Can a cow save a newt? The role of cattle drinking troughs in amphibian conservation

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Low genetic variability of the white‐clawed crayfish in the Iberian Peninsula: its origin and management implications

• 1. A study on the genetic variability of the white‐clawed crayfish was carried out based on mitochondrial cytochrome oxidase subunit I gene sequences. The sequences applied were more informative regarding white‐clawed crayfish genetic variability than others previously used.
• 2. Two haplotypes were found to exist in the Iberian Peninsula. The haplotypes exhibit a strong geographic subdivision (Φ_ST=0.83). One of the Iberian haplotype s was similar to north Italian haplotypes and the second differed in only one mutation. This pattern of genetic variability contrasts with those found in glacial refugial areas of France, Italy and the Balkan Peninsula.
• 3. Two hypotheses on the origin of the white‐clawed crayfish in the Iberian Peninsula are discussed: (i) one based on an anthropogenic origin, and (ii) a second based on a successive number of postglacial ancient and recent bottlenecks, i.e. the disjunction between Iberian and Italian populations of white‐clawed crayfish species is due to competition between A. italicus and A. pallipes, in addition to the impact of crayfish plague and human translocations.
• 4. New references for the white‐clawed crayfish in the Iberian Peninsula were found in medieval and Arabic texts. The results show that this species has been thriving in this peninsula since ancient periods and that its indigenous status should not be questioned.
• 5. Conservation action and plans should consider the low genetic diversity as a limitation for farm‐raising specimens more adapted and resistant to changing environments and diseases.

Copyright © 2007 John Wiley & Sons, Ltd.     

Basin‐scale distribution and haplotype partitioning in different genetic lineages of the Neotropical migratory fish Salminus brasiliensis

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Insights into population genetics,connectivity and demographic history of the longnosed skate Dipturus oxyrinchus (Linnaeus, 1758) in the western Mediterranean Sea

1. Genetic information is crucial for the conservation of Dipturus oxyrinchus (Linnaeus, 1758), a threatened large skate with declining populations over most of its geographical range. The main aim of the present study was to investigate the genetic structure, connectivity and demographic history of the longnosed skate in Sardinia (western Mediterranean Sea).
2. Patterns of population structure were assessed in 175 specimens from six sampling sites. Variation in two mitochondrial genes (cytochrome c oxidase subunit I (COI) and control region) highlighted high genetic diversity and low but significant genetic differentiation among sites, which clustered into three groups corresponding to the north‐west, north‐east and south Sardinian coasts.
3. The observed genetic structuring could presumably depend on a combination of past geological events, contemporary restrictions to dispersal and biological characteristics of the species (e.g. site‐fidelity, no pelagic larval stage, limited dispersal of juveniles and/or adults).
4. Demographic analyses showed signs of past population expansion, but substantial current stability of Sardinian populations. From a conservation perspective, these results are encouraging, and indicate that Sardinian populations are still large and stable, and seem not to have suffered negative side‐effects from the ever‐growing fishing pressure in the region.
5. The occurrence of genetic structuring strongly supported the close monitoring of populations to identify any erosion of their gene pool, and high genetic variability of the Sardinian D. oxyrinchus populations could thus represent priority populations for conservation purposes, providing potential sources for recolonization in cases of local extinctions in other areas of the distribution range of the species.
6. When the sequences from Sardinia were compared with those available from other areas, the data seem to exclude the possibility that the Atlantic and Mediterranean host totally isolated populations or even different species, as recently suggested. However, additional markers and a larger sampling sites are needed to confirm these findings.

