This year, I am amazed at how much barnacles and growth I have on the bottom of my boat. I'm located on the Sassafras River, Upper Chesapeake, MD. (Fresh water river) Could this be due to global warming? Is the river water warmer than in the past? Any marine biologists on this forum able to chime in? I hauled out in the spring for some light maintenance and the yard power washed the bottom. There was plenty of anti fouling ablative on the bottom when it went back in. Anyone?
Population blooms,
if that is what you are seeing an effect of, are usually correlated with increased food supply. For barnacles, which are filter feeders, that would be plankton, mostly phytoplankton but including bacterioplankton and detritus (bits and pieces of degraded algae). Phytoplankton blooms follow an increased supply of nutrients coupled with abundant sunlight. The most important nutrients for phytoplankton growth are nitrite, nitrate and ammonium. Most of this comes from
in situ (in the local place) nutrient recycling via bacterial decomposition of detritus and dead organisms plus reduction (fixing) of atmospheric (diatomic) nitrogen (N2) to ammonium (NH4+), which leads to production of nitrite and nitrate. The nutrient limiting nitrogen fixing (done by blue-green algae) is typically iron. The more iron in the water potentially the more the production of ammonium leading to more nitrite and nitrate; so the more phytoplankton, the more food for barnacles; thus more barnacles, up to a point.
It’s true that warmer conditions will speed up most chemical reactions, including metabolic and growth rates of “cold blooded” fauna but their food must be there first. Population blooms come and go in the marine/aquatic habitat, as elsewhere, both regularly and episodically. They are natural events, but they likely do include some anthropogenic factors in some instances, etc. However, I doubt your issue could be traced to “global warming.”