The development of the Seaport District is one of the city of Boston’s great accomplishments. In just a few years, vacant warehouses have been transformed into modern offices, empty waterfront lots have sprouted gleaming hotels and cool, water-view eateries bob on the horizon, enticing tourists and trend-setters to the neighborhood. Topping it all off, Boston Harborwalk and other public spaces create a park-like ambience along the water.

But as the Seaport District’s landscape changes on almost a daily basis, familiar landscapes – like Jimmy’s Harborside and soon, Anthony’s Pier 4 restaurant – are fast disappearing.

So are reasonable office rents.

Small businesses, such as architecture and design firms, which – along with local artists – helped transform the Fort Point Channel neighborhood and nearby area from an industrial wasteland to a hip extension of downtown Boston are being squeezed out by skyrocketing commercial rents.

Seemingly overnight, the Seaport District is one of the hottest office markets in Greater Boston, if not the hottest. The vacancy rate for brick-and-beam office space has been cut in half over the past two years, while asking rents for Class A space in the Seaport neighborhood have jumped to $51 per square foot.

A similar phenomenon is occurring in Kendall Square in Cambridge, where tech startups are being forced to flee because of skyrocketing rents.

Boston Mayor Thomas M. Menino’s Innovation Center in the Seaport District is aimed at supporting entrepreneurs. But to be successful, the Seaport District needs a diverse mix of businesses – not just tech startups, biotech giants such as Vertex Pharmaceuticals or financial heavyweights such as State Street Corp., all of which are grabbing up waterfront space. A range of businesses, including small law firms, architectural, advertising and other professional and creative services firms, have been critical in providing the economic engine that has powered the district’s growth.

Because it’s political season, the usually slighted small business community has been receiving much attention from U.S. Senate candidates Scott Brown and Elizabeth Warren.  Brown, while short on specifics, argues that keeping the lid on taxes will help grow small businesses. Warren, fighting the image of a tax-loving liberal, has pledged to help small businesses cut through the bureaucratic red tape strangling their growth.

But small businesses in the Seaport District and other high-priced neighborhoods in Boston and Cambridge need more than political lip-service. While it may be unreasonable to require commercial landlords to reserve space at reasonable rents for small businesses, it’s at least worth discussing.

And the Massachusetts Legislature needs to help control operating costs that threaten the viability of small businesses, regardless of location. Double-digit annual increases in health care costs are crippling small businesses in the commonwealth, leaving them with little cash on hand to negotiate viable leases for office space.

Small business owners in the Seaport District – and elsewhere in high-cost communities in Massachusetts – also need to muster some creativity of their own. The downsizing of the past several years has left many companies paying for office space they no longer need. In other cities, like-minded small business owners are cutting costs by sharing space. Teaming together with another business allows a firm to share conference rooms, support staff and even office equipment. Other expenses, such as purchasing supplies, can be done in a consortium.

Kendall Square in Cambridge offers a cautionary tale of what could happen in the Seaport District. An area needs a mix of large and small firms, startups and established companies, as well as business, commercial and residential stakeholders in order to foster innovations and support growth. Too much of one sector could stifle the very energy that so far has made the Seaport District a success

Political leaders, neighborhood activists, commercial landlords and business owners need to shine a beacon to provide safe haven for the Seaport District’s small businesses.