Sometimes there can be significant differences between observations in the field and peer-reviewed scientific opinion. This is not because the observations are not good. It is because correct interpretation of observations require systematic data and models; in short, a broader context.
Often cited cases include forage fish, which tend to aggregate. From the point of view of fishing activity, you can end up with very high concentrations of shrimp or forage fish in one place. However, when we do the assessment of indices or biomass at the scale of the study area, in some cases we can see a decrease in stocks.