scholarly journals Tracking the rising extinction risk of sharks and rays in the Northeast Atlantic Ocean and Mediterranean Sea

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Rachel H. L. Walls ◽  
Nicholas K. Dulvy
Keyword(s):  
Mediterranean Sea ◽  
Extinction Risk ◽  
Species Traits ◽  
Northeast Atlantic ◽  
Threat Level ◽  
Northeast Atlantic Ocean ◽  
Data Deficient ◽  
Increasing Trends ◽  
Threat Levels ◽  
Published Research

AbstractThe loss of biodiversity is increasingly well understood on land, but trajectories of extinction risk remain largely unknown in the ocean. We present regional Red List Indices (RLIs) to track the extinction risk of 119 Northeast Atlantic and 72 Mediterranean shark and ray species primarily threatened by overfishing. We combine two IUCN workshop assessments from 2003/2005 and 2015 with a retrospective backcast assessment for 1980. We incorporate predicted categorisations for Data Deficient species from our previously published research. The percentage of threatened species rose from 1980 to 2015 from 29 to 41% (Northeast Atlantic) and 47 to 65% (Mediterranean Sea). There are as many threatened sharks and rays in Europe as there are threatened birds, but the threat level is nearly six times greater by percentage (41%, n = 56 of 136 vs. 7%, n = 56 of 792). The Northeast Atlantic RLI declined by 8% from 1980 to 2015, while the higher-risk Mediterranean RLI declined by 13%. Larger-bodied, shallow-distributed, slow-growing species and those with range boundaries within the region are more likely to have worsening status in the Northeast Atlantic. Conversely, long-established, severe threat levels obscure any potential relationships between species’ traits and the likelihood of worsening IUCN status in the Mediterranean Sea. These regional RLIs provide the first widespread evidence for increasing trends in regional shark and ray extinction risk and underscore that effective fisheries management is necessary to recover the ecosystem function of these predators.

scholarly journals Growth patterns of the lanternfish Ceratoscopelus maderensis in the western Mediterranean Sea

2021 ◽  
Vol 85 (2) ◽  
pp. 71-80
Author(s):  
Enric Real ◽  
Ainhoa Bernal ◽  
Beatriz Morales-Nin ◽  
Balbina Molí ◽  
Itziar Alvarez ◽  
...  
Keyword(s):  
Atlantic Ocean ◽  
Mediterranean Sea ◽  
Western Mediterranean ◽  
Growth Patterns ◽  
Age And Growth ◽  
Mesopelagic Fish ◽  
Northeast Atlantic ◽  
Daily Increments ◽  
Western Mediterranean Sea ◽  
Northeast Atlantic Ocean

The age and growth patterns of the mesopelagic fish Ceratoscopelus maderensis (family Myctophidae) of the western Mediterranean Sea were described throughout its entire life cycle (from larvae to adult stages) using the sagittae otoliths of 59 individuals collected in December 2009. Three characteristic zones were identified along the cross-section of the sagittae (larval, metamorphic and juvenile-adult zones). Assuming growth rings as daily increments, the age of the analysed individuals (from 3.5 to 64 mm standard length [SL]) would range from 7 to 332 days. The relationship between the number of increments and the fish SL was fitted to a von Bertalanffy growth model (SL=70.5899Å~(1–exp(–0.0501(t+2.6705))). The growth pattern of C. maderensis in the western Mediterranean Sea was similar to that reported for this species in the northeast Atlantic Ocean. Though from a body size of 40-45 mm SL, growth rates declined more slowly in individuals from the western Mediterranean Sea, growth differences between these individuals and those from the northeast Atlantic Ocean were not statistically significant. This study provides new insights into the age and growth patterns of one of the most abundant mesopelagic fish species in the Mediterranean Sea that have clear implications for the study and management of marine ecosystems.

scholarly journals Regional patterns of δ 13 C and δ 15 N for European common cuttlefish ( Sepia officinalis ) throughout the Northeast Atlantic Ocean and Mediterranean Sea

