“How old are you?” is not a straightforward question for sharks


When we are asked the question “How old are you?” we can usually answer with a degree of accuracy. Things are somewhat more complicated for fish and very much more for sharks – and not just because they can’t literally tell us how old they are.

The ageing of fish is believed to originate from speculations made by the scientist Aristotle in 340 B.C. He noted, in the Historica Animalium, that fish age may be determined by examination of the size and hardness of fish scales. However, it was not until the invention of the lenses and the microscope in 1650s, that scientists were able to identify growths rings in the scales that were similar to those found in trees. By 1924, these rings, known as annuli, were found in otoliths (ear bones), vertebrae, fin rays, and other hard structures. It was also noted that there were variations in the amount of growth over the year with the majority of growth occurring during the summer months.

Sharks and their relatives, rays and chimeras, do not have a bony skeleton. Their skeleton is made of cartilage which is lighter and more flexible. Their otoliths, or staticonia, are similar in size to sand grains and their scales (known as dermal denticles) do not grow continuously. Some species have hard spines that contain rings suitable for ageing, but this is not the case for many elasmobranchs. Vertebrae are used to age the species without spines and this is only possible after the animal is dead.

A thin section of shark vertebrae under the microscope showing the banding pattern (NOAA Fisheries)

Today ageing fish and shark species is a vital part of fisheries management. Ages are important data that are used for assessing the health of a population of a species (also known as a stock). The age of maturity and growth rates may tell us how vulnerable a species is to being over harvested.

Before we can confidently use age estimates for a species, the rate of growth ring deposition must be validated. This is frequently achieved by injection of fluorescent dyes (e.g. oxytetracycline, calcein) into a tagged animal prior to release. The dye incorporates into the age structures so that when the animal is recaptured, the point in time when the animal was tagged will be visible. Thus the amount of growth deposited since the tagging event can be confirmed.

Another method of age validation uses the levels of the radio-isotope of carbon known as  C14 in the growth zones of the vertebrae to match it against references with known timelines such as  coral reef cores. This isotope is a direct result of nuclear testing during the 1950s and has hence earned the title “bomb carbon dating”. However, a recent review of both these methods has suggested that the underestimation of shark ages may be more widespread than previously thought. Growth bands on aged structures may actually only be reliable during the early years of life. This new evidence will be important to future ageing studies and the resultant impact to the life history and conservation status of sharks and rays.

Rock saw used to section otoliths and vertebrae

Thanks to the ongoing collaboration with Sea Leucas, a small start-up in the field of fish ageing, MarAlliance now has ready access to two age/production saws for taking sections of shark vertebrae and fish spines and otoliths. We have begun to process our collections and look forward to working with other researchers along the MesoAmerican Reef to age their animals.


Contrasting artisanal fishing communities in the Azuero Peninsula, Panama


Roxane Borruat taking length measurements of the fish landed at the port of Boca Parita, Azuero Peninsula, Panamá. Photo: EM Valderramos Piminchumo/MarAlliance

High fishing effort coupled with unsustainable use and destructive practices such as nets, has resulted in the loss of marine biodiversity and in the deterioration of marine ecosystem services since the middle of the 20th century. One of the most important of these services is the provision of food, which implies that the loss of biodiversity and the decline of marine populations engendered by unsustainable fishing practices have the potential to also affect food security. Assessing the impact of net fisheries has been challenging in many countries due to a lack of control sites where more sustainable practice such as hook and line are used.

Panamanian artisanal fisheries, including those of the Azuero Peninsula, follow the same global trends and yet also suffer from a lack of information which hinders adequate management. The Government of Panama’s Department for sustainable fisheries (ARAP), recently urged the need for improved scientific knowledge on the country’s small-scale fisheries which tied in well with our expertise. We were also keen to work with fishers from two communities located on Panama’s Azuero Peninsula who use different fishing gears to assess catch size and composition and highlight any differences due to gear preference.

