The Beginning of the End…of the Season: The 19-day mission to recover monk seal field camps and save seals

A beautiful morning outside Kure Atoll with Green Island in the distance.

This morning the sun rose into a clear blue sky, the wind gently tousled the flags on the ship’s masts, and the sea rolled slow and steady with barely a ripple on the surface.  These are perfect conditions for our first full day of real operations on the 19-day trip aboard the NOAA RV Hi’ialakai. The mission of research cruise HA-17-03 is to pick up 4 of our 5 monk seal research teams that have been deployed in the Northwestern Hawaiian Islands since May.  The teams, spread across the islands and atolls, have been collecting important population data, vaccinating seals, cleaning up marine debris and doing some life-saving interventions.  But, now it is time to come home.

So, today the Hi’ialakai sat just off the western outer reef of Kure Atoll, completing a long day running small boats to and from Green Island and the ship.  The boats headed to the islands carried additional water and supplies for the State biologists who will overwinter there and on the return carried buckets of gear (lightly dusted by bird guano), solar panels, gas cylinders, reams of data and more.  The last boat of the day carried our first two returning field team members, Ilana Nimz and David Golden.

HI-2 carrying a cargo of buckets, dewars, and a variety of other gear that helped our field teams survive and complete their conservation science mission.

Our ever so precious crane on the Hi’ialakai. Without this glorious piece of equipment nothing could get done. It lifts the boats. It lifts the gear. It lifts the people. In crane we trust.

One of many bags of debris we will be picking up from the NWHI this season.

Each camp will have a summer’s worth of stories to tell and we are going to ask each camp to share their highlights with you as we move down the chain.  First up are stories from Kure Atoll, so read on below, and stay tuned to hear the tales of the other 2017 NOAA’s Monk Seal ARC (Assessment and Recovery Camps).  We hope to not only successfully retrieve all of our crew but maybe a monk seal patient or two for Ke Kai Ola.

 

Scientist David G. taking his first step onto the ship after months at Kure Atoll.

Scientist Ilana N. can barely contain her excitement at the thought of fresh greens, showers and air conditioning after several months in the field.

Ilana and David bidding a fond farewell to Green Island and Kure Atoll and turning south back towards Honolulu. Check out the continuation below to find out what their highlights of the 2017 monk seal field season were.

 

First up in a story from Ilana Nimz, one of our biologists at Kure Atoll:

The Sounds of Seals: The trials and tribulations of monk seal acoustic studies.

By Ilana Nimz

Ilana and her field partner David have spent the last several months at Kure Atoll.  While they had many monk seal adventures this summer, a unique component of their work was conducting an acoustic study. Here are a couple stories from their many hours of recording.

Kure is the only island this year that recorded Hawaiian Monk Seal sounds in collaboration with a researcher in France who is analyzing their vocalizations in conjunction with their behaviors. Armed with a recorder and a microphone (with a wind-block cover that makes it look like a kid’s karaoke toy) that gets attached to a telescoping pole and is propped near the seals, we set out to find animals that look like they will talk. Whenever we are trekking out to do a recording, the DLNR team jokes about what interview questions we are going to ask the seals. David, my Kure partner in conservation, developed a pretty neat survey shelter/seal viewing blind consisting of our aluminum tent poles and a camo-print bedsheet. If it’s camo, the seals can’t see us, right? Operation Desert Kure. For the most part the seals pay us no mind, but if they do notice us they tend to give us a bored but perplexed look during set up, then go back to their business.

As I was recording, two of the mom/pup pairs had a pup switch.  Sometimes, when multiple mom/pup pairs are in the same area they might accidentally “exchange” pups.  Other times, a recently weaned pup might displace a smaller nursing pup without mom noticing.  In this instance the pair we were focused on was resting on the beach and the other mom/pup pair entered the water about 100 meters away. The pup I was recording seemed to have noticed he was with the wrong mom and booked it towards the water and started swimming and calling for its real mom. I picked up the giant microphone, turned on the video camera (Breaking news story!!!) and followed the pup down the beach and watched a very confusing confrontation between the moms. There were lots of barks, growls, flipper slaps, and pups calling at each other while going between the moms (Drama!). Eventually, one of the moms raised her flipper and began slapping the water, which looked like a parent waving “Child, get over here! Get over here NOW!” and her biological pup happily obliged and swam off with her. Whew.

 

We then spent the next couple of hours trying to code all of those behavior interactions associated with the vocalizations  …even with the video supplement to the audio recording, it was quite a challenge.

