Day 45 – THERE’S NO PLACE LIKE HOME

After 45 days at sea, the NRV Alliance pulled back into its home port of La Spezia today. The Sirena 10 sea trial culminated ten years of research at NURC regarding the impact of tactical active sonar on certain marine mammal species. We at the centre, and in the broader scientific community, have made great strides in this field over the last decade. Important research will continue in order to understand more about the life history of sensitive species and the potential impacts of certain human activities. Grazie mille to all those that have been involved in this project through the years.

Day 44 - The Acoustic Envelope Please

During the sea trial, several different passive acoustic monitoring technologies were used and evaluated, including: the tetrahedral array, two linear arrays, sonobuoys, and moored buoys. Software to automatically detect and classify signals were developed and tested, in addition to human watchstanders manually evaluating the signals. Detailed analysis of this data (many, many, many terabytes) will occur in the coming months. But below is a brief summary of probable animals detected and what their probable sounds look like:
Fin whale (Balaenoptera physalus)

Pilot whales (Globicephala sp)

Risso’s dolphin (Grampus griseus)

Sperm whale (Physeter macrocephalus)

False killer whale (Pseudorca crassidens)

Beaked whale (Ziphius sp)

Short-beaked common dolphin (Delphinus delphis), Striped dolphin (Stenella coeruleoalba), Bottlenose dolphin (Tursiops truncates)

Day 43 - The Visual Envelope Please

And now for the results… well, some of the results. Our scientists are still summarizing the phase 3 visual data, and the intensive analysis will happen over the next few months. But the initial visual results from the first two phases show that we sighted over 200 events that included over 1300 animals of the species:
Fin whale (Balaenoptera physalus)
Short-beaked Common dolphin (Delphinus delphis)
Short-Finned Pilot whale (Globicephala macrorhynchus)
Risso's dolphin (Grampus griseus)
Sperm whale (Physeter macrocephalus)
False killer whale (Pseudorca crassidens)
Striped dolphin (Stenella coeruleoalba)
Bottlenose dolphin (Tursiops truncatus)
Cuvier's beaked whale (Ziphius cavirostris)
Loggerhead sea turtle (Caretta caretta)

Day 42 – HERE WE GO!

The storm clouds, high winds, and lashing rain did not deter the science and ship crews from enjoying a special end of cruise BBQ upon our arrival in Malaga. The remaining 21 hours were spent saying goodbye to departing members of the crew and bringing on fresh food supplies. Once the weather cleared, some people explored the town – the Picasso museum, the prominent fort, the fresh markets, the discos, and the beaches.
The main science laboratory is now strangely quiet and there is only one meal shift as only a few people remain on board for the transit back to Italy.

Day 41 - STOP RECORDING

Our engineering coordinator proclaimed the end of the Sirena 10 sea trial. The visual observers came down from the flying bridge and the arrays were brought onboard. The Captain kicked up the speed and with haste (it’s all relative) we head to Malaga, Spain.

The third phase of the cruise would not have been a success without the contributions of our science and ship crews. Most of the science crew will depart in Spain and only a few Italian residents will continue on the return transit to La Spezia. To those that depart us, fair winds and following seas.

Stay tuned on the blog because over the next few days we will summarize the accomplishments of the trial. But until then, for the next few hours, we will enjoy seeing the sites of historic Malaga and eating paella on the sandy beaches.

Day 40 - Where's Lambert?

We are collecting and processing a lot of data during our Sirena 10 cruise - not only on whales and dolphins, through visual and acoustic surveys, but also on the marine environment in which we observe them. This data, which includes bottom topography, sea surface temperature, chlorophyll and salinity, will help improve our understanding of how cetaceans choose suitable areas to feed or breed. Once we identify and characterize such areas we can try to predict, using habitat models and their ecological significance, the presence (and absence) of cetaceans in other areas.

