Cetacean density and abundance in the Central and Western Mediterranean Sea

Another freshly accepted paper in the Deep Sea Research Part II Special Issue on European Marine Megafauna. It is currently available online at the link provided below. Enjoy reading. 

Panigada S., Lauriano G., Donovan G. P., Pierantonio N., Cañadas A., Vasquez J. A., Burton L. 2017. Estimating cetacean density and abundance in the Central and Western Mediterranean Sea through aerial surveys: implications for management. Deep Sea Research Part II: Topical Studies in Oceanography. DOI: 10.1016/j.dsr2.2017.04.018


Review of migratory patterns and strategies of Mediterranean marine mammals

The following review has just recently made available by the Mediterranean Science Commission (CIESM) as a chapter in the latest monograph series “Marine connectivity – migrations and larval dispersal“. The volume presents  current research on connectivity, from larval and egg dispersal models to tracking large migratory species.

Panigada, S., Pierantonio, N., 2016. Migratory patterns and strategies of Mediterranean marine mammals and relation to intersystem connectivity, in: Briand, F. (Ed.), Marine Connectivity – Migration and Larval Dispersal, CIESM Workshop Monographs 48. CIESM Publisher, pp. 95–104. (PDF)

It’s too loud in the Mediterranean: scientists present the first underwater noise map

Reblogged from the Tethys Research Institute website.


Human activities using loud noise sources cover very big portions of the Mediterranean Sea, as announced in a special press release by OceanCare. Their impacts on marine wildlife should be cause of concern; in several clearly identifiable areas noise-producing activities accumulate, and many of these so-called noise hotspots overlap with important cetacean habitats. This is a conclusion reached by scientists from France, Italy, Switzerland and the US who – for the first time – present a basin-wide map that shows the density of the main anthropogenic noise sources in the Mediterranean Sea. The results of the report ”Overview of the Noise Hotspots in the ACCOBAMS Area, Part I – Mediterranean Sea” for the period 2005 to 2015, are drawn from a dataset covering 1446 harbours and marinas, 228 oil drilling platforms, 830 seismic exploration activities, 7 million ship positions, publicly available information regarding military activities, and 52 wind farm projects.noise

 The increase in seismic activities is particularly striking, especially in connection with oil and gas explorations which deploy so-called ‘airguns’ sending loud impulsive noise of up to 260 decibels towards the sea floor about every 10 to 12 seconds for weeks or months at a time. While 3.8 % of the Mediterranean’s surface was affected by such airgun use in 2005, this share increased to 27 % in 2013. The scientists also found that an average value of around 1,500 commercial vessels are contemporarily present in the area – at any given time – not taking into account leisure crafts and fishing vessels. Considering that data surrounding military activities – such as manoeuvres, use of medium and low frequency sonar (LFAS, MFAS) for submarine detection, etc. are generally not available to the public, such results for this sector represents an underestimation of the reality of the situation as well.


Noise-cetacean interaction hotspots: overlap of noise hotspots and important cetacean habitats

Crucially, through such mapping exercise, the scientists were able to reveal several noise hotspots overlapping with areas that are of particular importance to noise-susceptible marine mammal species, and/or areas that are already declared protected areas. Such important cetacean habitats include the Pelagos Marine Mammal Sanctuary in the Ligurian Sea, the Strait of Sicily, and parts of the Hellenic Trench, as well as waters between the Balearic Islands and continental Spain where noise-producing activities accumulate, according to the report. The risk for the marine animals in such areas is thus high, as they are exposed to cumulative and synergistic noise, and hence, extensive sources of stress.

Such threat has also been recognised by the Spanish Government. Their Ministry of the Environment recently announced that the waters between the Balearic Islands and the Spanish mainland will be designated a protected migration corridor for whales and dolphins, which will also result in strict management measures for noise producing activities.

“This report is the first basis for a purposeful development of noise reducing measures. It substantiates the urgent need for action to establish a transparent data register on anthropogenic noise sources in the Mediterranean and to take measures to reduce the problem”, says Silvia Frey, PhD, co-author of the report and director for science and education at OceanCare. Implementing such a register is also part of the EU Marine Strategy Framework Directive’s current action plan.

“With this report, we stand at the beginning of an acoustic assessment of the Mediterranean Sea as a marine habitat. Thus far, only noise sources which are timely and spatially incomplete could be identified. Hence, there is further need for scientific investigations into noise levels within the Mediterranean and, moreover, into what can be assessed as an acceptable and safe noise limit. Nevertheless, this first glance is remarkable and the extent of the noise sources is worrisome”, explains Frey.

