rays

Another day, another milestone

These single ladies don’t need a man

Publication specs

Title: Facultative parthenogenesis in a critically endangered wild vertebrate

Authors: Andrew Fields, Kevin Feldheim, Gregg Poulakis, Demian Chapman

Journal: Current Biology

Year: 2015

The Internet exploded last year with news of a vertebrate capable of producing offspring without sex. Billions of people across the globe tuned in to learn about the smalltooth sawfish’s newly discovered ability. The study was led by our lead principal investigator, Dr. Demian Chapman, and his Ph.D. student, Andrew Fields. This ability, scientifically known as facultative parthenogenesis, where animals that generally need a male to produce offspring can do so without one, is not a new scientific concept. In fact, it has been discovered in many captive vertebrates like birds, reptiles, sharks, and more recently rays. So what’s so novel about it? Smalltooth sawfish are a type of batoid, or ray, that are critically endangered and in 2007 were among the first elasmobranchs to receive international trade regulations by the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). Since the 1960s, these rays have seen a population decline of about 95% due to habitat loss, overfishing, bycatch, and target capture – where their rostrum, or snout, was sold as curio, aka a bizarre object usually used for home decoration. Smalltooth sawfish are currently only found in Southwest Florida and parts of the Bahamas. This study provided the first evidence of facultative parthenogenesis in the wild and it may be more common than previously thought, particularly in populations on the verge of extinction. But don’t get too excited – there is no scientific evidence of this phenomenon occurring in mammals.

Global patterns of shark and ray bycatch

Publication specs

Title: Global patterns in the bycatch of sharks and rays

Authors: Shelby Oliver, Matias Braccini, Stephen J. Newman, Euan S. Harvey  

Journal: Marine Policy

Year: 2015

The left-behind, the unwanted, the unmanaged – whatever you want to call it, bycatch is prevalent in commercial fisheries. Sharks and rays are at risk of becoming bycatch in all commercial fisheries. So what exactly is bycatch? Bycatch is the discarded (dead or alive) catch and/or unmanaged catch from fisheries. While fishing for particular species, fishers often catch unwanted species using longlines, trawls, gillnets, and purse-seines. It is common for these so-called undesired species to be illegally kept and later sold, particularly in the case of some sharks and rays, whose fins sometimes end up in the lucrative fin trade.

This study reviewed relevant data from global commercial fisheries. Most of the data came from the North Atlantic Ocean, which is not where the majority of fishing occurs. This suggests that most fisheries are not effectively reporting bycatch data. Shark bycatch mainly occurred in the South Atlantic pelagic longline fishery. No patterns were found in ray bycatch, likely due to a lack of data reporting. For both sharks and rays, the largest total annual bycatch took place in pelagic longline and deep sea/coastal trawl fisheries. One shark species dominated longline bycatch – the blue shark, pictured above – which may make up more of the catch than the actual target species. Rays are not exempt from unregulated fishing, and as a group are considered more threatened than sharks. Perhaps even more alarming is that the majority of ray bycatch comes from commercial trawl fisheries where they are often thrown back into the ocean, left for dead. 

Below is an overview of the prevailing species caught as bycatch by region:

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Sharks

  • Blue sharks – North & South Atlantic, Western Pacific
  • Silky & thresher sharks – Indian Ocean & Eastern Pacific

Rays

  • Pelagic rays – South Atlantic, Western Pacific & Indian Ocean

Sharks

  • Sharpnose sharks – North Atlantic
  • Dogfish – South Atlantic, Eastern & Western Pacific
  • Carpet sharks – Indian Ocean

Rays

  • Skates – North & South Atlantic


Sharks

  • Blacktip shark – North Atlantic
  • Sevengill sharks & shortnose spurdogs – Indian Ocean
  • Catsharks – Eastern Pacific

Rays

  • Cownose rays – North Atlantic
  • Bat rays – Indian Ocean & Eastern Pacific


Sharks

  • Coastal sharks (e.g. blacktip, bull, and dusky sharks) – North Atlantic & Eastern Pacific
  • Silky sharks – South Atlantic & Indian Ocean

Rays

  • Manta & devil rays – South Atlantic, Eastern Pacific & Indian Ocean


These results suggest that global shark and ray bycatch monitoring – data collection and availability – should become high priority for management. Sharks and rays are important fishery and tourism resources, especially in developing nations, so it is vital to find out if these levels of bycatch are sustainable for each species. Should the current levels of shark and ray bycatch in commercial fisheries not be sustainable, regulations would have to be modified or developed and enforced to safeguard their future.

Bahamas Mission 2016

In 2016, the Chapman lab sampled six reefs in the Bahamas, thanks to the Moore Bahamas Foundation, Cape Eleuthera Institute, and the International SeaKeepers Society. In collaboration with these organizations, student Gina Clementi, project coordinator Jasmine Valentin-Albanese, and volunteer Jessica Quinlan set a total of 278 baited remote underwater videos (BRUVs), which produced amazing data and footage from the shark sanctuary.

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lemon-shark

tiger-shark

 

Our lead principal investigator Demian Chapman and social media manager Katie Flowers accompanied this mission by participating in local outreach sessions led by the Bahamas Reef Environment Education Foundation (BREEF). You can find their blog post about this mission, originally published on louisbacon.com, below.

