Glacial melting: an overlooked threat to Antarctic krill
نویسندگان
چکیده
Strandings of marine animals are relatively common in marine systems. However, the underlying mechanisms are poorly understood. We observed mass strandings of krill in Antarctica that appeared to be linked to the presence of glacial meltwater. Climate-induced glacial meltwater leads to an increased occurrence of suspended particles in the sea, which is known to affect the physiology of aquatic organisms. Here, we study the effect of suspended inorganic particles on krill in relation to krill mortality events observed in Potter Cove, Antarctica, between 2003 and 2012. The experimental results showed that large quantities of lithogenic particles affected krill feeding, absorption capacity and performance after only 24 h of exposure. Negative effects were related to both the threshold concentrations and the size of the suspended particles. Analysis of the stomach contents of stranded krill showed large quantities of large particles ( > 10(6 )μm(3)), which were most likely mobilized by glacial meltwater. Ongoing climate-induced glacial melting may impact the coastal ecosystems of Antarctica that rely on krill.
منابع مشابه
Nutrient Cycling: Are Antarctic Krill a Previously Overlooked Source in the Marine Iron Cycle?
Iron limits phytoplankton growth in large areas of the Southern Ocean. A new study shows that Antarctic krill play a crucial role in the recycling of iron in the iron-limited waters.
متن کاملContributions to International Polar Year Science
The life cycle of the Antarctic krill, Euphausia superba, intersects in space and time with the expansion and contraction of annual pack ice. Consequently, the circumpolar distribution of krill has often been defi ned as generally limited to an area bounded by the maximum extent of pack ice. Pack ice has both direct and indirect effects on the life cycle of krill. During the austral winter, lar...
متن کاملModeling studies of antarctic krill Euphausia superba survival during transport across the Scotia Sea
Antarctic krill Euphausia superba spawned on the outer continental shelf of the west Antarctic Peninsula can be entrained into the Southern Front of the Antarctic Circumpolar Current and transported across the Scotia Sea to South Georgia. A time-dependent, size-structured, physiologically based krill growth model was used to assess the food resources that are needed to sustain Antarctic krill d...
متن کاملZooplankton Gut Passage Mobilizes Lithogenic Iron for Ocean Productivity
Iron is an essential nutrient for phytoplankton, but low concentrations limit primary production and associated atmospheric carbon drawdown in large parts of the world's oceans [1, 2]. Lithogenic particles deriving from aeolian dust deposition, glacial runoff, or river discharges can form an important source if the attached iron becomes dissolved and therefore bioavailable [3-5]. Acidic digesti...
متن کاملAt-Sea Distribution and Prey Selection of Antarctic Petrels and Commercial Krill Fisheries
Commercial fisheries may impact marine ecosystems and affect populations of predators like seabirds. In the Southern Ocean, there is an extensive fishery for Antarctic krill Euphausia superba that is projected to increase further. Comparing distribution and prey selection of fishing operations versus predators is needed to predict fishery-related impacts on krill-dependent predators. In this co...
متن کامل