Major findings

Some of the most important species for the studied artisanal fisheries include slow growing and long-lived species, such as snappers and groupers. Such characteristics make these species especially vulnerable to fishing pressure. The majority of species that were landed at both ports were assessed by the IUCN as of least-concern in relation to risk of extinction, although it was unknown for most of them whether their population is increasing, stable, or actually decreasing.

Based on conservation status, economic value, and the amount of data collected, 8 focal species were chosen for further analysis. The landings of 7 out of these 8 species were biased towards smaller individuals. In some cases, the great majority of the specimens that were sampled were below the size of sexual maturity. Therefore, specimens may be commonly caught while still immature. Alternatively, these populations may have suffered from miniaturization due to fishing pressure, meaning that their specimens mature earlier (at smaller sizes) and their maximum size is smaller than normal, as a consequence of the selective removal by fishing activities of bigger fish from the population. The most worrisome result concerned landings of the endangered scalloped hammerhead shark (S. lewini), for which newborn specimens were prevalently landed. In other words, scalloped hammerhead sharks are commonly caught before they have reached sexual maturity and hence before they could reproduce. There is also a portion of the fishery specifically targeting adult scalloped hammerheads, of which the fins are worth more than the meat and are sold separately.

The landing site of the artisanal port of El Arenal, Azuero Peninsula. Photo: R. Borruat/MarAlliance

Juvenile blacktip sharks landed at the port of Boca Parita, Azuero Peninsula, Panamá. Photo: R. Borruat/MarAlliance

Sharks and rays: Our gateway to tackling urgent marine issues


Tino the tiger shark delights the crowds in Boavista, Cabo Verde.
Photo: MarAlliance


Engaging students and the public about sharks and rays, and the need for greater understanding and conservation measures, has created an unexpected space and platform with schools and the public to talk about other urgent issues impacting the sea, notably plastic pollution. Like many island nations, Cabo Verde has a problem with waste disposal. Being a group of small windswept islands, a large amount of waste – especially plastics, inevitably enters the sea. This long-lasting rubbish impacts marine species and their habitats, and increasingly ends up back on our plates inside fish. It is estimated about 1/4 of caught fish have ingested plastics, though it is not yet known what effect this might have on us.

A recent study estimated that by 2050 there will be more plastic in the ocean than fish. While this is disturbing on many levels, it is especially concerning because plastic and other synthetic materials contain persistent pollutants, some of which can mimic and disrupt biological hormones and can take hundreds of year to decompose. During the time plastics are at sea, they are often mistakenly eaten, and can accumulate at potentially harmful levels in fish. And it’s not just bony fish who are feeling the effects, but seabirds, marine mammals and even sharks fall victim to ingestion and entanglement of our waste and discarded fishing gear.

Although plastic pollution is being increasingly studied, for many the problem remains out of sight and out of mind. Because we appreciate a challenge, in May we decided to integrate this new threat into our education and outreach program in Cabo Verde. We spent the month running an educational campaign on the impact of rubbish on marine fauna. By visiting schools, running interactive workshops with students, taking part in radio shows and holding outreach events, we are raising awareness to ensure that this broad threat to the marine environment remains highly visible and that we help to identify solutions to minimize waste and pollution.


Cintia Lima shares the pitfalls of plastic pollution in the sea. Photo: Zeddy Seymour/MarAlliance


Combating plastics pollution also has a powerful ally in our new team member, our friendly mascot, Tino the tiger shark. In the wild, tiger shark numbers have fallen significantly in the last 50 years as a result of overfishing. We also know that tiger sharks are fairly omnivorous and have been found with all sorts of plastic and metal rubbish in their stomachs. Tiger sharks are often stigmatized and viewed as a senseless monster. By promoting scientific fact instead of fiction and putting a great face to conservation, including plastic pollution, we are dismantling myths and changing perceptions at an early age, with the goal of cultivating pride for this iconic and critical species and encouraging strong connections to the sea.

A shark is not always shark in Panama…



People are remarkably fascinated by sharks. Whether they evoke fear, love, or pure curiosity, it is usually not very difficult to get people excited about sharks, especially kids. This has been clearly evident during our education and outreach events in Panama this year. Since the beginning of the year we’ve been able to engage the public with an educational booth at two large fairs, as well as talk to over 800 students and teachers from primary schools in Panama City. Besides teaching people about the incredible diversity of sharks and rays and sparking their curiosity about shark biology and anatomy, we also share the reality of unsustainable fisheries and what is happening to many of Panama’s sharks. And they are devastated.