“The present mapping also reveals data weaknesses, as we have to assume that some areas currently identified as ‘quiet’, particularly along the coastline of Northern Africa, are only considered quiet due to a lack of data. In particular, activities by oil and gas companies, as well as the military remain largely obscure”, adds Nicolas Entrup, consultant on underwater noise pollution for OceanCare and for US-based organisation NRDC.

“For the first time we have a wide spatial and temporal vision of the multiple and often overlapping human activities that produce noise underwater and that may have synergistic and cumulative effects on marine life. We now need models to map sound levels and sound exposure. We should not forget that conservation also means ‘conserving the acoustic quality of the habitats’”, says Gianni Pavan, co-author of the report and professor of the University of Pavia, Italy.

“Loud noise sources appear to cover very big portions of the Mediterranean Sea, and, of course, their impacts on marine wildlife propagate, regardless of human boundaries. Although far from being exhaustive, results shown in this study point out the need of a regulatory framework which takes into account the transboundary effects of man-made noise on the marine environment”, Alessio Maglio, co-author and scientist at SINAY SAS, adds.

Manuel Castellote, PhD, co-author and scientist at NOAA, concludes: “With this report we have barely grasped the tip of the iceberg when it comes to underwater noise occurrence in the Mediterranean Sea. A major concern is the amount of silent Mediterranean countries, silent when it comes to information sharing, not underwater silence!”

The report was commissioned by the Agreement on the Conservation of Cetaceans in the Black Sea, Mediterranean Sea and Contiguous Atlantic Area (ACCOBAMS) in order to identify areas of concern, to propose the need for further scientific assessment, as well as to deduce appropriate conservation measures.


More information:

Full report “Overview of the Noise Hotspots in the ACCOBAMS Area. Part I – Mediterranean Sea“

Short video ‘Underwater Noise – The Overlooked Catastrophe’ and the brochure ‘Drowning in Sound’.

Further information on the Silent Oceans Campaign: www.silentoceans.com

Giuseppe Notarbarolo di Sciara awarded with the Mandy McMath Conservation Award

Giuseppe Notarbartolo di Sciara, the founder and current president of the Tethys Research Institute (among the other things) has beeen recently awarded with the Mandy McMath Conservation Award at the lates Annual Conference of the European Cetacean Society Conference in Malta. Read the speech by Mark Simmonds here.

Tethys contributions to the latest ECS annual conference in Malta

The latest 29th Annual Conference of the European Cetacean Society was held in Malta just a few days ago, between the 23rd and the 25th of march, and organised by the The Biological Conservation Research Foundation, BICREF, in collaboration with the The Conservation Biology Research Group Department of Biology, Faculty of Science, The University of Malta. Amongst the several contributions, the Tethys Research Institute was in Malta with two full talks, 2 posters and 1 envited talk. Here it follows the list of the contributions:


Oral presentations

Long-term trend analysis of deep diving cetacean species occurring in the Pelagos Sanctuary (Northwestern Mediterranean Sea).

Lanfredi, C., Airoldi, S., Moulins,  A., Rosso, M., Tepsich, P., Azzellino, A.

Several threats are known to affect cetacean species and their habitats in the Mediterranean sea, most of them being related to human activities. To enforce effective mitigation actions, extensive knowledge of cetacean ecology is required. In this study a 23-year sighting series (1990-2012) of sperm whale (Physeter macrocephalus), Risso’s dolphin (Grampus griseus) and Cuvier’s beaked whale (Ziphius cavirostris) was analysed to assess temporal patterns or trends in their presence in the Pelagos Sanctuary area. Sighting data were collected by Tethys Research Institute (n= 434) and CIMA research Foundation (n= 142) during shipboard surveys conducted between 1990-2012 and 2004-2012, respectively. This effort yielded a total of 576 sightings: 289 sperm whales, 164 Risso’s dolphins and 123 Cuvier’s beaked whales. For the purpose of the analysis a grid of 6.8 x 9.3 km cell units was created and used for the spatial analysis. The species’ encounter rate variability in time was analysed through a General Linear Model approach, which revealed the existence of a significant increasing trend (P<0.05) for sperm whales and Cuvier’s beaked whales presence in the area. Contrarily, no trend was found for Risso’s dolphin. This study provides evidence that the animal distribution in the Pelagos Sanctuary is affected by some drivers of change. Changes may be due to a wide range of causes (i.e. prey availabilities, climate change, noise). The correlation of the results obtained with this long term trend analysis with the available time series of  environmental variables (i.e. Sea Surface Temperature and Chlorophyll-a from remote sensing) and  anthropogenic pressure affecting the area (i.e. maritime traffic, fishing activities) will provide essential information to evaluate the implications of the different factors of variability and their possible interactions in order to support appropriate management and conservation strategies.


