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Luis Mariano Gonzalez - One of the best experts on this subject based on the ideXlab platform.

  • prehistoric and historic distributions of the critically endangered mediterranean monk seal Monachus Monachus in the eastern atlantic
    Marine Mammal Science, 2015
    Co-Authors: Luis Mariano Gonzalez
    Abstract:

    The present Atlantic range of the Mediterranean monk seal (Monachus Monachus), a critically endangered species, comprises two populations in the Desertas Islands and Cape Blanco region. The species is currently the subject of an action plan that encourages the recolonization of its former range. I investigated their causes of its disappearance using species records from paleo-archeological sites and historical sightings/toponyms. I hypothesize that the species' prehistoric range extended from the continental coasts of North Africa to the Iberian Peninsula, an area larger than its current known range. It is further hypothesized that the historic range included at least 13 colonies, seven more than the present number; and that the original optimal breeding habitat was open beaches, while sea caves were a suboptimal, marginal habitat. It is suggested that hunting and the disappearance of two islands due to a historical tsunami event explain the disappearance of the other populations, leaving only those at the Desertas Islands and Cape Blanco that were sheltered in sea caves. Furthermore, the use of sea caves, in conjunction with effective legal protection in the 20th century, explains the present-day survival of these Atlantic colonies of M. Monachus.

  • changes in morphology with age in mediterranean monk seals Monachus Monachus
    Marine Mammal Science, 2000
    Co-Authors: Roser Samaranch, Luis Mariano Gonzalez
    Abstract:

    In order to describe the pelage and external appearance of the Mediterranean monk seal (Monachus Monachus) and prepare an age-sex classification guide, 120 seals from the Cabo Blanco Peninsula colony in the Western Sahara/Mauritania were periodically photographed between 1993 and 1996. Analysis of the pigmentation pattern, pelage color and pattern of natural markings of each seal established 48 phenetic types, which were, in turn, arranged in five groups (morphological classes) with multivariate cluster analysis (UPGMA). The variables that best define these groups are size and color. The variation related to relative size, sex and age of 26 identified seals monitored over three years showed that: (1) after each molt, external appearance varied considerably only in non-adults, while adult appearance was invariable; (2) marked sexual dimorphism exists in adults' external appearance; and (3) a remarkable similarity of adult and neonate pelage exists. With these results, we propose an age-sex classification guide to facilitate monk seal identification in the field.

  • pup survival in the mediterranean monk seal Monachus Monachus colony at cabo blanco peninsula western sahara mauritania
    Marine Mammal Science, 2000
    Co-Authors: Manel Gazo, Miguel Ángel Cedenilla, Fernando Aparicio, Jorge F Layna, Luis Mariano Gonzalez
    Abstract:

    We surveyed pup survival in Mediterranean monk seals (Monachus Monachus), at Cabo Blanco Peninsula (Western Sahara-Mauritania) colony from May 1993 to December 1997. This species breeds and hauls out on beaches inside two main caves. During the study period we detected a total of 93 pups that died or disappeared. The survival rate of 84 pups through the age of first moult (approximately two months) was 0.47. This value is similar to those reported for other pinnipeds breeding in caves but lower than for those breeding on open beaches. Mortality varied seasonally and appeared to increase as a result of storms, large ocean swells, and high tides. Mother-pup pair separation (and resulting pup starvation) and physical injury caused by impact against the rock walls of the cave and cliffs were established as the causes of most deaths. Beach surface area inside the caves also appeared to be a mediating factor in the effects of sea conditions. High pup mortality may be a limiting growth factor in this population, although cave dwelling protects the population from predators and human disturbance.

  • pupping season perinatal sex ratio and natality rates of the mediterranean monk seal Monachus Monachus from the cabo blanco colony
    Journal of Zoology, 1999
    Co-Authors: Manel Gazo, Miguel Ángel Cedenilla, Luis Mariano Gonzalez, Fernando Aparicio, Jorge F Layna, Alex Aguilar
    Abstract:

