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Koschinski S, Owen K, Lehnert K, Kamińska K. Current species protection does not serve its porpoise-Knowledge gaps on the impact of pressures on the Critically Endangered Baltic Proper harbour porpoise population, and future recommendations for its protection. Ecol Evol 2024; 14:e70156. [PMID: 39267689 PMCID: PMC11392595 DOI: 10.1002/ece3.70156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Revised: 06/13/2024] [Accepted: 07/29/2024] [Indexed: 09/15/2024] Open
Abstract
Successful management requires information on pressures that threaten a species and areas where conservation actions are needed. The Baltic Proper harbour porpoise population was first listed as Critically Endangered by the International Union for the Conservation of Nature in 2008. Now, 16 years later, there is no change in conservation status despite ample conservation policy calling for its protection and an urgent need for management action to protect this population. Here, we provide an overview of the current status of the population, highlight knowledge gaps on the impact of pressures, and make recommendations for management of anthropogenic activities. Based on an exceeded limit for anthropogenic mortality, the high concentrations of contaminants in the Baltic Sea, combined with reductions in prey availability and increases in underwater noise, it is inferred that this population is likely still decreasing in size and conservation action becomes more urgent. As bycatch and unprotected underwater explosions result in direct mortality, they must be reduced to zero. Inputs of contaminants, waste, and existing and emerging noise sources should be minimised and regulated. Additionally, ecosystem-based sustainable management of fisheries is paramount in order to ensure prey availability, and maintain a healthy Baltic Sea. Stranding networks to routinely assess individuals for genetic population assignment and health need to be expanded, to identify rare samples from this population. Knowledge is still scarce on the population-level impact of each threat, along with the cumulative impact of multiple pressures on the population. However, the current knowledge and management instruments are sufficient to apply effective protection for the population now. While bycatch is the main pressure impacting this population, urgent conservation action is needed across all anthropogenic activities. Extinction of the Baltic Proper harbour porpoise population is a choice: decision-makers have the fate of this genetically and biologically distinct marine mammal population in their hands.
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Affiliation(s)
| | - Kylie Owen
- Department of Population Analysis and MonitoringSwedish Museum of Natural HistoryStockholmSweden
| | - Kristina Lehnert
- Institute for Terrestrial and Aquatic Wildlife ResearchUniversity of Veterinary Medicine HannoverHannoverGermany
| | - Katarzyna Kamińska
- Department of FisheriesMinistry of Agriculture and Rural DevelopmentWarsawPoland
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2
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Frie AK, Lindström U. Exploring the effects of methodological choices on the estimation and biological interpretation of life history parameters for harbour porpoises in Norway and beyond. PLoS One 2024; 19:e0301427. [PMID: 38968179 PMCID: PMC11226007 DOI: 10.1371/journal.pone.0301427] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Accepted: 03/15/2024] [Indexed: 07/07/2024] Open
Abstract
This study investigates effects of subtle methodological choices on the estimation and biological interpretation of age, growth and reproductive parameters for harbour porpoises. The core analyses are based on a focal Norwegian data set built on samples from 134 harbour porpoises caught incidentally in gillnet fisheries along the Norwegian coast during autumn 2016 and spring 2017. Two contrasting practices for interpretation of seasonal and ontogenetic characteristics of tooth growth layer formation resulted in significant age differences among spring samples of young porpoises and for older animals across seasons. In turn, these differences affected estimates of age at maturity and asymptotic lengths, respectively. We also found significant differences in male age at maturity between two well-documented maturity criteria and between mathematical estimators of age at maturity for both sexes. Two different criteria for corpus albicans classification furthermore resulted in different patterns of ovarian corpora accumulation, which may affect some estimates of fecundity rates and contaminant loads. Both corpora accumulation patterns were also found in reanalysed data from German and Greenlandic porpoises. Based on tabulated overviews of methodological choices made in previous harbour porpoise studies, we argue that several of the issues mentioned above have wider relevance and may affect the validity of meta-analyses as a tool for estimating harbour porpoise sensitivity to extrinsic pressures. Differences in cause of death (COD) composition between data sets can have a similar effect. We demonstrate this in a meta-analysis of published harbour porpoise pregnancy rates, showing significantly higher values for trauma-killed samples compared to samples comprising mixed COD categories. COD also affected the estimated impacts of three previously analysed extrinsic predictors as well as an added predictor for vessel noise levels. We discuss the potential contributions of methodological, biological and anthropogenic factors in shaping observed regional differences in estimates of harbour porpoise life history parameters.
