Several U.S. research teams report reproductive problems in Gulf Coast fish that periodically encounter oxygen at concentrations as low as those in so-called dead zones (SN: 6/5/04, p. 360: Dead ...

WASHINGTON — An all-female freshwater fish species called the Amazon molly that inhabits rivers and creeks along the Texas-Mexico border is living proof that sexual reproduction may be vastly ...

FRENCH RIVER, Minn. - The St. Louis River has a healthy population of adult lake sturgeon, but those fish are not producing the numbers of young fish that biologists had hoped to see. Few adult ...

Low oxygen levels in coastal waters interfere with fish reproduction by disrupting the fishes' hormones, a marine scientist has found. Incidents of seasonal low levels of oxygen, known as hypoxia, ...

Polar fish experience lower mortality than tropical fish, allowing them to delay reproduction until later in life when they are larger and can produce more eggs, according to a study by Mariana ...

Every year in September and October, fisheries biologists for the North Dakota Game and Fish Department conduct fall fish reproduction surveys on lakes and rivers in North Dakota. Game and Fish ...

Seasonal hypoxia, when dissolved oxygen concentrations in water drop below 2 milligrams per liter, is a normal summer occurrence in estuaries. Over the past 20 years, however, pollution has increased ...

The ability of fish to breed has been drastically affected, a study reveals, by 'gender bending' chemicals which are washed into rivers and oceans as a result of human activities. The ability of fish ...