The phrase "fish decreased" is a grammatically correct and commonly used phrase in written English.
It can be used to describe a decrease or decline in the number or amount of fish. Example: "Due to overfishing and pollution, the fish population in the lake decreased significantly over the past decade."
Total species richness, density and biomass of fish, decreased at both sites over the 30-year period.
From 2014 to 2015, the operational hygiene inspection scores of milk and meat increased and of fish decreased.
Fish decreased the dissolved oxygen (DO) and pH value compared to rice only, especially when supplementary feed was provided.
The United Nations Foodd and Agricultural Organisation reports that the haul of Caspian kutum (mahi sefid), one of the most common fish, decreased from the 1950s to the 1990s from 1,250 tonnes per year to 210.
Naphthalene treatment produced in previtellogenic fish decreased 17β-estradiol levels in plasma, increased plasma glucose or decreased liver gluconeogenic capacity whereas no major effects were noticed on parameters involved in lipid, amino acid and lactate metabolism.
Japanese medaka (Oryzias latipes) were fed dietary Microcystin-LR (0, 0.46, 0.85, 2.01 and 3.93 μg MC-LR/g dry diet for 8 weeks at 25 °C. The results revealed that dietary MC-LR inhibited growth at the end of 8 weeks. The survival of embryos and the RNA/DNA ratio of whole fish decreased significantly (P < 0.05) in fish fed 3.93 μg MC-LR/g dry diet.
Moreover, fish density can affect the efficiency of feed utilization; as the number of fish stocked in a pond increases, the amount of feed available to each fish decreases ([Chang 1988]).
The affected feed utilization in the present study is much more expected; as the number of fish stocked in an aquarium increases, the amount of feed available to each fish decreases ([Chang 1988]).
The streamlined body of the fish decreases the amount of friction from the water.
As a result, populations of large-bodied herbivorous zooplankton, which are consumed by small pelagic fishes, decreased, which in turn led to an increase in the phytoplankton.
For example, demersal destructive (for example, trawl) fishing decreased significantly in many European countries, pelagic high bycatch (for example, longline) fishing decreased in several parts of the Middle East, sea surface temperature anomalies decreased in the Line Islands in the Pacific and around Alaska, USA and nutrient input decreased in the Adriatic Sea.