     

Changes in threats to macroalgal forests (Cystoseira sensu lato) at three restoration sites in the Mediterranean Sea

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Management of a highly unlikely native fish: The case of arctic charr Salvelinus alpinus from the Southern Alps

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Colonization history and human translocations explain the population genetic structure of the noble crayfish (Astacus astacus) in Fennoscandia: Implications for the management of a critically endangered species

1. The noble crayfish (Astacus astacus) is an endangered freshwater species in Europe. The main threat is from lethal crayfish plague, caused by the oomycete Aphanomyces astaci that has been spread over Europe by introduced North American crayfish species, acting as chronic carriers of the disease.
2. Most of the remaining noble crayfish populations are found in the Baltic Sea area, and there is an urgent need to implement conservation actions to slow down or halt the extinction rate in this region. However, limited knowledge about the genetic structure of populations in this area has so far precluded the development of conservation strategies that take genetic aspects into consideration.
3. Key objectives of this large-scale genetic study, covering 77 locations mainly from northern Europe, were to describe the contemporary population genetic structure of the noble crayfish in the Fennoscandian peninsula (Sweden, Norway, and Finland), taking postglacial colonization history into account, and to evaluate how human activities such as stocking have affected the genetic structure of the populations.
4. Analyses of 15 microsatellite markers revealed three main genetic clusters corresponding to populations in northern, middle, and southern Fennoscandia, with measures of genetic diversity being markedly higher within populations in the southern cluster. The observed genetic structure probably mirrors two main colonizations of the Baltic Sea basin after the last glaciation period. At the same time, several deviations from this pattern were observed, reflecting past human translocations of noble crayfish.
5. The results are discussed in relation to the conservation and management of this critically endangered species. In particular, we recommend increased efforts to protect the few remaining noble crayfish populations in southern Fennoscandia and the use of genetic information when planning stocking activities, such as reintroductions following local extinctions.

     

The status and distribution of a newly identified endemic galaxiid in the eastern Cape Fold Ecoregion,of South Africa

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Conservation genetics of the broadstripe shiner,Pteronotropis euryzonus,an endemic species of the middle Chattahoochee River

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Newly developed microsatellite markers for the pan‐European duck mussel,Anodonta anatina: revisiting the main mitochondrial lineages

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The relevance of mitochondrial lineages of Taiwanese cultured grey mullet,Mugil cephalus,to commercial products of Roe

Mugil cephalus is an important aquaculture species in Taiwan with highly valuable roe. In order to obtain its roe, mullet fry from various Taiwan estuaries are raised in aquaculture ponds until maturity. However, not all female mullets have developed ovaries. Therefore, we have attempted to use DNA profiling to aid selection of mullet fry for aquaculture. A large proportion of North coast mullet and some West coast mullet were identified as cytochrome oxidase subunit I (COI) mitochondrial lineage 1. COI mitochondrial lineage 2 was dominant in the west and east coast estuaries, whereas COI mitochondrial lineage 3 was fewest and only was present in Chang‐hua county (middle west of Taiwan). The gonadosomatic index (GSI) of lineage 1 individuals ranged from 0 to 5, no matter where the mullet fry were captured. The GSI of both the west and east coast lineage 2 individuals ranged from 0 to over 15, but the GSI of lineage 2 of the I‐lan (north east of Taiwan) population was generally lower than that of western populations. These findings suggest that a genetic difference whereby west coast lineage 2 mullet yield heavier roe although the body size of lineage 1 individual is larger than that of lineage 2. Thus, lineage 2 individuals with their normal GSI distribution are the most economically viable. The application of the rapid screening of mitochondrial lineages is expected to help aquaculture farmers cultivate lineage 2 fry for roe production rather than lineage 1.     

Quantifying morphological and genetic variation of sympatric populations to guide conservation of endangered,micro‐endemic springsnails

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Conserving indigenous crayfish: stock assessment and habitat requirements in the threatened Austropotamobius italicus

