Big Tale of Dwarf Sperm Whales in the Marianas

By Marie C. Hill, Andrea R. Bendlin, Allan D. Ligon, Adam Ü, and Karlina Merkens

After spending five windy days working off Rota (21-25 May 2016) where we encountered spinner dolphins, spotted dolphins and a Mesoplodont beaked whale, we flew to Guam to finish off our Marianas survey effort (28 May -5 June).  We were greeted with incredibly calm conditions and a new species for us off Guam!  Our first two encounters were with dwarf sperm whales (Kogia sima), some of which we actually re-sighted six days later.  We’ve encountered a dwarf sperm whale off Saipan in 2011 but have not seen any others until now.  The dwarf sperm whale is a very cryptic species that is difficult to find (unless conditions are very calm) and difficult to approach (they are very shy of boats).  This year’s encounters were particularly exciting because we collected a biopsy sample, as well as acoustic recordings!  It’s exciting because dwarf sperm whales have rarely been biopsy sampled, and there has been only one other acoustic recording of visually-confirmed dwarf sperm whales in the wild!  In order to collect the recordings, we used a free floating hydrophone and recorder attached to a buoy and flag.  We call it the CARB (Compact Acoustic Recording Buoy).  At one point during our fourth dwarf sperm whale encounter a mom-calf pair swam directly toward, then passed by the CARB (Figure 1).  The acoustic recordings are of excellent quality and match up well with the only other recording of this species, which came from the Bahamas.  They will go a long way toward helping us understand and monitor Kogia species.

Figure 1_Kogia and CARB

Figure 1: Dwarf sperm whale mother and calf (inset) swim close to our acoustic recorder (photo credit: Adam Ü).

While surveying off Guam we also encountered the dwarf sperm whale’s much larger cousin, the sperm whale (Physeter macrocephalus).  The group of nine individuals included a newborn calf (Figure 2).

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Figure 2: Sperm whales off Guam’s west side, north of Orote Pt. (photo credit: Marie Hill).

During the sperm whale encounter we collected three biopsy samples (for genetic studies) and deployed a satellite tag (ID 141723) on an individual (to look at movements and spatial use).  The tag (ID 141712) that we deployed on a sperm whale off Saipan on 17 May was still transmitting on 10 June.  These tags are the first ones that we have deployed on sperm whales in the Marianas.  The tracks of the two individuals have come close but have not overlapped (Figure 3).  The sperm whale with tag 141712 spent several weeks north of Saipan and went as far north as Guguan. On 10 June, it was just southwest of Farallón de Medinilla.  Our Guam sperm whale, tagged on 31 May, spent several days off the west side of Guam and then traveled north.  It was approximately 50 miles west of Saipan on 10 June.

Figure3_Sperm whale tag tracks

Figure 3: Tracks of two satellite tagged sperm whales. Tag 141712 (red squares) was deployed on 17 May 2016 and tag 141723 (white squares) was deployed on 31 May 2016. Last tag locations pictured were on 10 June 2016.

Another first for us this year was the deployment of a satellite tag on a pantropical spotted dolphin (Stenella attenuata) off Guam.  People sometimes mistake spotted dolphins and spinner dolphins (Stenella longirostris) because they are similar in size and color.  Two features of spotted dolphins that make them easy to distinguish from spinner dolphins is the white tip of the rostrum and presence of spots on the bodies of adults (both features become more pronounced as individuals age) (Figure 4).

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Figure 4: A pantropical spotted dolphin. Note the white tip of the rostrum and the spots on the body (photo credit: Adam Ü).

The spotted dolphin that we tagged has moved up and down the west side of Guam and even went out to 11-Mile Reef (Figure 5).  On 10 June, it was just south of Agat Bay.

Figure5_Spotted dolphin tag track

Figure 5: Satellite tag track of a pantropical spotted dolphin (3-10 June 2016).

