Entity

Time filter

Source Type


Hale R.,University of Porto | Pires R.,Parque Natural da Madeira | Santos P.,University of Porto | Karamanlidis A.A.,MOm Hellenic Society for the Study and Protection of the Monk Seal
Aquatic Mammals | Year: 2011

Marine mammal and fishery interactions have increased concurrently with human population growth and subsequent increases in demand for fisheries products. As a result, populations of marine mammals and the livelihood of coastal fishermen have both been adversely affected. Mediterranean monk seals (Monachus monachus) are among the most endangered marine mammals in the world that have been impacted by fisheries. The aim of this study was to understand the nature and assess the magnitude of monk seal-fisheries interactions in the Archipelago of Madeira and to propose a set of conservation measures to mitigate them. Information on interactions was collected during questionnaire surveys conducted at the main fishing port of Madeira, where approximately 14% of all the fishermen and 59% of all fishing vessels in the Archipelago were interviewed. Most fishermen (91%) believed that fish stocks were declining in their region, but few (1%) considered the monk seal to be the principal reason for this negative trend. Furthermore, only 30% of the fishermen interviewed had experienced monk seal-fishing gear interactions. These interactions occurred mainly in summer, in the morning, at depths between 0 to 50 m and below 100 m, and affected mainly hand-lines for demersal species. At the same time, no records of entangled monk seals in fishing gear were reported. Compared to other areas in the species' range, the intensity of potentially negative monk seal-fisheries interactions in the Archipelago of Madeira is lower, and they do not currently constitute a threat to the survival of the species. We believe that this is due to the fact that the use of fishing nets in the region has been banned, and fishers have switched to alternative, less harmful fishing methods. Proposed conservation actions should include promoting environmental awareness, the production of a "Good Fishing Conduct" manual, and the increase in surveillance and enforcement of fishing regulations. Source


Giakoumi S.,Hellenic Center for Marine Research | Giakoumi S.,University of Queensland | Sini M.,University of Aegean | Gerovasileiou V.,Aristotle University of Thessaloniki | And 17 more authors.
PLoS ONE | Year: 2013

Spatial priorities for the conservation of three key Mediterranean habitats, i.e. seagrass Posidonia oceanica meadows, coralligenous formations, and marine caves, were determined through a systematic planning approach. Available information on the distribution of these habitats across the entire Mediterranean Sea was compiled to produce basin-scale distribution maps. Conservation targets for each habitat type were set according to European Union guidelines. Surrogates were used to estimate the spatial variation of opportunity cost for commercial, non-commercial fishing, and aquaculture. Marxan conservation planning software was used to evaluate the comparative utility of two planning scenarios: (a) a whole-basin scenario, referring to selection of priority areas across the whole Mediterranean Sea, and (b) an ecoregional scenario, in which priority areas were selected within eight predefined ecoregions. Although both scenarios required approximately the same total area to be protected in order to achieve conservation targets, the opportunity cost differed between them. The whole-basin scenario yielded a lower opportunity cost, but the Alboran Sea ecoregion was not represented and priority areas were predominantly located in the Ionian, Aegean, and Adriatic Seas. In comparison, the ecoregional scenario resulted in a higher representation of ecoregions and a more even distribution of priority areas, albeit with a higher opportunity cost. We suggest that planning at the ecoregional level ensures better representativeness of the selected conservation features and adequate protection of species, functional, and genetic diversity across the basin. While there are several initiatives that identify priority areas in the Mediterranean Sea, our approach is novel as it combines three issues: (a) it is based on the distribution of habitats and not species, which was rarely the case in previous efforts, (b) it considers spatial variability of cost throughout this socioeconomically heterogeneous basin, and (c) it adopts ecoregions as the most appropriate level for large-scale planning. © 2013 Giakoumi et al. Source


Karamanlidis A.A.,MOm Hellenic Society for the Study and Protection of the Monk Seal | Curtis P.J.,University of British Columbia | Hirons A.C.,Nova Southeastern University | Psaradellis M.,MOm Hellenic Society for the Study and Protection of the Monk Seal | And 4 more authors.
Isotopes in Environmental and Health Studies | Year: 2014