To meet the demand for more highly-prized fishes whose populations have drastically decreased in the last few years, it is not difficult to now find shark meat sold in fish markets and even supermarkets across the country. Ambiguously labeled as ‘cazón’, ‘corvinata’, ‘tollo’, or simply ‘pescado’ (fish) instead of ‘tiburón’ (shark), most of the public in Panama have no idea that the fish they are eating is actually shark meat. Hammerhead sharks are being hit particularly hard, as gillnets are used to catch large quantities of juveniles at coastal nursery sites along Panama’s Pacific coast. At the height of the reproductive season, when hammerheads migrate to Panama to give birth, a single boat may catch hundreds of newly born sharks in a day.


Trunks of juvenile hammerhead sharks caught in artisanal gillnet fisheries on Panama’s Pacific coast. Photo by Megan Chevis.


But what we’ve learned from our interactions with kids and the public at large in the last few months in Panama is that, once they know about sharks and their plight, people generally don’t want to eat them. Few of them know that there are hundreds of different species of sharks and rays inhabiting a variety of marine habitats around the world. Or that not every shark is a ‘white shark’ that wants to eat humans. Even fewer know that the meat from sharks and other large marine predators contains high levels of toxic methyl-mercury, or that it can take a hammerhead 10-15 years to reach reproductive age. Through these interactions we hope to not only change people’s perceptions of sharks (and inspire the next generation of marine biologists, divers, and ocean lovers), but arm them with knowledge so that they can make more informed decisions about what they consume that will ultimately make long-term positive changes for sharks.


Students marvel at a shark’s jaw as they learn about shark evolution and diets. Photo: Megan Chevis/MarAlliance

Zooming into the things that define the big animals


The wonders of the small world or a new view through a microscope. Photo: Rachel Graham/MarAlliance


Sometimes it’s not just the big things that inspire awe, it’s the little things too. The really small, microscopic things. When we educate students about fish, notably sharks and rays, we tend to talk about the whole animals, their diet, behavior, form and function. And yet to demonstrate the phenomenal diversity of each species, we are turning to microscopes to reveal a new world that generally remains out of sight and mind for most.

We recently began to use microscopes to expand our education program and relate the fine structure of skin, muscle, teeth, and more to how sharks and rays have evolved, how they eat, move and combat predation, all of which has inspired students learn about the biology and building elements of each species. Our original kids’ style microscopes made such a huge impression on students and adults at the Belize Punta Gorda outreach event that we were convinced to expand the program further. We happened to be looking for funding to purchase more units and integrate them into all of our country based educational programs when the Houston Zoo stepped in and coincidentally said “Wait, we have just what you need! Would you like some microscopes?”


MarAlliance’s Rachel Graham is marvelling at the generous microscope donation by the Houston Zoo’s Director of Education, Melanie Sorensen.


Our wonderful donation of eight high quality microscopes to MarAlliance is now enabling us to expand our educational programs in Belize, Honduras, Panama and Cabo Verde. We can’t wait to amaze and inspire more generations with science and beauty of the minute.

Monitoring a large shark aggregation that feeds wildlife tourism



Curious nurse sharks and southern stingrays dance with a snorkeler at Shark Ray Alley. Photo: Rachel Graham/MarAlliance


Tourism focused on encounters with sharks and rays has increased dramatically worldwide as people increasingly seek out the animals they once feared, and are keen to experience the thrill of meeting large marine wildlife up close. Successful wildlife tourism is predicated on predictability, and one way of increasing the possibility that visitors will encounter sharks and rays is by feeding the animals. This practice, also known as provisioning, has polarized biologists, who fear that feeding modifies natural behavior and also creates expectations where animals see people and expect food. There are studies that support all of these aspects, yet in countries where sharks and rays are killed, the positives of provisioning generally outweigh the negatives. Provisioning sites can help people to encounter animals that are otherwise feared and provides high non-consumptive value for sharks and rays through tourism.