Finally!  We found short-finned pilot whales again!  We didn’t encounter them during our 2015 small-boat surveys.  While working off Guam this year we had four sightings of short-finned pilot whales, during which we re-sighted individuals between days.   Most of the individuals are in our photo-identification catalog.  Some of these individuals have not been seen together before.  One of our favorites also showed up on the last day of our surveys (5 June).  “Chop Top” (Figure 6) is an adult male that we first photographed off Rota in 2011.  We last saw him in 2013 off Guam and were worried we wouldn’t see him again.

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Figure 6: Male short-finned pilot whale named “Chop Top” seen on 5 June 2016 for the first time since 2013 (photo credit: Marie Hill).

During three of our four short-finned pilot whale encounters we deployed six satellite tags. Since tagging, some of the individuals have stayed in close proximity to one another while others have split up, come together and split up again (Figure 7).  By having tags out on multiple individuals we can get a better idea of the spatial use of the population of short-finned pilot whales that we encounter off the southernmost islands in the Marianas.  We’re hoping that one of these tags breaks the previous record for longest duration (235 days).

Figure7_Pilot whale tag locations

Figure 7: Locations of satellite tags deployed on short-finned pilot whales encountered off Guam (29 May, 2 June, and 5 June 2016).

All survey operations including satellite tagging, photo-id, and biopsy sampling are conducted under NMFS permit 15240. Funding was provided by the NOAA Fisheries and the Commander U.S. Pacific Fleet. We would like to thank the vessel owners and captains of the Asakaze and Ten27, the Guam NOAA Fisheries field office, and all of our volunteers during the surveys.

Posted in Protected Species | Tagged , , , , , , , , , , ,

Helping Local Agencies in Guam and Saipan Understand the Life Histories of Their Fishes

By Dr. Allen H. Andrews

Understanding the age of a fish helps managers understand the population dynamics of a fish stock. For example, at what age is a fish species able to reproduce? Is its natural life span long or short? These basic facts are often poorly understood and all contribute to understanding the life history — the characteristics that make up the biological life cycle — of various fishes, from birth to reproduction to death.

Estimating the age of fish usually relies on examining the hard body parts that grow as the fish grows, of which the most commonly used is otoliths. Otoliths are stony, calcium carbonate structures that are functionally analogous to parts of the human ear. These “ear stones” help fish live in a three-dimensional environment by providing balance, orientation, and sound detection. They’re found in the skull next to the brain, and they lay down growth rings (akin to tree rings) as the fish grows older.

Fish otoliths are not all created equal.

The size of a fish has little bearing on the size or structure of its otolith. Some fish can have regularly shaped otoliths, while the ear stones of others may have numerous ridges or odd protrusions. Some can be quite small relative to the fish’s size (marlin have some of the smallest otoliths), while otoliths of other fishes can be massive and look like a small white rock. And though otolith rings are analogous to tree rings, they’re not as regular as we would like them to be — they can be influenced by a variety of conditions, such as water chemistry, temperature, and stress levels, among other environmental factors.

Otolith cross section from a deep-water snapper called onaga (Etelis coruscans). Age interpretation is quite difficult, but the regular banding pattern is there for counting with proper illumination under a microscope. This onaga was estimated to have lived for 53 years.

Otolith cross section from a deep-water snapper called onaga (Etelis coruscans). Age interpretation is quite difficult, but the regular banding pattern is there for counting with proper illumination under a microscope. This onaga was estimated to have lived for 53 years.

Using otoliths to estimate fish age is not new but it can still be technically challenging. To help fisheries life-history scientists in Guam and Saipan better understand the techniques involved in this process, I held two otolith age estimation workshops — functioning in my capacity as a life history scientist with the Pacific Islands Fisheries Science Center in Honolulu, Hawaiʻi — using regional fishes as test subjects.  The workshops enabled us to share technology and skills that focus on using otoliths as a means of describing the age and growth of each fish species.