Understanding the ecology and behaviour of endangered species is essential for developing effective management and conservation strategies. We used stable isotope analysis to investigate the foraging behaviour of critically endangered Mediterranean monk seals (Monachus monachus) in Greece. We measured carbon and nitrogen isotope ratios (expressed as δ13C and δ15N values, respectively) derived from the hair of deceased adult and juvenile seals and the muscle of their known prey to quantify their diets. We tested the hypothesis that monk seals primarily foraged for prey that occupy coastal habitats in Greece. We compared isotope values from seal hair to their coastal and pelagic prey (after correcting all prey for isotopic discrimination) and used these isotopic data and a stable isotope mixing model to estimate the proportion of coastal and pelagic resources consumed by seals. As predicted, we found that seals had similar δ13C values as many coastal prey species and higher δ13C values than pelagic species; these results, in conjunction with mean dietary estimates (coastal=61 % vs. pelagic=39 %), suggest that seals have a diverse diet comprising prey from multiple trophic levels that primarily occupy the coast. Marine resource managers should consider using the results from this study to inform the future management of coastal habitats in Greece to protect Mediterranean monk seals. © 2014 © 2014 Taylor & Francis. Source


Karamanlidis A.A.,MOm Hellenic Society for the Study and Protection of the Monk Seal | Dendrinos P.,MOm Hellenic Society for the Study and Protection of the Monk Seal | de Larrinoa P.F.,Fundacion CBD Habitat | Gucu A.C.,Middle East Technical University | And 3 more authors.
Mammal Review | Year: 2016

The Mediterranean monk seal Monachus monachus is the most endangered seal species. In this review we summarize the status, ecology, and behaviour of the Mediterranean monk seal, and identify the main threats that currently affect the species and the conservation priorities for securing its survival. Once abundant throughout the Black Sea and Mediterranean, as well as off the Atlantic coasts of northwestern Africa and Macaronesia, the Mediterranean monk seal has recently suffered dramatic declines, both in abundance and geographical range. It is now estimated that fewer than 700 individuals survive in three or four isolated subpopulations in the eastern and western Mediterranean, the archipelago of Madeira and the Cabo Blanco area in the northeastern Atlantic Ocean. Mediterranean monk seals are coastal marine mammals. When resting and pupping on land, individuals generally seek refuge in inaccessible marine caves; this behaviour is, in part, believed to be an adaptation to increased disturbance by humans. Larger aggregations or colonies of the species can now be found only at Cabo Blanco in the Atlantic Ocean and on the island of Gyaros in the eastern Mediterranean. The main threats to the survival of the Mediterranean monk seal are habitat deterioration; deliberate killing, mainly by fishermen; and accidental entanglement and drowning in fishing gear. Limited availability of food sources and stochastic and unusual events have occasionally also contributed to Mediterranean monk seal mortality. Based on a common consensus among scientists and conservationists, the main conservation priorities for the monk seal are: habitat protection; mitigating negative interactions between seals and fisheries; scientific research and monitoring of local seal populations; education and public awareness campaigns; and rescue and rehabilitation of wounded, sick, and orphaned seals. © 2016 The Mammal Society and John Wiley & Sons Ltd. Source


Murphy S.,University of St. Andrews | Spradlin T.R.,University of St. Andrews | Spradlin T.R.,West Marine | Mackey B.,University of St. Andrews | And 8 more authors.
Endangered Species Research | Year: 2012

Mediterranean monk seals Monachus monachus are classified as Critically Endangered on the IUCN Red List, with <600 individuals split into 3 isolated sub-populations, the largest in the eastern Mediterranean Sea. Canine teeth collected during the last 2 decades from 45 dead monk seals inhabiting Greek waters were processed for age estimation. Ages were best estimated by counting growth layer groups (GLGs) in the cementum adjacent to the root tip using un -processed longitudinal or transverse sections (360 μm thickness) observed under polarized light. Decalcified and stained thin sections (8 to 23 μm) of both cementum and dentine were inferior to unprocessed sections. From analysing patterns of deposition in the cementum of known agematurity class individuals, one GLG was found to be deposited annually in M. monachus. Ages ranged from 0.5 to 36 yr for females, 0.5 to 21 yr for males and 0.5 to 25.5 yr for individuals of un -known sex. The majority of seals (65%) were considered adults (≥4 yr), followed by juveniles (20%, <1 yr) and sub-adults (15%, 1-3.9 yr). Thirty percent of the aged sample had died from human-related causes, such as accidental entanglement in fishing gear and direct killings. A single-Gompertz growth curve was generated for both sexes using standard length data, resulting in asymptotic values of 212.3 cm for females and 221.8 cm for males. This study represents the first quantitative glimpse of sex-specific growth in monk seals and the age structure of dead individuals in this rare species' core range. © Inter-Research 2012. Source

Discover hidden collaborations