I could hear the faint clicking intensify as the school approached. Then the bottom of the river downstream of where I lay started to wriggle, and I realized that the school had arrived beneath me. The stonerollers were here. They moved across the bottom in a crazed grazing frenzy. Hundreds of them in the same school swam along the bottom scraping algae from rocks as they moved upstream. Their sides flashed silver with every twisting bite they gouged from the algae covering rocks and their jaws snapped, which explained the clicking sound. Stonerollers are some of my favorite fish partly because of the elaborate stone piling mating rituals the males use to attract females in the spring. But I also like them because they are really a non-descript fish for most of the year. However, careful observation reveals how well adapted they are for keeping algae in check in our rivers and streams, and the non-descript, even unnoticeable, become incredible. Their mouths slightly protrude downward, and hard bony plates on their upper jaw leave u shaped scrapes in rock coating algae. Dr. Mary Powers conducted an interesting exclusion experiment. Bass are stone roller predators, so she excluded stone rollers from sections of river by keeping bass there, and eliminated bass from other sections. The sections where the bass were kept became overgrown in algae. This demonstrates the importance of the stonerollers to the system, but it also illustrates the often unnoticed, and very hidden interrelationships between everything in nature. Everything matters and as John Muir said, “When we try to pick out anything by itself, we find it hitched to everything else in the universe.” Algae, bass, and marauding stonerollers.
Monday, July 18, 2011
Monday, July 11, 2011
Misidentified and Misunderstood
“There’s a copperhead down there in the creek bed. I wouldn’t go down there.”
“Thanks for the heads up” I said and continued to the stream as people piled out of a favorite swimming hole. Better visibility and more room for me. I knew it wasn’t a copper head. It was a northern water snake. The same kind of snake that bit Mike Rowe numerous times on my favorite Dirty Jobs episode.
Water snakes like any animal, including humans, will lash out when threatened or captured. So Mike was bitten time and again. I have never been bitten by a water snake, but then I’m not trying as hard. I don’t like snakes. I like to watch them, but I’m not big on handing them. Water snakes are common this time of year, and every time I see one in the water, I try to swim with it, but usually can’t keep up. They are incredibly striking animals, graceful and adept in the water, and fast on land. Unfortunately they are constantly confused with the poisonous copper head. Water snakes are not poisonous and will not come after people. Their diet is almost entirely fish and it is really amazing to watch them hunt and successfully snag a fish that are often surprisingly large for the snakes’ body size. But still they are regularly the target of rocks thrown by people who just don’t understand how harmless they are or how important they are to the stream system. Maybe they just can’t see past their unfounded fear to notice the beauty and agility of these extraordinary reptiles.
Friday, July 8, 2011
I’ve driven over this little non-descript and forgotten stream hundreds of times on my way to and from work, and each time I peer over the low barricade on the short bridge to get a glimpse of the water, and every time it looks clear, even after heavy rains. But it’s a small creek and not very accessible due to fast traffic and overgrown banks so I never considered exploring it. I decided to snorkel this stream when I got frustrated with the seemingly perpetual murky condition of other streams in the area due to flashy downpours this early summer season. This stream never seemed to be affected, and I wondered if this was just an illusion, or if the water really was clearer.
I struggled through the climbing bittersweet, and poison ivy, to get to a pool that was out of sight from the road. I was paranoid about being confused with a body, which has happened before.
As soon as I stuck my face in it, I knew the water was clearer. Fish were abundant and diverse. Tessellated and johnny darters sent small puffs of sediment into the water with every jerky leap off the bottom. Chubs slowly came in to explore what I was, and nervously shot off into the distance. A common shiner in reddish hue breeding color danced before me as blue gill and pumpkin seeds put on aggressive displays to defend their nests. A small school of northern hog sucker worked the bottom and I’m pretty sure I saw a stoneroller. It was like swimming in an aquarium. While the water is clear, it isn’t without impact. Algae covers everything.
I checked out this tiny gem on the map, to try to determine why it stays clear when many of the other streams in the area turn brown after rains. It’s called Stony Creek, and its watershed is about 40% developed, mostly in new houses. So, this stream should be as muddy as the others, unless the storm water management requirements of newer construction, like storm water retention ponds, work. Maybe that is why Stony Creek is clear, but overfertilized. We have required technology to reduce heavy flows that come from impervious surfaces, which reduces scouring flows from reaching streams like this which results in clearer water. But we haven’t done too much yet to control nitrogen runoff, which makes this stringy algae that covers everything in this stream. Stony Creek gives me hope that maybe newer storm water management regulations do work in reducing sediment loads to our streams, which translates to healthier streams and clearer water to snorkel. And lots of fish to see.
Tuesday, July 5, 2011
I heard a diver describe local diving conditions as braille diving because you dive by feel, the visibility is that poor. I used the same language when I was an avid diver and knew that there wasn’t much to see on the bottom of the deeper holes on the Susquehanna, or in the quarries turned diving destinations. But still, his comment bothered me, even if he did have a point. Maybe it was because that perpetuated the attitude that there isn’t anything of worth or value to see or protect in the rivers and streams in our neighborhoods, which certainly isn’t the case. But I think his comment hit a nerve because I caught the same attitude creeping into my psyche. There is a seasonality to water clarity here, and it seemed that the better summer visibility was really late in arriving. It seemed that in the last week I walked to the waters edge, gear bag in hand, watched clouds of sediments blur the bottom, shook my head, turned around and went home more than I got into the water. Maybe the comment from this diver bothered me because my reality, living in the developed east, is muddy water, compared to other places like Cherokee National Forest.
So when I got to the Octoraro tonight and saw less than clear water, my first inclination was to turn around. But it has been a few days since I was in any water, and it was hot, so I decided to get wet. I crept along in a foot of water with the bottom in clear view. Three feet of visibility might mean you can’t see anything in 60 feet of water, but in a foot of water everything is sharp. A small mouth bass confronted me behind his rock, circled around and confronted me again. Must have been in his territory. Further upstream, the water deepened, and things on the bottom of the four foot hole were hazy, but recognizable. I swam over a two foot long catfish. A small rapid dumps into this deeper pool, and I let the upstream eddy carry me into it.
A few male satinfin shiners were in a dog fight over prime breeding terrain. Their dainty iridescent blue dorsal fins and silver white pectoral and pelvic fins fluttered and flared like butterflies in a stiff breeze. I was able to watch this mid water column display of glowing blue and silver-white for quite some time as the males defended their spot, and enticed females, while creek chubs fed on the bottom. One of the males mistook me for another satinfin shiner and flared right in front of my mask. Maybe he saw his reflection in the lens. Either way it was an incredible display. The water was murky, and I couldn’t make out more than the outline of a large bedrock slab four feet away. But that didn’t matter. I had plenty of visibility to witness the beauty and drama of the Octoraro this evening. Creek snorkeling isn’t braille diving.