Working long hours on data processing may not sound as much fun as whale watching on the flying bridge, but it is has its rewards. Even some unusual ones, such as a rare sighting of Lambert, the elusive isobath whale, inhabiting a bathymetric map of an area we are surveying. We are still working on a taxonomic classification for this lone whale. Meanwhile, try to see if you can find Lambert hidden in the isobaths (contour lines) in the map below.

Hint: it seems to be swimming away from the coastline and prefers deeper waters! And if you're wondering, his name comes from the cartographic projection which best displays his looks.

Day 39 - May the Force be with You

As light propagates through the water column, it is quickly attenuated (reduced), but not all the colours are affected at the same rate (red light for instance is attenuated more rapidly, the remaining blue/green providing the ocean with its characteristic colour). The hyperspectral radiometer measures these variations, providing light spectrum measurements as a function of depth. It is deployed by hand and free-falls to a maximum of 100m.



Figures. Hyperspectral radiometer and some typical measurements of light spectra at the surface (left) and at 10 metre depth (right). Note how the red component of light (beyond 600nm) is attenuated leaving only the blue/green component.

Day 38 – E.T. Phone Home!

29 days ago we placed five buoys on the bottom of the sea to listen to marine mammal sounds. Today, we returned to these sites and recovered our data treasures.

When we positioned the mooring, the bridge team precisely recorded the positions where the buoys were placed. Today, the ship’s captain navigated the vessel over each position, at which point, the scientific engineering team sent an acoustic signal to the acoustic release on the mooring. The acoustic release (thankfully) “responded” back with a signal that it “heard” the release command and its hook came undone. The large yellow and orange buoys then propelled the hydrophone to the surface, sending signals to the ship at each 100 meters on it ascent. Once the floats surfaced, the ship was positioned alongside, and the ship’s sailors recovered the buoys with the bow crane.

A smooth, successful operation - thanks to all the crew!

Day 37 - CTD

Characterisation of the marine mammal habitat plays an important role in the understanding and interpretation of the visual and acoustic observations. The instruments used during Sirena 10 allow us to measure not only the traditional oceanographic parameters such as pressure, temperature and salinity, but also how the water column affects the propagation of light. Additional parameters such as oxygen and chlorophyll concentration further extend our knowledge of the marine environment.

Three main systems are used for these measurements. Today we talk of the CTD.

The CTD consists of a metal frame with multiple sensors attached to its struts. It is lowered into the water on a cable which also allows the electrical transmission of the data to the laboratory in real-time. In addition to the sensors, bottles are used to collect water samples for later chlorophyll analysis. During Sirena10, profiles were collected down to 1500 metre depth (see the picture for a typical profile). Timing of the casts coincides with satellite overflights, allowing offline comparison of remotely measured surface temperature and chlorophyll concentration.

Day 36 - It all comes together

On Day 34, we described how the visual team logs their sightings on a tablet PC. The visual sightings are then sent from the visual team on the bridge's roof all the way down to the science lab via a serial cable. In the lab, the information is received on a dedicated computer that also receives ship information and acoustic sightings. The ship information is received from the bridge via a serial cable and the acoustic sightings are received from the acousticians' computers in the science lab through our local network.

The GIS computer combines all information on a map, showing where the ship is, was, and what sightings were made. Acoustic sightings are placed on the ship track, because the location of the animal is not precisely known, with different colours and sizes representing the various species and loudness. The visual sightings include bearing and distance and can therefore be placed at the appropriate locations relative to the ship's position at the time of the sighting. This information is also color-coded per species.
The combined information is primarily useful for post-cruise evaluation.

During Sirena10, the map is not shown to everyone, to make sure that visual results will not influence acousticians' perceptions of the received audio.

Day 35 - V-V-V Visual Team!

Written words may not do justice to the fast paced, exciting times experienced by our visual team. Check out this video to understand how to be the newest member of the crew!

