How warming oceans increased marine biodiversity – Expert Reaction
New Zealand has marine fossil records that span the course of 40 million years. Now they’re giving us a glimpse at how
marine life responds to a warming ocean.
A new paper in Science has found past biodiversity increased alongside warming ocean temperatures over very long timescales. The study authors
say their results provide a baseline for what should be expected from future natural warming in these kinds of marine
ecosystems.
The SMC asked experts to comment on the research.
Dr Nic Rawlence, Director Otago Palaeogenetics Lab and Senior Lecturer in Ancient DNA, Department of Zoology, University
of Otago, comments:
“The past is the key to the present. How biodiversity responded to climate change in the past can help scientists to
predict how plants and animals may respond to human-driven climate change in the future.
“Tim Womack and colleagues at Victoria University of Wellington and the British Museum of Natural History have used
Aotearoa New Zealand’s shallow marine mollusc (i.e. seashells) fossil record to examine aspects of this big picture
question. This study is only possible with an excellent fossil record, excellent collections and a diverse and well
understood fauna – all of which New Zealand has.
“Using the mollusc fossil record, Tim Womack and colleagues showed that over tens of millions of years, increasing ocean
temperature due to natural climate change led to increased species richness (i.e. new species arising or species
expanding their range) and functional redundancy (i.e. multiple species filling the same role in the ecosystem).
“While this may seem like good news regarding the potential impacts of human-driven climate change, increased species
richness may come at the cost of the complete biological turnover of shallow marine molluscs, as has happened at the
start of the last Ice Age 2.5 million years ago, and increasing numbers of invasive species, both of which would be very
bad indeed.”
No conflict of interest.