The lack of information about many provisioned aggregations of sharks and rays worldwide extends to one of the longest-known provisioned sites: Shark and Ray Alley in Belize’s Hol Chan Marine Reserve.  With visitors to the marine reserve and its sharks and rays topping 75,000 people a year, the need to assess the size, demography, recruitment and diversity of species of the aggregation became the focus for our long term monitoring study. The methods are simple, consisting of weekly video and photo surveys of the individual nurse sharks (Ginglymostoma cirratum) and rays to determine whether feeding activity has affected the behaviors and habitat use of the animals at Shark Ray Alley.

Our research at Shark Ray Alley consists of individuals gathering size estimates and sexes of the sharks and rays. We also gather population counts and photo identification of the animals on site. To gather such information, we travel to Shark Ray Alley once a week with either a tour operator during their scheduled time if space is available, or with a Hol Chan Marine Reserve ranger. Upon arrival we make an initial count from the boat of the number of sharks, rays, and turtles  present. We also gather and record environmental conditions and a number of other factors including the number of guests, whether chum is used, type of chum used, and the number of other tour boats in the area. Most often we have two surveyors; one recording data and taking in water photos of individual dorsal fins, and the other using a size estimation tool with a GoPro attached recording underwater video of the animals. Here we continue the survey until the tour ends, or all of the animals vacate the area.


The most responsible tour operators use a chum tube stuffed with sardines and lowered to the seabed, to attract sharks and rays to their boat. Photo: Rachel Graham/MarAlliance


By gathering such information, we will be able to estimate average numbers of each species from the boat and in-water, average sizes, and proportions of males versus females, along with ecotourism data including average number of boats, how many tour boats feed/chum and how tour operators and tourists interact with the animals, and whether they are touching or handling the animals (which unfortunately several do).

Initial trials with a colleague’s drone highlights this as an efficient method of monitoring the provisioned aggregation from the sky. So our next step involves the purchase of a drone that will enable replicable aerial surveys to reveal abundance of animals and boats, animal behavior in relation to boats and will allow us to have a much more complete picture of the aggregation. We at MarAlliance have our very first GoFundMe campaign underway to make aerial monitoring a reality and a weekly occurrence with our surveyors. If you are keen to support our Eyes in the Sky project please visit our campaign at: https://funds.gofundme.com/dashboard/eyes-in-the-sky-to-monitor-sharks. Any size donation is most welcome.

It is clear that wherever shark and ray aggregations occur, either provisioned or natural, the sites are becoming tourism attractions. With good site management and shark and ray encounter etiquette applied by guides and rangers, such as no touching or chasing the animals, no hand feeding (use a feed tube or like), and briefing guests fully on the experience and protocol prior to entering the water, these predictable aggregations can transform a fear of sharks by many into appreciation, respect and stewardship for these magnificent creatures. And this is why we would much prefer a shark to be fed than dead.


A friendly Southern stingray checks out the photographer front as we take measurements to check on growth over time. Photos: Rachel Graham/MarAlliance


Exploration with Monaco in Cabo Verde


Two key boats for our research, Ze Luis Monteiro’s 6 m skiff “Stephanie” (Ze is in the light blue T-shirt) and the slightly larger Yersin belonging to Monaco Explorations (74m). Photo: Rachel Graham/MarAlliance


Our team of conservationist scientists and fishers loves boats. We love them. Big or small, but preferably trustworthy. They are a key vehicle to our objective of finding, studying and conserving fish. We usually work out of rather small boats 6-7 meters long outfitted with outboard engines that one can only work in during preferably good seas, so when the invitation to work with Monaco Explorations off of a large research vessel in generally unexplored waters popped into our inbox, we gasped with delight.

