Hudson RiverNet
News from the Hudson River Estuary Program

In This Issue

• 2021 Highlights of River Habitat Restoration
• Restoring Oyster Habitat in the Tappan Zee
• Research Supports the Resilience of the Estuary's Natural Resources 
• Mapping of Tidal Wetlands Guides Scientific Research

 2021 Highlights of River Habitat Restoration

To track progress in achieving long-term changes that ensure a healthy and thriving estuary ecosystem, the Hudson River Estuary Action Agenda 2021 – 2025 includes specific success measures. The progress on these programmatic achievements are reported annually, and includes restoring oyster habitat, detecting and treating invasive species, and restoring intertidal (shallow water) habitats in the Hudson River Estuary.

Last week, DEC and the Hudson River National Estuarine Research Reserve (HRNERR) launched the Hudson River Aquatic Invasive Species Task Force. The task force will facilitate communication about the invasive species work coordinated by DEC, New York State Parks, Partnerships for Regional Invasive Species Management (PRISMs), and other entities. With a collaborative vision for invasive species control on the Hudson River, the task force will develop priorities for monitoring, management, and early detection/rapid response.

HRNERR continues to annually treat invasive species phragmites in tidal wetland marshes, including 1 ½ acres at Tivoli Bays in 2021. Throughout the year, DEC's Estuary Program staff assessed 35 shoreline sites along the tidal Hudson to prioritize future restoration of shallow water habitat, critical to fresh water and migratory species. The oyster habitat enhancement final report was published in 2021 and informs the oyster working group for future oyster restoration priorities. Read more about this work below.

Restoring Oyster Habitat in the Tappan Zee

In 2018, HRNERR worked with the New York State Thruway Authority to create more than five acres of oyster habitat at three sites near the new Governor Mario M. Cuomo Bridge. Nearly 900 concrete reef balls and more than 400 oyster shell gabions were placed at strategic locations along the river bottom with existing oysters and depths greater than 12 feet. Despite the very low salinity in this section of the river, monitoring over the past two years has documented successful early reef development at all three restoration sites. Additional monitoring is needed to evaluate larval output and the long-term sustainability of the restored reef communities. Read the 2020 monitoring report (PDF).

Research Supports the Resilience of the Estuary's Natural Resources 

The Hudson River Estuary is changing. In tributaries, down the main stem, and along tidal wetlands that stretch to the Atlantic, climate change and other drivers are reshaping the region’s intertidal areas. Together with our partners, HRNERR identified focus areas for research that support the resilience of the Estuary’s natural resources and communities.

These focus areas are intended to inspire collaborative projects that address critical scientific questions and deliver the innovative technical assistance that resource managers and communities need to meet the demands of a changing estuary over the next five years. Collectively, they embrace the topics of Species, Restoration, and Habitat (PDF). The Research Focus Area Library identifies resources, partners, and current or past research projects supported by the Hudson River Reserve for each of the research focus areas identified at the 2020 Research at the Reserve Forum. That event brought  80 scientists together to identify research gaps and opportunities to explore over the next five years. 

Mapping of Tidal Wetlands Guides Scientific Management and Stewardship

Habitat maps help guide science, management, and stewardship in Hudson River waters and along its shores. We make dozens of free GIS data sets and mapping products available to researchers, managers, and members of the public to advance science and stewardship of the Hudson River and its habitats. Tidal wetland maps of the four HRNERR sites (Piermont Marsh, Iona Island, Tivoli Bays, and Stockport Flats) document 20 vegetation categories in 1991, 1997, and 2005. They were designed to document existing plant communities and analyze changes in this composition and distribution over time. In 2007, an aerial photo inventory for the entire Hudson River Estuary was used to produce tidal wetland maps from Troy to Hastings-on-Hudson. The goal was to assist in the review of river development plans by providing a comprehensive atlas of potential impact areas. Currently, 2018 aerial photos are being used to update both the HRNERR tidal wetland maps (completed in 2021) and the whole Hudson River Estuary Tidal Wetland maps (to be completed in 2022).