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Affiliation(s)
| | - Ulf Lindström
- Institute of Marine Research, Tromsø, Norway
- UiT The Arctic University of Norway, Tromsø, Norway
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3
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Palmer EI, Betty EL, Murphy S, Perrott MR, Smith ANH, Stockin KA. Reproductive biology of male common dolphins ( Delphinus delphis) in New Zealand waters. MARINE BIOLOGY 2023; 170:153. [PMID: 37811127 PMCID: PMC10558376 DOI: 10.1007/s00227-023-04266-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 08/02/2023] [Indexed: 10/10/2023]
Abstract
Reproductive parameters were assessed in 64 male common dolphins (Delphinus delphis) examined post-mortem from strandings and bycatch in New Zealand between 1999 and 2020. The stages of male sexual maturation were assessed using morphological measurements and histological examination of testicular tissue. Age was determined via growth layer groups (GLGs) in teeth. The average age (ASM) and length (LSM) at attainment of sexual maturity were estimated to be 8.8 years and 198.3 cm, respectively. Individual variation in ASM (7.5-10 years) and LSM (190-220 cm) was observed in New Zealand common dolphins. However, on average, sexual maturity was attained at a similar length but at a marginally younger age (< 1 year) in New Zealand compared to populations in the Northern Hemisphere. All testicular variables proved better predictors of sexual maturity compared to demographic variables (age and total body length), with combined testes weight the best outright predictor of sexual maturity. Reproductive seasonality was observed in male common dolphins, with a significant increase in combined testes weight in austral summer. This aligns with most other studied populations, where seasonality in reproduction is typically observed. Given the known anthropogenic impacts on New Zealand common dolphins, we recommend that these findings be used as a baseline from which to monitor population-level changes as part of conservation management efforts. Supplementary Information The online version contains supplementary material available at 10.1007/s00227-023-04266-5.
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Affiliation(s)
- Emily I. Palmer
- Cetacean Ecology Research Group, School of Natural Sciences, Massey University, 0745 Auckland, New Zealand
| | - Emma L. Betty
- Cetacean Ecology Research Group, School of Natural Sciences, Massey University, 0745 Auckland, New Zealand
| | - Sinéad Murphy
- Marine and Freshwater Research Centre, Department of Natural Resources & the Environment, School of Science and Computing, Atlantic Technological University, ATU Galway City, Old Dublin Road, Galway, H91 T8NW Ireland
| | - Matthew R. Perrott
- School of Veterinary Sciences, Massey University, Palmerston North, New Zealand
| | - Adam N. H. Smith
- School of Mathematical and Computational Sciences, Massey University, 0745 Auckland, New Zealand
| | - Karen A. Stockin
- Cetacean Ecology Research Group, School of Natural Sciences, Massey University, 0745 Auckland, New Zealand
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Narimanpour Z, Bojnordi MN, Hamidabadi HG. Spermatogenic differentiation of spermatogonial stem cells on three-dimensional silk nanofiber scaffold. MIDDLE EAST FERTILITY SOCIETY JOURNAL 2022. [DOI: 10.1186/s43043-022-00107-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
Nano-fibrous scaffolds provide a three-dimensional matrix that guides sufficient orientation of seeded cells similar to a natural niche. In this research, we designed a silk scaffold to improve the differention of mouse spermatogonial stem cells to spermatogenic cell lines. Spermatogonial stem cells were collected from neonatal mouse (2–6 days) testes (n=60) using a two steps mechanical and enzymatic method. Cells were seeded on a silk scaffold and were cultured in Dulbecco’s modified Eagle’s medium, supplemented with 15 % fetal bovine serum and 1000 units/ml leukemia inhibitory factor, and incubated at 32°C in a humidified atmosphere of 5% CO2 in air. SEM technique was done for confirmation of seeding cells.
In this study two major groups (i.e., 2D and 3D culture groups) of 30 mice each. Isolated testicular cells from each group were cultured in the absence of silk scaffold or the presence of silk scaffold.
For induction of differentiation, seeded cells on a scaffold were exposed to 1 μM and 50 ng/ml BMP-4. The specific spermatogenic genes, e.g.; VASA, DAZL, PLZF, and Piwil2, were assessed via real-time PCR and immunocytochemistry techniques. P values less than 0.05 were assumed significant. All experiments were performed at least three times.
