The oil spill in the Gulf of Mexico has been first and foremost a disaster for the environment as well as for those whose livelihood depends on the gulf – as I write this word comes that the “top kill” may have worked to finally put an end to this debacle.

Certainly BP’s public reputation is in terrible straits but another casualty is the reputation of the Nature Conservancy, which has embraced a working relationship with BP. See the first-rate reporting by Joe Stephens of the Washington Post, who broke this story. The Nature Conservancy-BP dustup has important lessons for all charities to bear in mind.

The simple reality is that at its core, the Nature Conservancy believes in having working relationships with corporations active in certain environmentally sensitive industries.

Yes, you can still hug a tree even if it’s covered in oil.

Readers can agree or disagree with the Nature Conservancy’s special relationship with industry, such as that with BP. However, it is not the relationship with BP but rather how the Nature Conservancy has mishandled its relationship that has caused it harm and damaged its reputation to the public and donors.

How a charity manages a major corporate donor can be of vital importance to protecting the charity’s reputation.

First, the charity should make certain that any significant donation from a corporation (say, over $25,000) is made public and information on the donation is easily available on its Web site.

The charity should make clear what the funds will be used for as well as any role the corporation may have with the charity and its work.

It is the rare corporation that is not happy to announce its good work. Also the charity should make clear if it has any relationship with the corporation such as a seat on the corporate board or outside contracts. But watch out for conflicts-of-interest — a sea of troubles.

The Nature Conservancy was viewed as less than forthcoming about the extent of its relationship with BP when it first started talking and blogging about the gulf oil spill.

In addition, while the Nature Conservancy did have information about BP and its relationship with the company on its Web site, I understand it was not a walk in the park to find all the relevant information.

After-the-fact proclamations of innocence fall on deaf ears when it takes digging to discover the full picture — base reasons for donations and other activities are given greater credence.

Being open, transparent, and candid about the relationship with a major corporate donor from the beginning is a better place to be.

Second, depending on the size of the gift (both dollar amount and proportion of budget) and the role of the corporation with the charity (board member, adviser) the charity needs to consider the public face it is presenting with this relationship — similar to a corporation when considering a public spokesman.

This public image is particularly important if the corporation is closely identified with the charity’s own mission and goals — for example, a pharmaceutical company that produces vaccines for children and a charity devoted to the health of children.

When a charity promotes a public relationship, the public naturally views the charity as “laying hands” on the corporation — again, especially if the charity and the corporation are occupying the same field.

The charity should weigh the reputation of the corporation with which it is forging a public relationship. It should consider whether the corporation is conducting best practices and if it a good corporate steward.

Finally, when bad days happen for the corporation, the charity needs to re-evaluate its relationship and make clear that the charity’s mission and goals come first. This is not to say drop and run at the first bad news story but rather that the charity needs to have its eyes open and ask the hard questions and insist on best practices.

When a major corporate sponsor is seen as a bad actor, it can bring into question the charity’s reputation as well. The charity and its board need to respond quickly and aggressively to protect the charity’s reputation and charitable mission.

By contrast, the Nature Conservancy wore kid gloves in its handling of its relationship with BP at the beginning of the spill — to the detriment of its role as a leader in environmental issues and the consternation of many of its donors.

It is my understanding that finally — after much damage to the charity — the Nature Conservancy stated this week in a live chat on its Web site that it is revisiting its relationship with BP and the actions of BP before and after the spill. Good marks for finally making the correct decision, but TNC board and leadership shouldn’t have taken this long to arrive at the obvious.

It is perhaps easy to look at the Nature Conservancy-BP imbroglio as something that would happen only to the other fellow.

Charities commonly have special relationships with large corporate donors. Those special relationships can bring much benefit. But more attention must be paid by charities to ensure that that corporate relationship is above board, open, and transparent and is always in the best interest of the charity and its mission.