Related by context. Frequent words. (Click for all words.) 72 invasive species 64 invasives 63 Zebra mussels 61 invasive weeds 59 invasive weed 57 nonnative species 56 aquatic invasive species 56 pests 55 Overfishing 55 Invasive 55 noxious weeds 55 species 54 aquatic species 54 zebra mussels 53 aquatic ecosystems 53 Emerald Ash Borer 53 gypsy moths 53 Invasive Species 52 Insects 52 ecosystems 52 noxious weed 51 coastal ecosystems 51 bark beetle 51 feral pigs 51 zebra mussel 51 milfoil 51 garlic mustard 51 aquatic vegetation 50 emerald ash borer 50 Bald eagles 50 pest 50 Global warming 50 eelgrass 50 wildlife 50 insects 50 insect 49 insect pests 49 Bed bugs 49 pine beetles 49 marine ecosystems 49 waterways 49 nutrient pollution 49 water hyacinth 49 Pests 49 feral hogs 48 ash borer 48 cormorants 48 critters 48 bullfrogs 48 hydrilla 48 quagga mussels 48 gypsy moth 48 ash trees 48 beavers 48 beetles 48 habitats 48 Viruses 47 Canada geese 47 aquatic organisms 47 wetlands 47 algal blooms 47 ecological 47 toxic algae 47 deer ticks 47 forest ecosystems 47 eutrophication 47 cheatgrass 47 ocean ecosystems 47 snapping turtles 47 biodiversity 47 invertebrates 47 gray squirrels 47 Droughts 47 Geese 46 Asian carp 46 wildlife habitats 46 wetland habitat 46 mollusks 46 silver carp 46 migratory species 46 Atrazine 46 Plastic bags 46 habitat 46 invasive 46 honeybees 46 Pesticides 46 borers 46 wildlife habitat 46 mussels 46 woody plants 46 weeds 46 mammals 45 algae blooms 45 fungi 45 pine beetle 45 Wind turbines 45 fragile ecosystems 45 snails 45 beetle 45 infestations 45 ecology