    Pupping seasonality, annual pup production, reproductive rate and sex ratio at birth were determined for the Mediterranean monk seal Monachus Monachus colony at Cabo Blanco, the only surviving population of the species which still shows a colony structure. Data were collected by means of a monitoring programme that operated continuously in the main reproductive areas of the population during the period March 1993–May 1997. Most (84%) of the pups observed were born in two caves separated by a short distance. Although both caves were used by females to bear the pups, preferences greatly fluctuated from season to season with no apparent trend. Reproduction occurred throughout the year with a small peak of births in October. This unusual lack of seasonality is associated with the low latitudinal location of the colony and the effect of the upwelling that provides constant food throughout the year. The neonatal sex ratio did not differ significantly from 1:1 and the estimated annual productivity ranged from 44–58 pups. Taking into account population numbers, the annual birth rates were estimated to range from 0.3 to 0.43 pups per reproductive female, an extremely low rate when compared to other pinniped populations, particularly those of a similar size. Such low rates may be either an evolutionary determined characteristic of the species or a demographic consequence of the low population density over the last few centuries. Coupled with high pup mortality rates, this may account for the observed non-recovery of the population.

  • status and distribution of the mediterranean monk seal Monachus Monachus on the cabo blanco peninsula western sahara mauritania in 1993 1994
    Biological Conservation, 1997
    Co-Authors: Luis Mariano Gonzalez, Alex Aguilar, Luis Felipe Lopezjurado, Esteve Grau
    Abstract:

    Abstract The current geographical distribution of the Mediterranean monk seal Monachus Monachus colony inhabiting the Cabo Blanco peninsula (Western Sahara-Mauritania) is described. Its distribution range has apparently not changed since surveys conducted in 1984–1988. Sightings of adults on the Tarf el Guerguerat coast, 20 km north of the known breeding caves, suggests the existence of other possible breeding groups further north. Two caves used by the seals are described for the first time. A review of historical trends in cave occupation by seals made it possible (1) to locate the so-called ‘maternity cave’, last reported in 1949; and (2) to establish that the colony, since its discovery, has occupied at least eight caves, five of which have collapsed. An index of population size based on counts of individuals of identified morphological types indicates that, during 1993–1994, the colony was composed of c.113–165 individuals (excluding pups), a larger number than previously assumed. Counting of seals at times of maximum haul-out is proposed as a tool to monitor population trends, although it is considered unreliable for estimating absolute numbers.

Panagiotis Dendrinos - One of the best experts on this subject based on the ideXlab platform.

  • genetic and demographic history define a conservation strategy for earth s most endangered pinniped the mediterranean monk seal Monachus Monachus
    Scientific Reports, 2021
    Co-Authors: Alexandros A Karamanlidis, Panagiotis Dendrinos, Tomaž Skrbinsek, George Amato, Stephen J Gaughran, Panagiotis Kasapidis, Alexander Kopatz, Astrid Vik Stronen
    Abstract:

    The Mediterranean monk seal (Monachus Monachus) is a flagship species for marine conservation, but important aspects of its life history remain unknown. Concerns over imminent extinction motivated a nuclear DNA study of the species in its largest continuous subpopulation in the eastern Mediterranean Sea. Despite recent evidence of partial subpopulation recovery, we demonstrate that there is no reason for complacency, as the species still shares several traits that are characteristic of a critically endangered species: Mediterranean monk seals in the eastern Mediterranean survive in three isolated and genetically depauperate population clusters, with small effective population sizes and high levels of inbreeding. Our results indicated male philopatry over short distances, which is unexpected for a polygynous mammal. Such a pattern may be explained by the species' unique breeding behavior, in which males defend aquatic territories near breeding sites, while females are often forced to search for new pupping areas. Immediate action is necessary to reverse the downward spiral of population decline, inbreeding accumulation and loss of genetic diversity. We propose concrete conservation measures for the Mediterranean monk seal focusing on reducing anthropogenic threats, increasing the population size and genetic diversity, and thus improving the long-term prospects of survival.

