study of Pristis pristis or sawfishes and representative of Protect Africa’s Sawfishes.

This was the first time I had heard about sawfishes. I had never seen them before, not in photos or drawings, in craft shops where often sell sawfish rostra (the 'saw' of the sawfish) or even in hotels or restaurants where the rostra are sometimes used as decoration. In fact, during the first week of the course, I wondered if there was perhaps a sawfish specimen at the restaurant in my hometown, called Máncora.  So I called the owner of the restaurant El Espada (‘The Sword’),  thinking the restaurant’s name might be significant, but unfortunately the owner had no information about sawfish. 

However, during the interviews we conducted with fishermen around Tumbes (northern Peru), we got testimonials of sightings and captures of sawfish in Peruvian waters, which have been very sporadic over the last five decades. The most recent sightings were during the austral summers of 2014 and this year.

Cristhian and Andres interviewing a fisherman on the beach

During the course, I learned to differentiate between sawfishes and saw sharks. I learned that there are five species of sawfish. Also I was able, by observing and following the advice of Ruth and other course participants, to perform interviews in the field and to collect information on the behaviour of sawfish. One behaviour of the sawfishes that caught my attention was their journey through estuaries, probably for reproduction. After that, we had some entertaining conversations about the Amazon. This led me to realise that the more we know about a species, the more we can know about the environment in which we live, and the more we can collaborate on researching and conserving these species.

I am grateful to have participated in this two-week course and want to thank Planeta Oceano for providing me with a scholarship to attend the course – thank you! And finally, I encourage beginners to participate in conservation initiatives. In my case, as an inhabitant of Peru’s north coast, I will now pay greater attention to what happens during the El Niño phenomenon we are currently experiencing.

Sawfish CSI: using DNA to unravel the past and protect the future

Dr Nicole Phillips and Kelcee Smith

The most distinct part of a sawfish is undeniably its saw. But this saw is also the Achilles heel of the sawfish, because it makes this iconic creature so susceptible to capture in fishing lines or nets and valued as trophies by recreational fishers. It is largely agreed on by experts that sawfishes have undergone substantial declines in range and abundance due to human activities, but the evidence for these declines is largely anecdotal. There is little information regarding past abundances of most sawfish populations, and it would seem impossible to go back in time to determine how large sawfish populations may have once been. It also seems impossible to know how ‘healthy’ these past populations were compared to the sawfish populations of today. But is it impossible? And why is it important to compare past and present populations of sawfishes?

 

A historic photo of a large number of sawfish captured by fishers.

Declines in abundance are typically also accompanied by declines in genetic diversity. Genetic diversity, in essence, is variations in DNA sequences, and when talking about genetic diversity in populations, this refers to animals in a population with different DNA sequences. Maintaining moderate to high levels of genetic diversity in a population is important because it allows a population to change and adapt to changes in the environment. Populations that have undergone drastic and sudden declines in abundance tend to have lower levels of genetic diversity, which may be less ‘fit’, more susceptible to disease, and less able to adapt in a changing environment.  If a population is very small, there may also be a risk of inbreeding, which is when close relatives mate and produce offspring that could have reduced fitness and possible birth defects, such as deformities.  

These peppered moths are the same species but differences in their DNA sequence has resulted in different physical appearances, making each more 'fit' or better suited for different environments. Genetic differences within a population may be relatively small and are not always observable.

It is important to have an understanding of the levels of genetic diversity in present day sawfish populations so we can identify and protect populations that are genetically less diverse. It is also important to understand how the levels of genetic diversity in present sawfish populations compare to those in the past to determine if these levels have declined over time. We are fortunate to have old sawfish saws available in museums, and sometimes in private collections, as these saws can be used as a resource for studying past sawfish populations. Some of these saws date back to the 1800’s and are the only remaining evidence that sawfish once existed in certain locations around the world. These old saws not only provide insights into the levels of genetic diversity of past populations, but the DNA can even be used to estimate past population sizes, which can be compared to current day sawfish population sizes to look for evidence of declines in abundance.

A sawfish saw that was kept as a fishing trophy.

Such research is not without its own set of challenges. Finding adequate numbers of samples is the first major hurdle; working closely with many researchers and museums is key. Once the samples are collected, the next set of challenges researchers are faced with is generating usable data from old saws that were not stored for DNA research. While at Murdoch University in Western Australia, and with some help from an honors research student, Dr. Nicole Phillips spent a number of years working out the best type of tissue to sample on a saw. This work included testing various ways to extract the DNA and testing different genes as well as different sizes of genes, since the DNA is often broken down into many small fragments. A lot of time was spent during this developmental phase so other researchers could take samples from rare saws efficiently and effectively. Nicole’s research into levels of genetic diversity of past sawfish populations has focused on the largetooth sawfish (Pristis pristis) and the green sawfish (Pristis zijsron) and she will be continuing this research at the University of Southern Mississippi later this year with a number of other researchers. This research will compare levels of diversity in past populations of the largetooth and green sawfishes to those of current populations to determine if there has been substantial declines in diversity (and abundance) and what may have been lost in terms of genetic diversity from regionally extinct populations around the world. 

