Monday, August 31, 2009

Fins, Brief Winds, and then Ziphius

The weather was good for the most part today as we worked through an area where Cuvier's beaked whales had been seen from ferries and a few sightings from other researchers. We covered a lot of water during the day and found a lot more marine mammals than the area covered yesterday.

Our first sighting was a group of three fin whales and throughout the day we would have more than 20 sightings of other groups or individuals. We saw several fin whales breaching, which is an impressive sight, and had several within a mile or less from the boat. There were also several large groups of dolphins leaping and skimming the water around us several times. The speed and maneuverability of these sleek animals never ceases to be amazing. After seeing the fins in the morning, the middle of our day was briefly interrupted by a small storm cell that we watched form over the sea and then move past us. The wind kicked up for about an hour and we had to stand down our visual team briefly. It actually rained for a few minutes, which we haven't seen for a long time, but it passed quickly and we could again work.

By mid-day the conditions were workable again and we continued searching for beaked whales. We found a group of three and our visual team guided the tag boat toward them. It was good for all to be back on our focal species again after the transit over and two days of searching here. We followed them through a number of surface intervals and the tag boat had two close approaches with reasonably good chances at tagging, but the animals then went down for a deep dive and again we ran out of daylight. The weather predictions for Tuesday look outstanding and we will begin in the same area where we had our first successful focal follow here.

Sunday, August 30, 2009

Searching...

Today was spent searching widely across our new operating area -- in search of suitable wind and sea conditions and, once we found those, in search of beaked whales. The day dawned rougher and windier than we expected from the forecasts, but we had a clear picture of where to find better seas. By mid-morning we worked into relatively calm winds and workable swell conditions and began running across some of the steep drops and seamounts on the bottom of this once-volcanic area. For the rest of the day we had relatively good viewing conditions and we worked at speeds where we could monitor as much area as possible using both our visual and acoustic teams. However, somewhat surprisingly to us, we didn't see a single beaked whale today and heard just one sperm whale on a sonobuoy. There were the occasional striped dolphins and a few sea turtles, but relative to where we were yesterday, this area was relatively devoid of marine mammals.

We have quite a lot of other promising looking areas to cover and the wind and wave forecasts for tomorrow are promising. We will try and work in an area where there have been some incidental sightings of beaked whales from ferries.

Saturday, August 29, 2009

Sperm Whale Central

We were all very happy today to be back on effort and for much of the day in very calm seas. After a short pit stop at dawn to restock with some supplies we began searching for marine mammals in our new operating area. Shortly thereafter we spotted a mother-calf pair of Cuvier's beaked whales. This was encouraging since the area where we are now has not been systematically surveyed and, despite some anecdotal observations and promising bathymetry (bottom features), we weren't sure what we would find. We subsequently ran across quite a bit of marine life, though not our primary focal species. We came through a cluster of loggerhead sea turtles, found patches of striped dolphins, and heard Risso's dolphins chattering away. But the mammals that would dominate our day were deep-divers like beaked whales.

Our first sperm whale sighting, which was in water about a mile (1.6 km) deep, was followed over the next eight hours by 19 other sightings of other (mainly) individuals or groups. We recorded a total of 26 individual sperm whales sighted. As with our other observations, we could have re-sighted some of the same animals more than once, but since we were moving at 10 knots in one general direction for much of the day to cover a good amount of water in this new area, most of these were probably different animals. We saw several sperm whales breaching and heard them on our acoustic arrays much of the day, but never saw any close enough to the boat for good pictures. It is a promising sign that we are seeing other deep-diving, primarily squid-eating marine mammals (like beaked whales are) and it is also interesting to observe such relatively high densities of sperm whales in this area.

The weather outlook for tomorrow is relatively promising and we are refreshed to be back in water that is more amenable to our objectives than what we left in the Alboran Sea; we hope to locate more beaked whales (and fewer sperm whales). Throughout this project that we have been treated to some fantastic sunrises and sunsets on the Mediterranean Sea, such as this one from yesterday.

Friday, August 28, 2009

Eavesdropping

We have been steaming for 48 hours now and are nearing our final operational area. The winds were a bit lighter for part of the day today as we moved further away from the north African coastline, but as got into quite deep water we did not see a great deal of marine life. Several sperm whales, dolphin groups, and a sea turtle were spotted throughout the day, however, as we came through these poorly-studied waters. As we did during our transit yesterday, we have used this time to process the large amount of biological, oceanographic, and acoustic data that have been obtained thusfar.

One of our primary tools in eavesdropping on the underwater acoustic scene to locate, identify, and track marine mammals are arrays of hydrophones. With these listening sensors towed behind the vessel (you can see one being deployed here), and with the expert acoustic observers we have to fine-tune measurements and interpret what we are hearing (and also seeing on special displays), different species can be discriminated and estimates of signal strength (to give a sense of near or far) and bearing to calling animals can (sometimes) be made.

There are two arrays of hydrophones towed in parallel behind the ship, one on the right side, one on the left side. Each array is composed by a 150m long towing cable (which can be extended to 300m) ending with a 12m long oil filled tube that holds two wideband acoustic sensors each and their preamplifiers. The electronics onboard amplify the signal to be digitized with a 4 channels AD converter at 192kHz sampling rate connected to a powerful computer with dedicated, custom software designed for both research and mitigation purposes.

This software allows us to acquire, record to disk, analyze and display up to 8 channels in real time. A high resolution spectrographic display (a picture of the sound showing frequency, or "pitch", over time) shows all the features of the incoming sounds, even those we can't hear, because they are too high in frequency or too brief for our ears to detect. Several examples of the kinds of recordings made with these specialized listening sensors and processing software are given here; these are of long-finned pilot whales and striped dolphins recorded recently in our research.

» Listen to Striped dolphin clicks shown on three channels (note 24kHz zoom on top channel)

» Listen to Pilot whale bursts and whistles with harmonics

A special directional display shows the signals coming from the two arrays (4 hydrophones) to provide intuitive cues as to the direction of incoming sound. By using these two displays, researchers can recognize sounds coming from different species and estimate the direction from which they came. This information is especially important in the current research project to position the tag boat as close as possible to the position where the diving animals are supposed to emerge at the surface.

Tomorrow morning we will be back on effort in our new operating area. The weather forecast is quite favorable for the next several days, while it remains quite poor for the Alboran Sea area we recently left. So, we embark on the last week of our collective efforts here with renewed hope and optimism for favorable seas and accommodating whales.

