Researchers in Sweden have discovered that traces of many medicines can be found in fish that have been swimming in treated waste water. One such medicine, the hormone levonorgestrel, was found in ...

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 ...

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 ...

A consistent metabolic ratio found across 133 Chinese marine and freshwater fish species provides new evidence in support of the idea that fish become sexually active—and spawn for the first time—in ...

(Beyond Pesticides, June 1, 2010) Atrazine, one of the most commonly used herbicides in the world, has been shown to affect reproduction of fish at concentrations below U.S. Environmental Protection ...

A new peer-reviewed research paper, authored by Shedd Aquarium and published in Journal of Great Lakes Research, assesses the fish species that spawn in the Chicago River to sustain and support ...

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 ...