 

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© Cay Focus Photography

 

Life’s Better in the Bahamas Shark Sanctuary

Most of you have probably heard it somewhere before, the iconic piece of information shared tirelessly and sometimes incorrectly attributed to nothing but shark finning, “100 million sharks are killed every year”. Although this is an alarming number, it’s actually better to look at the range from the larger study estimating exploitation rates of sharks: 63 million – 273 million sharks killed annually. One hundred million is thus a conservative estimate, and the shark fin trade is not fully responsible for those landings. Data aside, the more important question now is what can we do about these losses?

The answer may partially lie in the Bahamas. Before the study mentioned above even came out, the island nation made a progressive choice by fully protecting its sharks from fishing in 2011. Bahamians had put two and two together: many shark species in their waters live there either partially or year-round, and these sharks are worth big bucks alive – a 2007 estimate of $78M US in the Bahamas alone (Report of the Bahamas Ministry of Tourism). The Bahamas is one of the best places in the Caribbean and arguably the world to dive with sharks, which might not be the case if populations were under high fishing pressure.

Dr. Demian Chapman, a marine biologist and shark expert formally at Stony Brook University’s School of Marine and Atmospheric Sciences and now at Florida International University’s College of Arts, Sciences & Education leads a global study of sharks and rays called Global FinPrint. It is a project that partially stems from the 2013 study by asking some of the next most valuable questions including: where on the world’s coral reefs do we find many sharks and rays and why are they there? The project sets GoPro cameras on the seafloor to estimate shark and ray abundance and diversity. So far, the Bahamas has been one of the leaders in this study (see video), with sharks and rays on almost every survey, including several with endangered great hammerheads. This project along with a tagging expedition in its fourth year have certainly made life better for sharks in the Bahamas, thanks to Louis Bacon’s Moore Bahamas Foundation.

The Bahamas has emerged as a leader in shark conservation, and the sanctuary could be a model to replicate for countries looking to protect their sharks and boost their economy. Extending this same protection to rays, the lesser-known cousins of sharks who play their own vital roles in the ocean’s ecosystem, would make sense. The Bahamas is one of the few places on earth where you can find the critically endangered smalltooth sawfish, a ray that is often confused with a shark. Their populations have seen about a 95% decline since the 1960s. Yet these sawfish are not granted protection in the country, nor are the other species of rays that could bring in even more tourism money. It is the belief of Global FinPrint that the Bahamas can take the next innovative step to make them a world leader in shark and ray conservation by granting rays full protection.   

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Smalltooth sawfish Photo: Katie Flowers

 

Caring for conservation: the value of imagery

FinPrint Spotlight

PeterVerhoog_portrait-286x300Author: Peter Verhoog

Where to find his work: Underwater PhotographyDutch Shark Society

Sampling Location: Maldives

I am passionate about marine life, and I just love sharks. One of my favourite jobs is documenting shark and ray research in the field.

I have worked with Dr. Mark Meekan on the sharks of Palau, the manta rays of Hanifaru and the whale sharks of Ningaloo Reef. When he asked me to join the Global FinPrint expedition in the Maldives, I was over the moon. I love discovering new projects and research methods, and am always keen on understanding the science.

BRUV on reef

BRUV on reef

Global FinPrint is an extremely valuable project because of its scale and reach. This mission yielded visuals that will help communicate the project’s scientific and conservation message to a wide audience.

Peter waiting near a BRUV

Peter waiting near a BRUV

 

As a conservation photographer, I had to work around the baited remote underwater video set-ups without interfering with the research goals. I had to strategically choose a location for each dive that would not disrupt the fish attracted to the area. There are at least 500 meters between each BRUV, and I could not swim from one set-up to the other.

Nature is an additional challenge to our work because it is unpredictable and you never know where sharks and rays, my favourite subjects, will turn up. I did not see them every dive, but was able to capture some exciting pictures and footage.

I did have some unexpected encounters that I thoroughly enjoyed and after over 35 years of diving were a ‘first’ for me, like the one with a sailfish and with pink whiprays (check out the footage below).

 

 

I first dived the Maldives in 1990, and had great memories of the trips I made, the richness of the reefs, and the large predators on every dive. Like many other countries, Maldives is highly dependent on marine resources and tourism, and just like in many other places, there has been overfishing. It is therefore wonderful to see that the Maldivian government gave Global FinPrint the opportunity to document the reefs and its inhabitants, so that conservation regulations for the future can be established.

Bleached reef

 

 

What particularly struck me was the coral bleaching in the Maldives. This has become a widespread global problem. It is my hope that the reefs can and will recover so that all marine life can thrive in the area.

 

 

 

 

The atmosphere on board was great, and it was wonderful to meet great marine scientists. For me, it was a privilege to be a member of the Global FinPrint team!

 

BRUV

Peter Verhoog

You can find BRUV highlights from this mission below:

A special thanks to Vulcan, Inc., the Australian Institute of Marine Science, the Pew Global Shark Campaign, the Maldivian government, Atoll Editions, and the crew aboard the Conte Max for making this mission possible.