Day 34 – Sophisticated Surveys

After all the birthday celebrations, we finally returned to work. The winds subsided and the seas calmed slightly so that the visual team could stay “on-effort” all day today along the ship’s track line. Two teams of four persons rotate throughout the day in two hour shifts. Three people on the team look through the big-eye and regular binoculars while the fourth person records the sightings and the environmental effort on a small laptop.

A member of the MMRM project team designed software specifically for use on the Sirena cruises to record the sighting data. In seconds, the data recorder enters the species type, animal behavior, number of animals, aspect, presence of juveniles, distance, and bearing to the animal. In addition, the ship position is automatically entered and then the software calculates the location of the animals. The software makes it much easier to accurately record data – much better than the days of scribbling with pen and paper!

Day 33 - CELEBRATE!!!

Happy Birthday
Buon Compleanno
Herzlichen Glückwunsch
Feliz Cumpleaños
Bon anniversaire
Para béns
С Днем Рождения
palju õnne sünnipäevaks
Boldog szülinapot
La multi ani
Gefeliciteerd

No matter what language you say it in (and all those listed are spoken by someone onboard), a birthday is something to commemorate! A few fortunate crew members celebrated their 47th, 30th, and 23rd birthdays on board with an extra torta from the chef or extra special Haribo candies.

Day 31 - Taxi Dispatcher

As part of the acoustic survey, we are deploying sonobuoys periodically along the track of the ship. Unlike the arrays and the CPAM which are towed behind the ship, the sonobuoys are disposable - they are not attached to the ship but dropped over the side.

Prior to deployment, a sonobuoy is programmed with specific settings such as the depth to which the hydrophone will lower, the time it will transmit data, and the radio frequency channel that it will transmit data (no need to screen the channels to avoid Italian cab drivers out here!).

In the picture you see a scientific crew member choosing these settings. Once the canister is in the water, an orange float inflates and remains on the surface. The actual hydrophone drops down to the depth that was preprogrammed. At depth, the hydrophone receives all the sounds in its vicinity. These sounds are transmitted electronically to the surface and then sent back to the ship. On the ship, we have receivers which gather the data and transfer it into visual images on the computer screen in the laboratory.
The data that we collect with these buoys focuses on the lower frequency sounds in the water, allowing us to collect more information about different species of whales, as well as ships and other ambient sounds.

Day 30 – WORKHORSE Arrays

The almost annual Sirena sea trials began over 10 years ago. In each of these, the NRV Alliance has towed a two hydrophone array to receive the marine mammal acoustic sounds. This reliable equipment was supplemented with two newer arrays this year and they continue to collect sounds in the water for about 20 hours each day.

The entire array is actually made up of several pieces. First, the tow cable is firmly attached to a winch on the ship (orange in the attached picture). 220m of tow cable trail behind the ship and attach to the actual array – a 15m long piece of tubing, filled with oil in which two microphones (called hydrophones) are spaced 8m apart. The sounds are transferred from the hydrophones as electrical signals through wiring in the oil filled tubing, up the tow cable, through a deck cable and into the laboratory computer. The submerged array stays at about 18m deep in the water when the ship is traveling about 5 knots.

While we continue to test other pieces of equipment (smaller, different features, etc), this array continues to be the Cavallo vincente non si cambia

Day 32 - Main Science Lab

It all comes together in the main science lab onboard the Alliance. The last three days, you have read and seen the acoustic equipment that we use to listen to the marine mammals. In this feature film, see how it is all integrated.

Day 29 - CPAM

Numerous technologies, in various states of development, are being tested and used during this trial. The blogs in Phase III of the Sirena trial will describe these technologies in feature stories called "Focus on Technology". We begin this series with a description of the Compact Passive Acoustic Monitor (CPAM).

Grab your popcorn and enjoy the movie!

Day 28 - Hasta Luego Cadiz

The crew enjoyed a wonderful time in the historic town of Cadiz. It is the most ancient city still standing in Western Europe; traditionally, its founding is dated to 1104 BC. A day was passed wandering the narrow cobblestone streets, visiting the cathedral, sipping cafes in the numerous plazas, swimming in the surf, and devouring tapas. The setting sun splashed rays of light through the city, providing incredible ambience for the photographers onboard.