Dr. Phillips taking tissue samples from an old sawfish saw in northern Australia.

Dr. Sabrina Taylor and Kelcee Smith at Louisiana State University are currently tackling the question of whether there has been a loss of genetic diversity, and by extension, effective population size in the smalltooth sawfish (Pristis pectinata) in Florida. They are collaborating with scientists from the National Marine Fisheries Service (NMFS) and the Field Museum of Natural History. The smalltooth sawfish is currently the only species of sawfish found in U.S. waters and is listed as Endangered (since 2003) under the Endangered Species Act. If this research finds that there has been a substantial loss in genetic diversity over time, then management efforts should focus on maintaining and increasing abundances of these sawfish, particularly in a variety of locations and habitats across their distribution in Florida.

These research projects may demonstrate that genetic diversity in sawfish populations have declined, indicating that there have been substantial decreases in abundance of sawfishes. Alternatively, we may find that the current levels of diversity have been maintained throughout the 1900’s despite the anecdotal evidence of large declines during this time period. Regardless, the opportunity to use sawfish saws in genetic analyses provides us with a glimpse into the past and provides information vital to the conservation and recovery of these sawfish species.

Sawfish, and crocodiles, and mosquitoes! Oh my! The adventures of Team Sawfish

Sweltering heat, mosquitoes, angry crocodiles and swarms of flies characterise the typical late dry season (September-November) in northern Western Australia. And it’s here that we at Team Sawfish have found ourselves for the past 13 years, as we continue our research on several species of sawfish. This past October, Dr Ruth Leeney of Protect Africa’s Sawfishes and Dr Barbara Wueringer of James Cook University decided to brave these conditions as they joined our team during our month long expedition on the Fitzroy River. 

Map of Fitzroy River (blue line) in northern Western Australia.
Map source: Google Earth

The goal of our adventure was to investigate how barriers, such as dams, may impact the movements and health of the largetooth sawfish (aka freshwater sawfish) (Pristis pristis). Fish like the largetooth sawfish that live part of their life in freshwater are more likely to be influenced by human caused disturbances (e.g. dams, mines, pollution) than their marine relatives.

The Camballin Barrage, a small weir on the Fitzroy River used for irrigation of
cattle and crops. Photo: Jeff Whitty

This work was part of an ongoing project that involves several rivers throughout Western Australia, where sawfish are known to occur. The Fitzroy River itself is an ideal site for this study. This river is one of the largest known nurseries of the largetooth sawfish. In addition, the Fitzroy River has several barriers of various sizes, including a weir (a type of dam often used for irrigation) and several road crossings. 

While a lot of our trip was spent avoiding swarms of mosquitoes and checking for crocodiles, we also managed to sample numerous pools located between the mouth of the Fitzroy River and 380 km (236 miles) upstream from the river mouth. From these pools we captured seven different sawfish. This is fewer fish than we typically see, and was largely due to the lack of captures of young of the year (YOY; fish pupped within the year). The number of YOY that we captured earlier in the year was also relatively low, which suggests this may have been a poor year for these newborns.

Myroodah Crossing, a low-relief road crossing on the Fitzroy River.
Photo: Jeff Whitty

The sawfish we did capture were 2-3+ years old (juveniles) but still averaged a length of 205 cm (6.7 feet)! In addition, the majority of these fish were recaptures of those that we had previously tagged with individually numbered Rototags (i.e. cattle ear tags). Two of these sawfish were initially tagged as YOY (i.e. 2-3 years ago). Long-term recaptures like these are rare, but allow us to gather some important information on the distribution, movements and growth of this species. Although we can collect some of this vital information during the few months of the year that we are in the field, we also rely on local and visiting fishers to report their encounters, which we are very appreciative of (see instructions below on how to report an encounter with a sawfish). 

We also tagged sawfish with small acoustic tags. These tags transmit a unique acoustic signal that can be detected and logged by receivers, which we installed throughout the river. Data from downloaded receivers can tell us when a particular sawfish was near a receiver, and what water temperature and depth the sawfish was in. This data will help us to understand sawfish movements and how they are impacted by dams.

Release of a largetooth sawfish (Pristis pristis) in the Fitzroy River.
Photo: Jeff Whitty

As well as capturing the largetooth sawfish, we had hoped and expected to find the smaller dwarf sawfish (Pristis clavata), which we have been monitoring over the last few years. Although the largetooth sawfish is the only sawfish that lives in freshwater for long periods of time, the dwarf sawfish, which lives in marine and estuarine environments, is attracted to the tidally influenced estuarine pools of the Fitzroy River in the late dry season, when these pools become more salty (around 35 ppt; similar to the ocean). During this period, we primarily find dwarf sawfish in the estuarine pools as the majority of the largetooth sawfish appear to leave the area. It is also this time of year and area that we find large and angry estuarine crocodiles. This year however, we were surprised to only find a couple largetooth sawfish and a number of crocodiles, which made sure we knew they were present. 

