Biodiversity of the Moodna Creek Watershed - Orange County Water ...

Moodna Biodiversity
L. Heady, 19 June 2008 DRAFT
The wetland complex at the Moodna mouth provides breeding habitat for a number of birds,
including green-backed heron, black duck, wood duck, Virginia rail, spotted sandpiper, fish
crow, and marsh wren, and has been identified as important habitat area for least bittern (NYS
Threatened). (See Appendix A for conservation recommendations for least bittern.) Herons,
waterfowl, and shorebirds concentrate in the area during spring and fall migrations, and the creek
is thought to be a major crossing point for raptors migrating along the northern slope of the
Hudson Highlands. In addition, the NY Natural Heritage Program considers the Moodna mouth
an important “Waterfowl Winter Concentration Area.”
Submerged Aquatic Vegetation. The submerged aquatic vegetation (SAV) beds also contribute
to the overall habitat value of the Moodna mouth system. They occur in the lower reach of the
creek, in the embayment, and east of the train trestle along the Hudson shoreline. (See Figure 2.)
Unlike other tidal coves and bays in the Hudson where the invasive water chestnut often
dominates and poses management challenges, the SAV beds at the Moodna mouth are comprised
of water celery, a native plant. SAV beds trap fine sediment and organic matter, maintain
dissolved oxygen levels, and provide habitat for a rich diversity of fish and invertebrates
(Findlay et al. 2006).
Threats and Conservation Opportunities
• Water quality. Habitat value for fish and wildlife in the lower reach of the creek, and
associated recreation opportunities, is dependent on good water quality. Herring may
already be an indicator of declining conditions in the Moodna. In 1996, Hudsonia
reported a moderately large herring run on the Moodna (Schmidt and Cooper 1996).
Local fishermen have observed declines in this run in the last six years, and speculate that
this decrease coincides with sewage problems in the Moodna (L. Abuza, pers. comm.).
The NYS DEC Hudson River Fisheries Unit selected the Moodna for the 2008 Volunteer
River Herring Monitoring Survey due to its historically large herring run. Over 35
monitoring sessions in April and May found no evidence of river herring in the Moodna,
while the same protocols were used successfully to document herring in other monitored
streams in the estuary watershed. To address water quality concerns, the two sewage
treatment plants in the vicinity of the Moodna mouth should be assessed to understand
and avoid impacts to the rich biodiversity of the area. Riparian buffers should be
maintained and restored as necessary, and pollution from stormwater runoff should be
prevented.
• Marsh and mudflats. The large marsh and mudflat habitat complex may also be
vulnerable to pollution from the nearby sewage treatment plants, and to dumping,
channeling, and disturbing remaining upland buffers. An additional threat is invasion of
exotic species such as purple loosestrife and water chestnut. Recreational boat traffic that
scrapes mudflats at high tides degrades their important habitat value and should be
prevented. Hardened shorelines should be minimized or avoided and instead, low-sloped
shorelines should be maintained within the tidal zone. This will be especially important
as climate change causes sea level rise, and tidal habitats need to migrate inland.
• SAV beds. SAV beds are especially vulnerable to motorized boating activity and
shoreline access; recreational activity should be limited in areas of SAV. Maintaining
natural shorelines is strongly encouraged.
• Breeding marsh birds. Disturbance of breeding birds can result in failed nesting efforts
or abandonment of nests completely. Marsh bird communities have shown significant
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