• 1. As part of the Austropotamobius pallipes species complex, the crayfish Austropotamobius italicus is a species of community interest whose preservation requires the designation of Special Areas of Conservation (SACs) (Annex II, EU Habitats Directive). This study aimed at (1) assessing the conservation status of this threatened indigenous species by stock assessment in central Italy and (2) identifying some aspects of its elective habitat.
• 2. Surveys were conducted in nine streams harbouring A. italicus (streams WI) and in 10 streams where crayfish populations became extinct at least 5 years before the study (streams WO).
• 3. The results confirmed that A. italicus is a K‐selected species, with a relatively slow growth rate (males: 0.34; females: 0.37) and a long life expectancy (males: 8.2 years; females: 7.8 years). The extant populations are healthy, showing balanced sex‐ratios and well structured age‐class compositions. Mortality is mainly due to fishing, which is illegal in Tuscany.
• 4. Principal Components Analyses showed that the streams WI and WO differ in the abundance of allochthonous plant detritus but not in the taxonomic composition of their macroinvertebrate communities. Age classes were found to be spatially segregated, juveniles mainly using cobbles as substrates and adults seemingly avoiding them.
• 5. The loss of the pristine riverine landscape seems to have been responsible, together with illegal fishing, for the local extinction of the species. As a consequence, retaining, enhancing, and restoring the habitat and its complexity are required for the preservation of A. italicus.
• 6. The designation of SACs might help in this endeavour if accompanied by programmes aimed at publicizing the need for conservation of this species. Unfortunately, crayfish‐focused projects supported by LIFE in Italy since 1992 (4%) and the SACs involved (1.4%) have been relatively few, despite the poor conservation status of this species and its well recognized ecological role.

Copyright © 2008 John Wiley & Sons, Ltd.     

Global phylogeography of the smooth hammerhead shark: Glacial refugia and historical migration patterns

1. Extreme climate changes during the Cenozoic Era strengthened different biogeographical barriers that decreased the connectivity among populations, triggering lineage diversification of different species worldwide.
2. The mitochondrial DNA control region was employed to explore the phylogeography of Sphyrna zygaena, a globally distributed species threatened by unsustainable, illegal, unreported and unregulated fisheries triggered by the international shark fin trade. It is listed as ‘Vulnerable’ by the IUCN Red List and its trade is regulated by CITES Appendix II.
3. Only 13 haplotypes were found with low genetic diversity levels (hd = 0.686 ± 0.014; π = 0.00206 ± 0.00004) compared with other species of the Sphyrnidae family. The species has a very strong phylogeographic population structure among the Atlantic, Indian and Pacific Oceans (Φ_ST = 0.79132). Worldwide, there are six distinct populations with some haplotype sharing.
4. These populations are probably connected by a stepping-stone dispersal of a small number of migrants per generation from the Indo-Pacific towards the Atlantic. Modelling suggests that S. zygaena diverged into two lineages around 6.96 million years ago which have been isolated in glacial refuges in the Atlantic and Indo-Pacific oceans; and after deglaciation, a population expansion probably permitted secondary contact.
5. Conservation plans to establish differentiated management units should be adopted in each of the identified populations. Among these, the Eastern Central Atlantic and West Indo-Pacific are the most important areas for the species considering the historical migration routes that act as a bridge connecting the Atlantic and Indo-Pacific Oceans while the Gulf of Guinea connects the Atlantic populations. Still, further studies are required to know if these populations are also linked with nursery areas for the species.
6. The results herein can help to delimit the main evolutionarily significant units to implement effective policies to establish differentiated management units as starting points to genetic monitoring programmes for Sphyrna zygaena.

     

Sea turtle strandings reveal high anthropogenic mortality in Italian waters

• 1. Spatio‐temporal distribution and anthropogenic mortality factors were investigated in loggerhead turtles (Caretta caretta) found stranded or floating in the waters around Italy. A total of 5938 records for the period 1980–2008 were analysed concerning loggerhead turtles measuring from 3.8 to 97 cm curved carapace length (mean: 48.3 cm).
• 2. Results highlighted the following conservation issues: (i) in the study area, anthropogenic mortality is higher than natural mortality; (ii) interaction with fisheries is by far the most important anthropogenic mortality factor; (iii) longlines are an important mortality factor in the southern areas; (iv) trawlers are the cause of high numbers of dead strandings in the north Adriatic; (v) entanglement in ghost‐gear or in other anthropogenic debris affects high numbers of turtles; and (vi) boat strikes are an important source of mortality in most areas but mostly in the warm seasons.
• 3. Results also indicate that: (vii) the north Adriatic is the area with the highest turtle density; and (viii) the south Adriatic and to a lesser extent the surrounding areas of the north Adriatic and the Ionian, are important developmental areas for loggerhead turtles in the first years of life.
• 4. Italy is in the centre of the Mediterranean Sea and borders major foraging areas for the loggerhead turtles in the region, and these results confirm previous concerns about the level of anthropogenic mortality in Italian waters. Copyright © 2010 John Wiley & Sons, Ltd.

