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