Strategies for Enhancing Marine (and Human) Habitat at Brooklyn Bridge Park

Brooklyn Bridge Park, which opened its first completed segment to the public in June 2010, is the first major park to be built in Brooklyn, New York, USA in over a century. Replacing derelict pier sheds and paved upland areas with new public access amenities and natural landscape elements, the park will bring new social life and ecological vitality to a waterfront that has long been dominated by commercial and industrial uses. The Michael Van Valkenburgh Associates design works with the existing marine edge infrastructure and the materials of the landscape to introduce a new post-industrial nature to the site. The absence of anything resembling the native shoreline, coupled with the pressing need for outdoor recreational space in this area of Brooklyn, precluded the possibility of an overall ecological restoration per se, but it still left room to bring much greater diversity to the range of coastal habitats on the site and improve the ecological context. The design employs a multitude of strategies, affecting both marine and upland habitat, to establish a new balance between human use and environmental health along the Brooklyn waterfront. Attempts to reduce the net amount of over-water shade structures and their negative effect on marine habitat, discussed in detail below, are just one aspect of the larger, concerted effort to re-establish natural systems along the 2.1 km (1.3 mi) of shoreline contained within the project.

The large pier structures built along Brooklyn’s waterfront in the mid-20th century, several of which are 2.2 ha (5 ac) in area, created a multitude of environmental disturbances, including the creation of large areas of shaded water along the shoreline (Figure 1). The absence of sunlight from the water column has been demonstrated to have an adverse affect on fishes, most specifically by reducing foraging efficiency for a broad range of species that otherwise thrive in nearby areas of uncovered water (Able and Duffy-Anderson 2005). In our work on Brooklyn Bridge Park, which transforms several of these piers and the adjacent upland into a major new waterfront park, we developed a design that responded to concerns about the documented deleterious impact of large over-water structures on estuarine fauna.

Two studies undertaken during the 1990s, focused on the effect of the large piers on the Lower Hudson River on marine habitat, have been influential in shaping public policy with respect to the construction of new over-water structures (Able et al. 1995, 1998). In these studies, Able and colleagues conducted fish counts both under and at the edge of piers, in pile fields, and in open water over a number of years to determine species distribution in these areas. Despite rises and declines in various populations, fish abundance and species richness were consistently lower under the large piers than in other surveyed locations. The authors hypothesized that benthic prey availability was diminished beneath the piers, but surveys of benthic fauna demonstrated that food availability was not a limiting factor. In a separate study, Able and Duffy-Anderson (2005) held fish in cages beneath the piers and recorded growth rates. Fish that are visual predators experienced weight loss and reduced growth, whereas fish with alternative prey detection systems were able to grow under piers, albeit at a reduced rate. However, fish held in benthic cages at the edges of piers, where some sunlight penetrated, exhibited higher rates of growth, suggesting that shade was the driving factor behind decreased fish populations under large piers (Able and Duffy-Anderson 2005).

Figure 1.

The creation of the Brooklyn Bridge Park will transform 2.1 km of industrial shoreline along the East River, Brooklyn, NY, into a multi-use, public waterfront park. Prior to construction, large piers (approximately 25 ac of total area) extended into the East River, considerably shading the water and decreasing habitat quality for fish species.Photo Credit: Michael Van Valkenburgh Associates, Inc.

Figure 2.

Rendering of proposed walkway connecting Pier 1 and Pier 2 at Brooklyn Bridge...