  • trace element concentrations in the mediterranean monk seal Monachus Monachus in the eastern mediterranean sea
    Science of The Total Environment, 2017
    Co-Authors: C Formigaro, Panagiotis Dendrinos, Alexandros A Karamanlidis, Letizia Marsili, Marina Silvi, Annalisa Zaccaroni
    Abstract:

    The Mediterranean monk seal (Monachus Monachus) is one of the most endangered marine mammals in the world. The biggest sub-population of the species survives in Greece, where understanding the effects of pollution on the survival of the species has been identified as a national research and conservation priority. From 1990 to 2013 we collected tissue samples from 59 deceased monk seals in order to: (i) Define the concentration of trace elements (As, Pb, Cd, Hg, Se, Cr, Ni) in three different matrices (i.e., blubber, liver and kidney), (ii) Determine whether differences in trace element concentrations are age- or gender-related, (iii) Evaluate the potential effects of these pollutants. The study recorded differences in trace element concentrations among matrices, but in general, trace element exposure in Mediterranean monk seals in Greece was low and within the non-acutely toxic levels for Pinnipeds. Only arsenic concentrations were at the upper limit of the normal range observed in other marine mammals (0.69±0.55mg/kg w.w. in blubber, 0.79±0.62mg/kg w.w. in liver and 0.79±0.59mg/kg w.w. in kidney). We recorded also exceptionally high Hg concentrations in a single adult female (24.88mg/kg w.w.). Age- and gender-related differences were also recorded and were due to various biological, ecological and chemical factors. Based on the results of the study, potentially adverse effects on the immune and endocrine system of the Mediterranean monk seal from some pollutants (e.g., As, Cd, Se, Ni, Cr) cannot be ruled out, which may expose the Mediterranean seal population in Greece to epizootics and stochastic phenomena of mass mortality. It is therefore of utmost importance that pollutant monitoring becomes an integral component of the standard monitoring protocol of the endangered Mediterranean monk seal in the eastern Mediterranean.

  • the mediterranean monk seal Monachus Monachus status biology threats and conservation priorities
    Mammal Review, 2016
    Co-Authors: Alexandros A Karamanlidis, Ali Cemal Gucu, Pablo Fernández De Larrinoa, Panagiotis Dendrinos, William M Johnson, Cem O Kirac, Rosa Pires
    Abstract:

    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.

  • shaping species conservation strategies using mtdna analysis the case of the elusive mediterranean monk seal Monachus Monachus
    Biological Conservation, 2016
    Co-Authors: Alexandros A Karamanlidis, Panagiotis Dendrinos, Rosa Pires, Tomaž Skrbinsek, Stephen J Gaughran, Alex Aguilar, Djuro Huber, Jennifer K Schultz, George Amato
    Abstract:

    Abstract Halting biodiversity loss is one of the major conservation challenges of our time and science-based conservation actions are required to safeguard the survival of endangered species. However the establishment of effective conservation strategies may be hampered by inherent difficulties of studying elusive animals. We used analysis of control region sequences to obtain baseline information on the genetic diversity and population structure and history of the elusive and critically endangered Mediterranean monk seal that will help define an effective conservation strategy for the species. We analyzed 165 samples collected throughout the entire extant range of the species and identified 5 haplotypes. Based on levels of genetic diversity (haplotypic diversity: 0.03; variable sites: 0.6%) the Mediterranean monk seal appears to be one of the most genetically depauperate mammals on Earth. We identified three genetically distinct monk seal subpopulations: one in the north Atlantic [Cabo Blanco vs. Aegean Sea (FST = 0.733; P = 0.000); Cabo Blanco vs. Ionian Sea (FST = 0.925; P = 0.000)] and two in the Mediterranean, one in the Ionian and another one in the Aegean Sea (Ionian vs. Aegean Sea FST = 0.577; P = 0.000). Results indicate a recent divergence and short evolutionary history of the extant Mediterranean monk seal subpopulations. Based on the results we recommend continuation of the monitoring efforts for the species and systematic collection of genetic samples and storage in dedicated sample banks. On a management level we argue that, based on genetic evidence, it is justified to manage the Atlantic and Mediterranean monk seal subpopulations as two separate management units. In Greece, the existence of two subpopulations should guide efforts for the establishment of a network of protected areas and identify the monitoring of habitat availability and suitability as an important conservation priority.

  • age estimation growth and age related mortality of mediterranean monk seals Monachus Monachus
    Endangered Species Research, 2012
    Co-Authors: Sinead Murphy, Panagiotis Dendrinos, Eleni Tounta, Evgenia Androukaki, Alexandros A Karamanlidis, Trevor R Spradlin, Beth Mackey, Jill Mcvee, Emily Joseph, Christina Lockyer
    Abstract:

    Mediterranean monk seals Monachus Monachus are classified as Critically Endan- gered 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 age- maturity 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 sin- gle-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 individu- als in this rare species' core range.

