| /S/ JONATHAN W. BERGER |
| Jonathan W. Berger |
| Chief Executive Officer and Director |
| /S/ BRUCE J. BIEMECK |
| Bruce J. Biemeck |
| President, Chief Financial Officer and Director |
| March 9, 2012 |
| GREAT LAKES DREDGE & DOCK CORPORATION | ||
| By: | /S/ BRUCE J. BIEMECK | |
| Bruce J. Biemeck | ||
| President and Chief Financial Officer | ||
| Date: March 9, 2012 | ||