During another audio recording session of a mom and pup, the pup got curious and hauled up to the microphone and started sniffing it. In the recording, we could clearly hear the “SNIFF… SNIIIIIFFF” while the mom barks at the pup in the background. Eventually the mom decided she needed to take control of the situation and hauled up to the microphone as well, and barreled into it with her back. The microphone pole rolled off of the crate it was propped on, abruptly bringing an end to that listening session. Well played mom.

Unfortunately most of the time, the seals choose to plead the 5th, except for a few sneezes and snorts. Even though the animals are silent, we wait for an animal to cruise by to instigate a reaction and get them talking! In the meantime, we enjoy observing the seals, birds, clouds and soak up the simple pleasures of life on a remote island.

Once our ship returns to Honolulu, the recordings and data will be sent off to our colleague so she can unlock the secrets of monk seal communication.  If you are interested in similar work that was done with Mediterranean monk seals you can check out this scientific article.

 

The Saipan seen: from the big Bryde’s whale to the small spinner dolphin

By Marie Hill, Adam Ü, Allan Ligon, and Tom Ninke

After leaving Guam, the Cetacean Research Program conducted small-boat surveys for whales and dolphins off Saipan and Tinian during May 17-26, 2017.  During our second day on the water, we encountered a Bryde’s whale, which was only our 5th encounter with this species in the Mariana Islands and the first time that we have seen one off Saipan.  Our four previous encounters were in August 2015 off Guam and Rota.  Bryde’s whales are baleen whales and can grow to 51 ft in length.  They are sometimes mistaken for sei whales, but can be distinguished by the presence of three longitudinal ridges on the top of their rostrum.

Bryde’s whale encountered off Saipan on May 18, 2017. Photos: NOAA Fisheries/Marie Hill and Adam Ü

 

Bottlenose dolphin encountered off Saipan on May 25, 2017. Photo: NOAA Fisheries/Marie Hill

A few days later, we encountered two groups of bottlenose dolphins.  We recognized a few of the individuals from our existing photo-identification catalog.  The others may be new individuals.

We deployed two satellites tags on bottlenose dolphins, on one dolphin from each group.  They spent the next several days moving up and down the west side of Saipan and Tinian, going as far north as Marpi Reef (~10 nautical miles north of Saipan).  The tagged dolphins spent a few days moving around together, but went their separate ways and on 29 May, one was off the northern tip of Saipan, while the other was off the northern tip of Tinian.

Satellite tracks from tags deployed on two bottlenose dolphins, with the track from the dolphin with tag #141698 shown in white and the dolphin with tag #169421 shown in red. The larger squares with the tag numbers are the locations of the two dolphins at the time of blog writing.

The third species that we encountered was the spinner dolphin.  Spinner dolphins get their name from their aerial behavior.  Check out the following video where you can see a dolphin underwater preparing to launch out of the water and then see it spin in the air.

 

During our surveys off Saipan, we encountered spinner dolphins five times.  We saw some of the same individual dolphins during each encounter.  These individuals are in our spinner dolphin photo-identification catalog, and we have seen some of them in multiple years since 2010, when we began conducting small-boat surveys in the Marianas.

We were joined by our colleagues Kym Yano and Erik Norris on several days.  They were out here to refurbish and re-deploy the bottom-mounted passive acoustic recorders called High-Frequency Acoustic Recording Packages (HARPs) that are listening for cetaceans year-round.  We have one off the northeast side of Tinian and another off the west side of Saipan out at 300 Reef.  The NOAA ship Hi‘ialikai helped us out by picking up the Tinian HARP.

NOAA ship Hi‘ialikai under a rainbow off Saipan. Photo: NOAA Fisheries/Adam Ü

All survey operations including satellite tagging, photo-id, and biopsy sampling were conducted under NMFS permit. Funding was provided by the NOAA Fisheries and the U.S. Navy Commander, U.S. Pacific Fleet. We would like to thank the owner and captains of Sea Hunter, the CNMI NOAA Fisheries field office, and all of our volunteers during the surveys.

Scientists complete coral reef ecosystem monitoring work around the U.S. Phoenix Islands

By Kelvin Gorospe

The Pacific Islands Fisheries Science Center’s (PIFSC) Coral Reef Ecosystem Division (CRED) recently completed the Phoenix Islands portion of their Pacific Reef Assessment and Monitoring Program (Pacific RAMP) research cruise. The areas they surveyed included: Johnston Atoll, Howland Island, and Baker Island. All three islands are part of the Pacific Remote Islands Marine National Monument, which is co-managed by NOAA and the U.S. Fish and Wildlife Service (USFWS), as well as the National Wildlife Refuge System administered by the USFWS. These areas are among the most remote locations under U.S. jurisdiction and offer a unique opportunity to study and better understand coral reef ecosystems removed from direct human impacts.

