egg in water add salt slowly (teaspoon by teaspoon) what happens
warm water (dyed red with food colouring) and cold water (blue!) what happens when you put warm into cold? the other way round??
How can you group animals, common features shells etc (needs access to around 20 diff spp we use echinoderms, molluscs and crustaceans)
Who eats what? animals are grouped as filter feeders, grazers, predators and scavengers. we also have seaweed and plankton (both types) Discussion of adaptations for shore life and food capture (also predator avoidance) at the end kids can usually draw up a food web and point ot features of various animals. Usually ties in to who is the biggest predator....us! have a display of products with marine components....incl toothpaste, tinned fish, pickled jellyfish, surimi, spirulina etc etc
create a food pyramid with cards phytoplankton to zooplankton to small fish to large fish to white shark. Usually many phytos gets less through each level to 1 white shark, forms a triangle shape. Next the educator is a careless human factory owner (for eg) who dumps toxic waste into water (small rocks)the phytos get 1 or 2 each, they can still function ...little effect on them, the zooplankton eats them gets all the toxin etc on up to shark which gets overloaded.......demonstrates biomagnification.