Sharks play an essential rol in the health of our oceans

Information, News, Research

The EEA Meeting 2014 – A Summary

By Dorien Schröder, Dutch Shark Society, dorien@dutchsharksociety.org

 

safe_image (1)

 

The first day of the meetingen of the European Elasmobranch Association was themed Elasmobranch Policy. The conference was opened with a video message from Sylvia Earle, arranged by the Dutch Shark Society, stating that elasmobranch species are greatly reduced due to human actions and we’re at a turning point. That is the message of this conference: we CAN make a difference

Euan Dunn of the Royal Society for the Protection of Birds was the first keynote speaker of the day, talking about their experiences setting up Marine Protected Areas (MPAs) for seabirds and how their experiences can help with setting up MPAs for elasmobranchs. The seabird productivity was reduced by 50% due to sea warming and sandeel fisheries, after which the seabird productivity was used as a proxy for fishery measures. Euan Dunn emphasized that in setting up MPAs, stakeholder engagement is key, as well as data collection on the species the MPA was set up for.
The second keynote speaker of the day, Angelo Villagomez of Pew,  also touched on this data collection. It is part of what he calls the Circle of Shame where ‘no data’ -> ‘no science’ -> ‘no management’ -> ‘overfishing’. The Pew Charitable Trust is working towards breaking this cycle by helping implement legislation and advocacy for sharks around the work. Their message is very clear by saying: sharks are cool, diverse, important, more worth alive, wildlife and in trouble.

Ali Hood was speaking for Shark Trust to introduce their ‘No Limits, No Future’ program (http://www.nolimitsnofuture.org/). This program is aimed towards increasing the public passion for shark conservation. They have already accomplished finning regulation and catch limits, but they also want to establish science based catch limits. These catch limits are also discussed by John Richardson from the Shark Trust. He is looking at setting up a guide for fisherman depicting a regional focus on the species and their guidelines. This guide would be useful for seafood retailers, the fishing industry and consumers.

In the Dutch Caribbean this Circle of Shame is already being broken. Adolphe Debrot of WUR was involved in research on the shark abundance of the ABC islands. In the 1950s, sharks could be seen on the reefs regularly while snorkelling, however half a decade later sharks are a rare sight on the shallow reefs. Recently they had the chance to be involved in a deep sea exploration, where they found eight sharks of six different species during 24 deep sea dives beyond 100 meters. One of those was the rare grey six-gilled shark. Kalli de Meyer of the Dutch Caribbean Nature Alliance saw that the shark populations were strongly depleted. There is little information on shark populations and fishing, as well as a negative public opinion and poor enforcement of legislation. The Kingdom does care about conservation though and on several island research and outreach programs have been started. They are planning on implementing a shark sanctuary, banning shark fishing and to encourage islanders to benefit from sharks in the form of tourism. They want to do this with the help of fishermen, scientists and local communities.

Today, the ‘no management’ aspect of the Cycle of Shame has been broken, tomorrow we will look at the ‘no data’ and ‘no science’ with some without doubt interesting presentations.
The morning of the second day was themed Stock Assessment & Management.

Keynote speaker Enric Cortés talked about different stock assessment models used for Atlantic sharks in the USA. He said that the model you use has to evolve with the data availability. Since so much research is data poor, he emphasised that data-poor and data-moderate models should be developed.

