Fishery-independent abundance and density of swordfish in the Central Mediterranean

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. 

Lauriano G., Pierantonio N., Kelly L., Cañadas A., Donovan G. P., Panigada S. 2017. Fishery-independent surface abundance and density estimates of swordfish (Xiphias gladius) from aerial surveys in the Central Mediterranean Sea. Deep Sea Research Part II: Topical Studies in Oceanography. DOI: 10.1016/j.dsr2.2017.04.019


The Devil We Don’t Know

Dear readers, I am pleased to announce the publication of the followingpaper in the PLoS ONE journal. The full paper as well as supplementary material can be downloaded from the journal  webpage.

Notarbartolo di Sciara, G., Lauriano, G., Pierantonio, N., Cañadas, A., Donovan, G., Panigada, S., 2015. The Devil We Don’t Know: Investigating Habitat and Abundance of Endangered Giant Devil Rays in the North-Western Mediterranean Sea. PLoS ONE 10, e0141189. doi:10.1371/journal.pone.0141189
PLoS ONE Mm2015

new conference presentation

Recently presented at the Second Workshop on the Biology and ecotoxicology of large marine vertebrates: potential sentinels of Good Environmental Status of marine environment, implication on European Marine Strategy Framework Directive, organised by the Univerity of Siena, Italy.

Lauriano G., Pierantonio N., Donovan G., Panigada S. 2013. Knowledge of Marine Strategy Directive key parameters for the common bottlenose dolphin: a case study in the Western Mediterranean Assessment Area. Biology and ecotoxicology of large marine vertebrates: potential sentinels of Good Environmental Status of marine environment, implication on European Marine Strategy Framework Directive. Siena, Italy, 5-6 June 2013. (Oral presentation)

The common bottlenose dolphin (Tursiops truncatus) from the Mediterranean Sea has been assessed as Vulnerable according to the IUCN Red List Criteria. Moreover, the species is included in several International Agreements, European Regulations and Directives and amongst these a strict protection and identification of special conservation areas are requested from the Habitat Directive.

Despite the above considerations and that the species is the most studied cetacean, to depict the actual conservation status and compare it to the past distribution and abundances throughout the Basin is not possible. In addition, direct takes in the past, bycatch, chemical and acoustic pollution, prey depletion and a general habitat degradation and fragmentation have been indicated as detrimental for the species, but the degree to which they pose an effective population risk is unknown, so far.

From summer to autumn 2010, line transect aerial surveys were conducted in area covering the Ligurian, the Central and the south Tyrrhenian Seas and the Seas of Corsica and Sardinia (fig. 1). A total of 165 parallel line-transects, 15 km apart and totaling 21,189 km, were designed providing homogeneous coverage probability. Overall 21,090 km were flown on effort and 16 bottlenose dolphin sightings were recorded and used for abundance and density estimates using the dedicated software Distance 6. Differences in presences were detected across the study area. The overall abundance estimates resulted in 1,676 animals at surface (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 are the first estimates for the common bottlenose dolphin over a wide portion of the Western Mediterranean Assessment Area (WMAA) and possibly will represent a useful baseline dataset to provide information following the requisites, such as the species distribution and abundances, of the MSFD requirements. The line transect aerial surveys, in conjunction with other study methods (e.g. photo-identification, satellite telemetry) can provide a cost-effective means of fulfilling requirements, under the MSFD and offer a valuable contribution to conservation efforts.

Loggerhead sea turtles (Caretta caretta) in the Pelagos Sanctuary

The following paper was just published in the Marine Ecology Progress Series journal.  Enjoy reading!

Lauriano G, Panigada S, Casale P, Pierantonio N, Donovan GP (2011) Aerial survey abundance estimates of the loggerhead sea turtle Caretta caretta in the Pelagos Sanctuary, northwestern Mediterranean Sea. Mar. Ecol. Prog. Ser. 437:291-302.

ABSTRACT – Aerial line transect surveys, totalling 16590 km, were performed in winter and summer 2009 in the Pelagos Sanctuary, NW Mediterranean. A total of 207 loggerhead sea turtles were sighted, with only 9 sightings during the winter. In this season average raw ‘surface’ density (i.e. animals at or near the surface) was 0.002 turtles km–2, and on the basis of line-transect analysis, we estimated 237 specimens (CV = 34.33%; 95% CI = 122–461). The summer estimate resulted in 4083 animals at surface (CV = 14.59%; 95% CI = 3061–5466) in the study area, with a density of 0.046 km–2. Results indicated strong seasonal differences and lower densities than those found in comparable surveys in Spanish Mediterranean waters. Nevertheless, the ecological and oceanographic features of the Pelagos Sanctuary, established primarily for the protection of marine mammals, render it an important area also for Mediterranean loggerhead sea turtles. The potential for human-induced mortalities of turtles summering in the Pelagos Sanctuary is high. In this context, it is vital to obtain reliable estimates of absolute and relative abundance over time, monitor the status of loggerhead sea turtles and inform the development of effective conservation actions. This study illustrates the ability of aerial surveys to provide such data in this area.

striped dolphin and fin whale abundance in the pelagos sanctuary

The following paper has just been published on PLos ONE journal and can be downloaded for free.

Panigada S, Lauriano G, Burt L, Pierantonio N, Donovan G (2011) Monitoring Winter and Summer Abundance of Cetaceans in the Pelagos Sanctuary (Northwestern Mediterranean Sea) Through Aerial Surveys. PLoS ONE 6(7): e22878. doi:10.1371/journal.pone.0022878

Abstract – Systematic long-term monitoring of abundance is essential to inform conservation measures and evaluate their effectiveness. To instigate such work in the Pelagos Sanctuary in the Mediterranean, two aerial surveys were conducted in winter and summer 2009. A total of 467 (131 in winter, 336 in summer) sightings of 7 species was made. Sample sizes were sufficient to estimate abundance of fin whales in summer (148; 95% CI = 87–254) and striped dolphins in winter (19,462; 95% CI = 12 939–29 273) and in summer (38 488; 95% CI = 27 447–53 968). Numbers of animals within the Sanctuary are significantly higher in summer, when human activities and thus potential population level impacts are highest. Comparisons with data from past shipboard surveys suggest an appreciable decrease in fin whales within the Sanctuary area and an appreciable increase in striped dolphins. Aerial surveys proved to be more efficient than ship surveys, allowing more robust estimates, with smaller CIs and CVs. These results provide essential baseline data for this marine protected area and continued regular surveys will allow the effectiveness of the MPA in terms of cetacean conservation to be evaluated and inform future management measures. The collected data may also be crucial in assessing whether ship strikes, one of the main causes of death for fin whales in the Mediterranean, are affecting the Mediterranean population.