Probably. Ecosystems are connected. While scientists do break the world
down to study it in smaller pieces because we can't comprehend the
ecosystem of the whole world at one time, the whole world is one big
ecosystem. Some parts of it are more directly connected to others, and
some parts are less directly connected. If something catastrophic
happened in one ecosystem, it would affect other ecosystems. But also
remember that the bigger the network, the less any one species affects
it. Because<span> there
are so many species in the world, the world is a HUGE ecosystem. The
affect would be somewhat absorbed by the vastness of the ecosystem.
However, if the extinction of one species (such as fish) has a large
impact on one ecosystem, it's impact on surrounding ecosystems might be
noticed. When you look at the world as a whole, it's not the extinction
of any one species that is very, very dangerous but the extinction of
many species. If enough species (like the fish) died in "separate"
ecosystems, eventually the ecosystem of the whole would be affected.</span>
