The growing pups of egg-laying sharks rely on the ambient ocean temperature to incubate. But what happens as our climate changes? Noémie is thinking ahead, looking to test the impact of a warming and acidifying ocean on the developing embryos of small-spotted catsharks. She’ll be investigating everything from how the embryo develops to whether the sex ratio of the shark pups is skewed by temperature and whether the warmer waters influence how the hatched pups behave. Noémie hopes to influence managers and policymakers to think about how this shark, and more vulnerable ones, will be impacted by our decisions now.
Since I was a child, I have been attracted to all kinds of animals and I always knew I wanted to work with them. However, I was afraid of the ocean and the creatures in it. It wasn’t until my first dive, at the age of 19, that fear turned into passion. After that, I dedicated my studies to oceanography and marine ecology. I first studied larval fish recruitment during El Niño events as an undergraduate, determined the abundance of small pelagic fish using acoustics in the Bay of Biscay (in France) and, as a Master’s student,...
The main objective of my project is to examine the effects of water acidification and warming on the development, physiology and behaviour of small-spotted catshark embryos and juveniles in an integrated study.
Elasmobranchs have long been considered insensitive to changes in the environment and their vulnerability to climate change has been overlooked, even though such change is likely to increase existing anthropogenic pressures on their communities, particularly by affecting young stages. Since sharks and rays are key species in the marine environment, a sharp decrease in the number of individuals reaching adulthood could lead to the collapse of these species and the balance of the marine food web.
In oviparous shark and ray species, development of the embryo can last several months and is the most vulnerable stage because the eggs are incubated at the temperature of the surrounding water from when they are laid to when they hatch. They open to the environment for about the last two-thirds of the embryo’s development, during which time there is an active exchange of water with the (acidified) water of the external environment. Thus, a temperature increase of up to 4 °C (39 °F) and a pH decrease of 0.5 predicted by 2100 by the IPCC in the north-eastern Atlantic represent a challenge for the survival of oviparous elasmobranchs, which represent 40% of the total number of species. The small-spotted catshark Scyliorhinus canicula is a widely distributed species in the north-eastern Atlantic that is not threatened with extinction. Why study it then? Ultimately, we believe that showing effects on a species that is widely distributed in this area will raise awareness of the fragility of species that do not possess as much ecological versatility to climate change and will help managers and policy-makers to take proactive measures. To this end, the project aims to test the combined effects of water acidification and warming on development, physiology and behaviour in an integrated study that proposes to analyse species’ responses to two ‘Shared Socio-economic Pathways’ scenarios of global socio-economic changes projected to 2100.
Outside the USA, The Bahamas is the only place where Critically Endangered smalltooth sawfish can reliably be found. Tristan wants to ensure that protection measures in The Bahamas are understood and enforced as far as sawfish are concerned to close the current gap between policy and the people. He’ll be using aerial surveys, sonar and BRUVs, combined with interviews that draw on local knowledge, to identify essential sawfish habitats that need protection. Engaging with the community through workshops and by training students and meeting with government, Tristan intends to advocate for smalltooth sawfish protection throughout The Bahamas’ territorial waters.
Steven and Kevin are using genetic techniques to understand how Caribbean reef shark populations are connected across the extent of their range. Populations of this Endangered shark are in decline generally, but where they are managed and there is effective protection, their numbers are stable. With the integration of the correct information, Steven and Kevin are convinced that we can give Caribbean reef sharks a better shot at recovery and population stabilisation. They will also explore any barriers to connectivity, looking to the future recruitment and recovery of these sharks.
With very little information available about Endangered sicklefin devil rays, their seasonal aggregations at sea mounts in the Azores give Sophie an opportunity to learn more about their lives. She will be collecting satellite-tracking data that show how they move in the Azores’ exclusive economic zone. The information she collects will be used to develop maps of how the rays are using the zone and to identify essential areas that multiple species use. With this information at hand, Sophie hopes her work can contribute to a network of marine protected areas.