1. Preservation of endangered species is now recognized as a relevant component of regional and global conservation actions achieved through the maintenance of the remaining populations in a favourable conservation status. The Mediterranean common dolphin (Delphinus delphis) is listed as an Endangered subpopulation in the International Union for Conservation of Nature Red List, with declining numbers in some of the areas where it has been studied for numerous years. Prey depletion, fisheries bycatch, pollution, health risks, and climate change are among the recognized threats that the species is facing in the region.2. The existing national, regional, and international legislation pertinent to Mediterranean countries should aid greater science-policy-management integration and support innovative research and monitoring towards effective conservation. The challenges inherent in studying the pelagic D. delphis should not preclude the use of long-term, year-round, multiplatform surveys, side by side with the latest molecular tools, which aid our understanding of its populations' genetic diversity, resistance to diseases, and resilience in a semi-enclosed fast-changing sea.3. Addressing the multiplicity of problems confronting the species requires collaborative effort at all levels to share and merge resources, data, and expertise more efficiently. In this review, we provide an overview of the current knowledge on the Mediterranean common dolphin, the main threats, and knowledge gaps that are priorities for addressing its conservation, while providing clear recommendations for effectively safeguarding the species and its habitat at both local and regional levels.

Visual observations of the behavior of over 150 loggerhead turtles (Caretta caretta) were collected over a period of 2 weeks during a seismic survey in the Mediterranean Sea off Algeria in September and October 2009. All turtles were observed during active operation of an airgun array that had a peak source level of 252 dB re 1 μPa. Recordings from three hull-mounted hydrophones allowed concurrent estimation of near-surface airgun array source signatures and sound exposure levels. Of the 53% of turtles that were successfully visually tracked until they had passed more than 100 m behind the seismic vessel, 51% dived at or before their closest point of approach to the airgun array. Among animals that dived, approximately 20% did so immediately following an airgun shot, often showing a startle response that was clearly distinguishable from the predominant basking behavior. Turtle dive probability as a function of distance from the airgun array and sound exposure level will be considered in detail. The observed diving behavior may be interpreted as an avoidance response and may have negative consequences for turtles if it interferes with thermoregulation (basking) or results in inhabitual energy expenditures.

Seismic airgun arrays are among the most powerful sound sources used at sea, and they have the potential to disrupt the behavior of marine life. Little information is available on marine turtle responses to airgun sounds, and few regulations mandate specific actions to protect turtles from potential impacts of airgun exploration. As part of the French-Algerian project SPI-RAL (Sismique Profonde et Investigation Régionale du Nord de l'Algérie) in September and October 2009, visual observations of 164 loggerhead turtles Caretta caretta were conducted during a seismic survey in the Mediterranean Sea off Algeria. The turtles were part of a large aggregation, basking at the surface in calm seas. All sightings occurred during airgun operations, in which shots were fired every 19.4 s (array source level 252 dB re 1 µPa [peak]). Recordings from 3 hydrophones allowed estimation of near-surface airgun sound levels. Of 86 turtles visually tracked until their passage >100 m behind the array, 49 (57%) dove at or before their closest point of approach to the airguns. At least 6 dove immediately following an airgun shot, often showing a startle response. Binomial regression indicated that turtle dive probability decreased with increasing distance from the airgun array. The observed diving behavior may be interpreted as an avoidance response to airguns. KEY WORDS: Loggerhead · Sea turtle · Caretta caretta · Airgun · Seismic · Noise · Dive behavior Resale or republication not permitted without written consent of the publisher

1. Marine mammals stranding data provide valuable information on causes of mortality for cetacean populations. The aim of this study was to investigate the characteristics of the stranding events of common dolphins along the Algerian west coast, and estimate the proportion of human vs. non-human induced mortality of the population. 2. Between 2008 and 2012, out of the 52 cetacean stranding records along the Algerian west coast, common dolphins (Delphinus delphis) were recorded in 14 cases. All recorded strandings were of individual cases with no mass strandings registered during the reported period.3. To examine the proportion of human and non-human induced mortality affecting this population, necropsies were conducted. In 10 cases, an interaction with some type of fishing gear had occurred; in three, there was no link with human activity; and in one case, it was not possible to determine the cause of death due to the condition of the carcass (severely decomposed).

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