The trick with environmental indicators is that sometimes they need to change to adapt to new circumstances. So our indicator for phosphorus on Lake Erie we may have met under the Great Lakes Water Quality Protocol, but what we're finding now is that we're still seeing algae blooms, and the reason is because the context is changing. We have warmer waters, we have different types of phosphorus.
So we do need to continuously adapt and look at those indicators and improve them with the understanding of new science that becomes available.