Exhibit 99.1

Great Lakes Dredge & Dock Corporation Announces Pricing of $250 million of Senior Notes

OAK BROOK, Ill., January 25, 2011 – Great Lakes Dredge & Dock Corporation (NASDAQ: GLDD) (“Great Lakes” or the “Company”), today announced that it has priced its previously announced offering of Senior Notes (“Notes”).

The face value of the Notes is $250 million, with an interest rate of 7.375%. The Notes were priced at 100% of face value. The Notes will mature on February 1, 2019.

The Notes will be sold to qualified institutional buyers pursuant to Rule 144A and to certain persons outside the United States pursuant to Regulation S, each under the Securities Act of 1933, as amended (the “Securities Act”), with closing expected to occur on January 28, 2011, subject to customary closing conditions.

The Notes have not been and will not be registered under the Securities Act or any state securities laws and may not be offered or sold in the United States absent registration or an applicable exemption from the registration requirements of the Securities Act and applicable state securities laws. This press release does not constitute an offer to sell or the solicitation of an offer to buy the Notes, nor shall there be any sale of the Notes in any jurisdiction in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such jurisdiction.

Any issuance of the Notes will be subject to customary closing conditions.

The Company

Great Lakes Dredge & Dock Corporation is the largest provider of dredging services in the United States and the only U.S. dredging company with significant international operations. The Company is also one of the largest U.S. providers of commercial and industrial demolition services primarily in the Northeast. Additionally, the Company owns a 50% interest in a marine sand mining operation in New Jersey which supplies sand and aggregate used for road and building construction. Great Lakes has a 120-year history of never failing to complete a marine project and owns the largest and most diverse fleet in the U.S. industry, comprised of over 180 specialized vessels.

Cautionary Note Regarding Forward-Looking Statements

Certain statements in this press release may constitute “forward-looking” statements as defined in Section 27A of the Securities Act, Section 21E of the Securities Exchange Act of 1934 (the “Exchange Act”), the Private Securities Litigation Reform Act of 1995 (the “PSLRA”) or in releases made by the Securities and Exchange Commission (“SEC”), all as may be amended from time to time. Such forward-looking statements involve known and unknown risks, uncertainties

and other important factors that could cause the actual results, performance or achievements of Great Lakes and its subsidiaries, or industry results, to differ materially from any future results, performance or achievements expressed or implied by such forward-looking statements. Statements that are not historical fact are forward-looking statements. Forward-looking statements can be identified by, among other things, the use of forward-looking language, such as the words “plan,” “believe,” “expect,” “anticipate,” “intend,” “estimate,” “project,” “may,” “would,” “could,” “should,” “seeks,” or “scheduled to,” or other similar words, or the negative of these terms or other variations of these terms or comparable language, or by discussion of strategy or intentions. These cautionary statements are being made pursuant to the Securities Act, the Exchange Act and the PSLRA with the intention of obtaining the benefits of the “safe harbor” provisions of such laws. Great Lakes cautions investors that any forward-looking statements made by Great Lakes are not guarantees or indicative of future performance. Important assumptions and other important factors that could cause actual results to differ materially from those forward-looking statements with respect to Great Lakes and its business, include, but are not limited to, risks associated with Great Lakes’ leverage, fixed price contracts, dependence on government contracts and funding, bonding requirements and obligations, international operations, government regulation, restrictive debt covenants and fluctuations in quarterly operations, and those risks and uncertainties that are described in Item 1A of its Annual Report on Form 10-K/A for the year ended December 31, 2009, and in other securities filings by Great Lakes with the SEC.

Although Great Lakes believes that its plans, intentions and expectations reflected in or suggested by such forward-looking statements are reasonable, actual results could differ materially from a projection or assumption in any forward-looking statements. Great Lakes’ future financial condition and results of operations, as well as any forward-looking statements, are subject to change and inherent risks and uncertainties. The forward-looking statements contained in this press release are made only as of the date hereof and Great Lakes does not have or undertake any obligation to update or revise any forward-looking statements whether as a result of new information, subsequent events or otherwise, unless otherwise required by law.