Figure 1: Launching and recovering teams of scientists from NOAA R/V Hi‘ialakai. Photo credit Kelvin Gorospe.

Figure 1: Launching and recovering teams of scientists from NOAA R/V Hi‘ialakai. Photo credit Kelvin Gorospe.

Figure 2: Group photo of scientific divers on the fantail of the ship. Photo credit Jim Bostick.

Figure 2: Group photo of scientific divers on the fantail of the ship. Photo credit Jim Bostick.

During the expedition, small boats were launched from NOAA ship Hi‘ialakai carrying teams of scientists to survey reef fishes, benthic and microbial communities, and study the effects of ocean acidification and warming on reef ecosystems (Fig 1). A total of 17 scientific divers, one data manager, and two terrestrial biologists participated in operations (Fig 2). For the U.S. Phoenix Islands portion of the cruise, fish data are highlighted below. Blog posts from the upcoming legs of this 103-day research expedition will highlight information from other reef assessment surveys.

Over the course of 13 diving days, the fish team surveyed a total of 102 rapid ecological assessment (REA) sites (31 at Johnston Atoll, 35 at Howland Island, and 36 at Baker Island). The team used a stratified random survey design, whereby the reefs around each island are divided into three depth zones (0-6 m; 6-18 m; and 18-30 m) and the total number of sites surveyed in each depth zone is proportionate to the total amount of reef area found in that depth zone. Site locations are then spatially randomized around the island. Click here for more details on the methodology of fish REA surveys.

Figure 3: Total fish biomass (all species) at all sites surveyed around Howland Island.

Figure 3: Total fish biomass (all species) at all sites surveyed around Howland Island.

Figure 4: Total fish biomass (all species) at all sites surveyed around Baker Island.

Figure 4: Total fish biomass (all species) at all sites surveyed around Baker Island.

At Howland and Baker Islands, the subsurface eastward-flowing Equatorial Undercurrent encounters the submerged portions of these undersea mountains to create areas of intense upwelling of nutrient-rich waters that help sustain high biomasses of reef fishes. This is clearly shown in the bubble plots above (Fig 3 and Fig 4), depicting high levels of fish biomass around both islands. Each circle on the graph is centered on a dive site.

Figure 5: Manta rays swimming through a fish survey at Howland Island. Photo credit Louise Giuseffi.

Figure 5: Manta rays swimming through a fish survey at Howland Island. Photo credit Louise Giuseffi.

Figure 6: Fish REA diver collecting data on fish species ID, sizes, and abundance at Johnston Atoll. Photo credit Louise Giuseffi.

Figure 6: Fish REA diver collecting data on fish species ID, sizes, and abundance at Johnston Atoll. Photo credit Louise Giuseffi.

Among other large-bodied species, schools of manta rays were frequently reported around both Howland and Baker Islands (Fig 5). At each site, two fish divers collected replicate data on the sizes and numbers of fish species that swam through their survey area over the course of five minutes (Fig 6). The size of the circle is proportionate to the calculated total biomass of fish (g per m2) at each site. These graphs demonstrate the high reef fish biomasses in these upwelling areas of the Pacific Remote Islands Marine National Monument.

Figure 7: Total fish biomass (all species) at all sites surveyed around Johnston Atoll.

Figure 7: Total fish biomass (all species) at all sites surveyed around Johnston Atoll.

In contrast, Johnston Atoll, which doesn’t experience this strong upwelling of nutrients (Fig 7), sustains lower levels of reef fish biomass than Howland and Baker. However, its importance is highlighted by the fact that it is known to be an important genetic stepping stone between the central Pacific and the Hawaiian Islands, maintaining evolutionary connectivity between these areas. During our time at Johnston on this cruise, CRED scientists spotted three coral species (Acropora speciosa, Acropora retusa, and Pavona diffluens) recently listed as threatened under the Endangered Species Act.

In addition, CRED scientists reported frequent sightings of overturned Acropora table corals and observed that much of the coral on the northwest side of the atoll experienced recent damage, likely as a result of the large ocean swell from the northwest that came through as we were leaving Oahu at the end of January. Protection of these areas from the degrading effects of fishing and extraction is important to ensuring that the reef can recover from natural environmental impacts such as these large ocean swell events.