Fast forward several months and we are actually working off of said vessel, whose use for research during a three year circum-tropical exploration mission was recently inaugurated by the Prince Albert II of Monaco. Named after a famous doctor who identified the plague, Monaco Exploration’s motor yacht is named the Yersin; it measures 74 meters long, has three tenders, a back wet deck, wet and dry labs, lots of fabulous cold storage and a computer room. And everything is rounded off by beautifully outfitted cabins with chic moderne decor, splashes of art nouveau and ancient mariner trinkets. It has been a huge treat for our crew to be able to easily take a shower after hours at sea, be fed by the ship’s two super cooks and sleep in such comfy beds while in the “field”.

Lowering one of the Yersin’s tenders into the sea off the coast of Boa Vista, Cabo Verde


But we digress (so easy to do on this boat…did we mention we love big comfy boats?), we’re all here to explore and advance science and understanding of fish, and these are exactly some of objectives for working in Cabo Verde. With four scientific teams (MarAlliance, University of Montpellier, ZSL and SpyGen) and traditional Cabo Verdian fishers collaborating to better understand the diversity and abundance of marine megafauna (large fish, turtles and cetaceans), we are focusing on the capture and tagging of sharks and the in-water tagging of megaplanktivores (manta rays and whale sharks) to better understand their use of the island’s seas, notably in relation to the coastal and offshore industrial fishing fleet that overlap with many of the animals habitats.

Team leaders meeting with Expedition Chief Pierre Gilles and Yersin Captain Jean Dumarais. Photo: Rachel Graham/MarAlliance.


Our voyage of discovery has just begun but we’re off to a promising start with the tagging of two manta rays with satellite tags. We look forward to sharing more of the expedition details and keeping all of our team – and this includes you, our readers and supporters – apprised of our discoveries in upcoming posts and via our Facebook and Instagram feeds when at sea internet permits. Until then, happy motoring.




Extracting an otolith from the head of a Great Barracuda (Sphyraena barracuda) Photo: Pete Oxford

How old is that fish? You’d be surprised.

Extracting an otolith from the head of a Great Barracuda (Sphyraena barracuda) Photo: Pete Oxford

Extracting an otolith used to age the fish from the head of a Great Barracuda (Sphyraena barracuda) Photo: Pete Oxford


An increasing number of studies are revealing that fish are far older than we ever thought. You may ask why this important: sound management of a fishery requires a good understanding of how quickly (or slowly) individual fish in a species grow, at what age they begin to reproduce, and how long they live. These factors represent some of the most basic biological information required to understand the status of a population and or species, because we need to ensure that enough fish are able to replace themselves before they are removed from the sea. A study that seeks to answer these questions is known as an age and growth study. As great variability in growth occurs across populations and within a same species, age and growth studies should be conducted for every distinct population of a species that is subject to fisheries.

Before an age and growth study can be conducted, we need to figure out how to age the fish. How do we do that? Well, as fish grow, seasonal variation in temperatures cause differences in growth rates, with fish growing more quickly when the water is warmer and food more abundant than during the cooler months. These differences in seasonal growth form annual ‘bands’ in calcified structures within fishes’ bodies, and otoliths are one such type of structure. Otoliths are mineralized structures located in the fish’s inner ear, which enable accurate sensing of body orientation to gravity. By carefully extracting the pair of otoliths from two capsules near the top of a fish’s head, we hold the key to the life history of that individual fish. In order to view the annual bands, and therefore age the fish, a variety of methods may by used, but most involve cutting these delicate structures in half through the center, and counting the bands using a microscope. The fish’s age is then linked to its weight, length, sex and reproductive condition at the time of capture. Once we’ve collected otoliths from hundreds of fish, these data will not only give us the growth rates and ages at maturity for the population, but can indicate important factors such as natural mortality and the species overall risk of over-exploitation by fisheries. Determining the age of fish is a tedious but relatively simple process, and the growth rate of a fish’s body has been found to be generally proportional to the temperature of their environment.


