Meekan

Marine protected area helps shark populations recover from fishing

Publication specs

Title: Evidence for rapid recovery of shark populations within a coral reef marine protected area

Authors: Conrad Speed, Mike Cappo, Mark Meekan

Journal: Biological Conservation

Year: 2018

The diminishing number of sharks around the world is no longer a topic of interest just for scientists and fisheries managers. Many people who rely on these animals as resources – whether as food or for ecotourism operations – are becoming aware of the menacing situation facing certain shark populations due to overfishing, shark finning, habitat loss, and climate change. Until now, there has been little evidence that marine protected areas benefit sharks in coral reef habitats. Thanks to Paul G. Allen Philanthropies, the first results coming from our sampling provide insight into the recovery of grey reef sharks and apex predator species like the tiger shark and lemon shark at a remote atoll in the Indian ocean.

Ashmore reef is situated 350km northwest of Australia’s mainland, and has been an enforced no-take marine protected area (MPA) since 2008. Although the official establishment of the Ashmore Reef National Nature Reserve was in 1983, only occasional monitoring of the area was happening until 2008 when a government vessel became stationed there 300 days out of the year. Prior to the inception of the MPA, there was legal and illegal targeted shark fishing. In 2004, researchers from the Australian Institute of Marine Science (AIMS) conducted baited remoted underwater video surveys (BRUVs) at Ashmore Reef. The AIMS research team then returned in 2016 to repeat the study as part of our global survey of sharks and rays on coral reefs around the world.

This provided the ideal set-up to study Ashmore Reef shark populations before and after full protection. Findings show:

 

The relative average number of grey reef sharks (measured as the maximum number of individuals per camera drop; MaxN) increased from about 0.16 individuals per hour in 2004 to approximately 0.74 individuals per hour in 2016.

 

 

The proportion of reef sharks (grey reef sharks, blacktip reef sharks, and silvertip sharks) in the assemblage increased from 28.6% in 2004 to 57.6% in 2016.28.6%  57.6%
 

 

The proportion of apex species (tiger sharks, lemon sharks, scalloped hammerheads, and fossil sharks) in the assemblage increased from 7.1% in 2004 to 11.9% in 2016.
 
 
 

 


 7.1%  11.9%
 

 

This study is not only our project’s first publication, it is also one of the first of its kind in a coral reef ecosystem to highlight that enforcement in a marine protected area aided shark population recovery and at a rate much faster than previously predicted by demographic models.

Another day, another milestone

CORDIO samples Tanzania

FinPrint Spotlight


Author: Clay Obota, MSc

Organization: CORDIO East Africa

Biography: Clay joined CORDIO as an intern working under the Fishery Aggregating Devices project and advanced to a research assistant working on marine biology/ecology, fish population dynamics, fish stock assessment, and fisheries management.

On March 13th 2017, representatives from Kenya and Mozambique set off by road from Mombasa on the Kenyan coast to Tanga, 175km south of Mombasa, in Tanzania, to learn how to do baited remote underwater video surveys (BRUVs) to record shark populations as a part of the Global FinPrint project. The travelers were myself, Clay Obota, Kennedy Osuka, and Melita Samoilys from CORDIO, Benedict Kiilu from Kenya Fisheries Service, and Gelica Inteca from Uni Lurio in Pemba, Mozambique. That evening we met at the Mkonge Hotel in Tanga with our three Tanzanian counterparts: Hassan Kalombo, the Regional Fisheries Officer, January Ndagala, Acting Warden of the Coelacanth Marine Park, and Hakim Matola from TAFIRI in Dar es Salaam, as well as the lead trainer, Dr. Jordan Goetze, from Curtin University in Perth, Australia.

All the participants were guileless and eager to learn about BRUVs, in particular how to analyze, interpret, and use the data collected from the videos. Jordan kicked off the training with a day on land including lectures, discussions, and hands-on practice with the equipment. The lectures covered how to survey fish abundance using BRUVs with detailed procedures on calibration, deployment, and field data management. This was followed by hands-on training setting up all the equipment for deployment. This consisted of five GoPro cameras mounted in housings on a light aluminium frame or rig, and meters of rope.