The Convention on Migratory Species and the European Cetacean Society: working together to bridge policy with science in support of cetacean conservation

Giuseppe Notarbartolo di Sciara (Keynote presentation)

The Convention on Migratory Species (CMS) was adopted in 1983 to address the many threats faced by animal species which regularly cross borders between states, recognising that international cooperation is essential to the implementation of effective conservation measures for such species. Within CMS cetaceans occupy an important place, with 16 species listed as endangered in Appendix I, and 44 as requiring special agreements or cooperation for their conservation, listed in Appendix II. Of these species, many occur in European waters and will benefit from a cooperative effort between CMS and the ECS. CMS also has promoted the creation of several Agreements and MoUs among Range States to conserve cetaceans in specific regions; of these, ACCOBAMS and ASCOBANS are particularly well known within the ECS circle and have directly involved ECS members in many of their activities. Throughout CMS’ history, policy was always based on a solid scientific foundation: science has served the role of flagging issues needing urgent political attention, and of alerting to new issues, such as the danger posed by microplastics and the conservation relevance of dealing with animal culture. In turn, CMS has often served as a connective tissue creating functional links within the wider Multilateral Environmental Agreements (MEA) world, in order to achieve greater conservation effectiveness. One example among many is the 2014 Resolution on “advancing ecological networks to address the needs of migratory species”, containing an explicit encouragement to Parties to engage in the current Convention on Biological Diversity (CBD) effort on Ecologically or Biologically Significant Marine Areas (EBSAs), as well as in the application of the criteria for identifying Important Marine Mammal Areas (IMMAs) developed by the IUCN Marine Mammal Protected Areas Task Force.


Conserving the Mediterranean open sea ecosystems: lessons from the Pelagos Sanctuary

Giuseppe Notarbartolo di Sciara, Simone Panigada, Arianna Azzellino, Tundi Agardy

In 2006, in response to the Johannesburg Plan of Implementation call to establish protected areas globally, the Convention on Biological Diversity (CBD) started to develop and apply criteria to describe and designate Ecologically of Biologically Significant Areas (EBSAs) in the world’s oceans, which will, inter alia, support the nations’ commitment to achieve the Aichi Biodiversity Targets by 2020. The CBD also encouraged governments and international organizations to identify and adopt measures for conservation and sustainable use in relation to EBSAs, including establishing representative networks of marine protected areas. As part of this effort, the Parties to CBD declared 15 Mediterranean EBSAs in 2014. These EBSAs could portend designation of an ecologically representative network of Mediterranean open sea marine protected areas, which would facilitate the attainment of Aichi Target 11 by the Mediterranean nations. One of the most important EBSAs identified is in the wider Northwestern Mediterranean – an area covered in part by the Pelagos Sanctuary for Mediterranean Marine Mammals. Established in 1999 by a treaty amongst France, Italy and Monaco and inscribed in 2001 in the Barcelona Convention’s List of Specially Protected Areas of Mediterranean Importance, the Pelagos Sanctuary has done much to raise awareness about the value of the area for marine mammals and biodiversity, but the current management mechanism is insufficient. Nonetheless, Pelagos is the ideal laboratory for the experimental application of a regional open seas management mechanism, to help achieve a Mediterranean MPA network by 2020. We suggest that establishing a Biosphere Reserve in the North West Mediterranean Pelagic Ecosystem EBSA, which encompasses the Pelagos Sanctuary as well as currently unprotected cetacean critical habitat to the west and the south, could offer demonstration of such a management mechanism in order to pave the way to effective region-wide conservation of the Mediterranean open seas.



Diet of bottlenose dolphin (Tursiops truncatus) of the Gulf of Ambracia, Greece, through stable isotope analysis 

Joan Gonzalvo, Morgana Vighi, Carme Salvador, Alex Aguilar, Ioannis Giovos, Tilen Genov, Asunción Borrell

