Pitcairn Islands Expedition: Nearly 90 Species Found on One Dive

By Alan Friedlander, USGS & University of Hawaii

For 30 years Alan Friedlander has been examining population regulation in marine fishes throughout the Hawaiian Archipelago, the Caribbean, and the wider Indo-Pacific region.

After 4 days of 10-foot seas and 25-mph winds, we finally made it to the southern end of Henderson Island. The weather has made the diving very challenging so we were really excited about the opportunity to get in the water at the extreme southern point of the island, which is directly exposed to the full force of Antarctic storms and strong waves and currents.


Our dive was well worth the wait! What an incredible reef. We descended directly over a massive coral head that was more than 30 feet across, ten times larger than average, and loaded with an astonishing diversity of fishes. Living coral covered more than 60% of the bottom and provided huge amounts of vertical relief. The reef community here was unlike any we have seen on the trip so far in terms of both the large numbers and large sizes of the organisms, as well as the diversity of corals and algae. At 100 feet below, we gazed out over a solid wall of coral that extended down as far as the eye could see.


We were greeted by dozens of large jacks and red snappers that followed us throughout the dive and a few curious sharks that passed close by on a number of occasions. Fishes of every shape and color blanketed the reef and we recorded nearly 90 species during the dive. Juvenile surgeonfishes numbered in the tens of thousands and moved over the bottom like an enormous black wave. Our heads were spinning from all the life and colors. With over 6,000 hours underwater, I’ve never seen anything like it in my life. Although Henderson Island did not give up its riches easily, we ended our surveys there on an exhilarating note and can’t wait to see what tomorrow brings.


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