timber, deep harbors, and fish
harbors
Its natural resources were timber, fish, and deep harbors.
These are generally called "Natural Harbors"
New England was well suited for commerce because of good coastal harbors.
There are many different harbors in this world, some having very deep water, and others being shallow. Ships enter harbors all the time.
it has good terrain and climate, good for fishing
Your grammar is a bit...ambiguous, but perhaps you mean "did Europe's navigable rivers and good natural harbors make trade difficult? If this is the case, then the answer is no. Rivers and harbors HELPED European trade. Goods could be moved up rivers or into natural harbors for docking, making trade easier.
The coastlines of the Atlantic provinces in Canada provide excellent harbors for fishing, shipping, and marine activities due to their natural sheltered bays and deep waters. These harbors support local economies by enabling trade and transportation along the eastern coast of Canada.
Usually, a natural harbor is a deep area, that has such a great depth that massive cargo ships can anchor.
Good coastal harbors
New England was well suited for commerce because of good coastal harbors.