A niche for each species
We climbed out of the Zodiac which had taken us across Wrangell Narrows from Petersburg, and were about to ascend the steep incline up from the floating dock, when I noticed the fouling community on the massive piles that allow the dock to slide up and down with the tides. It being new moon and low tide, not only the intertidal organisms that are exposed to the air regularly twice every day, but also some of the lower parts of the community that normally stay submerged, were clearly visible. As the group gathered around, and we focused our attention on the various organisms that were clinging to the poles or in a jumble to one another, we first noticed the dominant mussels and barnacles, but then we started to see sea stars, whelks, bits of seaweed, and various other denizens of the intertidal zone. But, however interesting and exciting these different species were, the observation that quickly became the crux of our conversation was the obvious zonation of the major species. At the bottom of the piles there were no mussels at all, then a bit higher up there were only small mussels, above this they were much larger, but towards the top they became smaller again. Similarly, the barnacles and other species had their own vertical zone of preference or best success.
To the amusement of my audience, I speculated out loud about hours of being submerged per day, effect of predators, oxygen tension, temperature, and species specific requirements, but I think it was obvious to us all that that was all it was, speculation. But let's face it, finding clear patterns in nature is one thing, explaining such patterns is another matter.
As we continued with our hike to Petersburg Creek and the extensive area of muskeg I thought about how each species in an ecosystem has its own limited 'niche', as ecologists call it. I think the real problem we face in the world, is that one species, mankind that is, has through the use of technology spilled over the borders of its niche, thereby exerting tremendous pressure on all other species. So far, the mussels and barnacles are still masters in their own little part of the world, but the Steller's sea cow and many others are gone.
I did not let my brooding thoughts spoil the pleasure of our hike. There still is a lot of beauty in our world, and we sure saw a lot of it today. Lets hope we can keep it this way.
We climbed out of the Zodiac which had taken us across Wrangell Narrows from Petersburg, and were about to ascend the steep incline up from the floating dock, when I noticed the fouling community on the massive piles that allow the dock to slide up and down with the tides. It being new moon and low tide, not only the intertidal organisms that are exposed to the air regularly twice every day, but also some of the lower parts of the community that normally stay submerged, were clearly visible. As the group gathered around, and we focused our attention on the various organisms that were clinging to the poles or in a jumble to one another, we first noticed the dominant mussels and barnacles, but then we started to see sea stars, whelks, bits of seaweed, and various other denizens of the intertidal zone. But, however interesting and exciting these different species were, the observation that quickly became the crux of our conversation was the obvious zonation of the major species. At the bottom of the piles there were no mussels at all, then a bit higher up there were only small mussels, above this they were much larger, but towards the top they became smaller again. Similarly, the barnacles and other species had their own vertical zone of preference or best success.
To the amusement of my audience, I speculated out loud about hours of being submerged per day, effect of predators, oxygen tension, temperature, and species specific requirements, but I think it was obvious to us all that that was all it was, speculation. But let's face it, finding clear patterns in nature is one thing, explaining such patterns is another matter.
As we continued with our hike to Petersburg Creek and the extensive area of muskeg I thought about how each species in an ecosystem has its own limited 'niche', as ecologists call it. I think the real problem we face in the world, is that one species, mankind that is, has through the use of technology spilled over the borders of its niche, thereby exerting tremendous pressure on all other species. So far, the mussels and barnacles are still masters in their own little part of the world, but the Steller's sea cow and many others are gone.
I did not let my brooding thoughts spoil the pleasure of our hike. There still is a lot of beauty in our world, and we sure saw a lot of it today. Lets hope we can keep it this way.
