In research just published in the journal Functional Ecology, a James Cook University study covering more than a quarter of a century has found coral bleaching has changed the type of fish found on the Great Barrier Reef.
Leading the innovative study, JCU Ph.D. student Helen Yan measured fish biomass production (the weight of new fish flesh accumulated each day) on the GBR over 26 years. She explained, “Species richness (the number of different types of fish) declined following the 1998 bleaching event, but later rebounded and have remained relatively stable,”. But she said there has been a considerable reshuffling of fish types in regard to their respective numbers following the first mass coral bleaching event in 1998.
She said brightly coloured fish, which are associated with high coral cover, declined drastically immediately after the 1998 bleaching event and that fish shifted towards communities that are characteristic of degraded reef habitats.
“It appears the loss of corals and coral-associated fishes creates new niches that can be quickly colonized by fishes that prefer degraded reefs and are less dependent on corals,” said Ms. Yan.
Image: A school of fish swims in the Coral Sea. Credit: Rick Stuart-Smith
More information: Helen F. Yan et al, Multi‐decadal stability of fish productivity despite increasing coral reef degradation, Functional Ecology (2023). DOI: 10.1111/1365-2435.14319
Journal information: Functional Ecology