Alex Aguilar - One of the best experts on this subject based on the ideXlab platform.

  • shaping species conservation strategies using mtdna analysis the case of the elusive mediterranean monk seal Monachus Monachus
    Biological Conservation, 2016
    Co-Authors: Alexandros A Karamanlidis, Panagiotis Dendrinos, Rosa Pires, Tomaž Skrbinsek, Stephen J Gaughran, Alex Aguilar, Djuro Huber, Jennifer K Schultz, George Amato
    Abstract:

    Abstract Halting biodiversity loss is one of the major conservation challenges of our time and science-based conservation actions are required to safeguard the survival of endangered species. However the establishment of effective conservation strategies may be hampered by inherent difficulties of studying elusive animals. We used analysis of control region sequences to obtain baseline information on the genetic diversity and population structure and history of the elusive and critically endangered Mediterranean monk seal that will help define an effective conservation strategy for the species. We analyzed 165 samples collected throughout the entire extant range of the species and identified 5 haplotypes. Based on levels of genetic diversity (haplotypic diversity: 0.03; variable sites: 0.6%) the Mediterranean monk seal appears to be one of the most genetically depauperate mammals on Earth. We identified three genetically distinct monk seal subpopulations: one in the north Atlantic [Cabo Blanco vs. Aegean Sea (FST = 0.733; P = 0.000); Cabo Blanco vs. Ionian Sea (FST = 0.925; P = 0.000)] and two in the Mediterranean, one in the Ionian and another one in the Aegean Sea (Ionian vs. Aegean Sea FST = 0.577; P = 0.000). Results indicate a recent divergence and short evolutionary history of the extant Mediterranean monk seal subpopulations. Based on the results we recommend continuation of the monitoring efforts for the species and systematic collection of genetic samples and storage in dedicated sample banks. On a management level we argue that, based on genetic evidence, it is justified to manage the Atlantic and Mediterranean monk seal subpopulations as two separate management units. In Greece, the existence of two subpopulations should guide efforts for the establishment of a network of protected areas and identify the monitoring of habitat availability and suitability as an important conservation priority.

  • concentrations and patterns of organochlorine pesticides and pcbs in mediterranean monk seals Monachus Monachus from western sahara and greece
    Science of The Total Environment, 2007
    Co-Authors: Assumpcio Borrell, Alex Aguilar, Gemma Cantos, Eugenia Androukaki, Panagiotis Dendrinos
    Abstract:

    Abstract Blubber from Mediterranean monk seals ( Monachus Monachus ) from the Western Sahara coast (Atlantic), sampled during 1996–1999, and from the Greek coast (Mediterranean), sampled during 1995–1999, was analyzed for organochlorine pollutants (OCs). In both populations, no significant difference was found between sexes. In the Atlantic population, mature females presented greater percentages of higher chlorinated PCB (polychlorinated biphenyl) congeners in relation to total PCBs (sum of 25 congeners) than pups, indicating a differential transfer of PCB congeners through lactation. In the Mediterranean, the reduced sample size of adult individuals precluded proper statistical investigation of age-related variation. Significant differences in concentrations and pollutant patterns were found between populations. Thus, Mediterranean individuals presented significantly higher levels of HCB (hexachlorobenzene), tPCB, and DDTs (dichlorodiphenyltrichloroethane) concentrations and DDE/tDDT and tDDT/tPCB ratios than their counterparts from the Atlantic. Moreover, the relative proportion of different congeners in relation to the total PCB load (congener/tPCB) was also different between the two areas. The 100  ⁎  tDDT/tPCB ratio in Atlantic seals was 38.46, which indicates a predominance of industrial inputs over those associated with agriculture. Conversely, in the Mediterranean seal population, the 100  ⁎  tDDT/tPCB ratio was 177.1, denoting a proportionally higher contribution of pollutants of agricultural origin.

