Research Archive: Biodiversity Assessment
'Assessment of population levels, biodiversity, and design of substrates that maximize colonization in New York Harbor: An Experimental Study'.
This study assesses the biological richness of the New York Harbor portion of the Hudson Estuary by taking an experimental approach to monitor the pool of organisms dispersing and colonizing very shallow subtidal hard substrata at a site in Lower Manhattan: an area we believe is a good sample of the regionally well-mixed waters of the harbor estuary. As a result of improved water quality over the past few decades, the shipworm Teredo navalis, and two gribbles L.lignorum and L.tripunctata are destroying the harbor's wooden infrastructure, which, over the next two decades, will have to be completely rebuilt. This presents an opportunity to provide advice for designing the substrata types that will maximize organismal colonization. The total area of vertical substrate involved exceeds a hundred thousand square meters. Plates of various in-water building materials will be monitored for 'bio-attractivity', to identify materials that will maximize biodiversity, supply habitat for the filter-feeding organisms that clarify water, and provide significant new substrate for the base of the food web.
Over two seasons in 2002 and 2003, we performed a colonization study of hard substrates at Pier 26, which faces the Hudson River in lower Manhattan. Using a stratified design our objective was to measure the biodiversity and amount of coverage of experimental colonization tiles. We used a point count method, assigning randomly located points, at which species or open space was identified. We used several frames with replicate panels, which allowed a study of microspatial variation when necessary.
The most detailed data set was collected from tiles set in from late spring 2003 and followed into the fall. The number of taxa increased linearly with time, so biodiversity increased steadily. We identified 31 taxa on the tiles, but more taxa were found on the frame edges. Occupation of space was very high, but in the early part of the season tiles were covered to an extent by soft sediment, which was later replaced by sessile invertebrates such as colonial tunicates.
To download the full report click here (Report Date: 11/13/2006).
Dr. Jeff Levinton, Professor, Ecology and Evolution, SUNY, Stony Brook
Cathy Drew, Executive Director of The River Project
Aya Kristen, Ph.D. candidate