Thursday, August 27, 2009

MED-09 Oceanographic Measurements

Today was the first of two days transit to our new operating area in the Tyrrhenian Sea. We continued both visual and acoustic observations while traveling and were quite interested in what we might see or hear because the areas we are passing through have not been well-studied. Some dolphin groups were detected, but not much else. We had reasonable seas and the wind was just 10-12 knots, but it was straight from the east and on our bow so effectively closer to 20 knots which made things tough for the visual team. As we transit, we continue to process all of the biological and oceanographic data that have been collected thus far.

An important and interesting kind of oceanographic sampling that is being done is to measure different properties of sea water at various depths in areas where we have been operating. We use a device to measure the conductivity (a proxy for salinity), temperature, and depth (measured with pressure) of the water (called a "CTD"). Measurements are made by lowering the CTD slowly in the water column to provide real-time data about biologically-important ocean parameters. The CTD has two salinity probes, two temperature sensors, and one pressure sensor; it passes through and samples the water for these parameters at approx one meter/sec. It also operates a pumped system from the different sampling tubes seen in the picture here to guarantee that the same sample of water is measured at specified times. Additionally the Alliance CTD includes two sensors, which directly measures the oxygen content in the water column. In this way we can fully characterize the oceanographic parameters of the water column and can also calculate how sound travels at different depths in real-time using the salinity, temperature, and depth information.



In the images here you can see four different plots from a recent deployment of the CTD to 1000m, each of them showing a different measurement with increasing depth (downward on the plots). The temperature plot shows the much warmer surface water and colder deep water; note that below about 200m there is almost no change in the ocean temperature here. The salinity trace shows another common pattern in this area which is fresher water near the surface and saltier water with depth. The oxygen plot shows higher levels near the surface (where waves mix the water) and lower levels deeper. Finally, the sound velocity profile resulting from the other measurements shows more rapid sound speed at the surface and deeper, with a minimum sound speed around 150m. Like light, sound bends to areas where it travels more slowly and the minimum seen here is called a "sound channel" that would tend to carry sound greater distances than where the sound velocity is higher.


By making these measurements in different areas of interest, and at depths down to 1000m (over 3,000 feet), and comparing them to where we see and hear different marine mammals, we can get a better sense of which kinds of environmental conditions are most important for different species. Additionally, the sound velocity profiles are useful in predicting broadly the underwater sound fields during controlled exposure experiments using real-time oceanographic measurements; these are also directly measured at different places with other sensors (e.g, acoustic tags, sonobuoys).

Wednesday, August 26, 2009

Still Rolling

The winds gradually came down from the gales of last night throughout the day, but the swell from the sustained strong (Beaufort 7) winds remained prohibitively high for us. Our visual observers went on watch several times as we looked for pilot whales. We did find some, but with the seas and the fact that most of the sub-groups had small calves, we did not attempt to attach acoustic tags. As usual, we had our passive listening arrays deployed and had intermittent detections of marine mammals at different points during the day.

Overall it was another day where the weather prevented us from achieving our primary objective. Based on our experiences the last few weeks and the wind and wave forecasts for the next five days, we will be leaving our current location and transiting to one of our other large operating areas closer to Italy. Thus, the next few days we will be in fast transit survey mode as we cover a large amount of ocean. We will listen with one array in the water and conduct visual surveys as the conditions allow. The area we will be passing through has not been surveyed systematically and thus even as we transit through this area we hope to provide some useful contributions to the scientific understanding of part of the western Mediterranean Sea.

Tuesday, August 25, 2009

Rough

The wind blew steady all day today from the west at 20-25 knots with gusts to 30, building heavy swell. The combination of Beaufort 6-7 winds and resulting seas was way beyond what our visual or tag team could work in for any species and they were not placed on effort at any point today. We did continue to monitor acoustically, while holding on, and covered some interesting-looking areas. But even our acoustics team was affected by the conditions to some extent with the rough seas and had limited detections.

We are hoping for better wind conditions at some point tomorrow as it changes from the west back to the east, but we know we will still be dealing with residual swell from it the strong and steady winds today. We are having strategic discussions about our next course of action.

Monday, August 24, 2009

Hot Spot

Our read of the weather was right on today. We had excellent conditions in the morning, workable weather in the middle of the day, and strong winds by mid-afternoon. As has been the case every day we have been in beaked whale areas with suitable sea conditions, we saw many animals today. If you look closely at the picture here you can see the three different sizes of binoculars we use to monitor visually at different distances. Initially we were spotting just single animals, who are very difficult to tag relative to groups, and we kept moving. Soon, however we came into an area with many different groups.

It was difficult to track who was who and how many groups there were because it seemed very likely that some of the groups were splitting apart and re-forming in different configurations while traveling in the same general direction. Some of these groups had calves, but generally speaking we were seeing more large and workable animals. With the excellent conditions, we soon got a good read on a group of four animals without calves. We followed them through several surface intervals and "shallow" dives and had a good bearing on their direction. The tag team had two close approaches to within about 10m of the animals (the picture here is of the focal group during one of these approaches), but was not able to attach one of the DTags to the animals. We continued to track them as they went into a long, deep foraging dive and began producing echolocation clicks, using our listening assets. As yesterday, with the integrated information on bearing from the visual teams and acoustic bearings from the listening arrays, we felt quite confident that we maintained them on our port side and had a probable zone where they would resurface. Also like yesterday, however, as we positioned ourselves like this and were ready, the winds came up quite rapidly to 20 knots and we were forced to break off the search. We continued to search for pilot whales in the marginal conditions and ultimately found a moderate size group - using acoustic cues since the wind caused poor visibility. However, there were small calves in their groups and both that and the sea state would have prevented a CEE with them as well, so we did not attach pilot whale tags.

The weather forecast for tomorrow looks poor with strong winds from the west; Wednesday may offer us another window of calm as the winds shift back to the east. We will, of course, be ready to go tomorrow if the forecast is incorrect, but if we cannot look for beaked whales visually, we intend to conduct acoustic surveys over what looks to be an interesting seamount and submarine canyon area that has not been extensively explored. Once we have good conditions again, we will likely return to the area where we worked today. Even accounting for likely re-sighted animals, a conservative estimate of the number of individual Cuvier's beaked whales we saw is about 20 within about a 60-square-mile patch of ocean -- quite a high density for our newest "hot spot".

