People

Bio:
Cassy grew up in various locations around the coast of Australia starting in Perth, Western Australia, and ending up in Townsville, North Queensland. After undertaking a research project at the age of 8 focussing on deep-sea anglerfish, she was hooked on the marine world. This may have also been where her interest and excitement over frogfish (to the dismay of her supervisors and anyone who stops long enough to listen) was first sparked. A first-time snorkel at Coral Bay, and a dive with Dad’s giant SCUBA gear in the home pool, followed shortly thereafter cementing the love for being underwater. After completion of undergrad studies and volunteering at the Australian Institute of Marine Science (AIMS) in Townsville, she landed a short-term contract there as a technical assistant on an aquaria-based ecotoxicology study of seagrass that when finished, led to other short-term positions at AIMS until accepting a job at Lizard Island Research Station (LIRS). Between finishing at LIRS and starting her current employment and study adventure she travelled through south-east Asia and worked as a divemaster and survey techniques instructor for Operation Wallacea on Pulau Hoga, Wakatobi Marine Park, Indonesia in both 2015 and 2016. Currently she is working as a research assistant in the Pratchett Lab, and studying part time towards her Master of Philosophy under the supervision of Prof. Morgan Pratchett, Dr. Andrew Hoey, and Dr. Mia Hoogenboom. Her work for the Pratchett Lab includes investigating spatial and temporal variation in population dynamics of crown-of-thorns starfish, investigating traits of corals specific to aquarium trade fisheries, and conducting surveys for coral monitoring (on the Great Barrier Reef and in the Coral Sea).

Personal profiles:
OrcID | ResearchGate | Twitter | Google Scholar

Project title and description: 

“Effects of coral loss on reproductive biology and population viability of Chaetodon Butterflyfish”

Coral reefs worldwide are experiencing severe and sustained habitat degradation, with declines in the abundance of habitat-forming and reef-building corals due to coral bleaching and damage from more frequent and severe storm events. Ongoing declines in abundance of corals have direct effects on many reef-associated organisms and especially those species that rely on coral for food or habit

Collecting CoTS settlement traps on SCUBA. Photo credit: Ciemon Caballes

at. Specialised fishes such as butterflyfish, that have evolved close and critical relationships with scleractinian corals may be extremely vulnerable to widespread reef degradation and coral loss. Exploring changes in abundance and behaviour of coral-feeding butterflyfishes across spatial and temporal gradients in live coral cover will increase our understanding of disturbed coral reef ecosystems. Species-specific vulnerability of coral-feeding butterflyfishes to severe and widespread coral loss will depend not only on their specific reliance on corals, but their sociality and reproductive mode. Most species of butterflyfishes are pair-forming and presumed to be highly monogamous. However, some butterflyfishes such as the obligate corallivore Chaetodon trifascialis (Chevron butterflyfish) exhibit much more complex sociality. In areas with high cover of preferred coral prey, individuals of C. trifascialis reside in small overlapping territories suggesting that this species is haeremic, whereby males mate sequentially with the several different females within their territory. If so, this mating system may be extremely vulnerable to declining availability of coral prey. As their food source diminishes, their territories may become further apart, which may also affect the energy costs of maintaining a harem, decreasing the reproductive viability of fish in that area. It is also unclear how harems form and are maintained, unless C. trifascialis is capable of changing sex, a trait not yet recorded for this genus.

Publications:  

• Thompson CA, Matthews S, Hoey AS, Pratchett MS (2019) Changes in sociality of butterflyfishes linked to population declines and coral loss. Coral Reefs. doi:1007/s00338-019-01792-x
• Burn D, Pratchett MS, Heron SF, Thompson CA, Pratchett DJ, Hoey AS (2018) Limited cross-shelf variation in the growth of three branching corals on Australia’s Great Barrier Reef. Diversity 10 (122). doi:10.3390/d10040122
• Pratchett MS, Thompson CA, Hoey AS, Cowman PF, Wilson SK (2018) Chapter 11: Effects of coral bleaching and coral loss on the structure and function of reef fish assemblages, Page 265-293. In M van Oppen and J Lough (eds). Coral Bleaching: Patterns, Processes, Causes and Consequences. Springer, Heidelberg.
• Pratchett MS, Caballes CF, Wimes JC, Mathews S, Mellin C, Sweatman HPA, Nadler LE, Brodie J, Thompson CA, Hoey J, Bos AR, Byrne M, Messmer V, Valero-Fortunato S, Chen CCM, Buck ACE, Babcock RC, Uthike S (2017) 30 years of research on crown-of-thorns starfish (1986-2016): Scientific advances and emerging opportunities. Diversity 9 (41). doi:10.3390/d9040041
• MacNeil, M.A.; Chong-Seng, K.M.; Pratchett, D.J.; Thompson, C.A.; Messmer, V.; Pratchett, M.S. (2017). Age and Growth of An Outbreaking Acanthaster cf. solaris Population within the Great Barrier Reef. Diversity 9 (18), doi:10.3390/d9010018
• Pratchett, M.S.; Dworjanyn, S.; Mos, B.; Caballes, C.F.; Thompson, C.A.; Blowes, S. (2017). Larval Survivorship and Settlement of Crown-of-Thorns-Starfish (Acanthaster cf. solaris) at Varying Algal Cell Densities. Diversity 9 (1), doi: 10.3390/d9010002

Conference Presentations: 

• Thompson CA, et. al (2018) Long-term changes in sociality of butterflyfishes linked to population declines and coral loss. Australian Society for Fish Biology Conference 2018, 7-11 October, Melbourne, Australia
• Thompson CA (2017) The decline in abundance of Chaetodon butterflyfish and the effects on sociality due to coral loss. Australian Society for Fish Biology Conference 2017, 22-24 July, Albany, Australia.
• Thompson CA (2017) The decline in abundance of Chaetodon butterflyfish and the effects on sociality due to coral loss. 90^th Australian Coral Reef Society Conference, 16-19 July 2017, Townsville, Australia.

Professional Societies: 

• AMSA – Australian Marine Sciences Association (since 2018): North Queensland chapter student council member, 2018-present
• ACRS – Australian Coral Reef Society (since 2017)
• ASFB – Australian Society for Fish Biology (since 2017)

Teaching: 

2016 Reef Survey Techniques instructor – Operation Wallacea, Pulau Hoga, Sulawesi, Indonesia