  • lactation and mother pup behaviour in the mediterranean monk seal Monachus Monachus an unusual pattern for a phocid
    Journal of the Marine Biological Association of the United Kingdom, 2007
    Co-Authors: Alex Aguilar, Manel Gazo, L H Cappozzo, T Pastor, Jaume Forcada, Esteve Grau
    Abstract:

    This paper presents baseline information on maternal behaviour and lactation in the Mediterranean monk seal, with particular focus on the age at which pups are weaned. The study was conducted in the western Saharan population, the only surviving colony of the species. The first moult finished at a mean pup age of 72.3±17 d (N=17) and, in contrast to other taxonomically-related phocids, this process was not associated with weaning. Lactation lasted a mean of 119.4 d (N=9; range: 103–149 d) in the pups that could be monitored until full weaning had taken place. This period almost doubles the maximum lactation length reported in other phocid species. During the first week after birth the mother–pup bond was well developed and mothers always remained with their pups. The time invested in nursing (17%, SD: ±36) and in mother–pup interactions (14%, SD: ±32) was higher during this period than afterwards (8%, SD: ±23 and 4%, SD: ±19, respectively). After the first week, nursing continued but mothers started to leave their pups in order to feed at sea. Weaning occurred gradually. Already since birth, pups were active and mobile, and swam frequently before moulting or weaning occurred. Fostering and milk stealing were common patterns of behaviour for both lactating females and pups. In 26.6% of the suckling episodes observed in mother–pup pairs of known identity, pups suckled from females other than their mothers. Some females nursed more than one pup, at least occasionally, and in some cases a pup was fostered long-term by an alien female. The Mediterranean monk seal exhibits maternal-care characteristics that are more like otarids than phocids. This observation contradicts previous proposals that a short lactation period is a phylogenetic characteristic of phocids. Several of the unusual maternal traits observed may be favoured by year-round access to abundant food supply, availability of breeding sites, and mild climatic conditions. This information should be taken into account when designing conservation strategies for the species and, very particularly, in the implementation of pup rehabilitation programmes.

  • pupping season perinatal sex ratio and natality rates of the mediterranean monk seal Monachus Monachus from the cabo blanco colony
    Journal of Zoology, 1999
    Co-Authors: Manel Gazo, Miguel Ángel Cedenilla, Luis Mariano Gonzalez, Fernando Aparicio, Jorge F Layna, Alex Aguilar
    Abstract:

    Pupping seasonality, annual pup production, reproductive rate and sex ratio at birth were determined for the Mediterranean monk seal Monachus Monachus colony at Cabo Blanco, the only surviving population of the species which still shows a colony structure. Data were collected by means of a monitoring programme that operated continuously in the main reproductive areas of the population during the period March 1993–May 1997. Most (84%) of the pups observed were born in two caves separated by a short distance. Although both caves were used by females to bear the pups, preferences greatly fluctuated from season to season with no apparent trend. Reproduction occurred throughout the year with a small peak of births in October. This unusual lack of seasonality is associated with the low latitudinal location of the colony and the effect of the upwelling that provides constant food throughout the year. The neonatal sex ratio did not differ significantly from 1:1 and the estimated annual productivity ranged from 44–58 pups. Taking into account population numbers, the annual birth rates were estimated to range from 0.3 to 0.43 pups per reproductive female, an extremely low rate when compared to other pinniped populations, particularly those of a similar size. Such low rates may be either an evolutionary determined characteristic of the species or a demographic consequence of the low population density over the last few centuries. Coupled with high pup mortality rates, this may account for the observed non-recovery of the population.

  • status of the mediterranean monk seal Monachus Monachus in the western sahara and the implications of a mass mortality event
    Marine Ecology Progress Series, 1999
    Co-Authors: Jaume Forcada, Philip S Hammond, Alex Aguilar
    Abstract:

    The largest aggregation of the highly endangered Mediterranean monk seals Monachus Monachus is located on the Cap Blanc Peninsula on the coast of the western Sahara. Photographic identification of individuals was used in a capture-recapture analysis to estimate the abundance and composition of the colony during 1993 to 1998. Results of the application of these techniques to Mediterranean monk seals were satisfactory, and allowed independent annual population estimates. No significant trends in abundance over the period 1993 to 1996 were detected, and the mean estimate for the period was 317 seals (CV = 0.16; 95% CI: 237 to 447). Environmental changes affecting suitability of habitat, particularly food availability, are suggested as major factors for limited population recovery during this period. In spring 1997, a mass mortality event reduced the population size to 109 individuals (CV = 0.14; 95% CI: 86 to 145). Mortality was age-specific and resulted in a severe change in the stage composition of the population. Adults were the most affected, and therefore the proportion of juveniles increased from an initial 12% before the event to about 29% after. As a result of both the decrease in seal numbers and the change in population composition, the number of individuals potentially contributing to reproduction fell to about 77 or fewer. This number may not be enough to maintain genetic variability and overcome the effect of demographic stochasticity. The demographic changes caused by the die-off are expected to have both positive and negative effects on the reproductive success of the colony. However, they are undoubtedly factors which potentially threaten the stability and survival of the colony in the near future.