Evan Cuevas measures a barracuda prior to removing the otoliths. Photo: Rachel Graham/MarAlliance


A remarkably recognizable and yet poorly studied species that we frequently encounter during our fieldwork is the great barracuda (Sphyraena barracuda). This charismatic, predatory fish species can often exceed 1 meter (3.3 ft) in length, and in fact can grow as large as 1.8m (5.94ft)! Popular as a food and sport fish, great barracuda are often targeted by fishers throughout the tropics, and surprisingly the fishery is currently unmanaged throughout most of its range. Equally surprising is the lack of scientific studies on this important species. In order to remedy this glaring deficit, we have collected measurements and samples from 290 great barracuda throughout the primary reefs of the MesoAmerican Reef (Mexico, Belize and Honduras), to create the needed age and growth study for this species.

Our study will significantly improve understanding of how great barracuda age and grow, and will provide important information in the development of local, national and regional management strategies for this commonly captured fish. Already we are finding that the fish we see are older than we expected, with barracuda of moderate size easily reaching 19 years of age. This gives us something to think about when assessing whether the populations of a fish we consider common can withstand the increasing fishing effort recorded worldwide.

“We’re gonna need a better BRUV”


“Wait, WAIT…WHAT WAS THAT?… go back… go back…!”. This is a familiar cry when we are reviewing footage from our underwater camera traps. Through this sneaky peep show of sorts we have made countless discoveries of big fish and other marine wildlife and their preferred habitats. And this work has been critical to understand the diversity and abundance of large marine wildlife and reveal hotspots for specific species, notably those threatened with extinction and in more dire need of conservation attention.

Compared to our terrestrial counterparts, we marine conservation scientists often struggle to work with a limited toolkit in our quest to study wildlife. Camera “trapping”, originally developed to capture images or video of rarely encountered terrestrial species and a key component in censuses, has recently exploded onto the marine stage. The miniaturization of technology and vastly reduced costs of underwater cameras, notably the ubiquitous GoPro, has enabled just about anyone to spy on fish. Commonly known as Baited Remote Underwater Video or BRUVs, these installations were developed in the 90s and are now commonly used in shallow marine projects as a non-invasive means of assessing fish diversity and abundance.

With limited means at our disposal and a desire to make the installations as cheap and easy to make as possible we built our first units in 2012 to conduct the first Belize Barrier Reef census of large marine wildlife. Randomly placed on coral fore-reefs, patch reefs and lagoon areas we found several hotspots for sharks, rays, turtles and big snappers and groupers that we have integrated into our conservation strategies. These surveys have notably highlighted Lighthouse Reef Atoll as being Belize’s site with the highest abundance and density of large marine wildlife. Initially built with PVC pipes with a design pioneered by Ben Fitzpatrick, we found that continual breakages forced us to move to metal frames in 2015. Bulky and taking up precious space on the small boats we use for our work, we also found these far too heavy for our incipient deep-water shark work that required us to drop and retrieve BRUVs by hand to over 500 meters.

It was at this point that we declared in a parody of the iconic film Jaws that “we are going to need a better BRUV!”. Cue the sound of trumpets as one of our volunteers, Sam Owen, came to our technological rescue. Self-effacing and incredibly ingenious, a literal Jacques of all trades and staff at the Royal Albert Museum in Edmonton Canada, Sam has helped us to function in several of our project sites by ensuring that our technology works. He took on our “Build a Better BRUV” challenge and created a streamlined, lightweight and collapsible unit that can easily be transported to our various study sites. Recently tested in Honduras, we were thrilled at the ease of deployment and retrieval, and have gained several new fisher ambassadors for the work that we do. And just what did we see you dare to ask? Well…you will just have to stay tuned for that nugget of info. And it’s worth the wait to see what our “box of chocolate” camera traps reveal. We just never know what we’re gonna get on the videos as we push the science and conservation envelope beyond the shallow seas and into the nearly unknown deep-sea realm of our Barrier reef.