The CRED team will remain at sea until May 3, 2015, continuing to conduct coral reef ecosystem monitoring surveys throughout American Samoa (Tutuila, Ofu, Olosega, Ta‘u, and Swains Islands and Rose Atoll) as well as the U.S. Line Islands (Jarvis Island, Palmyra Atoll, and Kingman Reef). Stay tuned for more updates from the field.

Coral reef monitoring in the Mariana Archipelago: preliminary results from visual surveys of fishes and benthic habitats

By Kathryn Dennis and Bernardo Vargas-Ángel

The PIFSC cruise HA-14-01 officially concluded yesterday, Monday, June 2, when the NOAA Ship Hi`ialakai arrived back at Ford Island, Pearl Harbor, from Saipan. During this expedition, which began on March 5, scientists from the PIFSC Coral Reef Ecosystem Division (CRED) and partners conducted ecological surveys, collected water samples, and deployed monitoring instruments and platforms at Wake Island and in the Mariana Archipelago as part of the CRED-led Pacific Reef Assessment and Monitoring Program (Pacific RAMP). As a part of the National Coral Reef Monitoring Plan of NOAA’s Coral Reef Monitoring Program, researchers established climate monitoring stations at 4 islands in the Mariana Archipelago and at Wake Island, where integrated activities provide for long-term collection of data on ocean temperature, chemical composition, benthic cover, calcification, bioerosion, and biodiversity to monitor the effects of climate change and ocean acidification.

The volcano on the island of Pagan emits plumes of gas and steam on the evening of April 20, as seen in this photo taken during the PIFSC cruise HA-14-01. NOAA photo

The volcano on the island of Pagan emits plumes of gas and steam on the evening of April 20, as seen in this photo taken during the PIFSC cruise HA-14-01. NOAA photo

From March 25 to May 6, during Legs II and III and part of Leg I of this latest research cruise at Guam and the Commonwealth of the Northern Mariana Islands (CNMI), CRED scientists and partners completed 100 broad-scale towed-diver surveys, covering more than 220 km of coastline and, at Rapid Ecological Assessment (REA) sites, conducted 329 fish surveys and 158 benthic surveys. Members of the CRED Climate and Ocean Change Team installed 15 climate monitoring stations around Guam, Saipan, Pagan, and Maug, deploying 15 subsurface temperature recorders (STRs), 55 calcification accretion units (CAUs), 45 autonomous reef monitoring structures (ARMS), and 75 bioersion monitoring units (BMUs)—in addition to installations of 70 CAUs at supplementary monitoring sites and 55 STRs at strategic locales associated with climate monitoring stations and long-term (>9 years) time series. For a summary of activities conducted and preliminary results from REA surveys at Wake Island during Leg I, go to the previous blog post published on April 10.

A cursory review (prior to the data being fully analyzed) did not reveal any observations of notable changes in the structure of the fish and benthic communities, in comparison with survey results from the previous Pacific RAMP cruise in the Mariana Archipelago in 2011, at Rota, Aguijan, Tinian, Saipan, Sarigan, Guguan, Alamagan, Pagan, Asuncion, Maug, and Farallon de Pajaros in the CNMI or at Guam are reported at this time. However, unusual cold-water temperatures (~17°C) were experienced at Asuncion, Maug, and Farallon de Pajaros, as was volcanic activity that originated mainly from Ahyi Seamount located nearly 18 km southeast of Farallon de Pajaros.

Preliminary results from the surveys at REA sites of fishes and benthic habitat conducted at depths of 0–30 m by scuba divers from the CRED Fish Ecology Team during the PIFSC cruise HA-14-01 are provided in the fish monitoring brief below. The islands on the Mariana Arc can be divided into 2 groups: the old southern islands and the young, volcanic northern islands. The summary below also was published on May 23 (and is available for download) as 2 separate 2-page PIFSC Data Reports, one for the southern islands of this archipelago and the other for the northern islands.

Pacific Reef Assessment and Monitoring Program
Fish monitoring brief: Mariana Archipelago 2014

By Adel Heenan

About this summary brief

The purpose of this document is to outline the most recent survey efforts conducted by the Coral Reef Ecosystem Division (CRED) of the NOAA Pacific Islands Fisheries Science Center as part of the long-term monitoring program known as the Pacific Reef Assessment and Monitoring Program (Pacific RAMP). More detailed survey results will be available in a forthcoming annual status report.

Sampling effort in the southern islands

  • Ecological monitoring took place in the southern Mariana Archipelago from March 25 2014 to May 07 2014.
  • Data were collected at 178 sites. Surveys were con- ducted at Saipan (n=11), Tinian (n=19), Aguijan (n=10), Rota (n=28), and Guam (n=73).
  • At each site, the fish assemblage was surveyed by underwater visual census and the benthic community was assessed.

