You need to check the laws of your area on your own. Any place that sells fishing tackle should be able to give you at least some information on the subject or point you to where the regulations are to read them in detail. I don't know the laws up there, but it could well be illegal or require a permit - even for invertebrates like crabs and frequently for things like rocks and sand as well. A lot of little fish you'll run across at certain times of year can be juveniles of much bigger things, making them both a bad choice for a tank and also possibly illegal to collect if the species is regulated by fishing laws. Another problem is that those animals outside your house are COLDWATER and may not even survive at ambient room temperature for very long. There can be some exceptions, but you would have to thoroughly research the animals first - there is no such thing as a generic "mini crab" (some of those as well may be youngsters of crabs that grow quite large) so you need to know the species in your area, read up on them, and learn how to identify them. Tidal invertebrates also tend to be escape artists and/or require land access, and can require specialized setups as a result.