Altered Fish Communities' Dynamics in 26 Healthy Lakes in Latvia—Possible Impacts of Limited Fisheries Management

ABSTRACT This study investigated fish community dynamics in 26 healthy Latvian lakes to determine the balance between top‐down versus bottom‐up controls. We employed a multi‐methodological approach, combining multi‐mesh gillnetting with structured stakeholder interviews and management plan analysis to quantify anthropogenic pressures. We hypothesized that fish community regulation would diverge based on the presence or absence of top predators. Results demonstrated a strong negative correlation between large piscivores and omnivorous fish biomass, validating trophic cascade predictions. While lake area and depth influenced fish length, bottom‐up drivers like total phosphorus had limited explanatory capacity. Interestingly, structured stakeholder interviews revealed that fisheries resource management might be an important predictor of ecosystem health. Lakes with perceived low illegal fishing pressures maintained healthy predator proportions, while those under higher pressure had notably fewer large piscivorous fish. We conclude that in otherwise healthy lakes, effective fisheries regulations' enforcement might be more critical than nutrient management for maintaining balanced fish communities.