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)

Fin whales migration in the Mediterranean Sea

(From the International Whaling Commission website)

A collaborative satellite tagging programme under the auspices of the IWC has shed light on the migration patterns of Mediterranean fin whales.  This latest research develops understanding of the routes travelled by the whales, and therefore the threats they face.

The project began in 2013, but the first tagging attempts were unsuccessful due to an unfortunate combination of harsh weather conditions, erratic whale presence and tag failure.  In March, scientists successfully tagged two whales in waters around the island of Lampedusa, between Sicily and the North African coast.

After several weeks feeding in this area the whales separated, but both ultimately travelled across the Strait of Sicily towards the Pelagos Sanctuary in the northern Mediterranean.  This journey gives the first clear indication that the whales feeding in the Strait of Sicily in winter are the same animals that congregate in the Pelagos Sanctuary in summer.  This research also confirms that fin whales migrate north-south across one of the busiest east-west shipping lanes in the world.

The number of collisions between whales and ships, known as ‘ship strikes,’ is hard to quantify.  Collisions with large ships often go unnoticed or unreported.  The IWC has developed a global ship strike database and is gathering information to build a clearer picture of the problem, in order to develop solutions.

What is already clear is that ship strikes are more likely in areas where whale migration routes and shipping lanes cross.  More work is needed to understand and address the threat to whales when they leave the safety of the Pelagos Sanctuary.  Further work will also be undertaken to establish if there is any relationship between these whales and other known congregations in the eastern Mediterranean.

This programme is a multi-agency collaboration, funded by the Italian Ministry of the Environment, through the IWC and the Tethys Research Institute.  The research is conducted in conjunction with the Institute for Environmental Protection and Research (ISPRA), the National Oceanic and Atmospheric Administration (NOAA), the University of Siena, and the Pelagie Islands Marine Protected Area.

You can read more about the project on the website of the Tethys Research Institute as well as the website of the Pelagos Sanctuary.

See also

Monitoring fin whales in the Central Mediterranean Sea

The Tethys Research Institute, with the support of the local Marine Protected Area of Pelagie Islands, is monitoring fin whale movement and migration patterns in the Mediterranean Sea through a satellite telemetry programme. Research activities are carried out in the Island of Lampedusa, Central Mediterranean Sea. In the following video (sorry only in italian, but hopefully soon with subtitles) The Tethys vice-president, Simone Panigada, explains why.

back from portugal

The 27th annual conference of the European Cetacean Society (ECS) finished only few days ago and we are already thinking about 2014. In fact, the next annual conference of the ECS will be held in Liege, Belgium, between 4-8 April.

My personal contribution to the 27th ECS conference, related to my work with the Tethys Research Institute,  was given through one long talk during the main conference, one poster presentation and one invited talk at one of the workshops. If interested, please give a look at the following:

Lauriano G., Panigada S., Pierantonio N., Donovan G. 2013. The Marine Strategy Framework Directive abundance and distribution indicators: a case study for the common bottlenose dolphin (Tursiops truncatus) in the central Mediterranean Sea based on aerial survey data. 27th Annual Conference of the European Cetacean Society, Setubal, Portugal, 8-10 April 2013. (Poster)

Knowledge of baseline parameters for a given population is fundamental to address many questions of ecological importance and for the implementation of conservation measures and an assessment of their effectiveness. Under the pillar of the European Habitat Directives, monitoring the status of species of community interest represents a legal obligation for the Member States. Recently, the Marine Strategy Framework Directive (MSFD), which is aimed at achieving or maintaining a “good environmental status”, has requested regular reports on the population dynamics, range and status of species in Europe’s waters. The Mediterranean Sea common bottlenose dolphin sub-population is included in international agreements and conventions and it has been assessed as Vulnerable according to the IUCN Red List Criteria. In 2010, line transect aerial surveys were conducted in a wide area included in the Western Mediterranean Sea Assessment Area (the Pelagos Sanctuary, the Central and the south Tyrrhenian Seas and the Seas of Corsica and Sardinia). Overall, 165 parallel transects, 15 km apart and totaling 21,189 km, were designed providing homogeneous coverage probability. In total, 21,090 km were flown on effort and 16 bottlenose dolphin sightings were recorded and used for abundance and density estimates. Differences were detected across the study area. The uncorrected (for availability and detection bias) abundance for the whole study area was 1,676 (CV= 38.25; 95% CI= 804 – 3492) with a density of 0.005 (CV=38.25%) and an encounter rate of 0.000758 groups/km (CV=27.5%). These first estimates for this species over such a wide area represent a useful baseline dataset to provide information following the requisites of the MSFD requirements and to inform conservation measures on both national and international levels. Aerial surveys, in conjunction with other studies (e.g. photo-identification) can provide a cost-effective means of fulfilling requirements under the MSFD and provide a valuable contribution to conservation efforts.

