Two brand-new studies of water quality in Shelter Island Yacht Basin indicate lower levels of dissolved copper here than had been seen in previous research. In addition, the new studies show that levels of copper in the water are actually low enough that they are not toxic to most marine life.
The new studies provide evidence to refute claims of some hard-line environmental activists that boats are somehow polluting harbors by their mere presence. Over the past few years, there has been hysteria over findings of dissolved copper in local boating harbors.
Dissolved copper found in San Diego Bay water is usually blamed on recreational boats’ copper-based antifouling bottom paint — although far more of it probably comes from automotive copper brake pad dust that washes off nearby roadways. Whatever the other contributing factors may be, some environmental researchers believed that the sheer number of recreational boats concentrated in Shelter Island Yacht Basin made it a potential copper “danger zone.”
In 1996, the San Diego Regional Water Quality Control Board became convinced that then-current levels of copper in Shelter Island Yacht Basin were unacceptable and issued a Total Maximum Daily Load (TMDL) standard for the basin. The TMDL order stated that there had to be a reduction in the amount of dissolved copper in Shelter Island Yacht Basin of 10 percent by the end of 2012, 40 percent by 2017 and 74 percent by 2022.
The Port of San Diego, bound by this order, implemented restrictions on hull-cleaning activities and created incentives to convince local boaters to replace their copper-based antifouling paint with alternative coatings. And a bill was drafted by California Sen. Christine Kehoe — State Senate Bill 623 — aimed at banning copper-based bottom paint use for recreational boats statewide.
The bill advanced last year, it was later altered to allow low-leach copper bottom paints and it was eventually shelved, to be reconsidered in 2012. Currently, the bill is in the Senate Appropriations Committee, having passed the Senate and Assembly Policy Committee — and it is expected to be heard again in June.
However, the latest research seems to show that current levels of copper are not harmful to marine life. Cleve Hardaker of the boater advocacy group Recreational Boaters of California recently told boaters at a forum in Dana Point that a copper TMDL order similar to the one affecting Shelter Island Yacht Basin had been issued in recent years in San Francisco Bay — and it was later removed, when further testing showed that high copper levels did not have an adverse effect on marine life in the bay.
“Admittedly, the argument is made that there is excess copper in a lot of the harbors in Southern California, but there is no copper (toxicity) problem whatsoever in San Francisco Bay,” Hardaker explained.
It would seem to us that the San Diego Regional Water Quality Board’s current TMDL order for Shelter Island Yacht Basin, planned legislation to ban copper boat paints and most of the ongoing regulatory moves to restrict recreational boaters’ use of approved copper-based paints amount to “a cure in search of a problem.”