Sampling effort in the northern islands

  • Ecological monitoring took place in the northern Mariana Archipelago from April 19 2014 to May 06 2014.
  • Data were collected at 148 sites. Surveys were conducted at Farallon de Pajaros (FDP) (n=11), Maug (n=40), Asuncion (n=21), Pagan (n=43), Alamagan (n=11), Guguan (n=11), and Sarigan (n=11).
  • At each site, the fish assemblage was surveyed by underwater visual census and the benthic community was assessed.

Overview of data collected

Figure 1. Mean total fish biomass at sites surveyed in the southern islands.

Figure 1. Mean total fish biomass at sites surveyed in the southern islands.

Figure 2. Mean total fish biomass at sites surveyed in the northern islands.

Figure 2. Mean total fish biomass at sites surveyed in the northern islands.

Figure 3. Mean hard coral cover at sites surveyed in the southern islands.

Figure 3. Mean hard coral cover at sites surveyed in the southern islands.

Figure 4. Mean hard coral cover at sites surveyed in the northern islands.

Figure 4. Mean hard coral cover at sites surveyed in the northern islands.

Preliminary results for fish biomass also are presented by consumer group and size class. Primary consumers include herbivores (which eat plants) and detritivores (which bottom feed on detritus), and secondary consumers are largely omnivores (which mostly eat a variety of fishes and invertebrates) and invertivores (which eat invertebrates).

Figure 5. Mean consumer group fish biomass (± standard error) at sites surveyed in the southern islands. Primary consumers are herbivores and detritivores, and secondary consumers are omnivores and invertivores.

Figure 5. Mean fish biomass (± standard error) by consumer group at sites surveyed in the southern islands. Primary consumers are herbivores and detritivores, and secondary consumers are omnivores and invertivores.

Figure 6. Mean consumer group fish biomass (± standard error) at sites surveyed in the northern islands. Primary consumers are herbivores and detritivores, and secondary consumers are omnivores and invertivores.

Figure 6. Mean fish biomass (± standard error) by consumer group at sites surveyed in the northern islands. Primary consumers are herbivores and detritivores, and secondary consumers are omnivores and invertivores.

Figure 7. Mean fish biomass per size class (± standard error) at sites surveyed in the southern islands. Fish measured by total length (TL) in centimeters (cm).

Figure 7. Mean fish biomass per size class (± standard error) at sites surveyed in the southern islands. Fish measured by total length (TL) in centimeters (cm).

Figure 8. Mean fish biomass per size class (± standard error) at sites surveyed in the northern islands. Fish measured by total length (TL) in centimeters (cm).

Figure 8. Mean fish biomass per size class (± standard error) at sites surveyed in the northern islands. Fish measured by total length (TL) in centimeters (cm).

Spatial sample design

Survey site locations are randomly selected using a depth-stratified design. During cruise planning and the cruise itself, logistic and weather conditions factor into the allocation of monitoring effort around sectors of each island or atoll. The geographic coordinates of sample sites are then randomly drawn from a map of the area of target habitat per study area. The target habitat is hard-bottom reef, the study area is typically an island or atoll, or in the case of larger islands, sectors per island, and the depth strata are shallow (0–6 m), mid (6–18 m), and deep (18–30 m).

Sampling methods

A pair of divers surveys the fish assemblage at each site using a stationary-point-count method (Fig. 9). Each diver identifies, enumerates, and estimates the total length of fishes within a visually estimated 15-m-diameter cylinder with the diver stationed in the center. These data are used to calculate fish biomass per unit area (g m–2) for each species. Mean biomass estimates per island are calculated by weighting averages by the area per strata. Island-scale estimates presented here represent only the areas surveyed during this cruise. For gaps or areas not surveyed during this cruise, data from this and other survey efforts generally will be pooled to improve island-scale estimates.

Each diver also conducts a rapid visual assessment of reef composition, by estimating the percent cover of major benthic functional groups (encrusting algae, fleshy macroalgae, hard corals, turf algae, and soft corals) in each cylinder. Divers also estimate the complexity of the surface of the reef structure, and they take photos along a transect line at each site that are archived to allow for future analysis.

Figure 9. Method used to monitor fish assemblage and benthic communities at the Rapid Ecological Assessment (REA) sites.

Figure 9. Method used to monitor fish assemblage and benthic communities at Rapid Ecological Assessment (REA) sites.

