President’s Column

January 2005

by Jim Clark

Science often leads us to more difficult questions and decisions, rather than simple answers and clear direction. This is the situation that has evolved with regard to the effect of oyster culture on eel-grass in Humboldt Bay.

Recent studies on the effect of the spacing of oyster “long lines” (elevated lines on which oysters are grown in the intertidal zone) over eel-grass revealed that line spacing had an effect on eel-grass density. Density increased with increasing distance between lines. Lines 2.5 feet apart showed significant density reduction compared to 5-foot spacing, and there was no significant difference between lines 10 feet apart and eel-grass control areas with no long lines. At the last Mariculture Monitoring Committee meeting, Greg Dale, manager of Coast Seafoods Humboldt Bay Operations reported that the 10-foot line spacing appeared to yield only about half as many oysters as the 5- or 2.5-foot spacing. We don’t know why eel-grass does better and oysters do worse with the 10 foot spacing. These findings, however raise several important questions about mariculture on Humboldt Bay:

Is there an optimal line spacing between 5 and 10 feet that is good for eel-grass and oysters? If 10 foot spacing is what is required to prevent eel-grass reduction, would it be appropriate to quadruple the mariculture acreage to get the same oyster yield compared to 5 foot spacing or eight times the area compared to 2.5 foot spacing? Could Coast Seafoods’ Humboldt Bay operation survive at such low densities? What is best for birds and the natural environment, high-density limited-area mariculture with less eel-grass, or low-density large-area mariculture? What is “permittable” by regulatory agencies? This type of dilemma is something that businesses, government, environmental organizations and the general public wrestle with on many public trust issues in Humboldt and Del Norte counties.

As an Audubon member, you can help find solutions to these dilemmas by letting the Board of Directors know what you think and offering suggestions. Each of us has a unique set of abilities, perspective, and experience that can help.

When we try to win, we create the possibility of losing. When we try to solve a problem, we create the possibility of resolution.