Step One: Preparation

Building new skills isn’t just about getting in the lab and doing the work; the preparations are especially important. As the cliché says, “Proper Planning and Preparation Prevents Poor Performance.”  Therefore, we began with an assessment of the equipment and supplies available to do the work, along with some instructions on how the equipment is used and maintained. The primary pieces of necessary equipment were:

  • Low-speed saw for otolith sectioning
  • Lapping wheel used for polishing otolith sections
  • A dissecting microscope with both transmitted and reflected light for viewing and interpreting proper sectioning, as well as the growth zones visible in good otolith sections

Step Two: Otolith Selection and Orientation

Properly selecting and orienting otoliths for sectioning is an important skill to learn. We examined whole otoliths of various species to understand the variations between species and how to mount them for the best chance at getting the necessary age data. Proper alignment of the otolith relative to the sectioning blades is crucial — the blades must be perpendicular to the ridges associated with the sulcus acusticus (a groove on the proximal side of the whole otolith). These ridges tend to have the best-defined growth zones for age estimation and the section angle can make the difference between a readable and unreadable section. The workshop participants each practiced sectioning otoliths from various species from each region. Ahead of time Eric Cruz (PIFSC-Guam) and Jane Boyer (University of Guam) prepared a range of onaga (Etelis coruscans) otoliths, which the participants used for age estimation while waiting for their mounted workshop otoliths to harden. I critiqued the work of each participant during the course of the day, and by the end of the day the participants had all successfully mounted otolith sections, along with a select set of whole otoliths for sectioning later.

Step Three: Otolith Section Interpretation

To determine the age of their otoliths, the participants examined their sections from the day before through the available microscopes. As they did this, I displayed example images of good and poor onaga otolith sections. We discussed, at length, what factors made the sections good or poor, what could have been done to prevent poor sectioning, and the various length-at-age scenarios we saw. Participants learned that the better the section, the more objective decisions they could make on what to count and what not to count. In addition, we focused a considerable amount of time on discriminating young (fast) growth from older (slow) growth structure in the older adult fish otoliths. Understanding the nuances of otolith age-reading requires practice and a keen eye, and it does not come easily.

In Guam, our emphasis was on the onaga otoliths, with discussions on what would be the best species to pursue in the near future. In Saipan, we investigated two emperor species (Family Lethrinidae). The Saipan team described the defining characteristics of growth zones and found a common pattern among the samples of the orange-striped emperor (Lethrinus obsoletus). We preserved sectioned samples (good and poor) to have a lasting example of the defining characteristics for the continued efforts to age this species.

During the week in Saipan, the local media highlighted the workshops I provided, as well as my additional seminars on the longevity of fishes.  For further information, please see:

1) Article entitled “Age Matters Even for Fish” in the Marianas Variety newspaper at: http://www.mvariety.com/cnmi/cnmi-news/local/81577-age-matters-even-for-fish

2) A televised interview with Tori Youngblood of KSPN2 News near minute 11 of the broadcast at: http://www.saipantv.com/video.asp?vidID=1232&secID=36

I would like to thank the participants for their time and attention during each week. I look forward to continuing to work with them to build on their new skills and to further investigate the life history of regional fishes.

Workshop Participants:

I. Guam Otolith Workshop at University of Guam

  • Frank Camacho, UoG – Biology Program
  • Eric Cruz, NMFS/PIFSC – Guam
  • Brent Tibatts, DAWR
  • Carl Delacruz, WPRFMC
  • Michael Duenas, GFCA
  • Cristopher Barcenilla, GFCA
  • Vince Pangelinan, GFCA

II. Saipan Otolith Workshop at Micronesian Environmental Services

  • John Gourley, MES
  • Eric Cruz, NMFS/PIFSC – Guam
  • Mike Trianni, DFW
  • Patrick Ito, MES
  • George Salas, Jr., MES
  • Tony Flores, MES
  • Manny Ramon, MES
  • Mike Tenorio, DFW
  • Trey Dunn, DFW
  • Frank Villagomez, DFW
  • Jane Boyer, UoG, Graduate Student
Allen Andrews with some of the participants in action at the Otolith Workshop in Saipan at Micronesian Environmental Services.

Allen Andrews with some of the participants in action at the Otolith Workshop in Saipan at Micronesian Environmental Services.

