Population ecology 25 Ecology 21 population ecology 13 Community ecology 11 Fish populations - ecology 10 Population Ecology 10 Biology 7 Marine ecology 6 Fish- Population ecology-- dynamics 4 Pollution 4 Biotic communities 3 Community Ecology 3 Environmental toxicology 3 Evolutionary ecology 3 Geographical ecology 3 Oceanographic environment 3 Plant population 3 Population biology 3 Zoogeography 3 community ecology 3 evolutionary ecology 3 Animal ecology 2 Animal populations 2 Animal populations-Ecology 2 BIODIVERSITY 2 Biogeochemical cycles 2 Dams 2 Ecosystems 2 Energy 2 Evolution 2