Earth Observation taken during the Expedition 36 mission ISS036-E-035635 (24 Aug. 2013) --- Plankton bloom and Lake Ontario are featured in this image photographed by an Expedition 36 crew member on the International Space Station. This photograph highlights a late summer plankton bloom visible throughout much of Lake Ontario (one of the Great Lakes, together with Michigan, Superior, Erie, and Huron). Cyanobacteria, or blue-green algae, can reach such large concentrations that they color the water to such an extent that the change is visible from orbit. Harmful algal blooms, or HABs, have been observed in all of the Great Lakes – particularly Lake Erie - and are associated with a variety of causative factors including changes in precipitation; drought; invasive species (quagga, zebra mussels, Asian carp); nutrient loading from runoff and sewage (nitrogen and phosphorus); and warmer average temperatures. In addition to reduced water quality and human health concerns, algal blooms can also lead to hypoxia (reduction of oxygen in the bottom waters) that kills large numbers of fish and other aquatic life. Lake Ontario, like the other Great Lakes Erie, Huron, and Superior is roughly divided between the USA and Canada. The USA side of Lake Ontario has its shoreline along the state of New York, while its Canadian shoreline lies within the province of Ontario. The city of Kingston, Ontario, is visible near the Saint Lawrence River outflow from the lake. Several other landscape features of New York State are visible in the image, including the Finger Lakes region to the west of Syracuse, NY (upper left). To the northeast of Syracuse, the dark wooded slopes of the Adirondack Mountains are visible at lower right. Patchy white cloud cover obscures much of the land surface to the west of Lake Ontario.