About the monitoring program

Pacific RAMP forms a key part of the National Coral Reef Monitoring Plan of NOAA’s Coral Reef Conservation Program (CRCP), providing integrated, consistent, and comparable data across U.S. Pacific islands and atolls. CRCP monitoring efforts have these aims:

  • Document the status of reef species of ecological and economic importance
  • Track and assess changes in reef communities in response to environmental stressors or human activities
  • Evaluate the effectiveness of specific management strategies and identify actions for future and adaptive responses In addition to the fish community surveys outlined here, Pacific RAMP efforts include interdisciplinary monitoring of oceanographic conditions, coral reef habitat assessments, and mapping. Most data are available upon request.

For more information

Coral Reef Conservation Program: http://coralreef.noaa.gov

Pacific Islands Fisheries Science Center: http://www.pifsc.noaa.gov/

CRED publications: http://www.pifsc.noaa.gov/pubs/credpub.php

CRED fish team: http://www.pifsc.noaa.gov/cred/fish.php

Fish team lead and fish survey data requests: ivor.williams@noaa.gov

 

To download a PDF file of PIFSC Data Report DR-14-009, the fish monitoring brief for the southern islands of the Mariana Archipelago, click here.

To download a PDF file of PIFSC Data Report DR-14-010, the fish monitoring brief for the northern islands of the Mariana Archipelago, click here.

 

Update from the Mariana Archipelago: monitoring cruise completes work in the southern islands

By Bernardo Vargas-Ángel
The NOAA Ship Hi`ialakai, seen off the coast of Anatahan, a northern island in the Commonwealth of the Northern Mariana Islands, during a previous monitoring cruise in the Mariana Archipelago in May 2009. NOAA photo by Bernardo Vargas-Ángel

The NOAA Ship Hi`ialakai, seen off the coast of Anatahan, a northern island in the Commonwealth of the Northern Mariana Islands, from a small boat during a previous monitoring cruise in the Mariana Archipelago in May 2009. NOAA photo by Bernardo Vargas-Ángel

On April 17, the NOAA Ship Hi`ialakai departed Saipan Harbor and began Leg III of the PIFSC cruise HA-14-01 with a few more days of monitoring operations around Saipan before transiting to the island of Sarigan. With work essentially complete in the southern islands of the Mariana Archipelago, the Hi`ialakai had been in port in Saipan Harbor for a short, 3-day pause between legs of this Pacific Reef Assessment and Monitoring Program (Pacific RAMP) expedition. Activities to monitor coral reef ecosystems of the Commonwealth of the Northern Mariana Islands (CNMI) began on April 5 during Leg II of this cruise and work around Guam took place on March 25–April 4, primarily during Leg I. Led by the PIFSC Coral Reef Ecosystem Division (CRED), this mission marks the 6th monitoring cruise in Guam and the CNMI by staff from PIFSC and partner agencies since 2003.

Around Guam, Rota, Aguijan, Tinian, and Saipan Islands, CRED scientists on March 25–April 18 conducted ecosystem surveys of fishes, benthic and coral communities, and microbes and deployed oceanographic instruments and biological installations. During Leg III, which is expected to conclude on May 6, CRED staff will conduct small-boat operations for coral reef ecosystem monitoring at the following northern islands and banks: Sarigan, Zealandia Bank, Guguan, Alamagan, Pagan, Agrihan, Asuncion, Maug, Supply Reef, and Farallon de Pajaros (or Uracas).

On a reef off the coast of Rota Island, divers conduct belt-transect surveys of the benthos on April 8. NOAA photo by Bernardo Vargas-Ángel

On a reef off the coast of Rota Island, divers conduct a belt-transect survey of the benthos on April 8 during the PIFSC cruise HA-14-01, the 6th expedition in the Marina Archipelago since 2003 for the Pacific Reef Assessment and Monitoring Program, which is led by the PIFSC Coral Reef Ecosystem Division. NOAA photo by Bernardo Vargas-Ángel

A diver on April 13 collects digital images of reef benthos along a transect at a Climate Monitoring Station off the cost of Saipan. NOAA photo

A diver on April 13 collects digital still photographs of the reef benthos along a transect at a Climate Monitoring Station off the cost of Saipan. Such benthic images can be analyzed to characterize benthic habitat and estimate percent cover of key functional groups. NOAA photo

At Rapid Ecological Assessment (REA) sites, surveys for reef fishes document species richness, abundance, and sizes, and surveys of benthic and coral communities study the percent composition of bottom-dwelling organisms in addition to the densities, sizes, and health conditions of coral colonies. During broad-scale towed-diver surveys, divers record observational data on large-bodied fishes (>50 cm total length), percent composition of the seafloor, coral stress, and conspicuous invertebrates. Studies of microbial communities document the diversity and abundance of bacteria and viruses and their interactions with coral reefs.

