At an industry conference last week, Hawaiian Holdings (NASDAQ:HA) CEO Peter Ingram told reporters that Hawaiian Airlines had experienced a modest decline in bookings due to the continued eruption of Kilauea: a volcano on the Big Island of Hawaii.

This week, Hawaiian Airlines gave investors a better sense of the damage. The carrier slashed its second quarter unit revenue guidance, which will pinch its profits -- particularly because fuel prices have risen since the beginning of the quarter. However, there's no real reason for long-term investors to worry. In fact, if Hawaiian Holdings stock continues to decline because of the guidance reduction, it could represent a nice buying opportunity.

Unit revenue momentum slows

Last quarter, Hawaiian Airlines achieved a strong 4.9% increase in revenue per available seat mile (RASM), despite facing a surge in competition on West Coast-Hawaii routes.

A Hawaiian Airlines jet flying over the ocean, with mountains in the background

Hawaiian Airlines has posted strong unit revenue growth in recent quarters. Image source: Hawaiian Airlines.

The timing of Easter helped boost first-quarter RASM at the expense of Q2 unit revenue. Nevertheless, as of late April, Hawaiian Airlines projected that RASM would remain in positive territory this quarter, rising 0% to 3% year over year.

The increase in Kilauea's volcanic activity, which began in early May, has negatively impacted this outlook. While the Big Island and its airports are open for tourists, there has still been a drop-off in bookings, likely due to a combination of uncertainty about what's next for the volcano and the indefinite closure of most of Hawaii Volcanoes National Park.

On Monday, Hawaiian Airlines updated its second-quarter guidance to take account of Kilauea's ongoing eruption. The carrier now expects RASM to be between down 0.5% and up 1.5% this quarter. At the midpoint of the range, that's a 1-percentage-point reduction of Hawaiian's unit revenue outlook. Hawaiian Airlines also tweaked its cost forecast slightly higher, which will add to the margin pressure it faces this quarter.

Hawaiian Airlines is already adjusting

Fortunately for Hawaiian Airlines, the carrier doesn't do much long-haul flying from the Big Island. It currently operates one daily roundtrip between Los Angeles and Kona, as well as a few flights a week from Tokyo to Kona. Other airlines operate far more nonstop flights from the mainland to Kona.

A Hawaiian Airlines jet parked on the tarmac

Hawaiian Airlines doesn't operate many long-haul flights to the Big Island. Image source: Hawaiian Airlines.

Thus, the primary impact to Hawaiian Airlines has been on its interisland routes from Honolulu to Hilo and Kona. These routes carry both local traffic between the islands and connecting traffic from the continental U.S. and international destinations.

The good news is that it's pretty easy for Hawaiian Airlines to match its capacity to demand on these routes, because it is currently the only significant player in the interisland air travel market. Hawaiian recently decided to cut one daily Honolulu-Hilo roundtrip and two daily Honolulu-Kona roundtrips for its July schedule. This will help stabilize unit revenue on those routes. Even after these changes, Hawaiian Airlines will offer an ample schedule of 14 daily roundtrips between Honolulu and Hilo and 21 daily roundtrips between Honolulu and Kona.

This doesn't mean anything in the long run

In total, Hawaiian Holdings' guidance update implies that its first-quarter pre-tax margin will be 1 to 2 percentage points lower than initially expected. However, Hawaiian is still on track to make more money than it did last quarter, when it achieved a strong 11% adjusted pre-tax margin.

Hawaiian Airlines' recent schedule adjustments should lead to better unit revenue trends as soon as the third quarter. And eventually, Kilauea's volcanic activity will subside -- or become less of a concern to tourists -- leading to a rebound in bookings.

In short, Hawaiian Holdings' strong fundamental position remains intact. With the stock trading for less than seven times earnings, I am considering buying more Hawaiian Holdings stock to capitalize on a likely rebound over the next year or so.

Adam Levine-Weinberg owns shares of Hawaiian Holdings. The Motley Fool has no position in any of the stocks mentioned. The Motley Fool has a disclosure policy.