Dead and dying fish strewn all over the harbor seafloor is not a pretty sight. Well, unless you’re a hungry pinniped or seabird.
We are suffering a die-off in the harbor area from natural causes, and one that we can’t do much about. Low oxygen content in the water is the killer. Normal oxygen content is rated over 7. Last week, we’ve seen readings as low as 1. That’s deadly.
Cyclical variations sometimes produce deadly conditions, as we have now. At other times, such low oxygen content is the result of a major plankton bloom or other natural causes. Whatever the cause, local fish suffer.
Some fish — especially larger ones — can easily swim out of the harbor or other affected area and find better conditions. Our harbor is currently plugged with baby mackerel, sardines and various species of fish. These little schooling fish don’t have sufficiently developed instincts nor stamina to get away from the problem. So, the weaker ones die. The stronger ones survive to reproduce and teach their species to adapt.
Over the years in various harbors, people have tried to fix these problems with various techniques, generally with poor results. One technique tried numerous times is the “Royal Flush.” Boaters throughout the harbor fire up their engines and put them in gear while still tied to their docks. The idea is that the churning propellers will stir up the water to infuse it with oxygen. Well, it gets some water moving and somewhat of a flushing action started, but we have little confidence in the results. I’m sure the folks at the fuel dock are in favor of the experiment.
In the food chain, when one group of species suffers, another benefits — at least temporarily. Sure enough, harbor seals, sea lions, cormorants, pelicans, herons, egrets and numerous other predators are scarfing up the dead and weak small fish. It is a bonanza for these critters, and they will happily clean up the mess before retiring for a digestive nap.
The rest of us watch and wait for conditions to return to normal. They will.
— Capt. David Bacon operates WaveWalker Charters and is president of SOFTIN Inc., a nonprofit organization providing seafaring opportunities for those in need. Visit softininc.blogspot.com to learn more about the organization and how you can help.