This mission also includes studies of the diversity of cryptic invertebrates; collection of data on water temperature, salinity, carbonate chemistry, and other physical characteristics of coral reef environments; and assessment of the potential early effects of ocean acidification on cryptobiota (e.g., small, hidden organisms) and the rates of reef carbonate deposition and coral calcification.

Researchers of the PIFSC Coral Reef Ecosystem Division use trays, like the one in this photo taken on April 13, to sort the cryptic reef invertebrates that they collect from autonomous reef monitoring structures (ARMS) retrieved during this current cruise from the nearshore locations where they had been deployed in 2011 during the previous Pacific Reef Assessment and Monitoring Program expedition in the Mariana Archipelago. NOAA photo

Researchers of the PIFSC Coral Reef Ecosystem Division on April 13 use this tray and others to sort the cryptic reef invertebrates that they collect from the autonomous reef monitoring structures (ARMS) retrieved during this current cruise from the nearshore locations where they had been deployed in 2011 during the previous Pacific Reef Assessment and Monitoring Program expedition in the Mariana Archipelago. NOAA photo

Thus far across the 5 southern Mariana Islands, including work on April 17, CRED researchers during this cruise have completed 66 towed-diver surveys along a combined 130 km of coastline and, at REA sites, 153 fish surveys and 62 benthic surveys. The instrumentation team deployed 4 Climate Monitoring Stations around Guam and 3 stations around Saipan, with each station containing arrays of subsurface temperature recorders (STRs), calcification accretion units (CAUs), autonomous reef monitoring structures (ARMS), and bioersion monitoring units (BMUs). Overall, no notable changes in the structure of the fish and benthic communities can be reported at this time for the areas surveyed at Guam or in the southern CNMI, in comparison to survey results from the previous cruise in this region in 2011. Additionally, no widespread coral bleaching or outbreaks of coral diseases or corallivorous crown-of-thorns seastars (Acanthaster planci) were observed.

Reef monitoring at Wake Island: preliminary results from fish surveys

By Dione Swanson

After departing Honolulu on March 5, the NOAA Ship Hi’ialakai arrived at Wake Island on March 14. It was the first stop for PIFSC cruise HA-14-01, a Pacific Reef Assessment and Monitoring Program (Pacific RAMP) expedition that also recently visited Guam and is currently focused on the southern islands of the Commonwealth of the Northern Marianas Islands. At Wake Island, staff members of the PIFSC Coral Reef Ecosystem Division (CRED) and partners conducted surveys of reef fish assemblages, coral populations, and benthic communities as well as deployed instruments and collected water samples to monitor effects of climate change and ocean acidification on coral reef ecosystems.

Our first 2 planned operational days on Wake Island were canceled because of poor weather conditions (strong winds and high seas). Relatively good weather returned by March 16, and we then were able to complete 4.5 days of small-boat operations before leaving for Guam on March 20. Over the course of our time at Wake Island, scientists accomplished the following field activities during a combined 229 dives: reef fish surveys at 45 Rapid Ecological Assessment (REA) sites; benthic surveys at 20 REA sites; collection of 12 water samples and 1 benthic sample for analysis of microbial communities; retrieval of 7 subsurface temperature recorders (STRs), 6 autonomous reef monitoring structures (ARMs), 15 calcification accretion units (CAUs), and 1 sea-surface temperature (SST) buoy; installation of 4 National Coral Reef Monitoring Plan climate stations—each of which includes 3 ARMs, 5 CAUs, 5 bioerosion monitoring units, and 3 STRs; and collection of 20 water samples for analysis of dissolved inorganic carbon; and completion of 11 shallow-water conductivity, temperature, and depth (CTD) casts.

Highlights of our research dives at Wake Island included incredible water visibility (>45 m), high coral cover that consisted of abundant large colonies with low partial mortality, overall low prevalence of coral disease and bleaching, and large patches of soft corals. There were only a few sightings of bumphead parrotfish (Bolbometopon muricatum) and Napoleon wrasse (Cheilinus undulatus).

Preliminary results from the surveys of reef fishes conducted by scuba divers at Wake Island (depth range: 0–30 m) during this cruise are provided in the below fish monitoring brief, which was issued on March 25 as PIFSC Data Report DR-14-007 (click here, to download a PDF file of this report). Wake Island is 1 of 7 islands, atolls, and reefs that make up the Pacific Remote Island Areas and, under the jurisdiction of the United States, are protected as the Pacific Remote Islands Marine National Monument.

