BDRI researchers have been collecting acoustical data for the past three years. Now, it is time to analyze the whistles that have been recorded. For this step of bioacoustics, we began going through all the days with whistles and entering the data into a new notebook. The course notebooks are used as references for the sighting information.

March 4, Tuesday

This morning we went to sea on a fishery boat. Unfortunately, the weather was not ideal for data collection. We did have a sighting early on, a brief 25 minutes of intermittent dolphin observation. Then the wind picked up and conditions deteriorated. The highest winds we clocked measured 20.8 m/s. Needless to say, the afternoon was spent in the lab.

March 5, Wednesday

The weather conditions have not improved, so we worked on the whistle collection in the lab again. We counted whistles and recorded acoustical data in the new notebook.

March 6, Thursday

Today we continued with the whistle project since a strong storm lingered over Golfo Aranci all day. Since last night, the rain continued on and off. In the lab, we counted and recorded seconds, minutes and whistles. Occasionally, we listened to recordings to detect more whistles that had not been located.  

March 7, Friday

This morning’s lab work included photo ID and whistle collection. Since the weather improved overnight and held out during the morning, we went to sea in the afternoon.

The sea was still amazingly calm, especially compared to yesterday when even the trawlers didn’t go out. Visibility improved as well. With such great conditions, we had 3 great, continuous sightings.

March 8, Saturday

Since the mechanic is coming tomorrow morning, we did our house cleaning today. After lunch we all went on a field trip to the other coast to the tide pools. Rock climbing and collecting species, we lost track of time. Eventually, we did make it make to the base house for some lab work – more whistle detection and recording.

March 9, Sunday

We met the Oblia mechanic at the harbor this morning to go on a trial run of the Spartana. After working on the boats until lunch, we had free time the rest of the day.

Monday: 

The total of this day was focused in the lab, in the morning and afternoon with a break at midday.  The weather was too windy for surveys.  Lab work consisted of Bioacoustics, and photo ID with Andrea.  Stephanie and I would switch between looking for whistles and recording the identity of dolphins per photo with Andrea.  We continued to try and learn the various falcate dorsal fin characteristics to help ID the dolphins captured on film in 2007.  Some of the nicks and marks are similar and we used their complied Catalog of 2005 and 2006 to help learn the different dolphins.  Bruno and the mechanic were working on the Spartana to get it ready for surveys. 

Tuesday: 

Today was basically a repeat of Monday, the only differences being what we did in our free time, and what we had for lunch and dinner.

Wednesday: 

Today we got to go to sea for a new course from a Fish Farm Boat.  Solitary dolphins did arrive at the fish farm while we were there.  Stephanie recorded behavioral data while I collected survey information, and Andrea and Bruno directed our recordings for accuracy and to help us learn the trade.  We came back for lunch and then did lab work in the afternoon transcribing data and continuing the work of Monday and Tuesday.

Thursday:

Today was a lot like yesterday, except I made the coffee for breakfast.  We went out in the morning on a Fish Farm Boat.  Unfortunately, it was cold and windy both days, but I enjoy the fieldwork of searching for dolphins and recording their behavioral data.  I also like any chance I can to see Italy and Golfo Aranci.  We went in for lunch and then had free time to see more of Golfo Aranci and catch-up with people at home.  Then we worked in the lab in the afternoon to finish the day.

Friday:

The important thing to note today was that a Mouflon fell off the mountain and broke it’s jaw.  It was found wandering the streets and is currently enjoying the local rehabilitation center, lucky mouflon.  Ok, back to the work at the BDRI.  Stephanie and myself drew the dorsal fin characteristics for seven frequently seen dolphins in the Golfo Aranci area today.  We drew fins in order to help us recognize individual dolphins for Photo ID and (eventually) in the field.  Then after lunch we worked with bioacoustics and finished with Photo ID work.

Saturday:

Again the morning consisted of Stephanie and myself drawing 16 more frequently seen dolphins of Golfo Aranci including new dolphins seen once or up to 8 times.  We finished our drawings after lunch, and then were tested on the accuracy of our drawings by being given 60 photos to ID.  It was rather fun to test our drawings with past photos.  Stephanie and I both ID all 60 photos accurately which was very rewarding.

Sunday:

In the morning we did in house cleaning (switching from the jobs we did last week) and free day.  Bruno and Andrea worked on the Spartana, while Stephanie and I mainly caught up with our journals and our families.  It was a beautiful warm day without a lot of wind and hardly any clouds in the sky. 

All in all it was a wonderful week at the BRDI to learn the vocation of wild dolphin research in the beautiful Mediterranean Sea.

