Nope, this article does not intend to convey that Middle East respiratory syndrome(yes, that is what MERS Stands for) can be contracted by swimming or skiing in a reservoir.
A reservoir can be any organism or a population that directly or indirectly transmits a pathogen while being virtually immune to its effects.
Maggie Fox reports that goats might be reservoirs for MERS meaning that farm or pet goats might wonder around like a perfectly healthy creature but be passing along the MERS virus to you and your family. I believe she wrote about outbreaks at dialysis clinics.
Bats and civets are other potential symptomless carriers of MERS or SARS which is particularly easy to contract if you have diabetes or kidney problems.