How are our fish doing? Monitoring can help answer the question


Exson Flores, a traditional fisher from Honduras, surveys the coral reefs for large fish over the course a transect kilometer. Photo: Rachel Graham/MarAlliance


Significant gaps of information exist globally on sharks and rays, collectively known as elasmobranchs, and this is proving a challenge to conservation efforts. The MesoAmerican Reef region (Mexico, Belize, Guatemala and Honduras) is no exception. Honduras is one of 15 countries worldwide that declared its waters a “shark sanctuary”, which bans shark fishing and the commercialization of their meat and derivatives. Unfortunately, with limited enforcement and an unknowing public, shark fishing continues largely unabated in Honduras to date. To create the necessary baseline to identify changes in populations and inform the public about the large animals that ply their seas, we conducted the first large-scale marine megafauna monitoring project in the Caribbean of Honduras. The surveys monitor large animals (megafauna), including sharks and rays, and also sea turtles and big finfish (barracudas, snapper and groupers). Our methods are standardized, which allows us to compare results among countries and sites. We usually use three methods: Baited Remote Underwater Videos (BRUVs), in-water snorkel transects and scientific longlines. This year we were able to complete broad training in capture and release techniques with traditional fishers from several communities, and for the first time sharks were caught and tagged in Honduras!

A snorkeler adjusts a BRUV as it descends to the seafloor to record fish/shark abundance. Photo: Rachel Graham/MarAlliance


Since many sharks are very long lived (think of the Greenland shark that reaches over 400 years old!) and like us humans take many years to reach sexual maturity,  it will take several years of monitoring to determine if there are any changes occurring in the populations of these large animals. However, we can compare our results with other surveys throughout the region to get an idea of the health of Honduras’s marine megafauna. We are also already seeing some common trends, especially in Roatan. Greater abundance and diversity of finfish exist within protected areas with enforcement and more sightings of sharks in areas with less human activity – areas that actually do not necessarily coincide with protected area boundaries. This is not surprising, as studies have shown that sharks are most abundant in remote and little fished areas.

A rarely encountered small juvenile tiger shark (Galeocerdo cuvier) was the first captured and tagged shark in Honduras. Photo: Patric Lengacher/MarAlliance.


Although we did not catch as many sharks as we would have wished for on our scientific longline, our star capture was a juvenile tiger shark (Galeocerdo cuvier). This was an unexpected surprise, especially for our partner fishers, many of whom had never seen, let alone handled a tiger shark, a species often feared for its reputation as a voracious predator. Seeing the fishers’ enthusiasm and excitement for the capture and subsequently the release of an often feared animal gives us great hope that perceptions and behaviours can change in the shark’s favour. We can’t wait to expand this training and work to more communities and link the monitoring into our already popular Kids Meet Sharks program in Honduras.

The Deep: A new frontier for shark science


Standing on the veranda of our Belize based office, we can readily see the Belize Barrier Reef with its jagged coral reef crest, and beyond this line of coral and waves, the open sea. What many people don’t realize is that the reef shelf drops rapidly from a shallow 15 meters to over 1,000 m depth within a stone’s throw of the reef, and this is literally mare incognita (or unknown seas).

This proximity to deep waters and ease of access becomes highly relevant to fisheries management as near-shore coastal fish and fisheries are declining globally, and fishers are increasingly moving into the deeper waters in a bid to maintain their catch and meet the rising demand for seafood. Yet the deep sea environment is very little known throughout the world, and especially in the western Caribbean. Despite our lack of knowledge of this ecosystem, fisheries continue to develop in the deep sea. In the MesoAmerican Reef Region (MAR), almost nothing is known about the species that inhabit the waters deeper than 150 m (500 feet). In fact, we don’t even have a full catalogue of the deep-sea shark species that are in the MAR. To counter this paucity of data, MarAlliance is currently conducting research on the species that inhabit the deeper waters of the MAR to determine which species inhabit this region and which might be vulnerable to overexploitation from fishing.

Deep-sea sharks are remarkably well adapted to their environments, with many possessing large eyes, specialized teeth, and spiracles for pumping water over their gills in low oxygen environments. Upon capture, these sharks undergo a bit of a shock, moving from up to 500 m (1,200 ft) to the surface in under five minutes: not only are they exposed to extreme light conditions, but undergo a change in temperature from as little as 11°C (52°F) to 29°C (84°F).

