The phrase "a decrease in fish" is correct and usable in written English.
It can be used when discussing a reduction in the population or availability of fish, often in environmental or ecological contexts.
Example: "The study revealed a significant decrease in fish populations due to overfishing and habitat destruction."
Alternatives: "a decline in fish" or "a reduction in fish".
In contrast with laboratory studies that reported a decrease in fish survival, the survival of the herring larvae in situ was significantly enhanced by 19 ± 2%.
Unesco last month "noted with concern that the ecosystem of the lake is reported to be under significant stress" and a decrease in fish stocks is just one observable effect.
Data gathered during the health studies demonstrated a decrease in fish consumption among pregnant women (Fitzgerald et al. 1995, 2004) and Mohawk men (Fitzgerald et al. 1999).
In contrast to Degerman et al., they found a decrease in fish species that shared prey with the crayfish, while piscivorous fish showed no such reactions.
Declines in fish stocks were also reported from other countries bordering the North Sea, with a similar pattern everywhere: a decrease in fish but improved catching technology as steam vessels became faster [36], and an expansion in the fish trade [37].
Several documents (e.g. Moore 2006, MMR 2008, MMR 2010) point to a decrease in fish consumption on Rarotonga.
Increased natural disturbance such as storm events may however, contribute to a decrease in fishing activity as the small boats can venture out less often.
Because of requirements that reduced power plant and incinerator emissions, the levels of mercury found in larger animals decreased as well: approximately a 60% decrease in fish and a 70% decrease in birds, though some levels still remain a health concern for people.
"We were surprised to see such a large decrease in fish size," says the study's lead author William Cheung.
From 1999 through 2004, BHg decreased without a concomitant decrease in fish consumption.
Impact on the fisheries was discussed briefly, with a predicted decrease in fish catch volume.