Sunday, August 23, 2009

Chances early...then more of the same

Today dawned much calmer than expected and we were on animals both visually and acoustically quickly. We searched around our first beaked whale acoustic detection and soon thereafter had a visual sighting. We also crossed paths with a large group of common dolphins (50 animals or more), saw some large Risso's dolphins riding on the bow of a nearby large ship, heard pilot whales, and saw a large tuna leap several times in the air with a large fish in it's mouth. We followed one promising group of three adult/sub-adult Cuvier's beaked whales, tracking them both visually and acoustically (see below), and had our tag boat over the side and ready to go. But we hadn't managed to tag them by about 1100 and the wind picked up from the east again rather quickly and by noon we had the Beaufort 5 conditions described yesterday that were predicted for today. We continued searching for pilot whales, but by mid-afternoon the winds again ended our day early.

During the mid-morning focal follow on the beaked whale group, we demonstrated again an effective capability to integrate information received from our visual and acoustic teams to position the ship relative to animals while adjusting for other environmental factors as well. In the figure here, you can see the track of the ship as the orange symbols in a line beginning in the southwest (lower left) section of this GIS plot; the closer together the symbols the slower the ship and the further apart the faster the ship. As we moved to the northeast, we had a visual sighting (red C1) of a beaked whale, identified as a single animal. We continued forward and had a subsequent acoustic detection of beaked whales (seen as the pink circle on top of the ship's track) and an approximate bearing to the animals ahead of and to the starboard (right) side. About 25 minutes later we had two good visual sightings of a group of three beaked whales (red C2 and C3) at the surface and had clear direction bearing (heading) for them to the northeast (direction of arrows). The animals then did a shallow dive that we expected would take another 15-30 minutes. Now we had a choice - and a problem. It was still morning at this point. The sun was coming up in the southeast and there was a serious glare on the sea that would prove difficult for our visual observers if we did not adjust the position of the ship relative to the whales. So we turned toward the sightings, sped up significantly (note the orange symbols spacing out), and cut behind them while maintaining acoustic detection. This maneuver worked perfectly as we passed them and then slowed down, turning to the north while continuing to hear them now off our port (left) side (additional small pink circles along ship track). The two purple lines show two of the acoustic bearings which predict direction to the animals underwater; they are close enough in time that where they cross is an estimated location. Using the sighting location, visual bearing, and these acoustic bearings, we had a good prediction of where they were and where they might come up. Now we had the sun on our stern (back) and also a better orientation to the significant current from the east as well. Ultimately we were precluded from seeing them come up despite, being in an ideal position, because throughout this maneuver the wind jumped from 5 to 15+ knots. Nevertheless, this kind of fairly complex tracking with integrated visual and acoustic information - reading the animals using these tools and orienting ourselves correctly relative to the sun and the current - demonstrates that everything is working together quite well.

The wind is dropping this evening and we hope to catch a nice calm window tomorrow as the wind switches from the east to the west. If we get flat seas we know the animals are here and that we are ready.

Saturday, August 22, 2009

Ditto

Today was a repeat of yesterday -- if anything a little worse. We had steady 15 knot winds for most of the day picking up to near 20 later on. We surveyed for pilot whales until afternoon when it became too strong to search for anything visually. As yesterday, we continue to search acoustically and some beaked whale clicks were detected during the day in areas where we had sighted them before. So they are still where we expect them to be and we can detect them using our acoustic assets, but even being right on top of them it is impossible to spot them visually in the Beaufort 5 wind conditions.

The Beaufort scale is an empirical measurement of wind speed that is related to sea conditions. To give you a sense of how remarkably calm we need the conditions to be, consider that the scale goes from 0-12 and 5 (our wind for much of today) is categorized as a "fresh breeze" of 15-20 knots (29-38 km/hr or 16-24 mph) and the resulting seas have moderate waves of some length, many white caps, and small amounts of spray. For sighting and tagging beaked whales, we need Beaufort 0 ("clam" with winds <1 knots), Beaufort 1 ("light air" with winds 1-2 knots), or Beaufort 2 ("light breeze" of 3-6 knots) conditions. Anything Beaufort 3, a "gentle breeze" of 7-10 knots (12-19 km/hr, 8-12 mph), or above makes it difficult or impossible to visually detect and tag beaked whales. Beaufort 3 and 4 ("moderate breeze" of 11-15 knots) can be workable with pilot whales and other cetaceans, but at Beaufort 5 we tend to put the covers on the big-eye binoculars, not because we can't take it but because it isn't worth looking.

We continue to refine and cross-calibrate all our detection systems and await the opportunity. Tomorrow looks as bad in terms of wind and the seas may be building with the steady wind from the east, though we have learned not to put too much faith in weather forecasts. We are moving to what we hope may be a better area in terms of weather where beaked whales have been spotted previously.

Friday, August 21, 2009

Blown Out

Despite the favorable predictions, the weather front we expected tomorrow seemed to arrive a day early. We experienced winds around 15 knots for most of the day with regular whitecaps - conditions that are inconsistent with spotting beaked whales visually. We continued in survey mode focusing on areas where we might expect pilot whales; the weather would have allowed us to work with them for most of the day. While we were waiting for conditions to improve, we made measurements comparing how our different acoustic systems performed in detecting the same underwater sounds in order to further refine capabilities and procedures. We also made additional oceanographic measurements and conducted acoustic surveys in support of the habitat modeling efforts that will benefit from MED -09 data.

Thursday, August 20, 2009

Many Beaked Whales (most with calves)

We had another very good day today in terms of wind and sea conditions. We consequently found many cetaceans, including our primary species of interest. We worked mostly in the deep axis of the same canyon area and detected many groups of Cuvier's beaked whales throughout a very long and full day of activity. Acoustic surveys begin at 0500, visuals come on at dawn, and both teams operated continuously throughout the day with these many animals. As you can see from the picture here, it was another pleasant sunset but we just missed getting a tag on at the very end of the day.

Around 20 different groups of beaked whales were sighted, in addition to a large number of the four other species we've been seeing regularly out here (pilot whales, and common, striped, and Risso's dolphins). While it is likely some of these were the same groups at different points in the day, or different combinations of groups (they do come together and break off from one another), with the distance we traveled it is likely we detected a dozen or so distinct individuals or groups. This confirms earlier evidence that this is an excellent place to find these elusive animals when the conditions are right and we have the capabilities that exist on this ship. However, despite the large number of sightings, it took many hours to find a good candidate group, as almost all those we found today (as yesterday) had one or more calves or were single individuals. In the late afternoon we found a good group of adult and sub-adult animals that we tracked for about four hours, both visually and acoustically through relatively shallow surface intervals and one deep foraging dive (after which we found them at the surface again). We vectored the tag boat during the subsequent surface intervals and we again came tantalizingly close (within a few feet) of tagging the animals before they slipped into the depths again.

