Welcome!
This page provides information about my research projects, course offerings and opportunities for graduate students. You can also access some of my publications for download. Drop me an email if you have questions ([email protected]).
News & Updates
Research Update: I published 3 papers in 2022.
The paper published in Biogeosciences (Volume 19, pages 4209-4226) presents carbon budgets for the upper estuarine segments of the James, Pamunkey and Mattaponi. Ecologists use budgets to document inputs, outputs and transformations of mineral elements in ecosystems. Carbon is of particular interest because organic matter inputs provide food resources for consumers, and the net balance of inputs and outputs determines whether the ecosystem acts as a net source or sink for C. The findings show that high secondary production in the tidal freshwater segment of the James Estuary is supported by high internal production by phytoplankton, and the trapping of terrestrial organic matter supplied by the James River. This supports our earlier analysis of food web processes showing that some consumers are dependent on internal sources of organic matter (e.g., zooplankton and planktivorous fish), whereas other consumers are largely supported by terrestrial organic matter (including catfish, gizzard shad and benthic filter-feeding clams). Together, these papers provide a basis for understanding the factors which constrain production at higher trophic levels. We estimate that the introduced catfish are utilizing 15% of total organic matter inputs to the system.
A second paper published in Estuaries & Coasts (Volume 45, pages 470-484) describes the factors regulating water clarity in the upper portions of the James, Pamunkey and Mattaponi. Water clarity is an important ecosystem attribute in part because it sets the depth limit to which submerged aquatic vegetation can grow. The depth to which light penetrates also influences the growth of phytoplankton (algal blooms are a common occurrence in the James tidal freshwater segment). We found that non-algal suspended particulate matter (e.g., clay, silt) was the key determinant of water clarity at all sites, but that dissolved color (CDOM) was also important in the Pamunkey and Mattaponi. These estuaries derive a greater proportion of their inputs from local (Coastal Plain) tributaries, which are naturally high in dissolved color derived from wetland plants. An analysis of long-term data collected by the Virginia Department of Environmental Quality showed that water clarity is improving, coinciding with decreases in river sediment inputs. These findings suggest that past and future efforts to reduce erosion and sediment transport will benefit these estuaries by promoting greater water clarity and allowing for recovery of submerged aquatic vegetation. This study was carried out with one of my recent graduate students, Rachel Henderson.
Lastly, I published a paper in Aquatic Conservation (DOI: 10.1002/aqc.3900) describing our efforts in biological restoration of urban streams. Freshwater mussels are important ‘ecosystem engineers’ that filter water and remove particulates. However, they have experienced widespread decline and are among the most endangered aquatic organisms. The USF&WS Harrison Lake Hatchery has started a program of mussel propagation to augment wild populations and re-introduce mussels to former habitats. We wanted to know whether mussels could survive in urban stream environments and carried out test stockings of caged individuals in urban streams located in Richmond and Reston, Virginia. This work was sponsored by a grant from the Resource Protection Group. We found low survivorship of mussels in Richmond streams due to frequent high flow events that damaged or buried the mussel enclosures. In the restored streams of Reston (modified to reduce bed and bank erosion) we found high survivorship and positive growth rates. Our findings suggest that stream restoration may provide conditions conducive to establishing mussel beds, even in urban environments. This work was carried out by one of my recent graduate students (Jack-Reid Ryan) and in collaboration with Rachel Mair at the USF&WS.
In Spring 2023 I will be teaching the Water class, which focuses on monitoring, assessment, and restoration of inland and coastal waters.
Dr. Paul A. Bukaveckas
Virginia Commonwealth University
Trani Life Sciences Room 037
1000 W Cary St
Richmond, VA 23284
[email protected]
804-828-0168