2021 ◽  
Vol 8 (9) ◽  
pp. 210345
Author(s):  
R. J. David Wells ◽  
Jay R. Rooker ◽  
Piero Addis ◽  
Haritz Arrizabalaga ◽  
Miguel Baptista ◽  
...  
Keyword(s):  
Atlantic Ocean ◽  
Mediterranean Sea ◽  
Distinct Pattern ◽  
Sampling Location ◽  
Sepia Officinalis ◽  
Regional Patterns ◽  
Northeast Atlantic ◽  
Sampling Locations ◽  
Northeast Atlantic Ocean ◽  
The Mediterranean

Stable isotope compositions of carbon and nitrogen (expressed as δ 13 C and δ 15 N) from the European common cuttlefish ( Sepia officinalis ) were measured in order to evaluate the utility of using these natural tracers throughout the Northeast Atlantic Ocean and Mediterranean Sea (NEAO-MS). Mantle tissue was obtained from S. officinalis collected from 11 sampling locations spanning a wide geographical coverage in the NEAO-MS. Significant differences of both δ 13 C and δ 15 N values were found among S. officinalis samples relative to sampling location. δ 13 C values did not show any discernable spatial trends; however, a distinct pattern of lower δ 15 N values in the Mediterranean Sea relative to the NEAO existed. Mean δ 15 N values of S. officinalis in the Mediterranean Sea averaged 2.5‰ lower than conspecifics collected in the NEAO and showed a decreasing eastward trend within the Mediterranean Sea with the lowest values in the most eastern sampling locations. Results suggest δ 15 N may serve as a useful natural tracer for studies on the population structure of S. officinalis as well as other marine organisms throughout the NEAO-MS.

scholarly journals Genetic population structure of European anchovy in the Mediterranean Sea and the Northeast Atlantic Ocean using sequence analysis of the mitochondrial DNA control region

2013 ◽  
Vol 71 (2) ◽  
pp. 391-397 ◽  
Author(s):  
Jordi Viñas ◽  
Núria Sanz ◽  
Luis Peñarrubia ◽  
Rosa-Maria Araguas ◽  
José-Luis García-Marín ◽  
...  
Keyword(s):  
Population Structure ◽  
Atlantic Ocean ◽  
Mediterranean Sea ◽  
Control Region ◽  
Genetic Population ◽  
Mitochondrial Dna Control Region ◽  
European Anchovy ◽  
Northeast Atlantic ◽  
Northeast Atlantic Ocean ◽  
The Mediterranean

Abstract Viñas, J., Sanz, N., Peñarrubia, L., Araguas, R-M., García-Marín, J-L., Roldán, M-I., and Pla, C. 2014. Genetic population structure of European anchovy in the Mediterranean Sea and the Northeast Atlantic Ocean using sequence analysis of the mitochondrial DNA control region. – ICES Journal of Marine Science, 71: 391–397. The European anchovy (Engraulis encrasicolus) exhibits a complex population structure in the Mediterranean Sea and Northeast Atlantic Ocean. To resolve the population genetic structure of this species, we surveyed sequence variability in the mitochondrial (mtDNA) control region in samples (n = 563) from 13 locations in the Northeast Atlantic, the Bay of Biscay, and the Mediterranean Sea. Based on pairwise ΦSTs, SAMOVA, and multidimensional scaling, a complicated population structure composed of multiple populations emerged. Combining these results with those from previous population studies based on mitochondrial and nuclear markers, we identified nine genetically differentiated European anchovy populations: (i) Canary Islands; (ii) Cádiz; (iii) Alborán Sea; (iv) Garona; (v) Arcachon and Donostia; (vi) a large population in the northwestern Mediterranean, including Cadaqués, Gulf of Lyon, Elba, and Sicily; (vii) southern Adriatic; (viii) northern Adriatic; and (ix) Aegean Sea. We suggest that independent management strategies should be implemented for each genetically differentiated population, and, in cases where several fisheries stocks are recognized within an area of genetic homogeneity, each stock should be managed separately.

scholarly journals Global analysis of threat status reveals higher extinction risk in tropical than in temperate bird sister species

