Understanding and resolving conflicts
between winter flounder and
dredging Thomas M. Grothues
Institute of Marine and Coastal Sciences, Rutgers University
Eleanor A. BochenekHaskins Shellfish Research Laboratory, Rutgers
University
Beth A. PhelanNational Marine Fisheries Service, NOAA
The conflict
Winter flounder – a valuable resource
Navigable waterways – a valuable resource
Nexus occurs in estuarine waters
Winter Flounder
• Valuable• Vulnerable
– to overfishing– to habitat degradation
• Protected– catch limits– Essential Fish Habitat
legislation
Essential Fish Habitat
• EFH- A legal term• Congressional Amendment to the
1996 Magnuson Stevens Fishery Act
• “…protect habitat necessary to continuation of the species”
• http://www.nefsc.noaa.gov/nefsc/habitat/efh/
Winter flounder reproduction
– Spawn in winter – Lay benthic egg clutches– Spawn in estuaries– Larvae (young) hatch and move
into water column– Larvae settle
When does dredging conflict with EFH?
When does dredging conflict with EFH?
When it is to occur in estuarine waters January through May
When does dredging conflict with EFH?
When it is to occur in estuarine waters January through May
– Marinas are in estuaries– Boat traffic and slip use
decreases in winter– NJ estuaries are typically
depositional environments
Refining EFH for winter flounder
• At the inter-estuary (coast-wide) scale– Includes historical ranges
• At the within-estuary scale– Estuaries are dynamic environments– May include areas or times of
unfavorable conditions to winter flounder spawning that can be used for dredging
• We can let the fish tell us their story
Telemetry study
• Tag fish with acoustic transmitters• Follow them synoptically and
automatically 24/7 in the study area
• Identify habitat use patterns• Identify spawning locations from
specific behaviors• Map to environmental factors in
the estuary
N
EW
S
N.J.
C.T.N.Y.
Study Area
Sandy HookBay
AtlanticOcean
Navesink River
0 3 km
Study Area
Sandy HookBay
Year OneBroad Scale Habitat Use
Hydrophone
Sandy HookBay
Year Two Sub-meter Scale Habitat Use
Hydrophone
Summary
• Winter flounder eggs are vulnerable to dredges
• EFH legislation protects them
• EFH designation may be unnecessarily broad
• Study could revise EFH designation
• Study could confirm EFH designation