After a month in the sweltering heat our food supplies, energy levels and time ran out. As we left the sawfish and the river behind, our team agreed that in spite of a few minor setbacks that our trip was a success. We were able to tag a few new sawfish and collected some important recapture data. This will help us to better understand these threatened sawfish and inevitably help to advance conservation efforts for these fishes.

Although, we had to finally part ways with our esteemed and much appreciated colleagues, we had enjoyed the time spent with them and the memories of fly bites, tasty porridge, not so tasty tree sap and most importantly, the sawfish.

Pictured is the October 2014 Team Sawfish field crew. Missing are Dr David 
Morgan and James Keleher. Photo: Ruth Leeney

To report a sawfish captured in Western Australia or for more information about Team Sawfish please visit www.freshwaterfishgroup.com. 

If you encounter a tagged or untagged sawfish outside of Western Australia please visit the Sawfish Consveration Society at www.sawfishconservationsociety.org, or the International Sawfish Encounter Database at www.flmnh.ufl.edu/fish/sharks/sawfish/sawfishdatabase.html.

This research was funded by Chevron Australia and was made possible by the Western Australia Marine Science Institute.

NEW: multilingual sawfish identification guides now available and in use in multiple countries!

Five species of sawfish exist today. However, each species is under threat of extinction. Research and conservation efforts are underway in a number of countries including the United States, Australia and Mozambique. However, to the untrained eye, sawfish can be difficult to tell apart and this can hinder conservation efforts. In their ‘Global Sawfish Conservation Strategy’, the IUCN suggested that the development of a species identification guide was a necessary step to further sawfish conservation. The Sawfish Conservation Society (SCS) has therefore developed multiple guides for all species of sawfish. Already, these guides have been distributed within Australia, Peru, Ecuador, Mozambique, The Gambia and Liberia.

Fishers in Mozambique being interviewed by local researchers with the assistance of the identification guides.

The different sawfish identification guides constructed by the SCS vary in layout and depth of detail. While researchers familiar with the features of a fish may find the “Detailed” guide more appropriate and more informative, fishers with little time to spare to identify a sawfish may find the “Quick and Easy” guide more useful. Still yet, the “Poster” guide may prove to be visually more appealing when posted at a marina or boat ramp. In addition, these guides can be transformed into a brochure/tri-fold pamphlet by printing them on the opposite side of the “Pamphlet Backing” and folding in thirds.

The four different identification guides and the pamphlet backing now available on the SCS website.

Each guide lists a number of features on the sawfish body and saw that are the most useful in identifying each species. Although a single feature can sometimes be used to identify a species, it is best to use multiple features to ensure accurate identification. In addition to listing these features, when combined with the pamphlet backing, each guide presents details of how to help conserve sawfish, where to report sawfish encounters and provides information regarding the SCS.

Currently, the identification guides are available in English, Spanish, French and Portuguese. We also have plans to offer additional languages including, at a minimum, Brazilian Portuguese and Arabic. Each guide has also been formatted to fit on Letter and A4 sized paper. All guides, languages and formats are available here on the SCS website.

Students learning how to identify sawfishes during a school visit by SCS volunteers.

While the standard guides are available online in a PDF version, these guides can be customized for specific purposes. Customizations can include the addition of a company’s logo and contact details, narrowing of the number of species present on the guide (useful if only a few species occur within an area where the guides will be distributed) or translation of the guide into a specific language not yet provided. Interested parties should contact the SCS at sawfishconservationsociety@gmail.com to inquire about such changes. In addition, printing of the PDFs available online can result in some pixilation of images when printed on some printers. If this should occur, please contact the SCS at the above address and a Word document will be sent to you to remedy this issue.

Many thanks are owed to the numerous people that have helped in the making and distribution of the identification guides. Most notably, these people include Nicole Phillips and Barbara Wueringer who assisted in the design of the guides, Ruth Leeney, Vanessa Figueroa, Rachel Graham, Ruth Higgins, Jeremy Kiszka and Jaime Penadés Suay who were vital in the translation of the guides, and Dana Bethea, John Carlson, David Morgan, Jason Stapley and Dean Thorburn whose photos are displayed within the guides.

If you have a suggestion on how to improve these guides, find a mistype or would like to assist in translating these guides into another language please contact the SCS at sawfishconservationsociety@gmail.com.

Sawfish identification pamphlets available at information centers, fishing stores and truck stops throughout Western Australia.