Some species are caught or killed in one country but would be sold in another country
it may be difficult to control the collection of the species but if moving them out of the country can be stopped there would be no point collecting them
CITES
the main international agreement that regulates the international trade in wildlife
the Convention on International Trade in Endangered Species
selected species are grouped in lists called appendices:
Appendix 1 -
includes species that are threatened with extinction, so all international trade is banned except movement for conservation breeding programmes
for example all the Great Apes and blue whales
Appendix 2
includes species that may be threatened with extinction if trade is not closely controlled
trade is permitted from countries where species is relatively well protected so limited exploitation does not threaten their survival