Marine deforestation combined with growing demands from the alginate market, reliant largely on wild kelp harvesting, has heightened concern for the potential broad and cascading effects of kelp removal on ecosystem functioning and services. Kelps are foundation species providing key habitat and resources for other organisms, including other fished species and thus their overharvest is often anticipated to have important and complex ecological and socioeconomical consequences. However, constructing expectations and strategies as to where, when, how, or how much kelp can be safely removed is often difficult to discern from the array of individual research studies quantifying the effects of kelp removal on kelp populations and associated communities because evidence appears mixed and results could depend on kelp species, removal methods and monitoring scales. This review of observational and experimental studies aims to identify and synthesize the effects of kelp removal, their monitoring, and the trends of significant effects. Here we show that monitoring has focused mainly on kelp populations effects, and effects on the local associated algae and sessile fauna. Almost no experiment assessed spatial patterns resulting from kelp removal. Most statistically tested effects of individual studies (64.3% of total) were non-significant. From those considered statistically significant, most (60.1%) showed decreasing trends (e.g., in kelp size, abundance, reproductive potential and the abundance and diversity of some associated taxa). Long-term studies and evaluated responses to kelp removal at the relatively large spatial scales (in extent and grain size) that include the patchy mosaics of kelp forests and critically match the geographic scale over which management strategies are applied were scarce. We note that temporal and spatial monitoring scales appear limited when compared to kelp's lifespan and dispersal potential, as well as the scale of commercial harvest areas. Thus, we seek to call attention to the need for expanding monitoring scales and metrics to better meet the knowledge required to manage kelp forests and fisheries, which becomes urgent in countries where kelp fisheries control is difficult and as the effects could be magnified by climate change.