From memory, minelaying commenced as part of the Imperial Russia's premobilisation, mobilisation - the Russians have a long history and expertise with naval mines. I understand the Russians initially retained one army for the defense of Petrograd, which suggests a priority that likely included the naval approaches to Petrograd including the Gulf of Finland. I recall there were significant naval batteries (beit of mixed quality) positioned to defend Petrograd/Gulf. Due to Russian paranoia, even early in the war, I don't think there would be very many soft targets in the approachs to Petrograd/ Gulf of Finland - which would be precarious spot for any hostile naval forces to loiter.
The first Russian mine barrages at the approaches to the Gulf of Finland were laid literally within hours from the beginning of the war IOTL. These barrages included c. 2100 mines. In late summer and fall of 1914, several barrages more were laid by the Russians in the Gulf of Finland (I'd have to check my sources for actual numbers). And then c. 1650 mines were laid offensively in parts of the southern Baltic Sea, in 13 different operations, by the fall of 1914. In the late summer and fall of 1914, though, the extent of the coastal artillery positions, and their armament, was still very limited. The main work to build up the coastal artillery around the Gulf of Finland and in the areas just outside it begun in the spring of 1915. The summer of 1915 was also a time of a major mining effort by the Russians.
I'd say that with a quick and strong enough attack, the Germans
could take the Ålands, Dagö and Ösel before the Russians have the time to occupy them with enough infantry and artillery to defend them. The attack would need to happen on the first weeks of the war to achieve the needed surprise. The Germans would have to be prepared to meet a Russian naval task force in battle somewhere to the north or northeast of Gotland, though, and they would have to expect the Russians to have laid some defensive mine barrages at least. It would then be a matter of contingency what ships the Russians would send to meet the German attack, under what orders, and under whose leadership. It would have to be a very bold attack and an ambitious landing operation, though, to the point of being seen as reckless by some, and such an idea might well get rejected if cooler heads and more careful minds prevail during the planning stage. Even if the German operation(s) would be successful in general, they would probably also lose many ships of different sizes - more likely to Russian mines than in actual battle against Russian ships, but both losses would be to be expected.
When we think of Operation Albion, we need to remember that it was realized at a time when the Russian fleet had been rendered practically useless as a military force, due to internal strife, revolutionary incitement and plummeting morale. This would not be true at the beginning of the war, so we would have to expect the Russian navy to be a more active and committed, actually battle-worthy adversary in that case - even if it would suffer from most of the traditional weaknesses we attribute to the Russian navy in this timeframe.