Stream acidification

[agentaqua]

Interesting questions - yes, Fishmyster, Not sure they could be easily answered. Lakes are quite complex - and any pH spikes from tribs might initiate a suite of interacting synergistic WQ changes (flushing, nutrient availability, etc) - and dependent upon seasonal changes in the lake, as well (stratification, turn-over, etc). There are also interacting potential predation and competition issue with other organisms, as well as density-dependent mechanisms operating. Each lake is unique in the combination and variability of all of these factors (see attached files). Lakes are also tougher and more expensive to fully sample - verses benthic stream inverts - and are therefore often less sampled with a continuous time series. Then there are other scales and residences of life histories to consider, as well - like the ocean.

 

[Fishmyster]

Thanks for the links AA. Those will keep me busy for a bit.
Yes it is very complex. Although complex, there is interesting chronological similarity to depression of many aquatic species and critters that depend on both fresh and marine environments. Although ocean survival has been mostly blamed there has been equal disruption of stream productivity but it is not well documented. The biggest gap in knowledge is the monitoring of chemistry. This is why I keep leaning towards rain chemistry and toxicity as the most influential factor in that it best fits the big picture of what could be causing such ecological changes. It will effect both environments. My prophecy is that the salmon depression is over and stocks should grow until the next acidic rain events move the heavy metals around and poisons the environment again.
Some other good news. I was at my floathouse last weekend. Every night we have a dock light shining in to the water and I am down on my stomach staring into the water to see what new form of life there is. There was the typical soup of life going on as there is every night. There was more salmon fry and sand lance larvae than three and four years ago. General abundance of life in the water was up!! Got me excited!!