I have written about the “Blob” in the past (most recently, here and here).  It is the much higher ocean temperatures in the North Pacific which have disrupted food chains and imperiled many historic fish runs.  An argument can be made that ocean heating is currently the most worrisome of all the conditions leading to the drastic declines in salmon and steelhead populations in the Pacific Northwest.  Here is the first part of a three-part article from NOAA discussing the Blob.  Below is a graphic showing the re-emergence of the Blob this year.  It could be worse than the original one, it already has more area of the most extreme warming, and is still forming.