Fuel in our tanks and food in our refrigerator, our short stay concluded. We are now transiting out to the starting point of our third and final phase – hoping for calm winds and following seas.

Day 26 Adios Amigos

After eight short days at sea, we conclude Phase Two of the Sirena10 sea trial. It is time again to say adios to colleagues and friends. We appreciate all of their efforts; those in preparation of the trial, those on the rolling seas and in strong winds, and those in the countless hours yet to come doing data analysis. We look forward to swapping stories over tapas tonight in the Port of Cadiz, Spain. Thank you to our personnel that are leaving us and we wish them fair winds and following seas as they journey home.

Day 25 - There She Blows

False Killer Whale, Pseudorca crassidens
An active, playful whale that has an affinity for boats.

That was very true today as 10 whales surrounded the Alliance. For many of us, it was the first time seeing this species, so the cameras were all clicking to capture a photo. The acousticians enjoyed it just as much; the Main Science Laboratory was filled with the sounds of the Pseudorca and the computer screens were lit with color from their clicks and whistles.

Day 24 - Whale Interpreters

Coda… Whistle…High Click…Ziphius…Burst…Trumpet…Ship Noise…Sonar…Nacchere

These may seem like random words strung together, but to a bioacoustician they are the sounds of the sea. As sounds are received on the equipment behind the ship, they are translated into spectrograms on the computer. In front of these spectrograms, sit bioacousticians who are trained to classify these lines and squiggles as particular types of vocalizations from particular animals.

Loudness: 1 – 2 – 3

Duration: 1 - 2 - 3

In addition, these trained scientists listen to some of the sounds on headphones and then select the loudness of each sound (based on what they hear or on how faint or bright the images are on the screen) and for how long these sounds last.

According to one scientist, “I like to close my eyes and listen to the sounds and imagine who or what is making them. I create a 3D picture of the underwater environment in my head.”

Day 23 - What We See is What We Hear

As we mentioned yesterday, whales and dolphins make a wide variety of sounds which span a range of frequencies from very low (<50hz)>100kHz). Because humans can only hear in a narrow frequency band (20hz – 20Khz), it is often necessary to see the sounds that we can’t hear (and even those that we can). Using special software, the sounds that are received on equipment behind the ship are visualized on the computer in a spectrogram – a colorful display with time on the x axis and frequency on the y axis.
In the picture, the lines represent the clicks of the Cuvier’s beaked whale, Ziphius cavirostris. The features of their clicks include a center frequency around 40 kHz and spacing about 0.4 s apart. The distinguishing trait is that the pair of lines always appears close together, one represents the directly emitted click from the animal and a second one that is simply the reflection of the click from the surface of the sea. Thus, it is possible for the scientist to look at this picture and identify it as a signature of the Ziphius.

Day 22 – Visual and Acoustic in Unity

The acoustic team listens day and night to vocalizations and clicks. Sounds from dolphins are often noted as "undetermined dolphin species", because several different species produce very similar sounds. However, sometimes a group of animals comes so close to the vessel that the acousticians can visually confirm the detections.
In some lucky situations, the animals travel with us for many miles, as happened with a group of common dolphins that approached the ship in the late afternoon and remained with us after sunset. From the hydrophones, we appreciated how really close they were by their strong echolocation clicks, bursts and whistles. It was not a surprise when, at midnight, we looked outside and under a strong light from the ship that shone into the water, we discovered that the dolphins were still there …maybe the same dolphins we saw before.

Day 21 - What does a whale sound like?

Dolphins and whales produce many different kinds of sounds related to different situations. Listening to an animal, one can guess which behavior it is doing; "clicks" are used for navigation, "bursts" to focus the acoustic energy on an object, "whistles" to communicate and "nacchere" are thought to be associated with feeding behavior.