04/02/2008

This morning we went out early on a fishery boat to observe dolphins around the fish farm. As during every course, we took environmental surveys every 20 minutes. The first sighting was early – a solitary male hunting around the nets and anchoring ropes. The day was mostly scanning the water and taking measurements – wind speed and direction, lat/long, depth, visibility, sea conditions, number of boats and what types and what types of nets in the water, etc. Back at the base in the afternoon, we transcribed all the environmental and sighting data for the day. Later, the data will be taken from the transcription notebook and entered into the database.

05/02/2008

A brisk morning walk to the market proved that the wind was too strong to go out to sea. Instead, we worked on transcription in the lab. There is a lot of transcribed data that needs to be put into the database, plus photo ID to be done and acoustic recordings to be analyzed.

 06/02/2008

Since yesterday’s programme was canceled due to wind, we adopted it today. This morning called for more database entry and acoustics interpretation. To go out to sea this afternoon, we planned on taking the smaller boat. Once we got to the harbor, it was discovered that a support post on the motor had broken, rendering it useless. So we jumped aboard a fishery boat for a free ride to the fish farm. We watched for dolphins over the cling-cling-cling and plop-plop-plop of the food pellets falling into the dispenser, then being rocketed through the air into the fish cages. No dolphins today – too windy (4 on the Douglas scale). Back at the harbor, we stopped to talk to a local fisherman. Bruno lent him 2 pingers, in return for which Bruno got a bag full of today’s catch – connari. After an afternoon of transcription, these little fish became our dinner.

07/02/2008

Last fall, the institute bought the Spartana, 32-year old wooden boat that wasn’t maintained properly. So they have taken on the project of restoring it after having it inspected. Instead of lab work this morning, we worked on the boat repairs. The town mechanic gave it a clean bill of health last week. Unfortunately, everything in the interior was removed – like hooks and hatch covers and ceiling panels. The work is almost completed, but pieces still need to be reattached and their electronics installed. After lunch, we continued with the transcription in the lab.

08/02/2008

The winds grew stronger overnight. The fishery boats still went out, so we climbed aboard and held on. The strongest winds measured blew at 92 m/s, versus the usual 5-10 m/s. Everything had to be held down, which made data collection difficult. But the dolphins were out nonetheless! We heard their whistles as they were bow riding below us. We tracked 5 dolphins all morning. The wind brought us back to port before 10. We stopped at the Spartana for more repairs and enhancements. Tonight, data transcription.

09/02/2008

More Spartana fix-up!

04/02/2008

This morning we went out early on a fishery boat to observe dolphins around the fish farm. As during every course, we took environmental surveys every 20 minutes. The first sighting was early – a solitary male hunting around the nets and anchoring ropes. The day was mostly scanning the water and taking measurements – wind speed and direction, lat/long, depth, visibility, sea conditions, number of boats and what types and what types of nets in the water, etc. Back at the base in the afternoon, we transcribed all the environmental and sighting data for the day. Later, the data will be taken from the transcription notebook and entered into the database.

05/02/2008

A brisk morning walk to the market proved that the wind was too strong to go out to sea. Instead, we worked on transcription in the lab. There is a lot of transcribed data that needs to be put into the database, plus photo ID to be done and acoustic recordings to be analyzed.

 06/02/2008

Since yesterday’s programme was canceled due to wind, we adopted it today. This morning called for more database entry and acoustics interpretation. To go out to sea this afternoon, we planned on taking the smaller boat. Once we got to the harbor, it was discovered that a support post on the motor had broken, rendering it useless. So we jumped aboard a fishery boat for a free ride to the fish farm. We watched for dolphins over the cling-cling-cling and plop-plop-plop of the food pellets falling into the dispenser, then being rocketed through the air into the fish cages. No dolphins today – too windy (4 on the Douglas scale). Back at the harbor, we stopped to talk to a local fisherman. Bruno lent him 2 pingers, in return for which Bruno got a bag full of today’s catch – connari. After an afternoon of transcription, these little fish became our dinner.

07/02/2008

Last fall, the institute bought the Spartana, 32-year old wooden boat that wasn’t maintained properly. So they have taken on the project of restoring it after having it inspected. Instead of lab work this morning, we worked on the boat repairs. The town mechanic gave it a clean bill of health last week. Unfortunately, everything in the interior was removed – like hooks and hatch covers and ceiling panels. The work is almost completed, but pieces still need to be reattached and their electronics installed. After lunch, we continued with the transcription in the lab.