The interactions among diet, ecology, physiology and biochemistry affect C and N stable isotope signatures in animal tissues; therefore, their analysis provides an effective means to investigate their diet and trophic relations. In this study, skin samples of 16 bottlenose dolphins (Tursiops truncatus) obtained through biopsy techniques in the Gulf of Ambracia, north-western Greece, in July 2013, were analysed for stable isotopes. Ongoing research showed the Gulf hosts a highly ‘resident’ community of about 150 dolphins. Since all 16 animals were photoidentified during the sampling process, based on our existing dolphin catalogue, it was possible to establish that 4 of them were younger than 5-years (i.e., first identified as newborns/calves in 2008/9) and 12 older. The stable isotopes of potential prey locally available in the Gulf, which included 11 species of fish, 1 crustacean and 1 cephalopod, were also analysed and the diet of the dolphins determined through a mixing model. Results indicated that dolphin diet was mostly based on horse mackerel (Trachurus trachurus), which represented about 25% of the biomass ingested, followed by species of the family Sparidae (Diplodus annularis and Lithognathus mormyrus) and of the order Clupeiformes (Engraulis encrasicolus, Sardinella aurita and Sardina pilchardus). When age-related variation was examined, younger dolphins were found to present values of δ13C and δ15N lower than the others, which indicated that young animals are likely to exploit a lower trophic level than the adults, probably due to inexperience in foraging or to some particular behavioural adaptation. It is noteworthy that bottlenose dolphins inhabiting this almost enclosed embayment are frequently engaged in surface-feeding. Gaining a better understanding of their feeding habits not only provides important information about the species, but also may be key to identify adequate management measures consistent with an ecosystem-based approach.


Historical records of fin and sperm whale mortality events in the waters around Italy, 1584-2014

Nino Pierantonio and Federico De Pascalis

Fin and sperm whales are the largest cetaceans regularly occurring in the Mediterranean Sea where they classify as ‘Vulnerable’ and ‘Endangered’, respectively, according to the IUCN criteria. Considerable knowledge on their ecology has been gained during the last decades, yet limited information exists on their past mortality patterns. Here we present a review of fin and sperm whale mortality events in the seas around Italy encompassing 5 centuries. Through a review of historical and recent sources a total of 144 (46.8%) and 164 (53.2%) records were validated, for fin and sperm whales, respectively. For both species the most common event was a stranding (60.9%, 61.4%), followed by floating carcasses (15.8%) and collision events (12.8%) for fin whales and by-catch (15.7%) and deliberate killings (9.8%) for sperm whales. The spatial and temporal patterns were only investigated for strandings. Kernel Density Estimation and Hexagonal Polygon Binning showed an uneven occurrence of strandings for both species, with the majority of events occurring along gently sloping beaches, away from suitable species habitat. Strandings occurred at all times of year, but specific seasonal differences were observed. While fin whales mostly stranded during summer, the majority of sperm whale strandings occurred during spring and winter. Although strandings of both species showed a negative trend after peaking in the 1990s, an overall increase of mortality records was apparent throughout the centuries when considering all different types of events. This is most likely the result of rising research effort, as well as greater awareness of the general public. This review presents valuable baseline information for environmental history of cetaceans in a region where sea-related human activities have a long historical presence. Furthermore, they represent a useful tool to investigate the natural and man-related processes and dynamics responsible for cetacean mortality, in particular strandings.


The Tethys Research Institute on Wikipedia


European Cetacean Society Annual Conference (update)

As previously posted the next European Cetacean Society Annual Conference will be held in Liege, Belgium, between the 7 and the 9 of April 2014. The conference website is still far from being complete an the upload of information is rather slow. Nonetheless, finally, the scientific program as well as the abstract book, with the full list of oral presentations, short talks and posters, are available online.

As always, together with the main conference, there will be a series of workshops open to members, students and scientists. The full list of workshops is available here.

My personal contribution to the main conference and workshops will be the followings:

Pierantonio N., Airoldi S. 2014. Acoustically derived growth-rates of male sperm whales (Physeter macrocephalus) in the NW Mediterranean Sea. 28th Annual Conference of the European Cetacean Society, Liege, Belgium, 7-9 April 2014. (Oral presentation; Main Conference)

Abstract – Knowledge of body size and growth-rate is crucial to understand species’ macroecology. Although sperm whales’ length can be estimated using different techniques, to date they were not implemented for enough long time to gather knowledge on growth. Here, we present acoustically derived male sperm whale annual growth-rates for the North-Western Mediterranean Sea. Audio recordings were used to estimate the length and growth of 16 individuals repeatedly recorded and photographically recaptured between 2005 and 2013 in the Ligurian Sea. Using documented relationships between the Inter Pulse Interval (IPI) and total length, the growth-rate was estimated for those animals measured at least twice, more than six months apart. IPI was automatically computed via cepstral analysis using an ad hoc plug-in developed for the PAMGUARD software. Length and annual growth ranged between 11.14 and 13.12 m (mean= 12.36 m) and 0.00 and 0.28 my-1 (mean= 0.09 my-1), respectively. As expected, all whales showed an increasing or stable IPI over time with the annual growth decreasing as the body length increased. Based on the current knowledge, we assumed all animals to be males. While our length estimates agree with previously published data from the same area, little knowledge exists on growth-rate for the Mediterranean Sea. Nonetheless, no differences in the growth-rate with other populations outside the Basin were found (Kolmogorov-Smirnov test: D = 0.2604, p-value = 0.5948). This study is the first example on the use of non-invasive and non-lethal tools to investigate the growth of sperm whales in the Mediterranean, where the species classifies as ‘Endangered’ according to the IUCN criteria. Body size and growth can be used to summarise diverse biological information and can be affected by many factors including anthropogenic activities; understanding their role can be essential to manage potential detrimental stressors and implement proper conservation measures.

