## Access

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

## If You Use a Screen Reader

This content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.

Millicent L. Quammen and Christopher P. Onuf
Estuaries
Vol. 16, No. 2 (Jun., 1993), pp. 302-310
Stable URL: http://www.jstor.org/stable/1352503
Page Count: 9
Preview not available

## Abstract

Vegetation maps of the lower Laguna Madre prepared from surveys conducted in 1965-1967, 1974-1976, and 1988 document a $>330\ {\rm km}^{2}$ decrease in cover by Halodule wrightii, an increase of almost 190 km2 in other seagrass species, and an increase of 140 km2 in bare bottom. Loss in seagrass cover is confined to deeper parts of the laguna; turbidity caused by maintenance dredging is the suspected cause. The species shifts are consistent with observed reductions in salinity maxima. Although the hydrological alterations and climatic shift responsible for moderating the salinity regime occurred between 1948 and 1965, the biological changes continue. Establishment of patches away from source meadows appears to be the process for displacing species that limits their rate of expansion into suitable habitat in this elongate embayment.

• 302
• 303
• 304
• 305
• 306
• 307
• 308
• 309
• 310