Who I am
According to my mother, the first time I saw the sea I froze in awe and cried ‘Too much water, Mom! Too much water!’ I was two years old, city-born, and we were on the shore of the Gulf of Mexico, in that country’s Veracruz state. As she took me into the waves I began to cry. But all that changed when I was eight and had the opportunity to live by the same sea for a whole year. I fell in love with the ocean and used to daydream about being a scuba diver while my cousin Juan and I played by the sea with toy submarines, divers and sea creatures. Sharks were always the biggest thrill: majestic, mysterious and, in a child’s mind, mortally dangerous. It wasn’t until I was about 11 that I saw my first real shark in an aquarium in San Diego. Sharks remained fascinating to me throughout my studies in marine biology at the Autonomous University of Baja California in Ensenada. However, I never thought it would be possible to become a shark scientist.
But life is full of surprises. For my first job after graduation I was charged with generating the basic information needed for the sustainable management of the shark fishery of Yucatán – the defining moment of my career! Although I knew basically nothing about sharks, I immediately fell in love with them and spent nearly five years teaching myself all I could about shark biology, ecology and fisheries.
Now, 30 years, an MSc and a PhD later, I have become an internationally recognised shark expert. My passion for sharks and rays has taken me around the globe conducting field research projects, attending science, management and conservation meetings, acting as a consultant and providing training courses. Perhaps most rewarding of all was working with live great white sharks. I was responsible for initiating research into the migrations and movements of great white sharks in South Africa and New Zealand, in collaboration with local scientists and government organisations, and in this way pioneering the study of great white sharks with different kinds of satellite tags. During this time I made the greatest discovery of my career: we tagged ‘Nicole’, a female great white shark that travelled from South Africa to Australia in the first recorded transoceanic return migration for any shark species. Interestingly, that’s when I met my friend and the Save Our Seas Foundation’s (SOSF) current CEO Michael Scholl, who collaborated with us on the project and whose own research was instrumental in completing the cycle of Nicole’s return migration.
Although learning about this misunderstood, threatened and fantastically imposing fish was the highlight of my career, I have also worked in elasmobranch taxonomy and identification, fisheries data and assessment training, ecology and fisheries modelling, conservation and management.
Where I work
I have been lucky enough to work with sharks and rays while living in nine different countries (talk about a gypsy lifestyle!). However, I am currently leading two projects that have me dividing my time between Brazil and my native Mexico.
The first is a study on the spatial dynamics of devil rays in both countries. Our main study site in Brazil is an amazing, remote and inhospitable place of great beauty. The Archipelago of St Paul and St Peter sits right on top of the Mid-Atlantic Ridge, almost halfway between the easternmost tip of Brazil and West Africa – literally in the middle of nowhere! This equatorial rocky outcrop hosts a great diversity of marine life: dolphins, whales, tunas and jacks, billfishes, sharks and at least two, if not three, species of devil rays (Mobula tarapacana and M. thurstoni) and one of manta ray (Manta birostris).
The islets’ barely 15,000-square-metre (3.7-acre) jagged surface of pure volcanic rock offers no easy footing for walking around and no protection from wind or sun. There is no fresh water and we have to bring every single piece of life-support and research equipment and all our food and water on a gruelling three-day boat trip from the Brazilian port of Natal. But the research station and accommodation built here by the navy has incredible facilities, including electricity, satellite phone and of course Internet (slow and iffy, but Internet nonetheless!).
With its abundant and pristine marine wildlife, this is a unique place for research – and adventure. Just a few metres from the shoreline, the sea floor drops to a depth of more than 4,000 metres (13,000 feet). There are numerous pelagic species, including marine turtles, which are a common sight around the islets and in the inlet, the archipelago’s only shallow section. Working here and studying the majestic devil rays is truly a thrill and a privilege!
Our Mexican field site for the devil ray project is another fabulous place: the Whale Shark Biosphere Reserve at the edge of the Gulf of Mexico/Caribbean transition zone, just off the north-eastern coast of the Yucatán Peninsula. Every summer, this very special place hosts the largest known aggregation of whale sharks in the world. Because of this it also attracts large numbers of ecotourists – and they in turn bring additional threats to the ecosystem. The area is known too for its great biodiversity, which includes marine mammals, manta rays, devil rays, spotted eagle rays, various shark species, rock lobster, shrimp, four marine turtle species, many seabird species and large schools of sardines and anchovies, as well as hundreds of species of reef, pelagic and bottom fishes, and echinoderms, polychaetes and other marine invertebrates.
