Squid and octopus populations on the rise
A recent study聽in Current Biology聽reveals that cephalopod populations, including squid, octopuses, and cuttlefish, have increased globally since the 1950s.
A recent study聽in Current Biology聽reveals that cephalopod populations, including squid, octopuses, and cuttlefish, have increased globally since the 1950s.
Human alteration of the environment has plagued the world鈥檚 oceans, contributing to both rising temperatures and acidification of waters.聽This change has led to the depletion of many marine species, but, as a聽recent study聽in聽Current Biology聽reveals, cephalopod populations, including squid, octopuses, and cuttlefish, have increased globally since the 1950s.
In the 1990s, scientists noticed a growth in cephalopod catches at fisheries across the world.聽From this data, scientists speculated that the cephalopod population was increasing.聽Because misreporting catch numbers is common and numerous factors can influence them, however, they could not conclude that the cephalopod population was increasing without a more rigorous study.聽
Dr. Zoe Doubleday, a marine biologist at the University of Adelaide in Australia and lead author of the study, and her research team sought out data that would provide a more reliable estimate of population numbers.聽After months of research, they obtained 60 years of scientific survey data and fisheries records with which to work.
A thorough evaluation of this data provided a clear conclusion: worldwide cephalopod populations have increased significantly since the 1950s.聽Cephalopods, an invertebrate group, include squid, octopuses, and cuttlefish.聽Why are cephalopod populations, unlike most marine species, booming? The study鈥檚 researchers say that the group is very efficient at adapting to changes in the environment, enabling them to overcome the disturbances that have contributed to the depletion of other species.聽Although they only live for one to two years, they produce many eggs, and these eggs have low mortality rates, allowing them to adapt rapidly to environmental changes.
The researchers do note, however, that they can only speculate about which environmental changes are responsible for the increasing population.聽It is possible that when humans catch predators of cephalopods, they create a gap in the food chain for this adaptable species to fill.聽Another factor that may facilitate the population growth is rising temperatures.聽Warmer temperatures may make them reproduce more quickly and, in turn, increase the rate at which the population increases.聽Dr. Doubleday told聽Science Magazine聽that pinpointing causal relationships will require more research, noting that 鈥渋t鈥檚 all speculation, what鈥檚 causing them to increase.鈥�
Regardless of the cause, the population increase could dramatically affect our oceans.聽While it could benefit the sharks, whales, and large fish that feed upon them, it could also lead to unstable fishing profits.聽The researchers acknowledge that we will only realize this impact with time.聽
This story originally appeared on Food Tank.