Complex sentence: After six years, as other aquariums acquired merpeople, the novelty of having one waned so the Sea Life centre decided to take advantage of the merman's intelligence and constructed a show tank in which Daniel was forced to perform tricks for the public.
Split into simpler sentences: After six years, as other aquariums acquired merpeople, the novelty of having one waned. So the Sea Life centre decided to take advantage of the merman's intelligence and constructed a show tank, in which Daniel was forced to perform tricks for the entertainment of the public.