Alexandros A Karamanlidis - One of the best experts on this subject based on the ideXlab platform.

  • genetic and demographic history define a conservation strategy for earth s most endangered pinniped the mediterranean monk seal Monachus Monachus
    Scientific Reports, 2021
    Co-Authors: Alexandros A Karamanlidis, Panagiotis Dendrinos, Tomaž Skrbinsek, George Amato, Stephen J Gaughran, Panagiotis Kasapidis, Alexander Kopatz, Astrid Vik Stronen
    Abstract:

    The Mediterranean monk seal (Monachus Monachus) is a flagship species for marine conservation, but important aspects of its life history remain unknown. Concerns over imminent extinction motivated a nuclear DNA study of the species in its largest continuous subpopulation in the eastern Mediterranean Sea. Despite recent evidence of partial subpopulation recovery, we demonstrate that there is no reason for complacency, as the species still shares several traits that are characteristic of a critically endangered species: Mediterranean monk seals in the eastern Mediterranean survive in three isolated and genetically depauperate population clusters, with small effective population sizes and high levels of inbreeding. Our results indicated male philopatry over short distances, which is unexpected for a polygynous mammal. Such a pattern may be explained by the species' unique breeding behavior, in which males defend aquatic territories near breeding sites, while females are often forced to search for new pupping areas. Immediate action is necessary to reverse the downward spiral of population decline, inbreeding accumulation and loss of genetic diversity. We propose concrete conservation measures for the Mediterranean monk seal focusing on reducing anthropogenic threats, increasing the population size and genetic diversity, and thus improving the long-term prospects of survival.

  • trace element concentrations in the mediterranean monk seal Monachus Monachus in the eastern mediterranean sea
    Science of The Total Environment, 2017
    Co-Authors: C Formigaro, Panagiotis Dendrinos, Alexandros A Karamanlidis, Letizia Marsili, Marina Silvi, Annalisa Zaccaroni
    Abstract:

    The Mediterranean monk seal (Monachus Monachus) is one of the most endangered marine mammals in the world. The biggest sub-population of the species survives in Greece, where understanding the effects of pollution on the survival of the species has been identified as a national research and conservation priority. From 1990 to 2013 we collected tissue samples from 59 deceased monk seals in order to: (i) Define the concentration of trace elements (As, Pb, Cd, Hg, Se, Cr, Ni) in three different matrices (i.e., blubber, liver and kidney), (ii) Determine whether differences in trace element concentrations are age- or gender-related, (iii) Evaluate the potential effects of these pollutants. The study recorded differences in trace element concentrations among matrices, but in general, trace element exposure in Mediterranean monk seals in Greece was low and within the non-acutely toxic levels for Pinnipeds. Only arsenic concentrations were at the upper limit of the normal range observed in other marine mammals (0.69±0.55mg/kg w.w. in blubber, 0.79±0.62mg/kg w.w. in liver and 0.79±0.59mg/kg w.w. in kidney). We recorded also exceptionally high Hg concentrations in a single adult female (24.88mg/kg w.w.). Age- and gender-related differences were also recorded and were due to various biological, ecological and chemical factors. Based on the results of the study, potentially adverse effects on the immune and endocrine system of the Mediterranean monk seal from some pollutants (e.g., As, Cd, Se, Ni, Cr) cannot be ruled out, which may expose the Mediterranean seal population in Greece to epizootics and stochastic phenomena of mass mortality. It is therefore of utmost importance that pollutant monitoring becomes an integral component of the standard monitoring protocol of the endangered Mediterranean monk seal in the eastern Mediterranean.

  • the mediterranean monk seal Monachus Monachus status biology threats and conservation priorities
    Mammal Review, 2016
    Co-Authors: Alexandros A Karamanlidis, Ali Cemal Gucu, Pablo Fernández De Larrinoa, Panagiotis Dendrinos, William M Johnson, Cem O Kirac, Rosa Pires
    Abstract:

    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.