Posted in Fisheries Research and Monitoring, Scientific Operations | Tagged , , , , ,

Kamusta! Fish tales from the Philippines

by Max Sudnovsky

1.EAFM_activityDuring the month of April, I had the opportunity to experience the islands of the archipelagic Republic of the Philippines. From upland areas to coastal communities, my adventure took me from the northernmost tip of Luzon Island, across the Visayas Islands, and all the way down to Mindanao. I made more than 100 new friends, stumbled my way through the Ilocano, Tagalog, and Cebuano languages, ate Danggit, Bangus, Turon, and yes, I even sang karaoke. Not only was I able to do all this in three weeks… I was able to do all of this without even leaving my hotel! Wait, how was that possible you ask? Well I’ll tell you.

Over the course of three weeks in April 2016, I was fortunate to be part of a team comprised of staff from the NOAA Coral Reef Ecosystem Program (CREP), the Philippines Department of Agriculture-Bureau of Fisheries and Aquatic Resources (DA-BFAR) and the Ecosystems Improved for Sustainable Fisheries (ECOFISH) Project of the United States Agency for International Development (USAID). At the request of Under Secretary and National Director Atty Asis Perez of DA-BFAR, and with funding from the USAID Philippines, our team worked together to deliver three Essential Ecosystem Approach to Fisheries Management (E-EAFM) training sessions for 92 BFAR Provincial Fisheries Officers from the 18 administrative regions of the Philippines.

This highly participatory course was designed to introduce provincial fisheries officers to the key principals of EAFM, enhance their ability to work with the Local Government Units in their communities, foster cross-sector coordination, and practice the crucial skills of effective communication, facilitation, and conflict management. The ultimate goal of the course is for BFAR to assist the Local Government Units in improving their existing Integrated Coastal Resource Management plans and build upon existing working relationships through co-management to sustainably manage capture fisheries. Although the course is primarily focused on coastal marine ecosystems, the process of an ecosystem approach to fisheries management can be equally applied to inland ecosystems, offshore ecosystems, or aquaculture systems.

Although the participants came from different geographic regions, many of the conversations focused on the steady decline of fisheries and destruction of the critical habitats. The factors leading to the decline were intertwined and not easily isolated for purposes of management. Nevertheless, the primary issues and conflicts were the same—various kinds of pollution, illegal and destructive fishing practices such as dynamite, air-compressor or “hookah” fishing, and the use of small-mesh fishing nets, overfishing due to an open access fishing regime in the country, a lack of planning and control of development in the shoreline and beach areas, increasing poverty among coastal dwellers, a rapidly growing population, lack of enforcement, and variable political will to address these challenges. A key driving force behind many of these issues stems from a lack of alternative livelihoods that could reduce the dependency of these communities on their natural resources, ultimately threatening the potential for sustainable use.

There are many lessons I am taking away from these three weeks of training. I can’t share them all with you here today although I will share a few. The training sessions were a true manifestation a successful government-to-government partnership. Through the support and forethought of USAID Philippines and Director Asis, the NOAA-BFAR relationship has a strong foundation, one that we look forward to continuing over the long-term as both the Philippines and the United States enter new administrations. At the heart of the EAFM process, one of the key principals is increased participation and stakeholder engagement. During our time together we realized the importance of building, strengthening, and maintaining relationships both at the institutional as well as the personal level. We were able to re-examine the multitude of resources we have available to us as we try and incorporate more holistic considerations into fisheries management by addressing the trade-offs among ecological principals, legal mandates, and the varying interests of coastal communities and stakeholders.

I can also share with you that I have a deep admiration for the participants that I’ve had the pleasure to learn from—those who serve as fisheries managers in the Philippines. It’s a tough and often thankless job. The dedication, commitment, and passion of the participants, as well as the trainers, are truly inspiring.