     

A new map of the tiger shark (Galeocerdo cuvier) genetic population structure in the western Atlantic Ocean: Hypothesis of an equatorial convergence centre

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Regional population genetics and global phylogeography of the endangered highly migratory shark Lamna nasus: Implications for fishery management and conservation

1. The porbeagle shark Lamna nasus is a large highly migratory shark distributed in cold and temperate marine waters of the North Atlantic and Southern Hemisphere (SH). According to the International Union for Conservation of Nature, the porbeagle is assessed globally as Vulnerable and regionally as Critically Endangered in the North Atlantic and the Mediterranean Sea. This study explored, for the first time, the population genetics of L. nasus at a regional (south-east Pacific Ocean) and global scale.
2. In this study, the null hypotheses of no genetic discontinuities among populations (i) within the SH, and (ii) between the SH and Northern Hemisphere (NH) were tested. Also, the demographic history of L. nasus in different ocean basins was assessed. Two mitochondrial markers (Control Region [CR] and cox1) well suited for population genetics inferences in sharks were used.
3. Spatial–genetic analyses suggested two genetic clusters co-occurring in the south-eastern Pacific Ocean. A two-way ANOVA using the cox1 but not the CR mtDNA fragment detected an effect of genetic identity on shark body size. Phylogeographic analyses, haplotype networks, and analyses of molecular variance demonstrated genetic differences between populations from the NH and SH but not among populations in the SH.
4. Migration estimates indicated limited current maternal gene flow between the two hemispheres but high gene flow within hemispheres. Two well-defined haplotype groups with star-like shapes inhabited all ocean basins in the SH. These results could reflect a historical scenario of reproductive isolation and more recent mixture among previously isolated populations in the SH. A Bayesian skyline plot analysis indicated sudden population expansion in the SH occurring ~100–125 kya.
5. This study highlights the need for additional studies focusing on the population genomics (using nuclear markers, i.e. single nucleotide polymorphisms) and the general biology of L. nasus to explore the existence of genetically dissimilar populations in the SH. Such studies will help implementing efficient genetic monitoring programmes.

     

Reintroduction of a dioecious aquatic macrophyte (Stratiotes aloides L.) regionally extinct in the wild. Interesting answers from genetics

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Management of the exploitation of the lugworm Arenicola marina and the ragworm Nereis virens (Polychaeta) in conservation areas

• 1. In Europe, bait supply to anglers from the natural environment involves: (i) bait collection by anglers for own use, (ii) local semi-professional bait digging and (iii) professional bait digging contracted to distributors.
• 2. The management of bait digging activity is particularly acute where there is a conflict with conservation interests.
• 3. Two case studies are presented describing the population dynamics of: I Arenicola marina in the Lindisfarne nature reserve, and II Nereis virens in the Menai Strait; both in conservation areas.
• 4. Case I. Populations of A marina are subject to marked annual cycles in number and fresh weight. This case illustrates the response of the population to substantial overexploitation leading to a population crash. With the introduction of restrictive legislation the population was re-established by recruitment of adults from neighbouring unexploited populations.
• 5. Case II illustrates the dynamics of a N. virens population dominated by large old individuals; it does not represent a sustainable resource in contrast with populations of the same species in other locations.
• 6. The management of the exploitation of bait populations in conservation areas is discussed in relation to world patterns of utilization and supply.

     

Genetic differentiation and historical demography of wood stork populations in Brazilian wetlands: Implications for the conservation of the species and associated ecosystems

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