  • shaping species conservation strategies using mtdna analysis the case of the elusive mediterranean monk seal Monachus Monachus
    Biological Conservation, 2016
    Co-Authors: Alexandros A Karamanlidis, Panagiotis Dendrinos, Rosa Pires, Tomaž Skrbinsek, Stephen J Gaughran, Alex Aguilar, Djuro Huber, Jennifer K Schultz, George Amato
    Abstract:

    Abstract Halting biodiversity loss is one of the major conservation challenges of our time and science-based conservation actions are required to safeguard the survival of endangered species. However the establishment of effective conservation strategies may be hampered by inherent difficulties of studying elusive animals. We used analysis of control region sequences to obtain baseline information on the genetic diversity and population structure and history of the elusive and critically endangered Mediterranean monk seal that will help define an effective conservation strategy for the species. We analyzed 165 samples collected throughout the entire extant range of the species and identified 5 haplotypes. Based on levels of genetic diversity (haplotypic diversity: 0.03; variable sites: 0.6%) the Mediterranean monk seal appears to be one of the most genetically depauperate mammals on Earth. We identified three genetically distinct monk seal subpopulations: one in the north Atlantic [Cabo Blanco vs. Aegean Sea (FST = 0.733; P = 0.000); Cabo Blanco vs. Ionian Sea (FST = 0.925; P = 0.000)] and two in the Mediterranean, one in the Ionian and another one in the Aegean Sea (Ionian vs. Aegean Sea FST = 0.577; P = 0.000). Results indicate a recent divergence and short evolutionary history of the extant Mediterranean monk seal subpopulations. Based on the results we recommend continuation of the monitoring efforts for the species and systematic collection of genetic samples and storage in dedicated sample banks. On a management level we argue that, based on genetic evidence, it is justified to manage the Atlantic and Mediterranean monk seal subpopulations as two separate management units. In Greece, the existence of two subpopulations should guide efforts for the establishment of a network of protected areas and identify the monitoring of habitat availability and suitability as an important conservation priority.

  • age estimation growth and age related mortality of mediterranean monk seals Monachus Monachus
    Endangered Species Research, 2012
    Co-Authors: Sinead Murphy, Panagiotis Dendrinos, Eleni Tounta, Evgenia Androukaki, Alexandros A Karamanlidis, Trevor R Spradlin, Beth Mackey, Jill Mcvee, Emily Joseph, Christina Lockyer
    Abstract:

    Mediterranean monk seals Monachus Monachus are classified as Critically Endan- gered 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 age- maturity 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 sin- gle-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 individu- als in this rare species' core range.

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  • the mediterranean monk seal Monachus Monachus status biology threats and conservation priorities
    Mammal Review, 2016
    Co-Authors: Alexandros A Karamanlidis, Ali Cemal Gucu, Pablo Fernández De Larrinoa, Panagiotis Dendrinos, William M Johnson, Cem O Kirac, Rosa Pires
    Abstract:

    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.

  • shaping species conservation strategies using mtdna analysis the case of the elusive mediterranean monk seal Monachus Monachus
    Biological Conservation, 2016
    Co-Authors: Alexandros A Karamanlidis, Panagiotis Dendrinos, Rosa Pires, Tomaž Skrbinsek, Stephen J Gaughran, Alex Aguilar, Djuro Huber, Jennifer K Schultz, George Amato
    Abstract:

    Abstract Halting biodiversity loss is one of the major conservation challenges of our time and science-based conservation actions are required to safeguard the survival of endangered species. However the establishment of effective conservation strategies may be hampered by inherent difficulties of studying elusive animals. We used analysis of control region sequences to obtain baseline information on the genetic diversity and population structure and history of the elusive and critically endangered Mediterranean monk seal that will help define an effective conservation strategy for the species. We analyzed 165 samples collected throughout the entire extant range of the species and identified 5 haplotypes. Based on levels of genetic diversity (haplotypic diversity: 0.03; variable sites: 0.6%) the Mediterranean monk seal appears to be one of the most genetically depauperate mammals on Earth. We identified three genetically distinct monk seal subpopulations: one in the north Atlantic [Cabo Blanco vs. Aegean Sea (FST = 0.733; P = 0.000); Cabo Blanco vs. Ionian Sea (FST = 0.925; P = 0.000)] and two in the Mediterranean, one in the Ionian and another one in the Aegean Sea (Ionian vs. Aegean Sea FST = 0.577; P = 0.000). Results indicate a recent divergence and short evolutionary history of the extant Mediterranean monk seal subpopulations. Based on the results we recommend continuation of the monitoring efforts for the species and systematic collection of genetic samples and storage in dedicated sample banks. On a management level we argue that, based on genetic evidence, it is justified to manage the Atlantic and Mediterranean monk seal subpopulations as two separate management units. In Greece, the existence of two subpopulations should guide efforts for the establishment of a network of protected areas and identify the monitoring of habitat availability and suitability as an important conservation priority.