2016 ◽  
Vol 2 (1) ◽  
pp. 21-34 ◽  
Author(s):  
Jiří Reif ◽  
Klára Štěpánková
Keyword(s):  
Extinction Risk ◽  
Global Analysis ◽  
Species Traits ◽  
Breeding Habitat ◽  
Sister Species ◽  
Tropical Species ◽  
Tropical Zone ◽  
Threat Status ◽  
Threat Level ◽  
Latitudinal Range

Abstract Given increasing pressures upon biodiversity, identification of species’ traits related to elevated extinction risk is useful for more efficient allocation of limited resources for nature conservation. Despite its need, such a global analysis was lacking in the case of birds. Therefore, we performed this exercise for avian sister species using information about their global extinction risk from IUCN Red List. We focused on 113 pairs of sister species, each containing a threatened and an unthreatened species to factor out the effects of common evolutionary history on the revealed relationship. We collected data on five traits with expected relationships to species’ extinction risk based on previous studies performed at regional or national levels: breeding habitat (recognizing forest, grassland, wetland and oceanic species), latitudinal range position (temperate and tropics species), migration strategy (migratory and resident species), diet (carnivorous, insectivorous, herbivorous and omnivorous species) and body mass. We related the extinction risk using IUCN threat level categories to species’ traits using generalised linear mixed effects models expecting lower risk for forest, temperate, omnivorous and smaller-bodied species. Our expectation was confirmed only in the case of latitudinal range position, as we revealed higher threat level for tropical than for temperate species. This relationship was robust to different methods of threat level expression and cannot be explained by a simple association of high bird species richness with the tropical zone. Instead, it seems that tropical species are more threatened because of their intrinsic characteristics such as slow life histories, adaptations to stable environments and small geographic ranges. These characteristics are obviously disadvantageous in conditions of current human-induced environmental perturbations. Moreover, given the absence of habitat effects, our study indicates that such perturbations act across different tropical environments. Therefore, disproportionally higher conservation effort in the tropics compared to the temperate zone is urgently needed.

scholarly journals Predicting the conservation status of Europe’s Data Deficient sharks and rays

2019 ◽  
Author(s):  
Rachel H.L. Walls ◽  
Nicholas K. Dulvy
Keyword(s):  
Mediterranean Sea ◽  
Conservation Status ◽  
Cost Effective ◽  
Reproductive Mode ◽  
Iucn Red List ◽  
Red List ◽  
Northeast Atlantic ◽  
Extinction Rates ◽  
The Status ◽  
Data Deficient

ABSTRACTShark and ray biodiversity is threatened primarily by overfishing and the globalisation of trade, and Europe has been one of the most documented heavily fished regions for a relatively long time. Yet, we have little idea of the conservation status of the hundreds of Data Deficient shark and ray species. It is important to derive some insight into the status of these species, both to understand global extinction rates and also to ensure that any threatened Data Deficient species are not overlooked in conservation planning. Here, we developed a biological and ecological trait model to predict the categorical conservation status of 26 Northeast Atlantic and 15 Mediterranean Sea Data Deficient sharks and rays. We first developed an explanatory model based on all species evaluated on the International Union for Conservation of Nature (IUCN) Red List of Threatened SpeciesTM, using maximum body size, median depth (as a proxy for fisheries exposure), and reproductive mode, and then predicted the status of all Data Deficient species. Almost half of Northeast Atlantic (46%, n=12 of 26), and two-thirds of Mediterranean (67%, n=10 of 15) Data Deficient species are predicted to be in one of the three IUCN threatened categories. Northeast Atlantic Data Deficient species are predicted to be 1.2 times more threatened than evaluated species (38%, n=36 of 94), whereas threat levels in the Mediterranean Sea are relative for each (66%, n=38 of 58). This case study is intended for extrapolation to the global shark and ray dataset upon completion of the global IUCN Red List assessment. Trait-based, categorical prediction of conservation status is a cost-effective approach towards incorporating Data Deficient species into (i) estimates of lineage-wide extinction rates, (ii) revised protected species lists, and (iii) Red List Indices, thus preventing poorly known species from reaching extinction unnoticed.