We knew from other researchers’ studies that many deep sea sharks have extremely fatty livers and are therefore more buoyant than their coastal counterparts. Because of this, some species may have a difficult time swimming back down to depth after they are brought to the surface. We found that while smoothhound and night sharks swim rapidly back to the deep quickly after release, the bigeye sixgill sharks make a more meandering descent. Gulper sharks appear to have the hardest time, being both extremely buoyant and rather sluggish.

So we aim to get them back into the deep as quickly as possible.  Using a method commonly applied to finfish that we discovered also works well with sharks: a lead weight with a barbless hook attached to a line takes the shark down to depth very quickly. After a few trials, we feel like we have nearly perfected our technique, which we were able to use to successfully release a gulper shark on our last sampling trip.

As we have expanded our deep-sea shark research project in the MesoAmerican region, while working with the handful of traditional deep sea fishers to teach them monitoring techniques, we have also added to the number of species we are encountering. We now have a catalogue of seven species, a list that we are adding to with every major expedition we make. The deep is a new frontier that is both threatened by expanding fisheries, but also represents a region of new discoveries that keep us on our scientific toes.

Emerging Wildlife Conservation Leader


Building skill sets and knowledge and then applying them is what moving conservation forward is all about. Gabriela Ochoa, affectionately known by all as Gaby, is an enthusiastic conservationist focusing on sharks, rays and turtles and our National Coordinator for Honduras who has been keen to build her professional skills.

After much finger-gnawing, she received the great news that was awarded a place to pursue a masters at the University of Exeter’s top rated Center for Ecology and Conservation and simultaneously received a spot in the prestigious Emerging Wildlife Conservation Leader program. Spanning two years, this international program builds the capacities of young conservationists that have been identified as future leaders in their field.

Taking part in EWCL would not have been possible without the generous support of the World Wildlife Fund.
We look forward to Gaby applying the many lessons learnt to our program in Honduras as the programs unfold.

Networking fishers across ocean basins 


When Evan Cuevas grew up in the small un-electrified village of Monkey River in southern Belize, he never dreamt that he would become a trainer in good fishing practices. But that is exactly the journey this young lobster fisher embarked on earlier this year when he travelled half way around the world to the island of Pohnpei in the Federated States of Micronesia. Although Evan had been working with MarAlliance as a monitoring research assistant, his freediving prowess and canny lobster-seeking acumen came to the attention of Dr. Kevin Rhodes, MarAlliance’s Small Scale Fisheries Coordinator. Dr. Rhodes was seeking just the right person to train Pohnpei’s local fishers in methods to improve the sustainability of the country’s lobster fishery. Although we promote fisher exchanges between several countries where we work, this was an unprecedented exchange due to the distance traveled (more than 12,000 km!) and because the exchange focused on lobster and not sharks. We have learnt over the course of years that the conservation of large wildlife is often more successful when local needs and priorities are addressed first, and linkages between the health of wildlife and other species stocks are defined.

After a discombobulating trip across several countries and even more time zones, Evan met with the leaders in the fishing communities in Pohnpei and presented the story of lobster fishing in Belize. Evan was surprised to  find many similarities  between Belize and Pohnpei, as both countries have experienced declines in lobster stocks due to overfishing driven by rising demand. To protect the country’s most valuable fishery, Belize established a closed season and size limits and is now promoting the capture of live lobster through the use of the simple loopstick to reduce the capture of gravid females and undersize animals. Land based training with 40 of Pohnpei’s top traditional fishers focused on the making and use of loopsticks then rapidly transitioned to the sea. The fishers introduced Evan to stunning Pacific corals and reef fish that outshine their Caribbean cousins, while he showed them how to fish effectively with the new and more sustainable gear type. The exchange demonstrated that traditional fishers targeting the same resources don’t have to reinvent the wheel and a path to greater sustainability in the fisheries can be achieved through fostering peer to peer exchanges, in turn creating a vibrant network of traditional fishers across regions. We hope to support exchanges between fishers from Cabo Verde and the MesoAmerican Reef next as the west African fishers seek to organize themselves and become involved in the management of their fisheries.

We want to thank the fishers of Pohnpei for organizing the training, and Dr. Melissa Giressi who hosted Evan in Hawaii during his trans-Pacific journey.