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I would like to thank the BFAR trainers and provincial fisheries officers for taking me on this adventure to the Tanon Straight Bias Bay, San Miguel Bay, Sogod Bay, the Danajon Double Barrier Reef, Tinagong Dagat, Abba River Basin, Cagayan Valley, Anda, Bolinao, Bani, Alaminos, Tayabas Bay, Masinloc Bay, Babuyan Channel, Carraga, Sorsogon Bay, Sarangani Bay, Kalinga, and last but not least, Basilan. Throughout our time together we shared stories of our experiences, both the failures and success. We shared our hopes and concerns for the environment, the people, and the Philippines. We are hopeful that we can challenge and shift perceptions to make ecosystem-based management feasible.

Posted in coral reef ecosystem, Uncategorized | Tagged , , , , , , , , , , , , , , , , , ,

From the Village to the Pacific, coordinating coral reef assessments in Tutuila, American Samoa

by Kelvin Gorospe and Adel Heenan
1.Gorospe_survey

Kelvin Gorospe sets transects for a fish survey.

Following the American Samoa portion of the recent Reef Fish Survey cruise, Adel and I disembarked NOAA ship Oscar Elton Sette to remain in Pago Pago, American Samoa. From May 9 to 13, we met with partners from the American Samoa Coral Reef Advisory Group (CRAG), Department of Marine and Wildlife Resources, the Environmental Protection Agency, NOAA’s Coral Reef Conservation Program, National Marine Sanctuary of American Samoa, and National Park Service. During this time, we facilitated a workshop to initiate steps to achieve cross-scale coordination between our programs and cross-scale integration of our datasets. By bringing multiple agencies and institutions together, all of whom are engaged in coral reef ecosystem monitoring in Tutuila, American Samoa, we used our collective experience (more than 120 years!) in coral reef monitoring to think about cross-scale ecosystem monitoring. How can we combine our resources to complement each other’s monitoring programs? Can we integrate datasets collected at different scales, and if not, are there steps that we can take to facilitate this integration down the road?

2.Group

Several participants of the data integration workshop held in Pago-Pago, American Samoa.

To begin taking steps in the right direction, we had to figure out how to compare different datasets and understand the monitoring objectives of different agencies. Effective monitoring objectives determine the scope of inference for the data collected and more often than not, monitoring programs are optimized to report at a specific spatial scale. For example, data collected by the Pacific Islands Fisheries Science Center’s Coral Reef Ecosystem Program (CREP) for the Pacific Reef Assessment and Monitoring Program (Pacific RAMP) are primarily designed to report on key metrics of ecosystem condition at an island or sub-island scale for each of the U.S.-affiliated islands and atolls in the Pacific. In contrast, data collected by various monitoring agencies operating in Tutuila are designed to report metrics at the village/bay or site-specific scale. Coordinating efforts across scales is an important component of ecosystem-based management that allows for more effective comparisons between efforts. For example, how does the status of reef fish populations in a particular marine protected area compare to reef fish populations for the rest of the island, or islands in an archipelago? Such coordination and comparisons allow for inference at an ecosystem-relevant scale. Blending datasets and coordinating monitoring programs is, however, easier said than done.

One barrier to seamless integration that was identified at the workshop, was the existence of multiple survey methods. When identical methods are used to collect data for different scales, the data can be blended and compared on these different scales. Last year, the National Marine Sanctuaries of American Samoa partnered with CREP to collect baseline data for Aunu‘u and Fagatele Bay. Typically CREP collects island-scale data for the National Coral Reef Monitoring Program (NCRMP). However, since the method used to collect both the Pacific RAMP and National Marine Sanctuaries datasets were identical, the Sanctuaries’ baseline data could be easily compared to the island-scale data collected for NCRMP. For many of the monitoring programs operating in Tutuila, however, blending datasets will not be so easy. For example, many of them use belt-transects to conduct fish surveys, while CREP uses a stationary point count method. While both acquire the same type of information, the use of different methods makes blending the data a bit challenging.

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Workshop participant, Alice Lawrence from the Coral Reef Advisory Group, presenting a SWOT evaluation of the American Samoa Coral Reef Monitoring Program’s dataset.