scholarly journals Biological and extrinsic correlates of extinction risk in Chinese lizards

2021 ◽  
Author(s):  
Yuxi Zhong ◽  
Chuanwu Chen ◽  
Yanping Wang
Keyword(s):  
Body Size ◽  
Extinction Risk ◽  
Species Traits ◽  
Geographic Range ◽  
Range Size ◽  
Habitat Specialization ◽  
Mean Annual Precipitation ◽  
Mean Annual Temperature ◽  
Small Range ◽  
Extrinsic Factors

Abstract China is a country with one of the most species rich reptile faunas in the world. However, nearly a quarter of Chinese lizard species assessed by the China Biodiversity Red List are threatened. Nevertheless, to date, no study has explicitly examined the pattern and processes of extinction and threat in Chinese lizards. In this study, we conducted the first comparative phylogenetic analysis of extinction risk in Chinese lizards. We addressed the following three questions: 1) What is the pattern of extinction and threat in Chinese lizards? 2) Which species traits and extrinsic factors are related to their extinction risk? 3) How can we protect Chinese lizards based on our results? We collected data on ten species traits (body size, clutch size, geographic range size, activity time, reproductive mode, habitat specialization, habitat use, leg development, maximum elevation, and elevation range) and seven extrinsic factors (mean annual precipitation, mean annual temperature, mean annual solar insolation, normalized difference vegetation index (NDVI), human footprint, human population density, and human exploitation). After phylogenetic correction, these variables were used separately and in combination to assess their associations with extinction risk. We found that Chinese lizards with small geographic range, large body size, high habitat specialization, and living in high precipitation areas were vulnerable to extinction. Conservation priority should thus be given to species with the above extinction-prone traits so as to effectively protect Chinese lizards. Preventing future habitat destruction should also be a primary focus of management efforts because species with small range size and high habitat specialization are particularly vulnerable to habitat loss.

scholarly journals Global extinction risk for seahorses, pipefishes and their near relatives (Syngnathiformes)

Oryx ◽  
2021 ◽  
pp. 1-10
Author(s):  
Riley A. Pollom ◽  
Gina M. Ralph ◽  
Caroline M. Pollock ◽  
Amanda C.J. Vincent
Keyword(s):  
Threatened Species ◽  
Habitat Degradation ◽  
Extinction Risk ◽  
Conservation Status ◽  
Field Research ◽  
Selective Extraction ◽  
Iucn Red List ◽  
Point Estimate ◽  
Conservation Action ◽  
Data Deficient

Abstract Few marine taxa have been comprehensively assessed for their conservation status, despite heavy pressures from fishing, habitat degradation and climate change. Here we report on the first global assessment of extinction risk for 300 species of syngnathiform fishes known as of 2017, using the IUCN Red List criteria. This order of bony teleosts is dominated by seahorses, pipefishes and seadragons (family Syngnathidae). It also includes trumpetfishes (Aulostomidae), shrimpfishes (Centriscidae), cornetfishes (Fistulariidae) and ghost pipefishes (Solenostomidae). At least 6% are threatened, but data suggest a mid-point estimate of 7.9% and an upper bound of 38%. Most of the threatened species are seahorses (Hippocampus spp.: 14/42 species, with an additional 17 that are Data Deficient) or freshwater pipefishes of the genus Microphis (2/18 species, with seven additional that are Data Deficient). Two species are Near Threatened. Nearly one-third of syngnathiformes (97 species) are Data Deficient and could potentially be threatened, requiring further field research and evaluation. Most species (61%) were, however, evaluated as Least Concern. Primary threats to syngnathids are (1) overexploitation, primarily by non-selective fisheries, for which most assessments were determined by criterion A (Hippocampus) and/or (2) habitat loss and degradation, for which assessments were determined by criterion B (Microphis and some Hippocampus). Threatened species occurred in most regions but more are found in East and South-east Asia and in South African estuaries. Vital conservation action for syngnathids, including constraining fisheries, particularly non-selective extraction, and habitat protection and rehabilitation, will benefit many other aquatic species.

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