All Posts By

MarAlliance

“We’re gonna need a better BRUV”

By

“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.

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

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

By
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.

Exploration with Monaco in Cabo Verde

By

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.

 

Monitoring a large shark aggregation that feeds wildlife tourism

By

 

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

 

Zooming into the things that define the big animals

By

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.

A shark is not always shark in Panama…

By

 

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

Sharks and rays: Our gateway to tackling urgent marine issues

By

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.