The table shows some information about two closely related species of sea bird. Sewage pollution at the mouth of a river destroys its fish stocks. What is likely to happen to local populations of these birds?

• AThere will be no change to either species.
• BSpecies X numbers will decrease, species Y will remain constant.
• CSpecies Y numbers will decrease, species X will remain constant
• DBoth species numbers will increase.

Choose an answer — or press 1234