Using headphones connected to the acoustic instrumentations, trained listeners hear the ocean’s sounds, both natural and man-made. The frequency and intensity of the mammal vocalizations can be very different between species, allowing a listener to distinguish which particular species is making the noise. However, some species, like common dolphins and striped dolphins, produce similar kinds of sounds with similar features which are difficult to distinguish.

Click on the link below (from one of our collaborators) to listen to the sounds of whales and dolphins. A connectivity issue prevents the sounds from being uploaded here.
http://www-3.unipv.it/cibra/edu_medsounds_uk.html

Day 20 - What do we expect to find?

After our delightful time ashore in Lisboa, it did not take long before we were back in the routine of the survey. Over the next few days, we want to describe this survey in a little more detail to our readers. Today we begin with which animals we are looking and listening. In this part of the Atlantic, our teams expect to find:
Striped dolphins
Spotted dolphins
Common dolphins (seen here)
Spotted dolphins
Risso’s dolphins
Bottlenose dolphins
Fin whales
Sei whales
Blue whales
Humpback whales
Sperm whales
Short-finned pilot whales
Beaked whales

Day 19 - Adeus Lisboa

After two weeks at sea, the NRV Alliance pulled into Lisbon for a crew change and to fill up with provisions. 36 hours ashore was not enough time to enjoy all the wonderful sights, smells, and experiences that this beautiful city had to offer. The scientific and ship crews made the most of their time ashore:

• visiting the many historical sites, such as the Tower of Belem,
• eating typical Portuguese cuisine, like salted cod fish,
• experiencing typical music and food at a Fado restaurant,
• stretching their wobbly sea legs along the waterfront bike/running path,
  relaxing and surfing on the beaches of Cascais,
• shopping the bargains at the super mall,
• and for those that didn’t see enough sea life in the first phase, visiting one of the world’s largest and best Aquarium.

A truly memorable time; however, the sea trial continues. The new crew additions for Phase 2 (and those remaining from Phase 1) have already commenced our visual and acoustic survey in a new area, expectantly searching for marine mammals.

Day 16 - The People Make it Happen

Sirena Cruises are very people-power-intensive efforts because of the around the clock acoustic monitoring and visual watch teams which rotate every 2 hours. We have always been blessed with excellent volunteers who are very experienced and capable to make up the difference from the staff members from the Centre. As we approach the end of our first phase and the Port of Lisbon for a short Port Call, we will sadly be saying goodbye to some of our SIRENA Staff and gladly saying hello to their replacements. We thank our Phase One personnel that are leaving us and wish them fair winds and following seas as they journey home.

Some people just can't wait to get off...

Day 15 - Essential Piece of Equipment

Each day, the ship and science crew labor many hours working towards the scientific objectives of the cruise. The work can be arduous, the winds strong, the seas rough, and the equipment malfunctions. So, it is important to find activities that keep the morale high.

The most important piece of equipment for doing just that is the foosball table, or calcetto, in Italian. The significance of this equipment was emphasized during the ship’s recent repair period. A shipyard worker converted the game table into a sawhorse for cutting wood. The First Officer urgently informed the worker that an accidental cut of the coveted table would likely result in many angry crewmembers. The worker seemed confused, but replaced the table with a proper sawhorse, and the ever important foosball table was saved from potential harm.

Game on!

Day 14 - Name of this Creature?

Every day, we pull the passive acoustic monitoring equipment out of the water when we do our oceanographic data collection. Sometimes, more things come out of the water then what we put in. Our cook, may put the little shrimp (seen below) on our dinner menu tomorrow.

But today we had a surprise. This little creature pictured on the left hitched a ride aboard the Compact Passive Acoustic Monitor (CPAM). Our marine mammal experts could not identify it. Can you? Animal, vegetable, mineral? Post your best guess at its name in the comments section.

Day 13 - Passive Huh?

We often refer to our passive acoustics systems that are used to record marine mammal vocalizations; but what do we actually mean by this? Watch this video to hear dolphin recordings and to see them pictorally represented on a spectrogram display.

