An opportunity has come to respond quickly to a potential coral reef threat in the Northwestern Hawaiian Islands, and we should take it.

Marine scientists have found evidence of what may be a growing infestation of an aggressive alien seaweed near Mokumanamana, the place in the northwestern archipelago also called Necker Island.

The red alga, known by its scientific name Hypnea musciformis and the common label hookweed, has turned up in greater-than-usual quantities in lobster traps, and it's imperative to find out how bad the problem is. A few sprigs of hookweed first turned up around Necker three years ago and persisted in small amounts until this year, when traps were bringing up pounds of the seaweed — alarming, if it signals an algae bloom.

Fortunately, a scheduled research cruise arranged by the National Oceanographic and Atmospheric Administration will head to the area later this month. A marine botanist will be aboard and can do an exploratory dive during a stop near Necker Island. Once state and federal authorities are armed with more information, they can plan the most effective response.

That must happen as expeditiously as possible. Invasive species have become ecological threats around the more developed islands, and experts say this often happens because authorities don't act quickly enough.

In a separate case, citizen groups have sued the state for allowing Big Island imports of a freshwater alga, genetically engineered for medical uses, that could contaminate the environment. Similarly, the hookweed was brought to Hawai'i in 1974 as a potential cash crop to produce the food thickener carrageenan. Careless importing of alien species often produces more of a headache than an economic boost.

Saltwater organisms such as hookweed are especially worrisome because of their threats to coral reefs. The reefs harbor many marine species in a balanced environment that's easily destroyed when a true sea "weed" takes over. Kane'ohe Bay is an example of an ecosystem that has suffered because budding infestations of introduced species were allowed to languish.

It's great to see NOAA move quickly to take a closer look. Now officials who protect such pristine environments must intervene to see that a small problem doesn't become critical.