We expect good conditions again tomorrow and will give it our all again. We will be trying some similar areas where we hope to be less likely to find so many groups with calves that we cannot work around. Despite it impacting our ability to work many of the groups here, the large number of calves is encouraging and we are learning some interesting things about the ecology and behavior of these poorly known animals in when and where we find groups with different social structure. It is remarkable how challenging these animals are to work with, even with the amazing amount of expertise and technology available to us, but we know this can be done and we should have another good chance tomorrow if the forecast holds true.

Wednesday, August 19, 2009

Calmer Seas -- Many Animals

Today dawned calmer with light seas and winds between just 5-10 knots for most of the day dropping to almost zero by late afternoon and evening. These are the conditions we need to reliably sight and tag beaked whales. Throughout the day we sighted many cetaceans, including hundreds of common, striped, and Risso's dolphins, pilot whales, and about 8-10 different groups of Cuvier's beaked whales. Both teams monitored the vast horizon and the cacophonous underwater acoustic scene these animals covered, trying to find the right situation. Several times our acoustic teams were hampered in extracting the beaked whale clicks from similar vocalizations from other nearby species. Also, almost all of the groups of beaked whales we found today either had small calves or were single individuals, which meant we could not work with them for different reasons. We did follow two different (we think!) groups of adult animals near the end of the day as good candidates, but despite the flat seas, visuals, acoustics, and tag boat in the water, they gave us the slip.

The figure you see here shows a bit of our track from today and gives you a sense of the relative movement of the animals and some of our tactics in using different sensing gear in monitoring their movement and behavior. The orange line shows the movement of the vessel starting at the southern edge of the plot (note the depth contours in meters along the track). The crosses with numbers 1-10 show different positions of a real-time, high-frequency GPS sonobuoy we dropped early in this encounter. These locations are over about four hours and if you noted the sonobuoy tracks from the blog several days ago you can appreciate the quite different current conditions we encountered today. The red triangles are sequential positions and headings of the focal group of beaked whales we were tracking. The triangles of other colors are sightings of other cetacean species and the little boat symbol is the position of our inflatable tag boat. As you can see, the animals increasingly tracked to the north and then the northeast (away from our first sonobuoy) and we monitored them from some distance, relying entirely on the visual team to track them since they are silent during the surface diving interval. When the group went for a deep (~1000m or more) dive after the last red triangles, we dropped our towed arrays back in the water and initiated a large circle around their position to monitor for their clicks. You can see some orange symbols along the Alliance track during this circle, showing that we successfully detected the animals with expected bearings during this period. This plot shows the complexity and integration of the visual and acoustic capabilities we have here, how they complement one another to enable us to monitor deep-diving animals in real-time, and the importance of real-time GIS visualization to guide our decision making in this challenging task.

The forecast for tomorrow and Friday is for excellent conditions such as we had today followed by possibly high winds over the weekend so we are all very much focused on the window the next few days looks to hopefully afford us.

Tuesday, August 18, 2009

Unscheduled Stop -- Bumpy Seas

Last night we ran an all-night passive acoustic survey on our way back toward the Spanish coast through the dark. We needed to make a brief, unplanned return to enable some medical assessments and crew-changes. Safety comes first and everyone is well and on the ship ready for action. Nevertheless, it took much of the day away from our efforts to tag beaked whales, though we did return into deep water in search of them by late afternoon. However, our return to what we believe (based on previous observations) to be good beaked whale habitat largely confirmed the earlier weather forecasts of conditions that would be unsuitable for sighting and tagging beaked whales; none were sighted or heard on the acoustic systems today.


Multiple dolphin groups were sighted, and at one point several large groups of dozens of common dolphins were swimming and socializing on all sides of our vessel. We weren't traveling fast enough for them to want to ride on the bow wave, but they streaked gracefully around and by us for 20 minutes. A group of Risso's dolphins was sighted just after dinner, but by about 2000 the wind and swell were at unworkable levels. Tomorrow we plan to work through a deep canyon where many previous sightings of beaked whales have been made. The forecast is for marginal conditions much of the day but calming in the area where we will be operating in the afternoon.

Monday, August 17, 2009

Beaked Whales Near Sunset

Our first full day on effort for the second leg dawned windier than hoped. Seas were light, but the 10-15 knot winds made things difficult for the visual teams who came on at first light. Acoustics had a large amount of dolphin activity again before dawn but did not pick up any beaked whales while scanning. We ran a slightly westerly track across promising areas for deep-diving whales in order to keep the glare from the rising sun from making things harder for the visual team. Despite our efforts, there was little action through the morning and mid-day other than some scattered groups of dolphins and our regular oceanographic and ambient noise measurements.

As has been the case for much of the project, however, the weather began to cooperate in the late afternoon and early evening. We came back through some canyon-like areas where beaked whales had been detected previously and found five different groups as the seas began to settle, in addition to several groups of common and Risso's dolphins. Here you can see a Cuvier's beaked whale "spyhopping" to have a look above the surface. Unfortunately we had several groups that were not good candidates for tagging attempts because of their group composition or how they were traveling. The two groups we attempted to tag stayed too far from the tag boats for us to attach acoustic tags before the setting sun ended our efforts for today.

The outlook for tomorrow is for even stronger winds (up to 20 knots) and moderate swell, which will prove very challenging if the forecast is correct. We continue our passive acoustic surveys at all possible times and will conduct these throughout the night tonight.

Sunday, August 16, 2009

Drills, Waves, and By-catch

Today was the first operational day of the second leg of MED -09. Some gear had been adjusted or repaired and new personnel were in certain key roles, so we began the day deploying and testing the hardware and software needed for the very challenging task of finding, following, tagging, and safely exposing beaked whales to sound. We remained vigilant throughout these drills for animals either seen or heard (and we did have some -- see below), but the weather was marginal with winds around 10-15 knots for most of the day and a light swell. So we did not feel we were missing perfect conditions in working through the drills deliberately, and with so many things that must go right here to succeed we require considerable precision in the sequence and timing of deployments.

