Images

Silver carp are a large a troublesome invasive species from Asia found in the great rivers of the central United States. Silver carp have been observed to jump in response to rocks thrown in the water, passing trains, geese taking off from the water, or just when they unexpectedly find themselves in a tight place.

African rock pythons are the largest snake in Africa, but now some have been found in Florida. They can eat goats, warthogs, and even crocodiles. In Florida, they are an invasive species.

Image of the silica cell wall of the diatom 'Didymosphenia geminata' from Rio Espolon, Chile. The sample was collected early in 2010 from an extensive bloom on the river. The image has been processed to show the silica cell wall, removing the organic cell contents and the stalk
material.

This aerial view shows how Faka Union Canal (visible as a straight channel of water) connects the coastal environment, where manatees feed, to freshwater inlets. The Ten Thousand Islands region in the foreground supports sea grass beds where manatees feed.

A manatee feeds on sea grass beds in Ten Thousand Islands region of Florida.

Drought and climate change are causing extensive forest dieback in the U.S. West as well as worldwide. These photos show dead ponderosa pines in the Jemez Mountains of New Mexico killed by a combination of drought stress and attacks by bark beetles on weakened trees.

Pallid sturgeon caught in the Lower Missouri River.

SRX receivers (left) and a ruggedized laptop computer (right) are essential tools for telemetry tracking on the Lower Missouri River.

Wood frog embryos in a partly ice-covered Wisconsin wetland. Interconnected wetlands and uplands are critical elements of most North American landscapes and support our quality of life in profound ways. To provide much-needed information, the USGS is leading a growing network of U.S.

A brackish marsh in the Mississippi River Delta.

Research vessel Theodore R. Schmudde anchors in the swift water before lowering the sand cam (metal object suspended to the pulleys at the front of the boat).

Weighted, small mesh nets (left and right side of the boat attached to winches) are lowered to the bottom of the river near potential spawning sites.  After a set period of time, the nets are raised and the contents are hand-picked for any Acipenseriformes (sturgeon and paddlefish) larvae.  Samples are preserved for laboratory identification and genetic an

This lichen, Lobaria pulmonaria, is found in northern North America, where it is becoming rare in places.  Lichens -- which are often mistaken for moss -- are unusual plant-like organisms that are actually symbioses of fungi, algae and bacteria living together.

Acoustic telemetry tags have to be fairly small to fit inside a five to fifteen pound pallid sturgeon.  The average tag is about the size of your ring finger (60-90 mm long and 16 mm diameter).  That means the battery that powers the acoustic tag is small, too.  A small battery means that the signal from the tag is relatively weak, or fairly quiet.

Biologists prepare to tandem track a flooded Missouri River in search of telemetered Pallid Sturgeon.

A radio tracking boat cruises down a flooded Yellowstone River in search of telemetered pallid sturgeon. 

After a long struggle to position the fish just right, a double-crested cormorant finishes off a relatively young spotted gar.

Though not as charismatic, the underwater periphyton and other vegetation are the primary support for all other life in the ecosystem.

A pair of pelicans and in the background a Great Blue Heron in a Wetland at Summerlake Wildlife Area.

Bumble bee over a cone flower.

Three bumble bees around a cone flower.