Pacific Reef Assessment and Monitoring Program
Fish monitoring brief: Pacific Remote Island Areas 2014

By Adel Heenan

About this summary brief

The purpose of this document is to outline the most recent survey efforts conducted by the Coral Reef Ecosystem Division (CRED) of the NOAA Pacific Islands Fisheries Science Center as part of the long-term monitoring program known as the Pacific Reef Assessment and Monitoring Program (Pacific RAMP). More detailed survey results will be available in a forthcoming annual status report.

Sampling effort

  • Ecological monitoring took place in the Pacific Remote Island Areas from March 16 2014 to March20 2014.
  • Data were collected at 45 sites. Surveys were conducted at Wake Island.
  • At each site, the fish assemblage was surveyed by underwater visual census and the benthic community was assessed.

Overview of data collected

Primary consumers include herbivores (which eat plants) and detritivores (which bottom feed on detritus), and secondary consumers are largely omnivores (which mostly eat a variety of fishes and invertebrates) and invertivores (which eat invertebrates).

Figure 1. Mean total fish biomass at sites surveyed.

Figure 1. Mean total fish biomass at sites surveyed.

 

Figure 2. Mean hard coral cover at sites surveyed.

Figure 2. Mean hard coral cover at sites surveyed.

Figure 3. Mean consumer group fish biomass (± standard error). Primary consumers are herbivores and detritivores, and secondary consumers are omnivores and invertivores.

Figure 3. Mean consumer group fish biomass (± standard error). Primary consumers are herbivores and detritivores, and secondary consumers are omnivores and invertivores.

Figure 4. Mean fish biomass per size class (± standard error). Fish measured by total length (TL) in centimeters (cm).

Figure 4. Mean fish biomass per size class (± standard error). Fish measured by total length (TL) in centimeters (cm).

 

Spatial sample design

Survey site locations are randomly selected using a depth-stratified design. During cruise planning and the cruise itself, logistic and weather conditions factor into the allocation of monitoring effort around sectors of each island or atoll. The geographic coordinates of sample sites are then randomly drawn from a map of the area of target habitat per study area. The target habitat is hard-bottom reef, the study area is typically an island or atoll, or in the case of larger islands, sectors per island, and the depth strata are shallow (0–6 m), mid (6–18 m), and deep (18–30 m).

Sampling methods

A pair of divers surveys the fish assemblage at each site using a stationary-point-count method (Fig. 5). Each diver identifies, enumerates, and estimates the total length of fishes within a visually estimated 15-m-diameter cylinder with the diver stationed in the center.

These data are used to calculate fish biomass per unit area (g m-2) for each species. Mean biomass estimates per island are calculated by weighting averages by the area per strata. Island-scale estimates presented here represent only the areas surveyed during this cruise. For gaps or areas not surveyed during this cruise, data from this and other survey efforts will generally be pooled to improve island-scale estimates.

Each diver also conducts a rapid visual assessment of reef composition, by estimating the percentage cover of major benthic functional groups (encrusting algae, fleshy macroalgae, hard corals, turf algae and soft corals) in each cylinder. Divers also estimate the complexity of the surface of the reef structure, and they take photos along a transect at each site that are archived to allow for future analysis.

Figure 5. Method used to monitor fish assemblage and benthic communities at the Rapid Ecological Assessment (REA) sites.

Figure 5. Method used to monitor fish assemblage and benthic communities at the Rapid Ecological Assessment (REA) sites.

About the monitoring program

Pacific RAMP forms a key part of the National Coral Reef Monitoring Program of NOAA’s Coral Reef Conservation Program (CRCP), providing integrated, consistent, and comparable data across U.S. Pacific islands and atolls. CRCP monitoring efforts have these aims:

  • Document the status of reef species of ecological and economic importance
  • Track and assess changes in reef communities in response to environmental stressors or human activities
  • Evaluate the effectiveness of specific management strategies and identify actions for future and adaptive responses

In addition to the fish community surveys outlined here, Pacific RAMP efforts include interdisciplinary monitoring of oceanographic conditions, coral reef habitat assessments and mapping. Most data are available upon request.

For more information

Coral Reef Conservation Program: http://coralreef.noaa.gov

Pacific Islands Fisheries Science Center: http://www.pifsc.noaa.gov/

CRED publications: http://www.pifsc.noaa.gov/pubs/credpub.php

CRED fish team: http://www.pifsc.noaa.gov/cred/fish.php

Fish team lead and fish survey data requests: ivor.williams@noaa.gov