The Seattle Aquarium recently completed its seventh year of a research project off the northwest coast Hawaii’s Big Island: monitoring reef fish abundance. Data is gathered using a method similar to the one used in our temperate fish surveys: non-invasive monitoring through diver-performed video sampling. This work is being done in cooperation with Washington State University; California State University, Humboldt; and the Hawaii Division of Aquatic Resources.
Says Curator of Conservation Research Shawn Larson, “We are searching for shifting baselines, which are an ecological indicator of changes in fish abundance and diversity that may correlate with local environmental changes or other factors such as changes in human use activities.” Data collected has shown a steady increase in fishes in our study sites and has already been used for educational and management purposes in Hawaii.
Below, Dr. Larson shares her journal entries from the final two days of the research trip.
Day 4: Friday, February 6
Four days into the trip and we have only surveyed three out of our eight sites—and the surf continued to be too rough to access them from shore. Our plan was to pick up the rest of the Puako sites (2 and 5) from the Kohala divers’ boat. In the morning we drove up to Mahukona to see if we there was any way we could get divers in and out of the water without the ladder. When we got there we realized that wasn’t going to happen today as the whole access area had been closed due to high surf. Disappointed once again, we drove back to Puako and prepared to dive off the boat. Once on the boat it was a bumpy ride to site 5 through the biggest swells we had seen near Puako, but we were on a boat so we had no worries. We sent the first team of divers in and watched the swells mounting. We had surface communications with the divers so we could hear what they were doing and talk to them. We completed our surveys at site 5 with lots of surge and low visibility because of the swells. Even from a boat this site was challenging under these conditions. We then travelled to site 2 and found that the waves were so big snorkelers couldn’t set our surface marker, thus the divers would have a hard time finding the survey site. The water conditions were just too rough and after surveying only one site we were done for the day.
Day 5: Saturday, February 7
Today we headed back to Kona to meet up with Captain Pete again and try to survey site 8 off his boat. The swells were supposed to have died down to just 1–2 feet. Unfortunately that wasn’t the case and the swells were about 6-8 feet. We motored for about half an hour, halfway to our site, and decided to turn around as we knew the swell was too big to safely dive that shallow site. By early afternoon we were back up in Puako and looked at site 2 again. The swells were big but smaller than they had been most of the week. We decided to go for it and sent one dive team out. Making it through the surf wasn’t fun with all the gear. The conditions underwater weren’t the best with heavy surge and low visibility. Once the first team finished two transects, they surfaced and waited to hand off the gear to the next dive team. However the next team wasn’t in SCUBA gear, just in snorkel gear. When the first dive team was underwater the swells had picked up too much. The snorkel team was needed just to help the divers with their gear get into shore safely. Everyone made it in without getting significantly hurt although everyone had bumps and bruises.
Alas it was our last dive day and although we weren’t able to survey all our sites, we did get the same amount of data as we did our first year—and had to call it quits. We will just have to pick up sites 6–8 next year!
For details about the Seattle Aquarium’s other research projects, visit our website.