Over several days, partners presented the details (e.g., sampling design, quantitative objectives, etc.) of their individual datasets, reviewed examples and strategies for how datasets can be integrated, and conducted SWOT (strengths, weaknesses, opportunities, and threats) evaluations of their monitoring programs. Our purpose was to understand the intricacies of each other’s datasets before considering how we could potentially integrate.

The workshop culminated in a structured discussion on how to integrate community, jurisdictional, and federal coral reef ecosystem monitoring datasets. Participants were asked to detail concrete, short, and long-term steps that can be taken to overcome existing barriers to integrating our datasets. Recommendations ranged from conducting a calibration study between several of our datasets to facilitate the comparison of our different survey methods to publishing an information brief that co-reports multiple datasets for a single village’s marine resources. These recommendations fell into four broad categories that encapsulate the different components of a monitoring program – (1) communication strategy, (2) data integrity, (3) data relevance, and (4) non-data resources (e.g., creating a full-time interagency monitoring team in Tutuila) – and will be detailed in a forthcoming workshop report.

We are now working on an information brief, that will provide both an outreach tool and serve as a pilot study for how our multiple datasets could be co-reported. The information brief will report on biological and socio-economic indicators collected across multiple efforts for a single village. Our plan is to produce this informational product for a village where multiple datasets already exist. If successful, we hope to roll out similar products for other villages.

4.Data_Tutuila

A map of several different monitoring datasets collected around Tutuila, American Samoa

Funded by NOAA’s Coral Reef Conservation Program, the workshop and its outcomes are an important link between jurisdictional scientists in American Samoa focused on local monitoring efforts and PIFSC scientists focused on Pacific-wide and national efforts. Based on the next steps and recommendations identified at the workshop, the benefits to coordinating across multiple scales are clear: not only will integration allow us to understand more about the ecosystems in which we operate, but will also allow us to collectively achieve more.

Posted in coral reef ecosystem, Uncategorized | Tagged , , , , , , , , , , , , , , , , , , , ,

SE16-02: Jumping in the deep end

by Motu Vaeoso

Training in standard fish survey methods for the Pacific Islands Fisheries Science Center’s reef fish survey project was difficult, intensive work. As the new coral reef monitoring technician for the American Samoa Coral Reef Advisory Group (CRAG), I wanted to participate in this research cruise (SE16-02) to further develop the skills that will improve my role as a technician. Participating in the NOAA research cruise was also a tremendous personal development opportunity for me. Before Paula Ayotte from the NOAA Coral Reef Ecosystem Program (CREP) arrived to conduct the final training the week before the cruise, there was still a good amount of preparation to be done.

Two months before the date of the cruise, I had to study my reef fish species. Paula provided helpful tools, review aids, and exams to develop our fish identification skills. The American Samoa reef fish flashcards created for the Flashcard Deluxe app was a handy mobile tool that helped develop my fish identification skills. In addition to studying fish, there was the matter of acquiring the required certifications for Advanced Diving using Nitrox and all of the physical health examination documentation for reciprocity to dive with NOAA divers.

Parrotfish

Parrotfish (Chlorurus frontalis), NOAA Photo by Tate Wester

On the first day of the training week, we reviewed fish identification, size estimation, binning, and benthic cover estimates. We also completed a dry run of the survey method. For the next three days, we were in the field—diving underwater with Paula, Alice Lawrence, and Brittney Honisch, to practice the skills we learned and familiarize ourselves with the survey methods. The more we practiced going through the motions, the more comfortable I felt. At sites where fish diversity and population is high, conducting the reef fish surveys can be overwhelming. Closely following the protocol was important to staying on track. As a fairly new diver I had to master the skill of multitasking underwater, which included recording fish data, maintaining buoyancy, checking air supply, and maintaining contact with my dive buddy.