A good alternative stock assessment models is the use of genetics, on which we’ve seen a few presentations today. Lilian Lieber took mucus samples of basking sharks and used the genetic information to show high connectivity in the North East Atlantic population and a high allelic richness. From the samples, they could calculate an effective population size of 740 and a cencus of 7000 basking sharks. She is not alone in using genetics to learn more about shark populations. Aletta Bester used molecular techniques to identify similar species, a common problem in highly diverse South Africa. She also showed multiple paternity in dusky sharks, blacktip sharks and scalloped hammerheads. Michelle Frost worked with mtDNA of skates to show that there is close to no genetic variation in flapper and blue skate around the British Isles.
With tags getting smaller and are able to store more information, they are becoming an important tool in showing habitat use of shark populations. James Thorburn tagged spurdogs and found they resided in a loch that was a thermal niche over winter. Most age components were present, which indicates this loch could be an effective small scale protection tool to maintain a nationwide population. Rob Bullock used an accelerometer combined with an acoustic tag to find head trashing in the shark movements that indicate a prey handling event, more commonly known as a successful hunt. He was able to show tidally mediated foraging habits in select areas with high prey abundance.
Citizen science is a good tool to use local knowledge or extra help to collect more data to enforce other data collected research. The first results of the Great Eggcase Hunt of the Shark Trust (www.eggcase.org) shows that eggcase finds correlate with known geographic ranges of species. Adi Barash interviewed local fishermen to prove that shark abundance has increased around power plants in the past 20 years. Niels Brevé also made a case for involving anglers in elasmobranch research, by showing the success of their tagging program with a 20 year recapture of a skate and long migrations by tope and smoothound sharks. Erwin Winter also used data from sharks tagged by local anglers to show the Oosterschelde is a possible nursery and Neeltje Jans a summer feeding ground for starry smoothound sharks.
All these new developments will hopefully break the ‘no data’ part of the Cycle of Shame. Tomorrow will bring some talks on Husbandry & Elasmobranch Biology, breaking the ‘no science’ part.

 

The last day of the conference was themed Husbandry & Elasmobranch Biology. João Correira was the keynote speaker, giving us an insight in public aquaria and how they’ve changed in recent years to improve their reputation. He started by explaining how he used to be ‘the cool guy at the party’, working at an aquarium, however with public awareness being raised through the aquaria, so was the demand to change the way animals were being held. Nowadays aquaria are sharing veterinarian procedures and data, as well as working together with breeding programs. A lot of the bigger aquaria are also investing in conservation through for instance the development of seafood watchcards and supporting local and international research projects.
We saw a few talks from the aquarist sector today, all with a different focus. Max Janse from Burgers Zoo gave us an insight into how their monitoring programs work. Jean-Dénis Hibbit from SEALIFE went into detail about one of their monitoring projects, the managing of the genetics of undulate ray in captivity. They are looking at different minimally invasive ways of taking DNA samples, that are going to be used to isolate nucleic DNA. With that maternal and paternal DNA can be analysed to prevent inbreeding.

At the end of this Session, Georgina Wiersma of the Dutch Shark Society presented its work during its first two years.

 

Genetics were also broadly use today in the Elasmobranch Biology part of the conference. Dominic Swift presented on aplacental viviparity in tiger sharks, the only species in the Carcharhinids not to grow a placenta. He hypothesized that this was an evolutionary reversal, most likely by positive selection or change in gene expression. After DNA analysis he found eight genes in the tiger shark lineage had mutated as a result of positive selection. Four genes were responsible for the nervous system and immunity. Shark pups that develop placentally grow a bigger brain, which consumes more energy and the placenta connects shark pups to the mother, which is a compromise to the immune system. One gene was responsible for sexual reproduction by reducing mRNA synthesis and thereby slowing reproduction to a triannual cycle rather than biannual which is the norm in most other sharks. Another gene caused structural changes to the morphogenesis of the yolk sac into placenta.

Aude Gautier has already been successful in isolating spermatogonial stem cells (SSC) and give a morphological description. She has molecular markers to identify them and has accomplished in vitro SSC model establishment. In the future she wants to look at using SSC from endangered species to do xenotransplantation in similar species to aid preservation. Allison Luger tried to explain variety in jaw morphology by comparing diet and phylogeny in 87 shark species. She found that there is definitely adaptation based on diet, but also phylogenetics. By creating 3D images of jaws through CT scans she was able to create three morphological groups based on jaw structure: fish and cephalopod eaters, hard benthos eaters and soft benthos eaters.
The conference was concluded by awarding James Thorburn for best presentation and Lana Allertz won best poster presentation. In conclusion, the European Elasmobranch Association conference was a big success, with interesting speakers and a beautiful venue.

See you all next year in Portugal!

Comments are closed.

Contact info

You can contact us at +31 (0) 6 12195593 Or per email at: georgina@dutchsharksociety.org

Partner organisations

De Dutch Shark Society is proud to be a partner of several organisations. Check out our Mission page!
Show Buttons
Share On Facebook
Share On Twitter
Share On Pinterest
Contact us
Hide Buttons