Since most of us were new to using BRUVs, this was set to be a hard day for Jordan, but we worked against all odds and managed to do 15 drops. Just like experts, we picked up the science quickly. After multiple one hour deployments, we managed to deploy the BRUVs at two sites: Nyuli (2 sets) and Mwamba Nyama (1 set). Seven connected reef systems were mapped and marked for sampling on the rocky and fringing reefs along the coast of Tanga, North of Tanzania. The success of the first day was a clear indication of future productivity. The following days were a walk in the park where each team worked efficiently with smiles and laughter lighting up the experience. 


From bait preparation to BRUV deployments and pick-ups, everyone worked hard as a team on the second day of sampling the reef systems of Fungu Tangoni and Karange, where we set 20 BRUVs. We almost lost one video frame due to strong currents on the third day while sampling Karange and Jambe. We had to pull it out and redeploy it in shallower water. Mwamba Nyama, Mwamba Wamba, and Chundo Kiroba reef systems were successfully sampled on the fourth day, with the deployment and retrieval of 20 BRUVs before 4pm, the fastest day since the beginning of the field trip thanks to low currents and smooth deployments.

Chundo Kiroba and Mwamba Wamba reef systems were sampled on the fifth day. Although the team was eager to deploy as many BRUVs as the previous day, the tides were strong making this goal challenging. The last deployment for the day at Chundo Kiroba reef was set to a depth of 40m. It had to be retrieved and re-set at 35m since the currents were strong and the rigs were drifting. Even with the strong currents, the team managed to maintain 20 drops on this day as well.

On the last sampling day, the BRUV team worked without Jordan for a half day. The team completed 10 more drops for a total of 105 drops over the course of the entire sampling trip, 15 drops more than the initial target of 90 on Tanga’s reefs. This was a great achievement thanks to the excellent team spirit and enthusiasm from everyone who learned efficient BRUV techniques.

As we felt confident in this methodology, the idea of using BRUVs as a tool for estimating population size of large fishes including sharks became increasingly popular across the participants from the three countries. The team is now looking forward to opportunities to use these acquired skills. CORDIO will be coordinating reef sampling in Kenya and Mozambique later this year to estimate shark populations, again as part of the Global FinPrint project.

Collaborator Spotlight: Marine Research Centre, Ministry of Fisheries and Agriculture, Maldives

Funded by Vulcan, Inc. and the Pew Global Shark Campaign, the labs of Drs Demian Chapman and Mark Meekan headed to sample the Maldives in May 2016. Back in 2015, both Global FinPrint researchers were introduced to the Marine Research Centre, Ministry of Fisheries and Agriculture through Khadeeja Ali, a government employee, thanks to a meeting held by the Pew Charitable Trusts.


Khadeeja had the opportunity to join the research expedition in the Maldives and learn how to set baited remote underwater videos. One of our ongoing missions for this collaboration is to continue Khadeeja’s training and further her education. In doing so, she will acquire research experience that will benefit the Maldivian government and help them continue to make informed conservation decisions. She will be applying to work as a Masters student in Dr. Demian Chapman’s lab at Florida International University this summer.


The teams successfully sampled five reefs, and the results will update the estimate of the economic value of reef sharks and shark diving to the economy of the Maldives. The Maldives is a progressive leader for shark conservation, as they recently headed the successful proposal to list silky sharks on Appendix II of the Convention on International Trade of Endangered Species of Wild Fauna and Flora (CITES).

Marine Research Centre, Ministry of Fisheries and Agriculture, Maldives
Marine Research Centre, Ministry of Fisheries and Agriculture, Maldives

The mandate entrusted to the Marine Research Centre by the President’s Office (Letter No: 1-D/30/99/15 of 21 February 1999) are:

  • Plan, coordinate and conduct scientific research on marine resources of the country.
  • To undertake marine research directed at the conservation, enhancement and management of the marine environment in general and for fisheries exploitation in particular
  • Disseminate knowledge to the government and to the public with the objective of creating public awareness about the fisheries and the marine environment.
  • Study ways and means, which will increase the fisheries sector’s contribution to the economy of the country.
  • Conduct resource surveys in selected Areas within the country.
  • Compile and implement a database, holding data as well as scientific information on marine resources.
  • Undertake research on technological innovations, which will promote the rational utilisation of the marine resources. This also involves the introduction of these technologies to the fishing industry.
  • Publish research findings and reference materials with the objective of creating public awareness about the marine environment.