My second and latest project is on smalltooth and largetooth sawfishes, both of which are Critically Endangered, and it has me working all over Mexico. This exciting and challenging endeavour saw me and my team travel along the entire eastern coast and half of the Pacific coast of Mexico in 2015. In addition, I have recently surveyed some amazing sites, such as the large bays of Chetumal and Ascensión in Quintana Roo, most of the course of the Usumacinta River in Tabasco, the coastal lagoons of Tabasco and a couple of estuaries in Veracruz – all in search of the last living sawfishes in Mexico.
What I do
Both projects combine ecological and biological research with conservation efforts. Emphasis in the first is on unveiling the mysteries of devil rays: how they use different parts of the ocean and where they migrate to. We also compare the behaviour of ray species in each site and contribute to a global study led by the Manta Trust into the number of species, the relationships between different populations of devil and manta rays, and how these are exploited to supply the trade in their gill plates.
In recent years, the belief has arisen in China and eastern Asian countries that manta and devil ray gill plates possess magical powers to cure all kinds of human ailments. The trade driven by this dubious ‘traditional Chinese medicine’ is fuelling a huge increase in the fishing of these beautiful marine giants around the world. Brazil and Mexico have passed legislation protecting all manta and devil rays from fishing, but these measures are often poorly implemented. There are also many other countries that have not established similar legislation. We need to gather more accurate scientific information about the life cycle and movements of devil rays and to identify hotspots of interaction with fisheries in order to inform better implementation of conservation regulations. We also need to convince other countries that all manta and devil rays should be protected with as many types of legislation as are needed, especially now that devil rays have recently been added to Appendix II of CITES. This is why it is crucially important for their conservation that we discover where the rays go during each phase of their life cycle; how many species there are and how to recognise them; and where and which populations of each species are being overexploited.
During our field trips we deploy cutting-edge electronic satellite tags that measure depth, water temperature and light levels every few seconds. The information from the tags is relayed to us via satellites, enabling us to follow the movements of each individual ray for several months at a time. Both difficult and exhilarating, tagging the devil rays involves free diving with them in order to attach the tags to their backs by means of small darts. The tags detach automatically after a pre-programmed period and relay the information to our laptops at home. During our field trips we also try to measure and sex each individual and obtain small samples of its muscle and skin. These samples will enable us to conduct population genetic and taxonomic studies that are essential for mapping how many different species exist, their physical differences and which populations are being exploited for the gill-plate trade.
As I go to sea for each expedition, I am always filled with joy and awe at the prospect of swimming alongside these beautiful ‘flying’ sea creatures. I truly hope that with the combined efforts of everyone, we will preserve them for future generations to admire.
In my second and more recent project, I have focused my attention and hard work on saving sawfishes in Mexico – and hopefully also in countries of Central America in the near future. From a review I did in 2014 on the conservation status of sharks and rays in Mexico, I discovered that nobody had ever studied any aspect of sawfishes in my native country, even though these fishes are widely known to be on the verge of extinction globally. Therefore, since 2015 and shortly after my return to Mexico after living abroad for 25 years, I have been using various disciplines to try to save the smalltooth sawfish Pristis pectinata and largetooth sawfish P. pristis here.
We use sociological, ecological and conservation approaches in this project. The first stage, now nearly complete, has been to interview coastal and fishing communities along the entire coast of Mexico where we know sawfishes existed and where we suspect they may have existed. The information we have gathered helps us to understand the abundance and distribution of sawfishes in the past and, most importantly, their current status. This has also given us valuable insight into how important sawfishes were to Mexican fishers and what they were used for.
The second stage, which I launched last year, involves surveying coastal waters and rivers using non-lethal methods to search for the last remaining sawfishes in Mexico. For this, we are using traditional methods alongside cutting-edge technology: fishing nets and long-lines to try to capture live sawfishes, aerial transects with drones in areas with good water transparency, and innovative environmental DNA (eDNA) techniques. The last involves taking samples of water, filtering them on site and then sending the filtered material to a lab. There, geneticists extract the DNA that was floating in the water and, using special primers, look for sawfish DNA. Positive samples are then sequenced to find out if the DNA belongs to the smalltooth or to the largetooth sawfish.
We are currently planning field work to apply these combined methods and complete our survey of the entire former range of both species in Mexico. In this way we will be able to map which sites still host aggregations of sawfishes. As these areas are identified, we will launch strong environmental education and conservation campaigns in them in order to involve the local communities in the protection and recovery of these sawfishes. I strongly believe that the future of conservation lies in our power to educate, involve and empower local communities in the appreciation and protection of the habitats around them, as well as the flora and fauna those habitats contain. Most definitely, the enthusiastic support of the SOSF will go a long way towards helping us to contribute to the conservation of smalltooth and largetooth sawfishes in Mexico!