Anthropogenic impacts on our Ocean span hundreds of years and the effects of pollutants and xenobiotics have been documented for over two millennia. Those impacts, concomitant with climate change, have accelerated in recent years owing to insufficient efforts to mitigate contamination by many different pollutants, reducing fossil fuel consumption, and limiting the release of greenhouse gases. In parallel, biomes, biota, and biodiversity have suffered increased loss with extinction rates 50-500 times that of background levels in the wake of inadequate environmental conservation efforts. Under these circumstances, certain organisms are better suited than others to provide information on the status of the environment and the functioning of ecosystems; what we know to be ecological or biological indicators. One such group are the meiobenthos: easily sampled because of their microscopic nature, abundant and prevalent globally, and exhibiting a spectrum of characteristics and sensitivities that allow us to detect different types of ecological impacts and changes. Of note are the Nematoda: arguably the most abundant animal on this Earth, pervasive inhabitants even of the most extreme environments, and exorbitant in terms of diversity - the latter perhaps counterintuitive to what its simple body plan and lack of appendages would suggest. Nematodes have been used to infer ecological conditions for over half a century, but especially in the last couple of decades has their use as indicators grown and been accentuated in literature. In this presentation, we will highlight some of the characteristics that render Meiobenthos and particularly Nematoda as good indicator taxa and based on our studies, discuss the use of them in systems from the coast to the deep sea. While Nematoda serve this purpose, there is still much to learn, and current techniques and metrics merit continued research and advances to optimize how much information we can obtain from them.