Humans interfere with nature by existing. Unless you consider homo sapiens as just another species, in which case they don't interfere with nature no matter what they do to any greater extent than every other thing in the universe.

You step on grass, you're interfering with nature. You decide not to walk on grass and walk on concrete instead, you're walking on something that displaced grass (which displaced a native species and so on...).

You breathe air? That directly contributes to global warming, in its own small way. Have children, thus increasing the population, and causing more schools to need to be built or maintained, which requires more resources that must be harvested from nature? You guessed it, you're interfering with nature.

Fact of the matter is, you owning a computer contributes vastly more to the destruction of nature and the natural order of things than that random photographer taking a picture of a seal. Or wearing clothes. From a naturalistic standpoint, you should be exposed to the environment, mosquitoes should feast on you because you are their prey.

You could take the far viewpoint, and say that as a species that lives on this planet, it's natural that you should have some impact. A lion evolves teeth, and so eats a gazelle. It's natural, because he evolved that way. Similarly, homo sapiens evolved heavily in their cerebrum. It's natural that we should wear clothing, since we have the capacity to invent it, and it solves a problem for us (keeps us from freezing to death and such). As another species on this planet, everything we do is following the natural and logical course of our evolution. If you set fire to a pile of wood, you would consider it natural that it burns. If you put a lion in with a bunch of puppies, you could expect it to eat them. It wouldn't be at fault for doing that, it's reacting to its environment in a predictable and natural way.

Similarly, humans are in a place with a certain number of natural resources. They're following the logical path before them, which is to consume resources and reproduce. As a species, our motivation is to continue existing as a species. This means we eat things that can serve as food to us, wear things that can serve as clothes to us, make things that can serve as weapons (offensive or defensive) to us, and so on. If a monkey gained the capacity to use weapons to hunt, it would. Analyzing the environmental impact of hunting would come second to ensuring its own survival, even at the cost of other species. If a monkey learned how to domesticate and raise chickens for food, it would likely do that as well. Similar to ants farming aphids.

Humans would react in the same way, presented with the same circumstances. When we see a movie like Independence Day, we don't care if the missiles we're firing in our defense are likely to harm the wildlife with their emissions. We don't have space to consider all of the potential impacts a nuke would have on the lives of say, some fruit flies. That's because our first concern is ensuring our survival as a species. Remember, the aliens wanted our resources. They likely would have left the rest of the food chain in tact, and just eliminated the dominant species, (us). But we fought like we didn't care what happened to the random animals and plants who were effected by the fallout from our war, because fundamentally, we will always be our first priority.

So don't try and pick and choose your causes. Figure out what you actually believe, and stick to it. This 'the photographer is distracting the seal' bullshit isn't the real problem at all. If you want to fix the problems being created by your continuing existence, do that. Otherwise, shut up and eat your cheeseburger.