08/02/2008

The winds grew stronger overnight. The fishery boats still went out, so we climbed aboard and held on. The strongest winds measured blew at 92 m/s, versus the usual 5-10 m/s. Everything had to be held down, which made data collection difficult. But the dolphins were out nonetheless! We heard their whistles as they were bow riding below us. We tracked 5 dolphins all morning. The wind brought us back to port before 10. We stopped at the Spartana for more repairs and enhancements. Tonight, data transcription.

09/02/2008

More Spartana fix-up!

Day 1: Completed my first survey with Bruno, Andrea and Francesca at the Aranci Bay. We were in luck, the weather was beautiful (for winter, 20ºC and no wind) and we spotted seven dolphins after about 5 min on the opposite side of a marine fin fish farm then we tied up on. They were searching for food and we followed them though their countless circling searching behavior. When they found fish we knew it, speed increased and we sometimes witnessed jumps, fast surface, and flukes up. We studied them for many hours to and from the fish farm and open water. Several times they partnered up two, two, and three, and once two and five. After many hours they two by two by three headed away from the Fish Farm, back from whence they came, and we headed in for a much-needed lunch.

Day 2: Today we were not so lucky, upon reaching the Fish Farm we stayed for many hours without a dolphin in sight. Soon we called it a day after gathering several hours of environmental data, including accurate temperature, mV, pH, and Secchi disk readings. After returning to the Institute Francesca and I were taught the intricacies of transferring field data to notebooks for later transfer to the computer database.

Day 3: This day we were grounded from going out because of the wind. When it is too windy (Douglas 4 or more) we do not go out to study the dolphins because the waves decrease our observation quality. So today the four of us continued data transcription of the previous days as well as past years into the notebooks and database. Also, we took the opportunity to fix-up the Spartian for future surveys.

Day 4: The weather cleared up enough for us to get to the fish farm and find the dolphins (three) already at work feeding amongst the cages. We were able to gather about 2 to 3 hours worth of data before increasing wind drove us back to the harbor, and more data transcription.

Day 5: Again the wind prevented us from heading out and so we transcribed data and worked on the Spartana. One thing I learned this week is that I did not pack enough warm cloths and blankets, so I layered, layered, layered. Francesca and myself continued to increase our knowledge of current research on Bottlenosed Dolphins from research papers, and I continued to try and understand Italian. Day 6: Francesca left today at midmorning after completing her week of study at the BDRI, and we gained another intern, Stephanie who is from Florida and will be here for three months. We will be heading out tomorrow on a Fish Farm boat, if weather permits. Day 7: Today Bruno, Stephanie, Andrea and myself cleaned the BDRI then went to the harbor to talk to the fishermen and work on the Spartana. Then the rest of the day was for personal projects and some data transcription.

Felíz Navidad y próspero Año Nuevo 2008!

Buon Natale e Felice Anno Nuovo 2008!

today is an important day for us. The following paper was published in the prestigious  journal: Behavioral Ecology and Sociobiology. This journal publishes articles dealing with quantitative empirical and theoretical studies in the analysis of animal behavior on the level of the individual, population and community. The level of this journal is showed by the high impact factor 2.316 (2006).

Marine aquaculture and bottlenose dolphins’ (Tursiops truncatus) social structure

Bruno Díaz López & J.Andrea Bernal Shirai

Abstract:

In this study, we investigate association patterns of 249 bottlenose dolphin feeding groups off Sardinia Island (Italy) from January 2000–May 2007 and describe how their association behaviour is related to their response to food patches created by a marine fin fish farm. We also tested the hypothesis that dolphins have different social structures with different feeding activities: Associations should decrease during opportunistic feeding behaviours as it is easier to capture prey, and cooperation is not as necessary. Sixteen individually identified bottlenose dolphins were observed participating in both opportunistic and not opportunistic feeding activities, with a mean of 30 ± 8 times and 9.6 ± 1 times, respectively. Bottlenose dolphins show non-random social behaviour during feeding and this behaviour differs depending on their specific foraging activity. Dolphin associations during feeding can be divided into three categories: acquaintances, affiliates, and feeding associates. Association behaviour during fish farm feeding is consistent with our hypothesis that during opportunistic behaviours, benefits from cooperation decrease, as it is easier to capture prey. Group size homogeneity in both feeding activities demonstrates that the number of dolphins engaging in foraging is not necessarily related with cooperation levels. Moreover, an adult dolphin may prefer to associate with a specific individual, independent of the sex, who shares the same foraging priorities. This study is the first to show how aquaculture is not only directly affecting marine predators but could also indirectly affect their social structure and behaviour.