I knew that this cruise was going to be physically challenging, especially for me. But it wasn’t until I tried to climb aboard the the American Samoa Department of Marine and Wildlife Resources (DMWR) enforcement boat from the water without the ladder, that it hit me, this is going to be really hard. To increase my upper body strength, I was tasked with five push-ups, increasing the number each day during the remaining days before the cruise. The last day of training consisted of entering data in the database, quality checking (QC) with my dive buddy, and an introduction presentation to life aboard the NOAA Ship Oscar Elton Sette. Going through the training prepared me for the cruise in the survey method and developed my fish identification and size estimation, substrate height and benthic cover estimation skills. It also helped me realize where my limits lie and areas that I needed to focus on improving.

Abandon Ship Drill

Putting on our survival “gumby” suits for an abandon ship drill aboard the NOAA Ship Oscar Elton Sette.

On April 14, I boarded the Sette along with other scientists from NOAA. The first day consisted of settling into our staterooms, familiarizing ourselves with where gear is stored, going over safety protocols, running drills to be prepared in the event of fire, man overboard, or need to abandon ship. There was a lot going on that day, but all I remember is feeling nauseous because the floor was constantly moving. After a day, I got over that seasick feeling and was ready to start.

Diving operations began on April 15. As it was the first day of diving, we took it slow. I did a swim test, used the Redundant Air Source System (RASS) for the first time, practiced buddy breathing skills and the rescue skills of removing an unconscious diver from the water. All divers had to have alternate air sources just in case of an “out of air” situation. I had to adjust my weight system to account for the weight of the RASS and get used to the weird feeling of this protruding object on my right side.

I noticed great improvement in my fish identification skills after every dive. As I got to see certain surgeonfish like Ctenochaetus striatus and Acathurus nigrofuscus repeatedly, certain features became more prominent and easy to recognize. With each dive, I looked forward to checking off a new fish or two on my mental list and it was always a treat to see a new species.

In my first deep dive of about 75 feet off the coast of Ta‘u Island, I saw my first shark. I do not have a fear of sharks but I do have a healthy respect for them and believe in giving them adequate space. Seeing this 130-cm gray reef shark up close was one of the most exhilarating moments I have ever experienced.

First shark

My first ever shark sighting at the island of Ta‘u in the Manu‘a Group, NOAA Photo by Louise Guiseffi

I signed up for the first leg of the cruise, from April 14-25, surveying the islands of Tutuila and Ta‘u. After six consecutive successful dives days, operations had to be halted because of cyclone Amos which was heading towards Tutuila. It was an anti-climactic end to such a great start but it could not be helped. Fortunately, the chief scientist Kevin Lino extended my stay for the second leg to survey Tutuila, Ofu and Olosega Islands, and Rose Atoll from April 25-May 6.

There was so much beauty and life to be seen around each of the islands we surveyed in American Samoa. My most favorite part of the experience was diving in the gorgeous and pristine waters of Rose Atoll Marine National Monument. It was phenomenal to see the vibrant pink and purple crustose coralline algae of Rose and the life it harbors. I saw so many new species of fish in numbers I have never seen before.

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School of achilles tang (Acanthurus achilies) and whitecheek tang (Acanthurus nigricans) in an herbivorous feeding frenzy, NOAA Photo by Kevin Lino

Overall, my experience on the SE16-02 cruise was more enjoyable than I could have ever imagined. The quality of life aboard the ship was good, safety is a high priority, and the food was amazing! The crew and scientists were helpful, easy to work with, organized, and capable individuals. I had the opportunity to dive with almost all of the scientists and learned something new every day, a technique or skill, no matter how small. Louise Guiseffi showed me some helpful techniques to secure the rescue and tracking float with minimal tangling and easy removal. I was able to get on the small boats on my own with encouragement and coaching from Paula.

My last day of diving in the pristine waters of Rose Atoll was phenomenal and I could not have had a better last day for this research cruise. Although I did not get to see the Acanthurus hawaiiensis as I had hoped on my last dive, that is something to look forward to on my next visit to Rose. I am taking so much away from this cruise—not only in my professional development as a scientist but also in building character!

