The suitability of a single intertidal fish trap for the assessment of long-term trends in fish and epibenthic invertebrate populations

The suitability of a single intertidal fish trap for the assessment of long-term trends in fish and epibenthic invertebrate relies upon the assumption of an on-average constant sampling fraction from the study population. This assumption was examined by comparing trends over years in five different traps within the study area. For some species, like cod, the traps showed more or less parallel fluctuations. This is in agreement with the assumption. However, for other species, like mackerel, the assumption was invalidated by distinct trends over years.Publication no. 62 of the project Applied Scientific Research Netherlands Institute for Sea Research (BEWON)