Tracking tiger sharks

Publication specs

Title: Crossing Latitudes – Long-Distance Tracking of an Apex Predator 

Authors: Luciana C. Ferreira, Michele Thums, Jessica J. Meeuwig, Gabriel M. S. Vianna, John Stevens, Rory McAuley, Mark G. Meekan 

Journal: PLOS One

Year: 2015

Although some people may picture sharks as intimidating predators that roam long distances, that’s not the case for many of the more than 400 species. There are also small sharks and those that spend most or part of their lives in one area – a pattern known as residency. When it comes to tiger sharks, the big scary predator vision is at least partially true – they are large (sometimes more than 5m in length), can be frightening if you’re a turtle, and swim long distances (potentially up to 8000km). However, using satellite tags, this study showed some tiger sharks along the coast of Western Australia to actually be seasonal residents to the coastal waters near where they were initially tagged. The eight sharks spent about half their time in marine reserves. The sharks tended to prefer warmer coastal waters, but the results from these data demonstrated that they have the ability to migrate between tropical waters and cool temperate waters (as cold as 6°C – brr!).

Understanding tiger shark movements is important. Where sharks go influences population connectivity. In order to manage populations, we must first understand where individuals are – and in Western Australia, they are spending parts of the year along the coast near where the researchers deployed the tags. Tiger sharks in Shark Bay were shown to influence the behavior and movements of prey, so it’s no surprise that the tiger sharks likely have a sort of structuring effect on the ecosystem. Protecting sharks locally, along with both their habitat and prey, is vital.

One female tiger shark, tagged at Ningaloo Reef, had the longest duration track to date for a tiger shark (517 days) and moved 4000km in that time period. After being tagged, she moved to Rowley Shoals then impressively made it to Indonesia and back into Australian waters (a distance of about 1000km) in just two weeks. This movement pattern is known as site fidelity – where the animal makes a long-distance movement and then returns to the location where it was tagged. International cooperation between Indonesia and Australia will be needed to make informed conservation decisions since there was documented movement between both countries. For this tiger shark, local protection in Western Australia is not quite enough.

 

Mozambique Mission 2016

FinPrint Spotlight

                                                                      Anna FlamAlexandra Watts

In August, the Global FinPrint team headed to Mozambique to assess the marine life found on the reefs around Vilanculos and Bazarut Archipelago National Park. Anna Flam (left) and Alexandra Watts (right) from the locally based Marine Megafauna Foundation joined the team to deploy baited underwater videos (BRUVs). Alexandra Watts reports from the field.

The Marine Megafauna Foundation (MMF) has been researching large fish such as sharks and rays in southern Mozambique for over 10 years. So we were really excited when the Global FinPrint research team invited us to help them with the reef assessment in this beautiful and biodiverse part of Mozambique. The goal of this collaboration was to complete half the BRUV drops inside the Bazaruto Archipelago National Park and half outside, to look at the differences inside and outside the protected area. After the equipment arrived from Australia, we began setting up the BRUVs by securing frames, legs, GoPro housings, ropes, buoys and floats, batteries – these had to stay dry until ready for use.

central-mozambique-aug-2016

The first day, we waddled down to the beach; each laden with various bits of the BRUV kits, and loaded them onto the boat with the help of Zito, our local skipper. We were aiming for the northern end of the archipelago and dropped around ‘Spaghettis’ and ‘Three trees’ – reefs on the northeast side of Bazaruto Island. Luckily, the weather was on our side and we were able to drop here for several days. By day 3 and 4, the weather had closed in a little and so we stayed closer to Vilanculos, on our second site at Two Mile reef.

