Related by context. Frequent words. (Click for all words.) 67 cyanobacteria 63 alga 61 microscopic organisms 61 diatoms 61 microscopic algae 61 dinoflagellates 60 algae 60 Bacteria 59 Microorganisms 58 organisms 58 terrestrial ecosystems 58 Archaea 58 archaea 58 harmful algal blooms 57 Phytoplankton 56 Carotenoids 56 amoebae 56 bacteria fungi 56 nitrogen fixation 56 Microbes 56 toxic algae blooms 56 marine sediments 56 Didymo 55 algal blooms 55 diatom 55 microorganisms 55 multicellular 55 single celled 55 Toxins 55 abiotic 55 bacteria 55 algae blooms 55 microbes 55 single celled organisms 54 phytoplankton 54 Infestations 54 Zebra mussels 54 anoxic 54 nitrogen fixing 54 Fungal 54 Dioxins 54 marine organisms 54 organism 54 Prions 54 marine invertebrates 54 hydrothermal vents 53 toxic algae 53 lichens 53 multicellular organisms 53 Sediments 53 plankton 53 microorganism 53 Photosynthesis 53 Pollutants 53 naturally occurring bacteria 53 Microbial 53 freshwater mussels 53 mycobacteria 53 duckweed 53 sea squirts 53 anaerobic bacteria 52 naturally occurring 52 zooplankton 52 Daphnia 52 aquatic organisms 52 extremophiles 52 damselflies 52 Pathogens 52 fungi 52 Algae 52 gobies 52 Nutrients 52 organic acids 52 microbe 52 oxygen depletion 52 methyl mercury 52 protozoa 52 iron oxides 52 aquatic ecosystems 52 biogenic 52 seagrasses 52 copepods 52 algal 51 Earthworms 51 aquatic habitats 51 algal bloom 51 protozoan 51 toxic algae bloom 51 organic compounds 51 freshwater lakes 51 micro organisms 51 polycyclic aromatic hydrocarbons PAHs 51 Acrylamide 51 biota 51 endocrine disruptors 51 denitrification 51 Hydrilla 51 photosynthetic 51 Contaminants 51 chloroplasts 51 Bacterial