After a successful test of one of the repaired passive listening systems that had been having some problems, we conducted a drill of deploying an array of real-time listening buoys (called "sonobuoys") we will use to monitor vocalizing whales once a focal group is tagged. One of our small boats delivered the sonobuoys in a grid while we deployed the sound source for controlled exposure experiments to a depth of 75 m (but did not turn it on). Meanwhile, our visual team practiced tracking a "whale" (which was actually our own tagging boat) and we tested our ability to safely maneuver for visual monitoring with both the listening gear and the source in the water. As you can see from the plot here, we dropped a total of four sonobuoys (labelled A-D) in a counter-clockwise fashion at a spacing of about 2.5 km. These listening devices have a relatively deep listening sensor and relay sound information using a radio signal back to the ship; with them we can monitor the area around focal whale groups during a controlled sound exposure. This figure shows one of the challenges we face here in the dynamic Alboran Sea, which is the affect of currents on free-floating buoys. Notice that various green symbols (starting from the north) moved consistently to the SSE over time (on average about 4.5 km in 2.5 hours). For instance, note the four green bulls-eye symbols furthest to the east labeled "Sonobuoy B" and the consistent drift (time noted for just this example). We know from the ship's sensors that there was a fairly strong current (almost 2 knots) in this direction, so this was not surprising to us. However, it demonstrates another challenge facing us in being able to not only read the position and behavior of the animals, but also the position and behavior of our monitoring gear in relation to the movement of the water (and other factors such as the wind and sun). Practice and drills are required to understand and manage such challenges, which was part of why we worked so carefully through it today. Ultimately we were very pleased with the timing of the operation and in our ability to monitor an area in which we and all our gear was being strongly moved in the active sea.

We continued to monitor acoustically and visually for marine mammals and did manage a number of detections in both modalities of several species. Some Cuvier's beaked whales were heard early in the day but not seen and then a total of five animals were sighted near sunset. Additional detections were made of other cetaceans, including Risso's dolphins, striped dolphins, and common dolphins, although no attempt was made to tag these animals.

Unfortunately, one of the common dolphins we located had been caught in a fishing net and was floating dead in the water. As you can see from the picture here, it had been killed relatively recently and the flukes (tail) and dorsal fin were severed, presumably by fishermen trying to remove the entangled animal without cutting their nets. We approached the carcass in one of the small boats to document the species (Delphinus delphis) and sex (female) and to obtain photo documentation and samples for genetic analysis. We also sighted an ocean sunfish floating dead and seemingly entangled and what may have also been a dead sea turtle as well. By-catch (the incidental killing of animals in fishing gear) is a serious problem for marine mammals around the world, including here in the western Mediterranean.

We hope for better weather and less morbid observations tomorrow and are primed and ready to accomplish our objectives if weather and animals will allow. Knock on wood, the forecast looks more promising.

Saturday, August 15, 2009

Port Call

The past two days we made our scheduled port call in Málaga, Spain for supplies and to transfer several of the scientific crew. Those on the first leg of the project were glad to stretch their legs ashore for a short time in between the bustle of debriefing those arriving to ensure consistency in protocols and data collection. It was a festive time in the city; our brief time there happened to coincide with the beginning of Feria de Málaga which is celebrated for nine days beginning on the Friday of the second half of August in honor of the merging of Málaga to the Castilian Crown due to the conquest by the Catholic Monarchs in 1487. This made for some minor challenges in getting people and gear to the port with the crowds, but all went according to schedule and we are now steaming back out to sea. The picture here shows our departure from this Spanish port city under a pleasant sunset.

Tonight we had an all-hands meeting to discuss plans for the second leg and review the protocols with everyone as a group. We have a good deal of consistency between the two legs, but do have some changes in personnel in key roles. Thus we wanted to make sure we were all on the same page with the many specific protocols for safety and data collection for our different operational modes. Additionally, we will conduct several practice drills tomorrow deploying gear and personnel in a mock run of a tagging and controlled exposure exercise. The sound source will be deployed for practice and timing, but not turned on during this drill. After this drill, we will switch to survey mode and begin searching for animals. The weather forecast is for marginal conditions, but improving over the next several days.

Thursday, August 13, 2009

Tantalizing

The forecast last night was for winds around 12 knots this morning, but it dawned very calm. The whales we stopped working with at 9 last night were near a main concentration of beaked whales seen last year. To get the best odds of being with whales this morning, we conducted an acoustic survey of much of last year's concentration from midnight to 0700 when there starts being enough light for the visual team to work. Unfortunately, there were so many dolphins that it was difficult to search for the subtle clicks of beaked whales among the cacaphony of sound that dolphins make in the Med when they are feeding at night. In fact, one of the sounds is called nacchere in Italian. This is the word for castanets. When striped dolphins are around at night, there is often a constant background of these sounds.

Because it was so hard to detect beaked whales acoustically last night, we positioned the ship where we last were with whales at 9 the night before. The dolphins were still active acoustically, but the observation conditions were excellent for the visual observers. As the morning went on, the sounds of the dolphins became quieter, making it possible to search for beaked whale clicks acoustically as well.

Just before 11 AM the visual observers sighted beaked whales, and as before, several groups were sighted relatively quickly in the same general area. As before on this cruise, there seem to be clusters of groups of animals. The observers first settled on a group of 4 adult whales, 2 males (which can easily be identified by the white coloration of the front of their bodies), and 2 females.

The tag boat was deployed just before 1140. The best opportunity to tag this group came when the tag boat was within about 100 m of a surfacing, the perfect distance, but as the tag boat moved over, a group of dolphins swam over to the beaked whales and swam around them. Apparently, they were bothering the whales, as one of the beaked whale breached right among them. After the dolphin incident, the behavior of the whales changed. They changed their direction of travel and this prevented the tag boat from completing its approach.

At 1343, the visual observers switched to follow a group with two females and one male that was with a dorsal fin that was curled over to the side. This marking made it easier to make sure we were on the same group. In addition, this group seemed to keep surfacing in pretty much the same area, making it easier to position the tag boat.
After the observers switched to the group of three, the white male surfaced and blew normally, and then swam for about ten minutes just several meters below the sea surface. It was quite easy from the ship to observe the white shape of the male continuously, and the visual observers directed the tag boat close enough that they were able to follow him underwater even from their lower vantage point. They tailed long behind him until he and the females surfaced. Even though they were quite close, the beaked whales were travelling, and at this speed it was hard for the small tag boat to close on them for tagging.

In the end we were able to follow the same group of 3 beaked whales from surfacing to surfacing over a period of 5 hours. This leads to what probably are the craziest tracks that the Alliance has ever made. It is a tribute to the bridge officers that they are able to position such a large ship so well for following whales. The ability to make these kinds of observations is remarkable for a species that is so cryptic that new species of these large mammals are regularly discovered each decade. The coordination with the tag boat was excellent, and they had several good opportunities for tagging, but in the end we just were not able to close to a few meters distance for tagging. This is the reality with tagging beaked whales. There are a series of steps, each of which takes time, skill, and the appropriate equipment. It just takes a reasonable number of attempts even in the best of conditions to succeed in getting all steps done in time.