Day 12 - Color in a Sea of Blue

Every day it is the same blue view

Ocean down below and sky above

but today was a gift of color

As the sun rose three arches of beauty framed the blows of the whales.

As the day started, the day ended

An arc of brilliant color

bid us Boa Noit

Day 11 - Extra Ears in the Ocean

While most of the work that we do and the equipment that we use stays on the ship, such as our visual crew with their Big Eyes and the acoustic crew with their arrays, we also place long term acoustic monitors in the ocean to collect data. On SIRENA 10 we have 6 buoys that we will moor on the ocean bottom in water depths down to 1200 meters. Of the 6 buoys, there are 4 different kinds. Four of them are commercial “click” detectors and two of them were built by two of our university partners, just for this work. These detectors will listen and record marine mammal clicks during the four week period that we are on this cruise, although they can actually record for much longer. Before leaving our survey area to return home, we will go back to each buoy location and “call” out with a special transceiver (like an underwater garage door opener) that will signal a special release mechanism on the weighted anchor section to let go. The floats then bring the buoy and its valuable data back to the surface for us to recover and analyze upon our return to the Centre.

Day 10 - Torta Day

The galley and its crew on the Alliance are legendary. The Italian cooks prepare wonderful fresh focaccia in the morning and fantastic Italian meals to suit everyone’s tastes for the other two meals of the day. The stewards always greet us warmly with a big smile and ensure we want for nothing, including translations of the menu. One would think that is more than enough to keep the entire crew happy, and it really is…

… but the cooks go one step further on Thursdays and Sundays – Torta (Cake) Days. At 15:00 on these days, the laboratory empties as everyone migrates to the mess room for a special treat. Fruit torta, more traditional cake with frosting, or cannoli, everyone knows that a special treat awaits them on CAKE DAY!!!

Day 9 - One thing we realize...

… is that we can’t do anything about the weather. Yes, everyday isn’t all sunshine, smooth sailing and lots of animals. We run into some bad weather on occasion and today was one of those days. We woke up to 25 – 30 knot winds and force 4-5 seas, which only got worse as the morning progressed. The Visual Team, being the troopers that they are, were up on the Flying Bridge at 06:45, braving the winds. But as it got worse and started to rain they just couldn’t do any more and had to go off effort. Even though the weather hampers our visual efforts it doesn’t bother the Acoustic Team at all. They are our 24/7 all-weather team.

We hope the stormy seas are behind us and sun is on the horizon. It looks like the next 3 to 4 days in a row will be good weather.

Day 8 - Mountains under the Sea

Today, our journey took us over two sea mounts that are estimated to be over 4000 meters in height. A sea mount is a mountain underwater that does not touch the surface of the water. The topography of the sea mounts, which are formed by extinct volcanic rock, creates a rich environment for flora and fauna.

Sea mounts are also known to be migratory areas for whales. Among today’s sightings, the visual team reported groups of short-finned Pilot whales (Globicephala macrorhynchus), an undetermined specie of whale and some common Bottlenose dolphins (Tursiops truncatus). The acoustic team heard vocalizations of Sperm whales (Physeter macrocephalus) and numerous dolphins.

Day 7 - Home Away from Home

Now that the survey has begun, the science, engineering, and ship crews are settling into their daily life routines. For some of you that have never been on a ship for many days at a time, you may be wondering, “What is life like on the NRV Alliance”?

This 100m long ship offers everything that our group of 48 could need. Most people are rocked to sleep at night in individual cabins (a few do share) and some even wake to the morning light through port holes. Breakfast, and all other delicious Italian meals and of course cappuccino, are served from the full service galley The science crew then “commutes” upstairs to work in the laboratory and deck spaces. After work, free time is enjoyed working out in the gymnasium, wave-watching on deck, or relaxing in the lounge which is complete with books, movies, and occasionally a satellite tv signal. Life is just like at home – with a shorter commute!