ENVIRONMENTAL CHANGE

CLIMATE CHANGE

  • Thermal stressors on a coral reef fish's stress responseSlide1

We visited the Iles Eparses in the Mozambique Channel on the Marion Dufresne and measured the cortisol response of skunk anemonefish, Amphiprion akallopisos, to a generic stressor. Reef populations on these islands are rarely exposed to any anthropogenic stressors, but have experienced different thermal histories over the last 15 years. We found that those fish populations exposed to higher maximum sea surface temperatures showed greater cortisol responses to a generic stressor. We suggest that the stress-responses axis could have been permanently modified following a thermal stressors event. Such a modification could be adaptive if repeated thermal stress events were common within a reef organism's lifetime (Mills et al., 2015).

 

  • Ocean acidification and thermal stressors

Fabien_DSC_1804We are working on the effects of both ocean acidification and thermal stress on embyronic development in the sea hare, Stylocheilus striatus.

An elevated thermal environment accelerates planktotrophic development of this important benthic invertebrate, possibly at the cost of reducing fitness and increasing mortality (Horwitz et al., 2017). In collaboration with Eric Armstrong and Jonathan Stillman we have also found that oceanic conditions congruent with climate change predictions for the end of the twenty-first century suppress successful development in S. striatus embryos, potentially reducing their viability as pelagic larvae (Armstrong et al, 2017).

We are also evaluating whether developmental /or transgenerational acclimation by Stylocheilus striatus, to the combined stressors will mitigate the effects on embyronic development.

Read article (in french)


BOAT NOISE POLLUTION

In collaboration with Sophie Nedelec, Andy Radford and Steve Simpson from the Universities of Bristol and Exeter in the UK, we are investigating the effects of boat noise pollution on development, physiology and behaviour and whether marine organisms can habituate to boat noise.

 

  • Embryonic development in the opistobranch, Stylocheilus striatus.

Boat noise playback reduced successful development of embyros and increased the mortality of recently hatched larvae (Holles et al., 2014).

  • Habituation in juvenile and adult reef fish

Repeated exposure of boat noise playback to juvenile damselfish, Dascyllus trimaculatus, over three weeks revealed physiological habituation (Nedelec et al., 2017). In addition, a comparison of short- and long-term exposure of boat noise playback to adult clownfish, Amphiprion chrysopterus, suggests behavioural, but not hormonal habituation (Mills et al., in prep).

  • Honesty of client-cleaner interactionsP7080012.JPG

In collaboration with Isabelle Côté, from Simon Fraser University, our "dream team"  found that boat passage affects the honesty of the interactions between cleanerfish and their clients, despite cheating more, cleanerfish are not punished correspondingly (Nedelec et al., in press).

 


TOURISM

In collaboration with Johann Mourier and Serge Planes and their work on shark populations in the Pacific, we are investigating the effects of tourism on their hormones and metabolism.

  • Impacts of ray- and shark-feeding on sharks

Effects of rIMG_0404.JPGay- and shark-feeding on the growth, reproduction and metabolism of the blacktip reef shark Carcharhinus melanopterus was investigated in Moorea (Mills et al., 2010; Mourier et al., 2013; Mills et al., in prep).



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