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CHAPTER IV: WILDLIFE HABITATS FOR MISSISSIPPI’S SGCN,

THREATS AND CONSERVATION ACTIONS^266

14.4 Barrier Island Passes

„ Value to SGCN - 36

„ Rank - 11th of 17 Marine, Estuarine and

Estuarine Fringe Systems

DESCRIPTION
An additional Mississippi Sound type is the tidal
pass, a habitat type defined for areas between the
barrier islands where there is an enhanced tidal
current. The surge through the tidal passes creates
strong currents that inhibit the accumulation of finer sediments. The bottom substrates of tidal passes
are regarded as clean sandy bottoms. The tidal passes serve as major conduits for the exchange of water
and faunal recruitment between estuarine and marine waters. Benthic communities within these areas
are sufficiently different to warrant separation from the other communities of the Mississippi Sound.

LOCATION, SIZE, CONDITION AND CONSERVATION PRIORITY
NGM

The barrier island passes subtype is confined to the natural tidal
flow channels found between the barrier islands. Tidal currents,
which are much stronger in the pass areas, create sandy bottom
habitats because muddy sediments are unable to settle from the
water column. There are an estimated 500 acres of this subtype in
the state.

Some of the passes have been dredged to allow large ship travel.
The dredging may have disrupted the westward drift of sand movement along the southern shores of the
islands. Other factors that may have degraded this habitat are considered to have a minor impact on this
subtype.

Barrier island passes are considered secure in the state because few impacts are known at this time.

SPECIES OF GREATEST CONSERVATION NEED ASSOCIATED WITH
BARRIER ISLAND PASSES

GROUP SCIENTIFIC NAME COMMON NAME TIER
Birds Pelagic Birds 1
Sterna maxima Royal Tern 2
Sterna sandvicensis Sandwich Tern 2
Pelecanus occidentalis Brown Pelican 2
Sterna antillarum Least Tern 2

14.4 Barrier Island PassesRange of Barrier Island Passes