Comments on the "Scope of Services" for the State Parks Waterbird Study of the North Sailing Basin

Thank you for providing me with a copy of the draft "Scope of Services" for the North Basin rafting waterbird study.

I have a number of comments, suggestions, and corrections to various details in the draft. There are two major elements missing, and one important detail to correct:

1) Context of the Study

The study does not address the relative importance of the North Basin to rafting birds in the context of nearby locations.

See for example the chart of surf scoter habitat at

If this species is representative, it suggests that the North Basin has no unusual significance compared to other nearby habitat areas, and is far less important than very large subtidal regions to the north and south. The WTA study that generated this chart was presumably constructed from limited data, and one of the purposes of the current study should be to verify or modify this distribution of habitat, for this and other species of concern.

The relative importance of the North Basin habitat compared to other areas in the region is critical information for any agency that must evaluate possible trade-offs between habitat value and recreational value.

2) Measurement of Population Impact

The study does not measure anything that will directly assess the effect of non-motorized boating on bird populations.

This is very hard to measure, but perhaps the simplest way to analyze this effect is to expand the geographic reach of the study to include the South Sailing Basin, on the other side of University Avenue. This is a sub-tidal body of water of approximately similar size which, in addition to major bird habitat, also supports several large-scale year-round boating programs.

For example, the relationship of the mouth of Strawberry Creek to the South Sailing Basin docks is somewhat similar to the relationship of the Schoolhouse creek outflow to the proposed boating access facility in the North Basin. If boating activity in the South Basin (which includes outboard- powered support vessels) does not result in significant degradation of the habitat at Strawberry Creek, then it would be difficult to conclude that less intense and less obtrusive use my non-motorized boats in the North Basin would be damaging to Schoolhouse Creek.

By studying the two areas together we will have a unique set of "case" and "control" sites that might actually lead to some useful scientific results. Otherwise, we will only be restating what we already know: Birds and kayaks can not occupy the same space at the same time, and if you paddle a kayak through a raft of ducks they will fly away and relocate nearby.

The real question is, what effect does this level of disturbance have on the bird population? There is nothing in the study that will really answer this question. In fact, there is almost nothing in the literature that answers this question. See, for example, my January 2003 letter to the California Dept. of Fish and Game

Note especially how data on disturbance is confused with the degree of damage to the habitat. There are many studies that measure disturbance, but virtually nothing that relates non- motorized recreational uses to population decline in non-nesting habitats like the North Basin. In fact, the most applicable examples document thriving bird populations coexisting with non-motorized recreational uses.

Another example of the difficulty in relating kayaks to bird population is found in the Brandt's cormorant study by the Point Reyes Bird Observatory. From the winter 2003 issue of the "Observer,"

"In the past three years, we documented disturbance to birds on and around Alcatraz at some of the highest levels on record. In 2002, nearby boat traffic caused one-third of all recorded disturbances. Surprisingly, kayaks are particularly potent vectors of human disturbance because of their silence: they can sneak up to birds and startle them more easily than can a loud motorboat."

And yet, in the same article:

"The Brandt's Cormorant is the most numerous breeder on Alcatraz; in fact, the number of nesting pairs increased by 19% between 2001 and 2002, reaching the highest numbers ever recorded."

The point is that measuring frequency of disturbance and flushing distance does not necessarily measure a negative impact on population. The argument is often made that birds engaged in long migrations are seriously energy-depleted and must rest to survive. This is certainly true, but it is equally logical to assert that since they are traveling hundreds or even thousands of miles anyway, a short relocation adds an insignificant increment to their energy budget. Without actually demonstrating the effect of disturbance on the success of the migration, it is all conjecture.

3) Definition of the Study Area.

From paragraph 2 of the draft: "The North Basin is a relatively sheltered bay, totaling roughly 220 acres."

We need to clarify the boundaries of this body of water. The "sheltered bay" is the water to the east (downwind) of the protection of Cesar Chavez Park, part of the landfill that forms the Berkeley Marina. This protected water is roughly defined by a line from the north edge of Cesar Chavez Park to the foot of Gilman Street on the east side of the basin. The water area is 120 acres, not 220 as stated in the draft. So it appears that some of the water to the north, which is not sheltered by land, is also being included in the study. See, for example, the boundaries drawn on the aerial photo at If the boundary has been arbitrarily moved to the north, then it is not correct to describe the entire area as sheltered.

The water to the north is certainly used by rafting birds, and there may be good reasons for including it in the study. But this area is unprotected from the prevailing westerly winds, and will presumably have very different use patterns by birds seeking protection from wind and waves.

This is more than an academic point: Access improvements at the foot of Gilman St. are currently being considered by Caltrans as part of their Bay Bridge seismic retrofit eelgrass mitigation project. This location is just outside the north boundary of the sheltered water of the North Basin, and should not be subject to operating restrictions based on the habitat value of the more sheltered North Basin proper.

4) Goals and Recommendations:

The draft identifies three distinct purposes. The first is to determine the waterbird and shorebird use of the North Basin. No problem here. But the second purpose, "study the impacts that non-motorize boating activities may have on rafting waterbirds" will be difficult to achieve, for reasons outlined above. So the third purpose, "provide recommendations and management guidelines for boating activities…," will necessarily be made with less then complete data. The North Basin Rafting Waterbird Study should enable planners to make good decisions about possible water access restrictions on the basis of science rather than politics. It is unlikely that this goal will be achieved by the study as proposed.

The most critical change that needs to be made in this proposal is an expansion of the study area to include bird counts in the South Sailing Basin, so that the actual impact of boating on bird populations can be measured.

The contractor should also make an assessment of the relative importance of the North Basin to species of concern in comparison to other habitat areas in the region, so that the value of this particular bit of waterway can be realistically compared to the value of recreational uses if it is found that they are in conflict.

The north boundary of the North Basin should be clearly defined as a line from the north edge of Cesar Chavez Park to the foot of Gilman Street. The area north of this line is outside the area of sheltered water, does not border land areas of the Eastshore State Park, and does not have any special geographic characteristics compared to other large stretches of unprotected water along the East Bay shoreline. By any reasonable application of language and usage it is outside of the North Basin.

Finally, I extend an invitation to all State Parks staff and their guests to come out for one of my "three hour tours" of the North Basin, using one of the larger sailboats operated by the Cal Sailing Club.

Best Regards,

Paul Kamen