Posted in coral reef ecosystem | Tagged , , , , , , , , , , , , , , , , , , , ,

White Caps, Painted Dolphins, and Sperm Whales Galore!

by Marie C. Hill, Andrea R. Bendlin, Allan D. Ligon, and Adam Ü

After having to skip our surveys off Saipan last year because of the damage from Typhoon Soudelor, we were happy to return during 7-18 May 2016 to continue our ongoing study of cetaceans in the Marianas.  It is good to see and hear that Saipan is recovering.  Soudelor was the second strongest typhoon to develop in the northern hemisphere in 2015.  On 2 August 2015, it hit Saipan directly and devastated the island.  Homes and businesses were destroyed and others were damaged and without power for months.

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Figure 1: Two of four rough-toothed dolphins photographed together during 2013, 2014, and 2016 (photo credit: Marie Hill and Daniel Webster).

We had a bit of a slow start to our surveys because the winds and swells were up. Despite the rough conditions, we did find one of our favorite species, rough-toothed dolphins (Steno bredanensis), near Chalan Kanoa Reef, off the west side of Saipan.  Their crocodile shaped heads and their mottled bodies make them one of the most unusual looking dolphins alive, and some of the individuals present during this encounter are exceptionally mottled (Figure 1).  They look hand-painted.  What is also interesting about the Steno we encountered is that four of the five belong to our photo-identification catalog of six individuals.   We have seen them together in July 2013 and April 2014 off Aguijan and in July 2013 off Saipan, suggesting that they are resident to this area.  The fifth individual was a juvenile that may have been born in 2014.

Other strange looking cetaceans that we encountered during our surveys off Saipan were sperm whales (Physeter macrocephalus) (Figure 2).  They are the only cetacean species with their blow hole at the tip of their rostrum and it is canted to the left.  This characteristic can make them easily identifiable from a distance because their blow is angled.

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Figure 2: Sperm whales have a blow hole that is at the tip of their rostrum and is angled to the left (A), which makes their blows angled (B) (photo credit: Marie Hill and Adam Ü).

We encountered sperm whales on two separate days.  Some of the same individuals were present during both sightings.  We are able to identify them, primarily from their flukes but in some cases can recognize them from dorsal hump and body characteristics, such as scars.  Since 2010, we have encountered sperm whales five times.  In addition to our two encounters this year, we have seen sperm whales off Guam and Saipan in 2010 and off Saipan in 2013.  After doing some preliminary comparisons with fluke photos taken off Guam and Saipan in 2010 and those we took this year, we found two matches.  Both individuals were photographed off Guam 18 February 2010 and during both 2016 sightings (Figure 3). One of the individuals is missing its left fluke.  We collected a small tissue (or biopsy) sample from it, as well as five other individuals during our 2016 encounters, for future genetic analyses.

Figure 3: Re-sights of two individuals between Guam (February 2010) and Saipan (May 2016) (photo credit: Adam Ü and Marie Hill).

Figure 3: Re-sights of two individuals between Guam (February 2010) and Saipan (May 2016) (photo credit: Adam Ü and Marie Hill).

During the sperm whale encounter on 17 May 2016, we deployed a satellite tag on an individual, so that we can learn more about sperm whale movements in this area.  Between 17 and 23 May it traveled north and south offshore of Saipan and Tinian’s west sides (Figure 4). On 23 May, it was located approximately 37km WNW of Saipan’s NW tip.

In addition to rough-toothed dolphins and sperm whales, we encountered bottlenose dolphins (Tursiops truncatus) and spinner dolphins (Stenella longirostris) off Saipan.  Next, we head to Rota to conduct surveys during 21-25 May.

Figure 4: Track of a satellite tag (ID 141712) attached to a sperm whale off Saipan on 17 May 2016.

Figure 4: Track of a satellite tag (ID 141712) attached to a sperm whale off Saipan on 17 May 2016.

All survey operations including satellite tagging, photo-id, and biopsy sampling are conducted under NMFS permit 15240. Funding was provided by the NOAA Fisheries and the Commander U.S. Pacific Fleet. We would like to thank the vessel owners, captains, and crew of the Sea Hunter and the Regulator; the CNMI DFW, the CNMI NOAA Fisheries field office, and all of our volunteers during the surveys.

 

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