Voyager: How do scientists "sample" or study a "pristine" habitat such as the Line Islands without contributing to the human impact that we are concerned with in the first place?

A: Scientists study coral reefs using a variety of methods, and given the state of coral reefs today, we try to make sure we don’t damage them in the process. Even swimming through a reef can be destructive if steps are not taken to minimize contact, and carelessly throwing an anchor overboard can break a lot of coral. 

Some methods have essentially no measurable impact of reefs, such as counting fish while swimming or photographing the bottom so the images can later be used to determine what was living there.  Similarly, taking water samples for analysis has no impact on the reef. Other methods do have some impacts – for example, taking small samples of the coral to study its genetic make-up.  In such cases a scientist has to weigh benefits of the knowledge against the damage caused. For this reason, scientists must get permits to do their research in most places.

However, it is important to realize that reefs are not static environments – visiting a reef is not like stepping on the surface of the moon and leaving footprints that last for centuries. Even without human interference, reefs are always changing. Every day, fish eat the coral, other animals and seaweed. Hurricanes and typhoons periodically impact reefs and can lift giant pieces of the reef onto the shore. Learning about how healthy reefs function through field studies helps us to protect and restore reefs that have been seriously damaged by people. 

A few scientists visiting a remote, pristine reef will have very little impact if they do their work with care, bring their own food, and don’t leave any garbage behind.

—Nancy Knowlton, professor of marine biology; director, Center for Marine Biodiversity and Conservation