This was the last day of tagging effort before a partial change of crew tomorrow. We had to stop an hour before sunset and recover the tag boat. The entire team had a barbecue out in the middle of the study area as the sun went down before we head into port.

Everyone who is leaving wishes the second phase of the cruise fair seas and best of luck with tagging.

Wednesday, August 12, 2009

the mystery clicks

Today dawned calmer than predicted. In our efforts to find workable seas over the past few days, we have moved out of the area surveyed for whales last year. This morning we started heading back to the hot spots in the areas surveyed last year and during the earlier parts of this cruise, listening and watching for whales, with a course that we hoped would cover favorable habitat for beaked whales. Many who study the distribution of beaked whales have noticed that not only do beaked whales favor areas where the bottom is 1000m deep, they also seem to congregate in submarine canyons or seamounts. Our course took us in deep water past several sea mounts. In the early afternoon, the acoustic monitors started picking up faint clicks like those of beaked whales in the direction of the seamount where beaked whales had been detected on a survey track last year. When they noticed that there appeared to be several whales clicking at the same time, we diverted the ship to the area, pulled up the hydrophones for maneuverability, and maneuvered the ship for optimal sighting of where the clicks were detected. The sighting conditions were excellent, yet the observers did not sight any beaked whales at all. Beaked whales can dive for more than an hour, but in a concentration, some whales should certainly have surfaced at that time. In deciding whether to continue to wait or to move on, we noticed that our depth was shallower than optimal for beaked whales. We therefore decided to move directly into deeper water where concentrations of whales were sighted last year. As we reached this area, around 6:30 PM, the visual observers sighted several groups of beaked whales and the acoustic team heard clicks from at least one foraging dive. We approached toward the groups, recovered the hydrophone arrays for maneuverability, and once we got close, we deployed the tagging boat. For some reason on this cruise, the tag boat keeps getting deployed late in the day even though we start at sunrise! The visual team noticed calves in several of the groups and was able to position the tag boat near surfacings of a group that did not have a calf in it. However, we were not able to get the tag boat close enough to attempt to tag before the whales appear to have made a deep foraging dive. The daylight did not hold out for us to be able to follow the whales and attempt tagging later.

Today’s efforts reinforce again how difficult it is to tag a beaked whale. You have to find animals, select a promising group, get an idea of their behavior and movement patterns and get a small boat within a few hundred meters of a group of whales coming up from a 15+ minute dive, when the whales could move more than a few hundred meters.

Tuesday, August 11, 2009

Not so much wind, but waves remain


After the winds of yesterday, it was a relief today to have winds mostly around 10 knots or less. But swells and waves remained from yesterday, creating difficulties for the visual observers. The acoustic monitoring worked well, and we set a course outside of our normal survey tracks in order to get the best weather conditions we could find for beaked whales. Twice during the day, acoustics got good enough detections to direct the ship nearby the whales, get a bearing, and orient the ship for optimal location for the visual observers to monitor the location where the whales were heard. Both times the visual observers were able to sight whales even though the visibility conditions were marginal. Unfortunately, the conditions were too rough to attempt tagging. We considered using a large workboat from the ship for tagging, but even then the conditions were not good enough.

The tag team kept itself busy analyzing data from one of the tagged pilot whales from earlier in the cruise. The dive profile shows that this whale spent most of its time near the surface in the top 15 m, but it did make one deep dive to nearly 650 m that lasted 11 min. Even though we had great observation conditions of the pilot whales, none of the visual observers had any idea that the whale had made this dive. The whale made echolocation clicks starting at the red asterisk and ending at the green asterisk. The black asterisks in between mark times that the whale accelerated the clicks, which we think means that she had identified a prey item she wanted, and she attempted to capture it. The recordings from the surface also include lots of social calling. All in all, a fascinating glimpse into a few hours in the life of these whales.

» Listen to Pilot Whale Call 1
Social calls of pilot whales as recorded by the Dtag. The image to the right shows the spectrogram (visual representation) of the call.

» Listen to Pilot Whale Call 2
Social calls of pilot whales as recorded by the Dtag. The image to the right shows the spectrogram (visual representation) of the call.

Monday, August 10, 2009

Wind and waves

Today dawned with OK weather but a forecast for increasing winds. We had positioned the ship to an area where beaked whales had been detected and weather was forecast to be best, but we did not encounter workable weather nor beaked whales. The wind increased so much that the visual team had to come down from the flying bridge in the mid-morning, and reached above 30 knots during the afternoon. The acoustic monitors could continue listening, although wave noise made it a little harder to detect signals. The rest of the teams went over data from the earlier parts of the cruise. The seas will be up, and the forecast is for continued winds, but we are hoping for enough of a window to try to tag in the next 2 days.

It must be the start of the southward migration season for european birds. We have regularly been seeing hawks from the ship. Today a hoopoe landed on the railing of a crane for awhile to rest before resuming its flight. I am afraid that the Roman augurs thought that hoopoes could detect changes in the atmosphere and that they heralded storms.... We are relying on the best meteorological data our computers deliver us, and we hope for better auguries.

Sunday, August 9, 2009

Working to tag beaked whales

Last night we set a track line for today designed to get a combination of the best weather suggested by our forecasts and the best beaked whale habitat. This morning there were low waves and whitecaps -- marginal for sighting and tracking beaked whales, but possible. We were hearing pilot and beaked whales near sunrise. We were not able to sight the beaked whales we heard, but we did sight pilot whales by 9:30. We decided to continue to try for beaked whales as they are our top priority for tagging.

The weather did not cooperate with us through most of the day, and the wind came up in the middle of the day. However, at 6 PM, the wind had changed direction and the seas lay down quickly.

The visual observers sighted beaked whales and we directed the ship to head towards the whales. Within half an hour the acoustics team picked up beaked whale clicks, probably from a different group, as the sighted whales were still making shallow dives. Right in this area, we sighted several different groups of beaked whales in a relatively short time, and hauled in the hydrophone arrays to get better mobility of the ship.

We selected a group of 3 beaked whales with no calves and with a male with a well marked dorsal fin to be the focal group we would try to tag. We prepared the tagging boat to be ready to deploy and maneuvered the ship towards the whales, which surfaced just a few hundred meters from the ship. We then slowed down the ship and were able to deploy the tag boat close to the whales, which were doing shallow dives.