Panigada S., Lauriano G., Zanardelli M., Pierantonio N., Donovan G.P., Zerbini A., Geyer Y., Druon J-N., Fossi M.C., Notarbartolo di Sciara G. 2013. Satellite tracking of fin whales in the Pelagos Sanctuary (Western Mediterranean Sea). 27th Annual Conference of the European Cetacean Society, Setubal, Portugal, 8-10 April 2013. (Oral presentation)

In recent decades, several studies have been carried out to describe summer habitat use, behaviour, distribution and abundance of fin whales in the northwestern Mediterranean.  However, knowledge of their distribution and movements during other seasons remains scarce. The present project was funded by the Italian Ministry of the Environment to investigate post-summer fine scale habitat use, movements and migration routes/destinations of fin whales. Location-only satellite transmitters (SPOT5, Wildlife Computers) were attached to eight individuals in the Pelagos Sanctuary (September 2012). Deployments occurred as late in the summer as possible, to maximise information outside known summer feeding grounds. Two different models using different attachment mechanisms were used (‘LIMPET’ n=3 and ‘implantable’ n=5),  inter alia to examine potential differences in performance for future fin whales’ studies. An important component of the project was to evaluate the strengths and weaknesses of tag designs and deployment to assist worldwide efforts to improve telemetry research programmes. At the time of writing, two implantables are still transmitting; LIMPET tags lasted max=35 days (mean=25) and implantables thus far max=83 days (mean=55.2). Fine scale associations with oceanographic features and potential feeding habitats within the Sanctuary are being investigated. Preliminary results indicate that tagged fin whales remained in the Pelagos Sanctuary feeding ground longer than expected, possibly due to the current particularly mild climate conditions which allowed  prolonged feeding activities in the area. Two individuals left the Pelagos area and moved towards the Balearic Islands, remaining in a defined area (100×100 km) for approximately 20 days before moving towards the Gulf of Lions. Ongoing data collection, coupled with further deployments, could provide insights on small and large scale feeding behaviour and migratory routes. Alongside information on threats (e.g. vessel traffic), telemetry data are important for helping to develop focussed mitigation measures and providing baseline data to measure their effectiveness.

Pierantonio N., Airoldi S. 2013. Sperm whale monitoring in the Ligurian Sea: addressing present and future challenges. 27th Annual Conference of the European Cetacean Society, Setubal, Portugal, 8-10 April 2013. (Invited talk)

The Mediterranean subpopulation of sperm whales is currently classified as “Endangered” according to the IUCN Red List criteria. Despite the research effort carried out during the last decades in many sectors of the Mediterranean where the species is considered regular, various aspects of its ecology are still poorly understood. Filling the gap in our current knowledge is essential to inform conservation and to propose and adopt proper mitigation strategies. We have studied the species in the Ligurian Sea (NW Mediterranean) during the last three decades, generating one of the largest datasets throughout the Mediterranean region. Several aspects have been investigated such as the spatial and temporal distribution, the habitat use and preferences, population size, acoustics, the effects of climate change, ship strikes and other forms of interaction with human activity. Research effort and data collection is still ongoing, along with the investigation of other ecological aspects. Using different techniques short- and long-term movements and identification of migration patterns are under investigation, as well as animals’ size and growth rates. While some of these aspects might not have a direct relevance for the conservation of the species and/or might vary longitudinally throughout the basin, they constitute important pieces towards a better understanding of the macroecology of the species. Considering the current conservation status of the Mediterranean sperm whale sub-population and the volume and diversity of pressures with potential harmful effects, the regular monitoring of sperm whales at regional scale is highly recommended. Moreover, the necessity for adequate management actions is crucial considering that these threats likely result in a continuing decline in the number of individuals. Finally, a collaborative effort and interdisciplinary approach are suggested towards an effective conservation strategy able to cope both with the dynamism of anthropogenic pressures and the new challenges posed by climate change.

next stop!

Read more here and here.