Results
SEM analysis confirmed the homogeneity of fabricated silk scaffold and average diameter of 450 nm for nanofibers fibers. Silk scaffold induces attachment of SSCs in comparison to the monolayer group. Spermatogonia stem cell colonies were observed gradually after 1 week of culture. Electrospun scaffold supports the differentiation of SSCs to spermatogenic lines. Dates of real-time PCR showed that the expression of meiotic markers, VASA, DAZL, and Piwil2 as related to specific spermatogenic genes, had a significant upregulation in cell-seeded silk scaffold compared to the control group (P < 0.05).
Immunocytochemistry founding approved the expression of specific spermatogenic markers; DAZL and PLZF were higher in the experiment group compared to the control (P < 0.05).
Conclusion
It is concluded silk scaffold induces spermatogenic differentiation of mouse spermatogonial stem cells in vitro.
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Siebert U, Stürznickel J, Schaffeld T, Oheim R, Rolvien T, Prenger-Berninghoff E, Wohlsein P, Lakemeyer J, Rohner S, Aroha Schick L, Gross S, Nachtsheim D, Ewers C, Becher P, Amling M, Morell M. Blast injury on harbour porpoises (Phocoena phocoena) from the Baltic Sea after explosions of deposits of World War II ammunition. ENVIRONMENT INTERNATIONAL 2022; 159:107014. [PMID: 34883460 DOI: 10.1016/j.envint.2021.107014] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Revised: 11/26/2021] [Accepted: 11/29/2021] [Indexed: 05/21/2023]
Abstract
Harbour porpoises are under pressure from increasing human activities. This includes the detonation of ammunition that was dumped in large amounts into the sea during and after World War II. In this context, forty-two British ground mines from World War II were cleared by means of blasting in the period from 28 to 31 August 2019 by a NATO unit in the German Exclusive Economic Zone within the marine protected area of Fehmarn Belt in the Baltic Sea, Germany. Between September and November 2019, 24 harbour porpoises were found dead in the period after those clearing events along the coastline of the federal state of Schleswig-Holstein and were investigated for direct and indirect effects of blast injury. Health evaluations were conducted including examinations of the brain, the air-filled (lungs and gastrointestinal tract) and acoustic organs (melon, acoustic fat in the lower jaw, ears and their surrounding tissues). The bone structure of the tympano-periotic complexes was examined using high-resolution peripheral quantitative computed tomography (HR-pQCT). In 8/24 harbour porpoises, microfractures of the malleus, dislocation of middle ear bones, bleeding, and haemorrhages in the melon, lower jaw and peribullar acoustic fat were detected, suggesting blast injury. In addition, one bycaught animal and another porpoise with signs of blunt force trauma also showed evidence of blast injury. The cause of death of the other 14 animals varied and remained unclear in two individuals. Due to the vulnerability and the conservation status of harbour porpoise populations in the Baltic Sea, noise mitigation measures must be improved to prevent any risk of injury. The data presented here highlight the importance of systematic investigations into the acute and chronic effects of blast and acoustic trauma in harbour porpoises, improving the understanding of underwater noise effects and herewith develop effective measures to protect the population level.
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Affiliation(s)
- Ursula Siebert
- Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Foundation, Werftstr. 6, 25761 Büsum, Germany.
| | - Julian Stürznickel
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Lottestr. 59, 22529 Hamburg, Germany; Department of Trauma and Orthopaedic Surgery, Division of Orthopaedics, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg, Germany
| | - Tobias Schaffeld
- Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Foundation, Werftstr. 6, 25761 Büsum, Germany
| | - Ralf Oheim
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Lottestr. 59, 22529 Hamburg, Germany
| | - Tim Rolvien
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Lottestr. 59, 22529 Hamburg, Germany; Department of Trauma and Orthopaedic Surgery, Division of Orthopaedics, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg, Germany
| | - Ellen Prenger-Berninghoff
- Institute for Hygiene and Infectious Diseases of Animals, Justus Liebig University Giessen, Frankfurter Str. 85-87, 35392 Giessen, Germany
| | - Peter Wohlsein
- Department of Pathology, University of Veterinary Medicine Hannover, Foundation, Bünteweg 17, 30559 Hannover, Germany
| | - Jan Lakemeyer
- Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Foundation, Werftstr. 6, 25761 Büsum, Germany
| | - Simon Rohner
- Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Foundation, Werftstr. 6, 25761 Büsum, Germany
| | - Luca Aroha Schick
- Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Foundation, Werftstr. 6, 25761 Büsum, Germany
| | - Stephanie Gross
- Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Foundation, Werftstr. 6, 25761 Büsum, Germany
| | - Dominik Nachtsheim
- Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Foundation, Werftstr. 6, 25761 Büsum, Germany
| | - Christa Ewers
- Institute for Hygiene and Infectious Diseases of Animals, Justus Liebig University Giessen, Frankfurter Str. 85-87, 35392 Giessen, Germany
| | - Paul Becher
- Institute of Virology, University of Veterinary Medicine Hannover, Foundation, Bünteweg 17, 30559 Hannover, Germany
| | - Michael Amling
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Lottestr. 59, 22529 Hamburg, Germany
| | - Maria Morell
- Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Foundation, Werftstr. 6, 25761 Büsum, Germany
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Williams RS, Curnick DJ, Brownlow A, Barber JL, Barnett J, Davison NJ, Deaville R, Ten Doeschate M, Perkins M, Jepson PD, Jobling S. Polychlorinated biphenyls are associated with reduced testes weights in harbour porpoises (Phocoena phocoena). ENVIRONMENT INTERNATIONAL 2021; 150:106303. [PMID: 33454091 DOI: 10.1016/j.envint.2020.106303] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 10/27/2020] [Accepted: 11/23/2020] [Indexed: 06/12/2023]
Abstract
Polychlorinated biphenyls (PCBs) are highly toxic and persistent aquatic pollutants that are known to bioaccumulate in a variety of marine mammals. They have been associated with reduced recruitment rates and population declines in multiple species. Evidence to date documents effects of PCB exposures on female reproduction, but few studies have investigated whether PCB exposure impacts male fertility. Using blubber tissue samples of 99 adult and 168 juvenile UK-stranded harbour porpoises (Phocoena phocoena) collected between 1991 and 2017, here we show that PCBs exposures are associated with reduced testes weights in adults with good body condition. In animals with poor body condition, however, the impact of PCBs on testes weights was reduced, conceivably due to testes weights being limited by nutritional stress. This is the first study to investigate the relationship between PCB contaminant burden and testes weights in cetaceans and represents a substantial advance in our understanding of the relationship between PCB exposures and male reproductive biology in cetaceans. As testes weight is a strong indicator of male fertility in seasonally breeding mammals, we suggest the inclusion of such effects in population level impact assessments involving PCB exposures. Given the re-emergent PCB threat our findings are globally significant, with potentially serious implications for long-lived mammals. We show that more effective PCB controls could have a substantial impact on the reproductive health of coastal cetacean species and that management actions may need to be escalated to ensure adequate protection of the most vulnerable cetacean populations.
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Affiliation(s)
- Rosie S Williams
- Institute of Zoology, Zoological Society of London, Regent's Park, London NW1 4RY, UK; Department of Life Sciences, Institute of Environment, Health and Societies, Brunel University, Uxbridge UB8 3PH, UK.
| | - David J Curnick
- Institute of Zoology, Zoological Society of London, Regent's Park, London NW1 4RY, UK
| | - Andrew Brownlow
- Scottish Marine Animal Stranding Scheme, SRUC Veterinary Services, Drummondhill, Inverness IV2 4JZ, Scotland, UK
| | - Jonathan L Barber
- Centre for Environment, Fisheries and Aquaculture Science (CEFAS), Pakefield Road, Lowestoft NR33 0HT, UK
| | - James Barnett
- Environment and Sustainability Institute, University of Exeter, Penryn Campus, Falmouth, Cornwall TR10 9FE, UK
| | - Nicholas J Davison
- Scottish Marine Animal Stranding Scheme, SRUC Veterinary Services, Drummondhill, Inverness IV2 4JZ, Scotland, UK
| | - Robert Deaville
- Institute of Zoology, Zoological Society of London, Regent's Park, London NW1 4RY, UK
| | - Mariel Ten Doeschate
- Scottish Marine Animal Stranding Scheme, SRUC Veterinary Services, Drummondhill, Inverness IV2 4JZ, Scotland, UK
| | - Matthew Perkins
- Institute of Zoology, Zoological Society of London, Regent's Park, London NW1 4RY, UK
| | - Paul D Jepson
- Institute of Zoology, Zoological Society of London, Regent's Park, London NW1 4RY, UK
| | - Susan Jobling
- Department of Life Sciences, Institute of Environment, Health and Societies, Brunel University, Uxbridge UB8 3PH, UK
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Silk Nanofibrous Electrospun Scaffold Amplifies Proliferation and Stemness Profile of Mouse Spermatogonial Stem Cells. REGENERATIVE ENGINEERING AND TRANSLATIONAL MEDICINE 2020. [DOI: 10.1007/s40883-020-00189-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
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