Climate change may be coming for some sharks, new research suggests. The study found that eggs belonging to the small-spotted catshark are substantially less likely to survive under the worst case climate scenario by 2100. The findings still indicate that these sharks can continue to thrive under less disastrous climate conditions.
“The small-spotted catshark is already experiencing habitat loss in coastal areas, particularly during the summer months when egg-laying is at its peak,” said lead researcher Noémie Coulon, a PhD student at BOREA, in aTo better find out how these sharks will fare in the future, Coulon and her team raised and monitored batches of their eggs under three different scenarios. These scenarios were distinguished by the temperature and pH of the water that the eggs were kept in.
In the worst case scenario, only 11% of the small-spotted shark eggs hatched, compared to the 81% and 83% survival rate seen under the control and SSP2 condition, respectively. The embryos inside these eggs consumed less yolk, grew at a slower rate, and were less able to successfully form their internal gills.
“The hatching success of embryos is a crucial factor for population dynamics. In the case of skates and sharks, which have a slow pace of life, low hatching rates could be critical for population renewal,” Coulon said.). So the team’s overall results could be taken as somewhat reassuring, the researchers say. If humans can prevent the worst climate future possible, then these fish will still be around and kicking swimming.