For the next two hours until sunset, the weather and visibility conditions remained excellent, and the visual team used a plot of the times and locations of this group's surfacings to direct the tag boat to get as near as possible to where they thought the whales would surface. The plot comes from the GIS system that integrates all of the different kinds of data logged during the project, a real advance over earlier ways to store and display data from this kind of cruise. The key is to direct the tag boat to get within a few hundred meters of where the whales surface after a dive, so that the tag boat has time to maneuver to the whales with enough time to get close enough on a slow, quiet approach, to tag them. The tag boat did get within 20 m, but unfortunately, we ran out of daylight before we were able to tag them. The entire sequence from sighting, to acoustic detections, to maneuvering the ship and then the tag boat were as good as it gets!

It was great for the morale of the team to see how well our training has paid off. We just need more time with animals and good weather!

Saturday, August 8, 2009

A day in the work of tagging a beaked whale


The equipment and training that the teams on the Alliance have been doing are all dedicated to the difficult task of tagging beaked whales. The species we are working on in the Mediterranean Sea is Cuvier's beaked whale, Ziphius cavirostris. Today pretty much everyone on the ship was focused on this job all day.

The ideal weather for tagging a beaked whale is flat calm. Calm weather makes it easier to sight these hard-to-see animals when they surface for a series of blows lasting about 8 minutes. After a deep foraging dive that will typically last about an hour, they do a series of shallow dives each of which lasts for about 15 minutes or so. This means that the observers have to wait about an hour for their opportunity to sight whales when there is a deep foraging dive, but the duration of shallow dives is short enough that this provides the beset opportunity to tag. This means that it is critical for the research vessel to get near enough to the whales during the deep foraging dive that it can direct the tag boat near the whales during the first surfacings after shallow dives.

This morning there were light swells and light whitecaps from wind, which makes sighting beaked whales more difficult, but still possible with the excellent height of eye on this ship and with the powerful bigeye binoculars used by trained observers who know the cues that indicate a beaked whale sighting. The acoustic monitors have no problem hearing beaked whale clicks in these conditions. During the morning we detected several groups of beaked whales but they had small calves, which made them not good candidates for tagging efforts.

We continued the search throughout the day, with the teams rotating through a watch schedule to maintain high levels of attention for a difficult task. Looking for beaked whales, you need to scan the water systematically, looking for a cryptic surfacing. Unlike baleen or sperm whales, the blow is not very visible, and the beaked whale usually surfaces quickly and goes down again, meaning you have to be very attentive to see the surfacing and be able to recognize the species. Similarly for acoustics, when you are far from a beaked whale, all you will hear is a scan of several clicks as the whale’s sonar beam passes the hydrophone. This means that if the monitors take their gaze away from the computer screen for more than 10 seconds, they may miss the cue.

We continued to survey, focusing all of our efforts on detecting the beaked whales. At 5 in the afternoon, the visual team detected a group of 3-4 Ziphius at the surface with no young calf. These initial sightings are marked with a yellow triangle to the right of the figure, and are marked H and I. We left the survey line and headed towards this group. Within about 10 minutes after the whales dove, the acoustic monitors started to pick up beaked whale clicks in the direction of the group. A few minutes later as we approached closer, the acoustic monitors started hearing relatively constant series of clicks with the 0.4 sec interval between clicks that is typical of beaked whales. This meant that we were close enough to hear the clicks even when the whale was not pointing at the hydrophone. The two straight yellow lines on the plot here give acoustic bearings to the sounds of these whales at two different times. Where they intersect indicates an estimate for the location of the whales.

The ship was maneuvered to stay close enough to continue to pick up these clicks until they petered out about 20 minutes later. At this point, the ship was maneuvered to the west so that the visual observers could look away from the glare of the sun, and then was repositioned so the observers, who must orient towards the bow of the ship, had a clear view of where they expected the whales to come up. There was a strong current to the east, which caused the ship to move east. It typically takes about 20 minutes for whales to ascend to the surface after they stop clicking. The visual observers did not sight the whales for about 45 minutes after the stop of clicking, so they probably missed the first surfacing. Over this interval, the ship moved farther east than was ideal for observing the area where we expected the whales to come up. The next sighting is the one marked J1-J3 in the center of the plot, just to the left of the orange line indicating our survey track. As soon as that sighting was made, the ship could move closer and reposition.

This is the critical point to get the information required to place the tag boat near where the whales will next come up on one of their shorter dives. While one surfacing tells us where the whales are, we need a second surfacing to get an idea of their direction of travel. We prepared the tag boat for deployment, waited until the group was next sighted 19 minutes later, and deployed the tag boat 6 minutes later. For the next two hours, the visual team radioed the tag boat to position it near their estimates of where the whales would surface, then to direct it towards the whales as soon as they surfaced. Even though the tag boat was closer to the whales, the elevated platform and excellent optics of the visual team usually allowed them to sight the whales first. The whales usually only spend around 8 minutes at the surface, so the tag boat does not have long to approach the whales. We use a small quiet vessel for the tag boat and move slowly so as not to disturb the whales, so the tag boat needs to be within a few hundred meters of the whales when they surface in order to have a chance to tag.

One complication with our tagging attempt today, was that the whales, which had been moving consistently WSW the entire time until the sightings marked J13-J14, suddenly switched direction, surfacing to the E in surfacings J16 and J17, then off to the NE for the final two surfacings. While the tag boat could see the whales, they did not get close enough for any opportunities to tag before sunset and we recovered the tag boat a little after 9 PM.

The equipment and teams are intensely focused on tagging and are operating at a high level. Even so, beaked whales are so difficult, that our previous experience suggests that it will take days of these efforts to succeed in tagging a whale. We just need to keep doing what I have described here.

Friday, August 7, 2009

Tagging Pilot Whales

Today was predicted to have moderate winds. At first light, it was clear that it would be too windy to try to find and tag beaked whales, so we decided to work with pilot whales. As luck would have it, we heard distinctive sounds of pilot whales by 0700 and sighted them by 0800. One of the unusual things about pilot whales in this part of the Mediterranean is that they seem fascinated by ships. These whales came right over to the Alliance and inspected it, then swam along surfing in the wind-driven waves, following the ship for some time. We deployed the tag boat, which took photographs to identify individual animals, and attached tags to two adult female pilot whales. Unlike beaked whales, which are extremely difficult to find and approach for tagging, pilot whales are quite easy to follow and approach. In fact these whales approached the tag boat and the first whale was tagged within five minutes of the tag being readied for attachment. The tags attach to the smooth skin of the whales with four suction cups, and are attached using a long carbon fiber pole that you can see lashed to the port side of the orange tag boat. The whales showed little reaction, continuing to swim near the ship. The pilot whales form sub-groups that are usually well defined, although the subgroups will merge and separate at times. Adult males can be distinguished from adult females, and many females in these groups had calves, including neonates so young that fetal creases were visible. Under the conditions of our research permit, we did not conduct a sound playback with these groups, but we collected fascinating baseline data with bouts of complex vocalizations alternating with periods of silence. We tracked the tagged whale for more than six hours. After the tag released from the whale, it floated to the surface and broadcast a radio signal that we can use to recover the tag. Once the tag is recovered, we connect it to a computer and download the data before we can explore it.