Photo: Alexandra Watts

Photo: Alexandra Watts

After the first few days, we eagerly waited as the experienced BRUVers Conrad Speed and Jordan Goetze downloaded all the footage and replayed it. The footage was fantastic. Moon wrasse, yellow snapper, red fanged trigger fish, sailfin tangs and a giant guitarfish were just part of a kaleidoscope of species of all shapes and colour. Within the first day the guys had noticed something they had never seen before; schooling Moorish idols. They saw this species in Australia and other locations but never in such huge numbers before. Moray eels took a particular interest in the bait bags, grabbing them and death rolling to get access to the fish, while an octopus and a blotched fantail ray just sat on top of the entire bag, preventing anything else from getting access.

moorish-idols

Moorish idols surround bait bag

BRUVs are a useful tool to collect data on marine species composition and information such as this can be communicated to local government. Sampling is often done using underwater surveys. However, BRUVs are especially useful for avoiding biases with these techniques such as behaviour changes by species in response to a diver carrying out video surveys. This is important when carrying out species counts – fish which actively avoid divers may cause a species to be completely omitted from a study, resulting in an inaccurate account of species within an area. It is also an efficient census technique – they don’t require skilled divers in the water and all the associated risks and technical equipment. They can be left on the seafloor without an operator, simply with a marker nearby to make it easy to find them, whilst further work can be continued elsewhere.

Technically, this is an advantage. But, after reviewing some of the footage, we wish we had been there to see it with our own eyes – not only did we have visits from both reef and giant manta rays but also smalleye stingrays, round ribbontail (aka blotched fantail) rays, pink whiprays, Jenkins’ whipray, spotted eagle ray, bull sharks, blacktip sharks, blacktip reef sharks, grey reef sharks, and whitetip reef sharks.

We were also specifically looking out for dugongs, which are one of the only herbivorous marine mammals in the world and rare inhabitants off the coast of Africa. This animal is extremely sensitive to anthropogenic threats such as gill netting, hunting, pollution, habitat loss, and coastal development. Population numbers have been drastically reduced in East Africa. The Bazaruto Archipelago population is now possibly the only viable population in Africa, and the second largest in the Western Indian Ocean. And, although we didn’t manage to see one face to face, we did get a couple of glimpses of these curious animals on BRUVs!

A dugong casually swims past one of the BRUVs.

Analysis of the footage is (understandably) time-consuming and will take a little longer until we can begin to summarise the findings. It was an absolute pleasure for Anna and myself to be involved in this study and we hope it paves the way for further collaborations of this nature. The more marine scientists can connect and work together on both international and regional projects, the more efficient research becomes. Human pressures have exerted such a huge threat to so many forms of marine life that the oceans are reaching a breaking point. Targeted conservation initiatives – informed by projects such as this – are the only way we are going to begin to make a difference.

Conrad carefully drops the BRUV. Photo: Alexandra Watts

Conrad carefully drops the BRUV. Photo: Alexandra Watts

Shark sanctuaries need enforcement

Publication Specs

Title: Indicators of fishing mortality on reef-shark populations in the world’s first shark sanctuary: the need for surveillance and enforcement
Authors: Gabriel M.S. Vianna, Mark G. Meekan, Jonathan L.W. Ruppert, Tova H. Bornovski, Jessica J. Meeuwig
Journal: Coral Reefs
Year: 2016

When you think of a shark sanctuary what do you imagine? Perhaps a beautiful coral reef that is a blue haven for sharks? Hold that thought while we take a moment to examine reality through the eyes of science.

A recent study in Palau evaluated the world’s first shark sanctuary using underwater visual surveys. This shark sanctuary covers an area of 629,000km2 and was declared in 2009 to try to stop foreign long-line vessels from finning sharks. However, this study demonstrated that illegal, underreported, and unregulated shark fishing is still present within the sanctuary, particularly in remote offshore areas. In these areas, there was an abundance of lost fishing gear and there were fewer and smaller sharks than close to shore.

Sometimes marine protected areas, like shark sanctuaries, get a bad rap as “paper parks”, or protected areas that are essentially just written on paper because they lack the enforcement required to truly protect species living within them. Palau may have created an important management tool, but they are lacking the resources required to follow through on regulations. This study also sheds light on the fact that without baseline data on shark populations within the proposed protected zones, it becomes difficult to monitor their effectiveness over time. If we truly want a blue haven for sharks, the research demonstrates that enforcement within shark sanctuaries is an urgent need. The country’s government is currently expanding enforcement efforts within the shark sanctuary.

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.