Human activities are pushing all kinds of marine species to the edge of extinction in all types of ocean habitats. These ten represent the tip of the iceberg of imperiled marine biodiversity.

Vaquita (Phocoena sinus):It is found only in Mexico's upper Gulf of California, where threats include fishing and habitat loss. About 250 remain.

Mediterranean monk seal (Monachus monachus):Fishing activities, habitat loss and introduced species have diminished this species. Roughly 300 are believed alive in the wild.

Christmas Island frigate bird (Fregata andrewsi):Located on Australia's Christmas Island, it is threatened by introduced species. An estimated 3,200 remain.

Leatherback sea turtle (Dermochelys coriacea):The largest of the sea turtles, it is rapidly declining in many areas. Off the Pacific coast of Mexico, fewer than 100 remain.

Totoaba (Totoaba macdonaldi):Another species native to the upper Gulf of California, it is threatened by poaching activities and shrimp trawlers.

Brazilian guitarfish (Rhinobatos horkelii):Located in the western Atlantic, its population in Brazil decreased 96 percent from 1984-1994, largely due to fishing.

Speckled hind (Epinephelus drummondhayi):Overfishing has decimated this popular fish, which is found in the western Atlantic from Bermuda to the Gulf of Mexico.

North Atlantic right whale (Eubalaena glacialis):This species is threatened by fishing nets, pollution and ship collisions. In the Atlantic, fewer than 250 remain.

White abalone (Haliotis sorenseni):Past exploitation severely impacted this species. Fewer than 2,000 remain, largely off southern California and Mexico.

Johnson's seagrass (Halophila johnsonii):Located off the Florida coast, this smallest of seagrasses is threatened by intensive coastal development and boating.