Thursday, August 6, 2009

Listening to beaked whales

Beaked whales are very difficult to sight at sea. Their blows are seldom visible, they can hold their breath on a dive for 1 - 1.5 hours, and when they do surface it is for a short time. When beaked whales were first tagged with acoustic recording tags in early part of this decade, we learned that they make deep dives to almost 2 km deep, over one mile below the sea surface to feed on deep prey. Once they reach a depth of a few hundred meters, they start to produce echolocation clicks that are so high in frequency that they are barely audible to our ears. These clicks are short upsweeps that are different from the sounds of any other marine animals, so when we hear their clicks, we can know their is a beaked whale around. The whale directs most of the sound energy forward, like a flashlight beam, but some of the energy goes in all directions. When you are several kilometers from a clicking beaked whale, when the whale sweeps its beam past the hydrophone, the phone detects several clicks getting louder as the beam points towards the phone and then fainter as the beam points away. The photos show the hydrophones, or underwater microphones, that CIBRA from the University of Pavia provided for this project. They are designed to be towed from the ship.

In the past few years, scientists have learned to tow hydrophones and use these short scans to detect beaked whales on surveys. But Med09 needs to be able to listen to most of the clicks from when a whale starts clicking to when it stops. The Pavia towed hydrophone system uses 4 hydrophones that can tell us whether the whales are forward or behind us, left or right, so we can steer towards them. Today was the day that we used this ability to follow beaked whales during a dive and to link sightings with acoustic detections. Once we heard faint scans from a group of beaked whales, we approached it and started circling the group. Once the clicks stopped, we notified the visual observers to get ready for the whales to surface. The observers then sighted a group of whales where we expected them to come up, and we picked up clicks on the next dive. By circling the whales with a radius of about 500 m, we were able to hear clicks more or less continuously until the whales stopped to surface again. This capability was an important part of our study design, so we were very happy to show how well it could be achieved with the towed hydrophones.

The weather conditions were ok but not excellent for tagging. We put the tag boat out twice to follow and attempt to tag beaked whales, but the taggers were not able to approach whales close enough to do so. Tagging beaked whales requires a small boat being able to approach to within about 12 feet to attach the tag using a pole. We are hoping for better luck tomorrow.

Wednesday, August 5, 2009

Entangled whale

This morning the sea conditions were not perfect but were OK for sighting. We listened and looked for whales, picking up lots of animals as we near our primary study site. This afternoon the visual observers sighted a Cuvier's beaked whale, Ziphius cavirostris, and noticed that she was logging at the surface in an unusual way. This whale was entangled in a fishing net, with two cuts on her side. Her skin was abraded by the net and looked white on the top of her back. We sent out our small inflatable boat to approach the whale, which came over and actually rubbed on the side of the boat for a short time before sinking down very slowly in an unusual dive behavior. The crew on the tag boat tried to slowly approach the whale to attempt to cut free some of the net line loose, but they were unable to approach closely enough to help the whale. We have alerted Spanish marine mammal experts about her location and condition.

Globally, hundreds of thousands of marine mammals entangle in fishing gear each year, and many of them die slow painful deaths. We were unable to free this whale, which was very disappointing for the team. We hope that humans can change their behavior to reduce the risk of entanglement for marine mammals.

4 August Transit

Today we transit towards the Alboran Sea. This provides a time to talk about one of the most important parts of any ship -- the galley. The Italian cooks on the Alliance make sure that the crew eats at a level that is sure to keep up morale. Breakfast always has fresh focaccia and plenty of espresso. Lunch and dinner have antipasti, primi, secondi, dolci and caffe. I do not know how they keep bringing out such fresh vegetables and fruits so long from port, but the produce is fresh and wonderful. The photo on the top right shows the ship's crew making wooden cylinders for making cannoli. We'll report on the results when we taste them! It is hard to overemphasize how much the dedication and skill of the galley crew contribute to the morale of a ship. Complimenti!

Here is today's menu

Pranzo
Antipasto involtini di prosciutto cotto
Riso al curry
Minestrone vegetale
Trance di pesce in cartoccio
Polpette di zia caterina
Patate prezzemolate
Fagiolini lessi
Insalata
Frutta fresca/caffe'

Cena
Pasta e Ceci
Crema di cipolle
Costatine di agnello alla greca
Parmiggiana di melanzana
Crocchette fritte
Finocchi lessi
Insalata
Frutta fresca/caffe'
Gelato

Tuesday, August 4, 2009

3 August 09 Survey

This morning dawned unusually cloudy for this time of year. It was calm enough for the visual observers to work, but they needed to bundle up to stay warm. The wind came up by the afternoon, making it difficult to sight whales, but the acoustic monitors kept listening. At the same time, the engineers on the ship were working on troubleshooting one of the systems designed to measure the bearing to echolocating beaked whales.

At this point we have done 4 legs of the survey designed for the Balearic Sea with very few detections of marine mammals other than dolphins. There appears to be a much lower rate of detecting deep divers than in the Alboran Sea, so we have decided to transit to the Alboran Sea. On the transit we passed near Mallorca as the moon rose.

Sunday, August 2, 2009

Survey 2

Even though wind was forecast, the weather remained good for visual survey through the morning and into the early afternoon. The visual team got a good workout on the data logging program and GIS displays, but did not see any beaked whales nor many dolphins. Nor did the acoustic team hear them. We will continue to survey in this area for one more day as weather in the Alboran Sea looks like it will be windy by the time we get there, but we anticipate transiting before too long.

Saturday, August 1, 2009

Start survey

Today the teams and equipment were ready to start surveying for whales. The ship is towing hydrophones that allow the acoustic team to monitor for whale sounds while visual observers watch from the flying bridge. As you can see from the picture, the acoustic monitors spend all day inside the main scientific lab monitoring computer screens and listening, while tomorrow you will see that the observers spend all day outside watching for whales with special binoculars. The visual observers saw (and acoustic monitors heard) lots of dolphins today. The acoustic monitors heard one group of a few Cuvier's beaked whales, but the wind was up for a brief period during that time and the observers did not see any. The tagging team is champing at the bit!