Panigada S., Frey S., Pierantonio N., Garziglia P., Giardina F. 2014. Are humpback whales electing the Mediterranean Sea as new residence? 28th Annual Conference of the European Cetacean Society, Liège, Belgium, 7-9 April 2014. (Poster presentation; Main Conference)

Abstract – Once considered exceptionally rare in the Mediterranean basin, in the last decade the occurrence of humpback whales (Megaptera novaeangliae) in this Basin has increased. Since 2001, 14 sightings, 3 strandings and 2 by-caught individuals have been reported from different locations across the Region. All individuals, ranging between 7 and 12 meters, were estimated to be 2-3 years old juveniles. No re-sightings have been documented to date, suggesting scouting and exploratory behaviors. Here we report the first re-sightings of a humpback whale in three different locations in the Mediterranean Sea. A whale, approximately 8-9-meters long, was first observed in the Ligurian Sea, NW Mediterranean, in June 2012. The same animal was then re-sighted off Lampedusa Island, Sicily Channel, in March 2013 over 1,000 km away in a straight line from the previous location and again in August 2013 in the Ligurian Sea. During the last sighting, the animal was associated to a fin whale (Balaenoptera physalus), the only known resident mysticete in the Basin. In all the occasions the whale didn’t show any sign of distress and, in the Lampedusa sighting, several episodes of surface feeding were observed.  This specimen apparently managed to discover and exploit the main known feeding grounds for fin whales in the central Mediterranean Sea, where this species regularly preys on very abundant euphausiids species. These findings suggest that the Mediterranean Sea offer suitable habitats not only for fin whales but also for other mysticetes. The recent recovery of the North Atlantic humpback whale population might increase migrations of individuals in the Mediterranean through the Gibraltar Strait. This range expansion, possibly leading to a (re)colonization of the Mediterranean in the future, could expose the species to severe anthropic pressures (ship strikes, acoustic-chemical pollution) and urges appropriate mitigation measures to be considered and implemented also for this species.

Pierantonio N., Airoldi S. 2014. Length and growth of male sperm whales (Physeter macrocephalus) in the NW Mediterranean Sea. ‘Scientific progress on cetaceans and perspectives in the Pelagos Sanctuary’ Workshop, 28th Annual Conference of the European Cetacean Society, Liege, Belgium, 5 April 2014. (Oral presentation; Workshop)

Abstract – The Pelagos Sanctuary for Mediterranean Marine Mammals constitutes a potentialtool for the management of cetaceans. To capitalise on its potential a robust scientific knowledge is critical, especially for those aspects of cetacean ecology that remain scant. We have been conducting visual and acoustic surveys in the Ligurian Sea for almost three decades, focusing on the ecology, status and conservation of cetaceans occurring in the area, generating one of the larger datasets across the Mediterranean. Here, we present acoustically derived male sperm whale annual growth-rates for the North-Western Mediterranean Sea. Audio recordings were used to estimate the length and growth of individual whales repeatedly recorded and photographically recaptured between 2005 and 2013 in the Ligurian Sea. Using documented relationships between the Inter Pulse Interval (IPI) and total length, the growth-rate was estimated for those animals measured at least twice, more than six months apart. Length and annual growth ranged between 11.14 and 13.12 m (mean = 12.36 m) and 0.00 and 0.28 my-1 (mean = 0.09 my-1), respectively. As expected, all whales showed an increasing or stable IPI over time, with the annual growth decreasing as the body length increased. Based on current knowledge, we assumed all animals to be males. Our length estimates agree with previously published data from the same area, but little knowledge exists on growth-rate for the entire Mediterranean. While growth and length are not directly relevant for conservation, their knowledge constitutes an important element to better understand the species’ macroecology. In fact, body size and growth can be used to summarise diverse biological information and can be affected by many factors including anthropogenic activities. Understanding their role is essential to manage stressors and implement conservation measures. Furthermore, this study is the first non-lethal investigation of growth of sperm whales in the Mediterranean.