  • assessing accidental entanglement as a threat to the mediterranean monk seal Monachus Monachus
    Endangered Species Research, 2008
    Co-Authors: Alexandros A Karamanlidis, Evgenia Androukaki, William M Johnson, Stella Adamantopoulou, Archontia Chatzispyrou, Spyros Kotomatas, Anastasios Papadopoulos, Vangelis Paravas, Giorgos Paximadis, Rosa Pires
    Abstract:

    The Mediterranean monk seal Monachus Monachus is the most endangered seal in the world with <600 ind. currently surviving. The species faces a number of threats to its survival: acci- dental entanglement has been identified as one of the most important amongst them. Here we made the first attempt to systematically describe the nature of this threat and assess its impact on Mediter- ranean monk seal populations. We based our study on information from an extensive literature review, questionnaires carried out in various locations in Greece and necropsies performed in Greece and in the Madeira Islands, Portugal. Our results indicate that accidental entanglement has been, and still is, a major threat to the species in its main distribution area in the northeastern Mediter- ranean, and that this threat may increase throughout the seal's range. Accidental entanglement occurs mainly with fishing nets, and affects mostly sub-adult seals. Short-term conservation actions should include the identification of critical pupping sites and their protection through the establish- ment and enforcement of protective measures. A long-term course of action will require detailed knowledge of the causes of accidental entanglement of Mediterranean monk seals in fishing gear.

  • the critically endangered mediterranean monk seal Monachus Monachus in the archipelago of madeira priorities for conservation
    Oryx, 2008
    Co-Authors: Rosa Pires, Henrique Costa Neves, Alexandros A Karamanlidis
    Abstract:

    The Mediterranean monk seal is categorized as Critically Endangered on the IUCN Red List and is in urgent need of effective conservation measures. Following a steep decline in the 20th century, the National Park Service of Madeira initiated efforts to protect the species in the archipelago of Madeira, including habitat protection, scientific research and public awareness. The aim of this study was to analyse data collected during a monitoring project (19882005) to assess the conservation status of the species and identify priority conservation actions for the future. The study recorded the presence of the species at key pupping sites in a strictly protected area at the Desertas Islands, increased sightings in recent years around the main island of Madeira, an increase in the number of pups born, and low mortality. The population in the archipelago of Madeira is currently estimated to be 20-30 adults. These findings suggest that the species remains Critically Endangered in the area but that its conservation situation has improved because of the implementation of effective conservation actions. Conservation priorities identified include protecting suitable monk seal habitat at Madeira, investigating sealfisheries interactions, increas- ing environmental education, and strengthening regional legislation for the protection of the species.

  • the availability of resting and pupping habitat for the critically endangered mediterranean monk seal Monachus Monachus in the archipelago of madeira
    Oryx, 2004
    Co-Authors: Alexandros A Karamanlidis, Rosa Pires, Nadia Carina Silva, Henrique Costa Neves
    Abstract:

    In order to describe the resting and pupping habitat of the Critically Endangered Mediterranean monk seal Monachus Monachus and facilitate the identification of preferences by the species for suitable habitat for resting and pupping, 94 sea caves in the archipelago of Madeira were located, charted, and categorized using six characteristics. A cluster analysis indicated that there are eight different types of cave, in three groups. Observations of cave usage indicate that monk seals in the archipelago do not appear to exhibit a preference for certain cave types for resting. When taking care of young, however, the species appears to prefer sea caves that have beaches above sea level during high tide and long entrance corridors. Based on these preferences we believe that although there is a large number of caves in the area that are suitable for resting, only 16 (17%) of the caves are suitable for pupping. The survival of the Critically Endangered Mediterranean monk seal will depend on the allocation of sufficient suitable habitat for reproduction.