2018 Pacific Expeditions: Corals and Clean-Up

In 2018, NOAA scientists and partners embarked on two lengthy voyages, crossing through some of the most remote regions of the Pacific Ocean.

During the first mission aboard NOAA Ship Hi‘ialakai, researchers surveyed coral reef ecosystems in American Samoa and the Pacific Remote Islands. The goal of this annual expedition is to take a snapshot of the health and abundance of corals and reef fishes.

The second expedition, aboard NOAA Ship Oscar Elton Sette, focused on cleaning up marine debris from the remote Northwestern Hawaiian Islands. During this voyage, the team removed more than 160,000 pounds of lost or abandoned fishing nets and plastics from this ecologically and culturally significant area, part of Papahānaumokuāea Marine National Monument.

View our top five photos from each mission below. Then take a look at all available photos from the 2018 coral reef and marine debris missions to find your favorites.

1. Scar on the Reef

Derelict fishing nets wear down and break corals or even grow into the reef structure, smothering living coral. In this aerial photo, NOAA divers remove a large net from the reef at Pearl and Hermes Atoll. They painstakingly cut the nets off dense thickets of Porites compressa, also known as finger or hump coral, and pull it into deeper water to haul it away in the small boat. You can see the scar of bleached, dead reef in the upper right, where the net smothered the corals.

2. Damselfish and Anemone

A juvenile Orangefin Dascyllus damselfish claims this large anemone as his home. This species is found only in the Line and Phoenix Islands. During the 70-day Pacific Reef Assessment Monitoring mission, teams of scuba divers conducted rapid ecological assessments of corals and reef fishes near American Samoa and the Pacific Remote Islands.

3. Threats to Wildlife

In addition to damaging corals, derelict fishing gear poses a serious choking and entanglement hazard to many threatened or endangered marine species and seabirds in the Northwestern Hawaiian Islands. This green sea turtle (called honu in Hawaiian) got tangled in a ball of fishing line and nets at Pearl and Hermes Atoll. Luckily, the team successfully untangled and released it shortly after this photo was taken.

4. Schooling Jacks

A school of black jacks swim through a field of branching Acropora corals at Baker Island, where scientists were recording data. During the expedition, scientists measured physical and chemical characteristics of the coral reef environment such as water temperature, salinity, and carbonate chemistry. The teams also assessed impacts of ocean acidification on coral reef growth and removal.

5. All Hands On Deck

The team works together to pull a large mass of nets into the boat near the barrier reef at Midway Atoll. There is no easy way to get nets from the water to the boat, and a successful net pull relies on creative use of knots, line, and muscle. This pile of tangled nets weighed 3,900 pounds.

6. Coral Coring

Scientists work carefully to extract a core of skeleton from a coral head. This core acts as a record, allowing scientists back in the lab to learn more about the coral's history and possible ocean conditions over time.

7. Underwater Surveys

Marine debris divers are towed underwater to look for derelict nets along a sand margin dropoff just inside the barrier reef of Pearl and Hermes Atoll. As nets are washed in over the barrier reef from the open ocean, small coral heads can be ripped off the substrate and become entangled in the net ball, causing the net to sink. Waves and currents push the nets across the sand and down the sand margin dropoff where the divers find them sitting at the bottom of the slope. The dark strip in this photo is piles of loose algae that have also accumulated at the bottom of the dropoff.

8. Still Predator

An arc-eye hawk fish perches on a Pocillopora coral. These predators lie in wait for unsuspecting small fishes and crustaceans to swim by, but if something bigger shows up, they are quick to dart into the safety of the coral branches.

9. Lost at Sea

Do you recognize any of these items? In addition to fishing nets, buoys, and floats, the team also finds everyday items that you might have in your home, including bottles, cigarette lighters, toys, toothbrushes, umbrella handles, and even shoes.

10. Backreef

Ofu Island's backreef as a wave crests over the corals. After mass coral bleaching events across the Pacific Ocean in 2016 and 2017, scientists found major coral die-off in the Pacific Remote Islands. Scientists returned to the region to assess the health of coral reefs in 2018. The 2018 expedition marks the eight research voyage to American Samoa and tenth voyage to the Pacific Remote Islands Marine National Monument to assess coral reef conditions and recovery from mass bleaching.